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THE MINES ACT, 1952

Examination for Mine Manager’s Certificate of Competency under the Coal Mines Regulation, 1957

FIRST CLASS

MINE MANAGEMENT, LEGISLATION & GENERAL SAFETY

Monday, the 20th December, 2004 Full Marks: 100Time : 3 Hours

Answer any Six Questions(All questions carry equal marks)

Q.1.What do you understand by the term “flame proof equipment”? Draw a list of instructions, responsibility for compliance and records that should be maintained to ensure that flame proof features remain effective.

Ans:- Flame Proof Equipment:- Equipment enclosed in flameproof enclosure is called flameproof equipment. Flameproof enclosure is an enclosure for electrical machinery or equipments that will withstand (when the covers or other access doors are properly secured) an internal explosion of the inflammable gas or vapour which may enter or originate inside the enclosure, without suffering damage and without communicating the internal flammation ( or explosion) to the external inflammable gas or vapour in which it is designed to be used ( through any joints or other structural openings in the enclosures).FLP equipment used in mines are of approved design and every part of such equipment has standard specification. It becomes unsafe if it is not assembled, installed, maintained and handled in the manner required. Purpose of an FLP equipment is lost as soon as its original design, form of assembly and the specifications are in any way tempered. This call for utmost care and caution in maintenance of these equipments. Flameproof features of FLP equipment are often found disturbed due to improper handling and poor maintenance. To avoid this, the following are the list of instructions, responsibility for compliance and records that should be maintained to ensure that flame proof features remain effective:(Clue- NSS CCWO SPCA FIAT BDO )

S.N. Instructions Responsibility Records1 Nuts and bolts to be cleaned

with petroleum gel before refitting.

Electrician, Electrical supervisor and Engineer.

Record to be maintained in the register.

2 Studs, if broken, should not be removed by drilling.

Electrical supervisor and Engineer.

Every instance shall be recorded.

3 Shrouds should be kept free from dirt and should not be damaged or removed.

Daily- Electrician Weekly- Electrical Supervisor.Monthly - Engineer.

Damages shall be recorded.

4 Cast metal casings should be examined for fractures and cracks during installation and shifting and also after roof fall.


To be recorded.

5 Clearance of shaft glands and all joints shall be checked when ever motor is dismantled.


To be recorded.

6 Cracked and broken glass winds and walls should be replaced with fresh approved glasses complete with retaining rings.

Electrician, Electrical supervisor and Engineer

To be recorded.

7 Level of oil in oil immersed equipment to be checked frequently

Electrical supervisor and Engineer

Checks with topping up shall be recorded.

8 Spares should be obtained from original manufacturer.


Replacements shall be recorded.

9 Plug and socket connectors and coupler should be examined for tightness and overheating

Daily- Electrician Weekly- Electrical Supervisor.Monthly- Engineer.

To be recorded.

10 Level of compound in sealing boxes should be checked regularly and particularly in hot situation.

-do- -do-

11 Armour glands should be checked for its firm gripping and should be cleaned frequently

Daily- Electrician Monthly- Electrical Supervisor.

To be recorded for all new installations.

12 Every flange joints should be checked with fillers

Weekly- Electrical Supervisor.Monthly- Engineer

Clearance shall be recorded.

13 Interlocks should be examined frequently for broken & bent parts.

Weekly- Electrician. He should repair or report for action.

14 No alteration in design of flameproof enclosures.

Electrician, Electrical supervisor& Engineer

15 Terminal boxes to be kept free from dust and moisture

Electrician, Electrical supervisor(Weekly)

Suitable entry in the register for such cleaning jobs.

16 Bearing of switch spindles to be regularly inspected and lubricated

Daily- Electrician Weekly- Electrical Supervisor.Monthly- Engineer

To be recorded.

17 Doors, Covers, oil tanks whenever removed, shall be replaced correctly

Daily- Electrician Weekly- Electrical Supervisor.Monthly- Engineer

To be recorded in the register with the description of the work.

18 Correct setting and checking of overload and earth leakage trips to be ensured.


Setting shall be recorded.

19 Broken or missing bolts or set screws should be replaced by others of correct diameter, thread, length, type of head and quality of steel.


Every instance shall be recorded.

20 No cover of live FLP equipment should be opened at any time.


Q.2. A large mechanized opencast mine is being planned in a virgin area. Briefly state and discuss the statutory notices that are to be sent and permissions/ relaxations to be obtained. What steps should be taken to select, recruit and train the workman, staff and officers?

Ans: - The following are the various permission/exemption from statute for opening a big O/C mine in a virgin area:

i) Notice of opening :- For opening any new O/C mine, the notice shall be submitted in form I to the RIM, CIM, D.M. controller general IBM accompanied by a plan showing the boundaries of the mine and other prominent and permanent surface features.

ii) Communication of actual date of opening:- When mine has been opened, owner/Agent/Manager shall forthwith communicate the actual date of opening to CIM and RIM.

iii) Appointment of officials:- An intimation in form l shall be given to CIM and RIM for appointment of officials.

iv) Appointment of deemed agent:- A statement showing names and designation of every person authorized to act on behalf of the owner in respect of management, control, supervision of direction of the mine shall be submitted to CIM and RIM.

v) Exemption shall be applied for reduction the number of U/Ms / ACMs, Surveyors, as these are based on the production of the mine and not on extent of mine & machinery deployed, from the relevant statute.

vi) Exemption is required for bench height/ bench slope (bench geometry).vii)Exemption /permission shall be required under from CIM for gradient of roads

steeper than 1 in 14 at any place of the mine.viii) Permission to work within 45m of any public building or permanent structure not

belonging to owner is required from CIM.ix) Permission/exemption for temporary storage of explosives near the mine shall be

obtained.x) Exemption for not using cartridge in open cast mines( use of bulk explosives)xi) Exemption for blasting more than 120 shorts in a shift in O.C. Mines.xii) Permission for max. charge/hole as per requirement of the mine taking into

account the require blasted material to fulfill the target. xiii) Permission/exemption/ approval for new blasting technique from CIM/RIM so

that flying fragments from blasting can’t project beyond a distance of 10m from the place of firing.

xiv) a) Notice is to be given under IER for size and type of apparatus together with such particulars which may be required by the inspector.

b) 7 days notice to inspector for new installation in the mine. xv)Exemption/permission is to be applied for any voltage other than specified

voltage. xvi)Permission is required for using flexible cable with equipment in O/C mines and

length of cable more than 300m. xvii)Permission for using more than one type of explosives in the same hole is

needed. xviii)Prime and column charge if different, permission is required.

xix)If buildings / structures exists within 50m of site of blasting, permission from CIM/RIM is required.

Selection, recruitment and training of workmen, staff and officers:-For selection, recruitment & training of manpower for running a big open cast mine, we assume the following conditions:- Conditions assumed:-

Coal Production = 2.0 m.teOBR = 6.0 mm3 Average S.R. = 1: 3Thickness of Seam = 20mThickness of OB = 60mGradient of seam = 1 in 10No of coal benches = 2“ OB benches = 5

Height & width coal bench = 10m, 30m Height & Width of OB “ = 12m ,30m

Under the assumed conditions, we need the under mentioned equipment and manpower:

Requirement of Equipment & Manpower a) Equipment - Nos. Operators Officers, supervisors & Helpers Electric rope shovel (4.6m3) 05 15 Mining - 15 Dumper(35T) 30 90 Electircal - 12 Dozer (135KW) 03 09 Mechanical - 12 Drills ( 250mm) 04 12 Personnel & Motor Grader (100KW) 01 02 Finance - 10 Roller (25T) 01 02 Agent - 01 Scrapper (11m3) 01 02 Manager - 01 Pick up van 01 03 ACM - 08 Explosive Van 01 02 S.O. - 01 Light vehicles 04 08 G.Maz. - 30 Water Sprinkler 01 03 Surveyors - 02 Mobile crane 01 03 Trg.Officers - 03 Ambulance 01 03 Med.Officer - 01

Instructors - 06 Drilling & Blast.Gang - 15 Tripman/

Dumpman - 02__ 154 119 To run a big open cast mine in safe and efficient manner in order to fulfill the production target, deployment of skilled and trained manpower is first and foremost necessity. Selection and recruitment is the process of discovering manpower by disseminating information about the nature of vacancies and the education and skills required for its performance. As a result, persons who possess the requisite qualifications and skill, submit their applications for selection and appointment.Introduction of a new technology demands new skills for which suitable manpower has to be found either by recruiting people from outside or by selecting people from within the industry and training them to suit the needs. There is a close link between manpower planning and recruitment.Source of Recruitment:- There are a number of sources from which skilled or unskilled manpower may be recruited. These are: 1. Employment Exchange:- The mine management has to send its specific needs for manpower requirement mentioning the minimum qualifications and

experience desired. The Employment Exchange makes preliminary screening from the names of the persons registered and forwards the same to the requisitioning authority. 2. From Existing Employees:- By designing the training schemes and manpower development plans for upgrading skills, mine management can meet the bulk of its semi skilled and skilled manpower demand from its own resources.3. Recruitment from Institutions:- Recruitment Officers team from an industry make a round of visits to the universities, colleges and polytechnics. They meet the students, counsel them about the job opportunities in their firm and recruit suitable students.4. Advertisement:- This is the process by which senior and more experienced people are found.

After selection and recruitment of workmen, staffs and officers, initial / basic training shall be imparted to them in the following manner:-i) Training of workers and supervisors-Sl.No.

Categories of workers/staffs

Duration of

training

Course content

1 Surface workers

12 Organisation/lmine details, safety policies, role & function of ISO, Institution of SC & WMI, mine environment, dangers from fire, medical attention etc.

2 O/C workers 18 Method of mining, coal seams and geology, haul road & geometry, HEMM, traffic rules, code of practices, safety & other apparatus, use of explosives, shelter etc.

3 Special categories of workers & supervisors i. Drillers 36 Type of drills with specification and details, type of drill

bits and its use, drilling pattern, safety during drilling and marching, routine check up and maintenance etc.

ii Blasting crew 36 Drilling and blasting concept, types of explosives and accessories, importance of free face, code of practice for safe handling, storage, transport and use of explosives, fly rocks, fragmentation, ground vibration, danger zone etc.

iii Dumper Operators

60 Type of dumpers, functioning of dumpers and its safety devices, service and parking brakes, fire protection etc.

iv. Shovel Operators

60 Type of shovels, functioning of hoist, crowd, swing and propel system, code of practices, fire in HEMM and its fighting.

v. Dozer Operators

60 Dozers & its function, transmission and hydraulic system, steering / brake / final drive etc

vi Fitters & Mechanics

72 Various types of HEMM & other machinery, tools and its use, measuring instruments, lubrication, bearings etc.

vii Electricians 96 HEMM & other machinery, electrical tools, measuring instruments, type of motors and its use, cables and conductors, transformers, circuit breakers, earthing, semi-conductor devices etc.

viii Auto Electricians

90 Types of transportation machinery, motors and its use, transformer/batteries /dynamo, generator, alternator, control box, AVA etc.

ix. Electrical supervisors

18 Electrical layout, AC&DC, load, voltage drop, power factor, transformer, DG sets, important provisions of IER etc.

x. Sub-ordinate supervisory officials

Coal seams & geology, duties & responsibilities of Supervisors, mining methods, mine plan & section, traffic rules, safe code of practices of machinery etc.

ii) Training of Officers – (a) Induction/ Orientation training – Such type of training is imparted to newly recruited officers in order to make them familiar with the organisation and its structure, service conditions, duties, responsibilities and rights, career growth, social security, medical facilities etc. The duration of course is generally one week and the training is generally in-house.(bi) Medical Officer associated with PME should be imparted proper training in occupational health and use of ILO classification.(c) Supervision & Management Course – One month extensive training is imparted at Central Staff training College for developing officers through inter company management development programme as a continuous process.d) Special training facilities: - Special training related to introduction of special mining techniques and methods such as scraper mining, continuous mining, surface mining etc is imparted to officers engaged in mining operation. The duration of training is generally one week.e) External training facilities:- In-house training facilities are not adequate to meet all the training needs of the industry. Following external training facilities are given to officers:-

- Refresher and improved courses in technology at technical institution.- Management courses at administrative Staff training College.- Specialized technical skills and advanced management courses outside the

country.- Seminars and workshops organized by professional bodies like institution of

Engineers, Mine Managers association, educational institution etc.

Q..3.Answer the following:a. What should be the syllabus for pre-employment training for workers

for an underground mine? What is the need for refresher training?b. State the differences in statutory provisions relating to haulage and

winding ropes?

Ans:-a) As per statutory provision under MVTR1966, Pre-employment/basic/initial training should be imparted to workers of an u/g mine for 12 days under direct personal supervision of trainers. But as per recommendation of National tripartite workshop on Revised Modules for vocational training in mines held in 1999 at DGMS, U/G workers should be imported 48 days ( Theory – 10 days , on the job 28 days & Feed back – 2 days) pre-employment/initial training.

Syllabus for Pre-employment training for u/g workers:-A) Theoretical training -

1) General – i. Details of mine/organisation, types of jobs etc.ii. Organisation structure – company, area, mine etciii .Departments/ sections/ units etc & their function.iv. Service conditions, personnel matters, disciplinary proceedings.v. Safety policy of company, company objectives, mine objectives, individual objectives.vi. ISO and need of workers participation in safety management, Role of DGMS.vii. Duties of workmen viii.General Service condition & facilities to be provided.

2) Specific – i. General idea about the coal seams, formation of coal, types of associated

rocks, geological disturbances etc.ii. Different type of mining – O/C & U/G Mining, multi-seam workings etc.iii. Different type of outlets – Shaft /Incline/drift, second outletiv. Mining methods- Board & Pillar, Longwall, SDL / LHD / Continuous miners

district, Development working, Depillaring (caving, stowing method.)v. Strata control – Type of supports, method of support, RMR/ SSR, Timber, roof bolts, roof stitching, powered support. Hydraulic support, safe erection and withdrawal of supports.vi. Mine Ventilation & Environmental monitoring–

Quantity & quality of air, Natural & artificial ventilation, MMV, booster & auxiliary fans, ventilation stoppings. Monitoring of mine gases and their detection. Effect of inflammable & noxious gases etc.

vii. Dust & noise hazard- Coal dust, its formation, hazards (health and explosion), dust control measured, noise problems and control measures.

viii. Equipment, lighting, telecommunication and signaling – Face pumps, cap lamps, drills, CCM, FLP apparatus, earthing etc.

ix. Dangers of inundation – Common accidents due to inundation & preventive measures, emergency responses in case of inundation etc.

x. Dangers due to spontaneous heating / fire – System of workings on panels, precaution against spontaneous / fire etc

xi. Mines Rescue & Recovery work- Provision of rescue room, rescue station, rescue tracings etc.

xii.Mine Transport- Haulage and winding installation, safety devices, conveyors etc.

xiii. Dangers from Explosives- Explosives and detonators, reserve station, taking shelters, misfired shots etc.

Need of refresher training- Refresher training is needed to make the workmen safety concern and to

restrict them to do unsafe acts & unsafe habits. Over a period of time, people forget / de-learn what they have learned earlier. Hence, relearning / refresher training is essential in order to sharpen the knowledge and skill of the workmen.

No amount of safety regulations or technological advances in safety devices can pay dividends unless we train or retrain our workers and supervisors, who, together with equipment and capital, form the total system in a mine.

No training programme is complete unless it is given in repetitive dozes over a continuous period of time, in the form of refresher training.

Refresher training of workmen is an important factor in the performance & safety improvements. Events, which affect performance & safety (bad habits) must be eradicated, Technical competence should not be assured to ensure competence in safe working. It is a psychological fact that some 90% of the knowledge of the safe working, learned mechanically forgotten within hours. Furthermore, where there is no practical experience, the rate of forgetfulness is accelerated.

Recognizing the need for safety education to enable the mine workers to prepare them to face the challenges of mining, MVTR were framed in 1966. These rules provide for initial, refresher & specialized training to mine workers. As per rule 8 of MVTR 1966, refresher training are to be imparted in the following manner:-

Sl. No.

Category of workmen Duration of course (no. of lectures)

Remarks

1 Re-employed workers after break of service of one year or more:a. On surface & OC workersb. for UG Workers in gassy minesc. for UG Workers in non-gassy mines

031509

Training within one month of employment.

2 Already employed workers in gassy mines.

06 All persons to be trained during the 1st

year.3 Already employed workers categories

(a) & (c) as above.09 At least 1/5th of the

total number of persons in each category to be trained each year.

However, in tripartite workshop on training, the following recommendations have been made:

Category of workers Refresher Training (days) 1. Surface workers 06 2. O/C “ 06 3. U/G ‘ 12 4. Specific categories of O/C Workers/supervisors 9-12 5. Specific categories of U/G Workers/supervisors 6-12 Refresher training helps in improved quality of work, reduction in accidents,

increase in production and productivity & high morale. MVTR requires refresher training for persons already employed and also for persons who return to work after absence from work for a period exceeding one year

. The safety consciousness is an inherent and natural instinct present in all creatures and is more prominent in human beings. Due to different social and environmental setup and repetitive nature of jobs, this instinct is subdued in our work force.

Our task is to sharpen its natural instinct which can be best done by well designed and well implemented refresher training programme. Sharpening of the instinct will make safe working methods a natural habit. By enacting laws and their strict enforcement, we can bring compliance not commitment. It is needless to mention that performance through commitment is far superior, qualitativly and quantitativly to compliance by force or fear.

Ans: b) The differences in statutory provisions relating to haulage and winding ropes are tabulated below:-

Sl. No.

Parameters / particulars

Haulage Rope

Winding Rope

1 Construction Need not be made of cold drawn steel wires.

Except in a sinking shaft less than 80m in depth, every winding rope shall be made of cold drawn steel wires & the gauge of the wire used in construction of such rope shall be suited to dia of drums, pulleys and sheaves of the winding installation.

2 Splicing Splicing can be done No spliced rope shall be used.

3 Factor of Safety FOS not specified in the statute. However, FOS of new haulage ropes for material hauling should be at least 9. For man riding installations it should be at least 10.

Static factor of safety shall not be less than 10 as per statutory provision

4 Life of rope No specified life. Specified statutory life not more than 3½ Yrs.

5 Drum/ rope ratio Not specified. However it should be 80 as recommended by DGMS

100

Q.4.Write short notes on the following:a. Statutory provisions relating to working near mine boundaries, their

rationale and adequacy.b. Functions of Committee under Section 12 of the Mines Act.c. Statutory provisions relating to supply and use of dust respirators.d. Fly rocks in opencast mines, their causes and prevention.

Ans:- a) Statutory provisions relating to working near mine boundaries, their rationale and adequacy- Following are the statutory provisions while working near mine boundaries.1) The owner, agent or manager of a mine, shall before the commencement of any mining operation give notice in form l to CIM, controller (IBM), DM and a copy thereof shall be submitted to RIM with a plan showing the mine boundaries. This notice shall be so given as to reach the persons concerned at least one month before the commencement of any mining operation.

2) The surveyor shall record in a bound paged book kept for the purpose, the full facts when workings of the mine have approached to about 75 m from the mine boundary.

3)a) i. The surface plan and the u/g plan shall show the settled boundary of the mine or where the boundary is in the dispute, the boundaries claimed by the owner of the mine and the owner of the adjacent mine. If complete leasehold can’t be shown on the same plan, an additional key plan on any other suitable scale showing such boundaries and the outline of the workings shall also be maintained.ii. The u/g plan shall also show the workings, and all features as prescribed in above clause, both above and below ground of all adjacent mines as are situated within 60m, measured on any plane, of the boundaries claimed by the owners of the mine.b) The owner, agent and manager of every mine shall as soon as its workings extend to within 60m of the settled boundary with an adjacent mine (or where the boundary is in dispute within 60m of the boundary claimed by the owner of the adjacent mine) inform the owner, agent or manager of such mine about the fact of such extension.

4. Statutory precautions are required to be taken as in case of multi section and contiguous working.

5. a) Every mine shall have fixed boundaries and these shall not be changed except with the express permission in writing of CIM. If the boundary of a mine is changed, a plan showing the new boundary shall be submitted within 7 days.b) No workings shall be made within a distance equal to half the distance of pillar (length) corresponding to the depth of the seam being worked, of the boundary of any mine. No workings shall be made within the aforesaid distance from the boundary claimed by the owner of the adjacent mine (disputed boundary) until the dispute has been settled.

Provided that where work is done in more than one seam, the barrier kept at the boundary, shall, as far as practicable, be vertically coincident and of the same dimension.

c) The CIM may, permit the workings of any mine or part thereof to extend within any shorter distance than what is statutory laid down above or may require that the said workings shall not extend further than a specified distance.

6. Prior approval of the CIM should also be obtained whenever it is intended to cross boundaries and/ or 15m statutory barrier of between two adjacent mine under the control of different managers after the amalgamation etc.

7. Where the workings of any seam for any reason, may extended or get extended within any shorter distance than laid down in 5(c) the CIM may by an order in writing, require the owner to construct such protective works within such time as he may specify in the order.

8. If the adjoining mine is water logged, permission under Req. 127 is required.

Statutory provisions in respect of working near mine boundary are not adequate . In my opinion, the following additional provisions should be incorporated in the statute:

i) When the workings reached within 60m of a mine boundary, a fresh co-relation and joint survey should be made to ensure that the plan is correct.

ii) Every mine plan should be connected with at least two points of national grid so as to have a fixed geographical position so far as the boundary is concerned.

iii) For making a co-relation survey as aforesaid, instrument supplied by owner only should be used.

iv) It must be ensured that the surveyor checks the accuracy of the instrument and if necessary carryout the necessary adjustments.

v) The regulation should also provide that if the workings of any mine get extended to any shorter distance from the boundary as required under regulation, it shall be the duty of owner, agent and manager to report about the same immediately to RIM and CIM in writing.

vi) Reg. 107(2) requires the barrier in different seams should inter-alia be of the same dimensions. As dimension includes height also, the law should specify that the barrier should be of same width and length as falls of roof adjacent to the barrier pillar in a seam may make the height of the pillar greater than what should not be allowed in other seams.

vii)The law should provide that if one of the mines adjacent to the common barrier between two mines have been caved and got water logged, extraction of pillars near the mine boundary in the other mine should be so conducted that the lines representing the angle of draw due to caving in two mines do not interest at a point which is at a lower level than the water level. Inrush of water may take place in the working mine due to coalescence of the goaves above the point of intersection as aforesaid.

Ans. b) Functions of Committee under Section 12 of the Mines Act- Functions of Committee:

i) To consider proposals for making rules and regulations (not bye laws) and to make appropriate recommendations to the central Govt.

ii) To enquire into such accidents or other matter as may be referred to it by the Central Govt. from time to time and make reports thereon and

iii) To hear and decide such appeals or objections against notices or orders issued under the statute.

Ans:- 4(c)- Statutory provisions relating to supply and use of dust respirators- Reg.123 of CMR’1957 stipulates that the average concentration of airborne respirable dust in mine air shall not be more than 3mg/m3 of air in case of coal seam or where SiO2 is less than 3% and 15/ % of SiO2, if Si02 is more than 5%.When the dust survey results indicate that the concentration of air borne respirable dust at any place in a mine exceeds the permissible limit as mentioned above, immediate steps shall be taken by the mine management to minimize the emission of dust and to notify the DGMS. If, the average concentration of respirable dust in a series of 5 samples taken in 7 successive normal working shifts during the subsequent month exceeds 11/2 times the permissible limit, the relevant operations causing excessive dust shall cease till the dust concentration is well below the permissible limit as established by fresh dust sampling.In case of non-functioning of dust control mechanism of any machinery/ equipment, operation of such machinery / equipment shall cease and shall not be resumed until the defects have been rectified.In a work situation, wherein it is technically not feasible to reduce the respirable dust concentration below permissible limit or during the time period necessary to install and commission any device or to institute any new work practice for dust prevention or suppression, the following steps shall be taken:

remote operation of machinery / equipment job rotation of workmen.

However, in case of failure of above steps, the owner, agent or Manager shall provide dust respirators in sufficient numbers to the workmen free of cost for their use. The mine management shall also provide for

regular cleaning & disinfecting of dust respirators maintaining dust respirators in efficient working order through training of workmen in the need for and correct use of respirators.

It is obligatory on the part of all the workman to whom dust respirators provided shall wear the same.

Ans: d) Fly rocks in opencast mines, their causes and prevention- Fly-rock is a rock which is unexpectedly propelled from a blast site well beyond normal expectations. It occurs when explosive energy in the form of gas expansion energy is vented into the atmosphere and propels the rock in front of it. All blasts more or less produces fly-rocks. Fly-rocks also increase air blast. Due to crater effect, it can travel in any direction and throw of fly-rock depends upon local geological conditions and blast parameters.

Apart from being physically dangerous, fly-rock is economically undesirable and causes delay and litigation. Fly rock is an indicator of inefficient utilization of explosive energy as the energy goes waste in propelling rock fragment to undesirable distances. If any open cast mine resorting to heavy blasting in hard rock is situated in within a few kilometers of airdrome, special permission for blasting may be required from air port authorities so that no blasting takes place when a plane is about to take off or land.

Causes of flyrock:-

(i) Poor blast design like use of large diameter blast holes for small benches, variation in burden due to over break or toe, drilling deviation, inadequate burden and too close spacing.(ii) Improper charging and firing – High specific charge, concentration of free flowing slurries at the bottom of holes, inadequate length of stemming column, improper size of stemming material, top initiation and simultaneous firing.(iii) Presence of major geological discontinuities such as faults, weak planes, cracks, bedding planes, mud seams, open fractures, open joints etc.

iv) Poor blast site control. v) Presence of loose stones at the blast site. vi) Presence of water in the blast holes.vii) Improper profile of bench.viii) Less cohesion and adhesion of rock bed.ix) Speed and direction of wind. x) Presence of uncharged holes in the vicinity of charged holes.

Control of flyrocks:-(i) Accuracy in the interpretation of the geology of the area.(ii) Proper blast design according to the site conditions.(iii) Monitoring of loading of explosives.(iv) Deck charging in weak rock in between hard rocks.(v) Muffle blasting in populated areas. (vi) Ensuring that with the stemming material boulders do not fall into the hole.

Such boulders act as missiles and are thrown over very long distances. (vii) While charging explosive in watery holes, it is to be ensured that it settles

down and des not float.(viii) Use of Nonel’s

Q.5. a) State and discuss statutory provisions relating to taking shelter while blasting in opencast mine. How would you ensure adequate shelter when there are private hutments and public road within the danger zone?b) In an underground mine, the Overman has reported probable explosion in a mechanized development district and 16 persons missing. Draw a list of actions, in order of priority that you would take to deal with the emergency and rescue/recover the missing persons.

Ans:- (a) :- Following are the statutory provisions relating to taking shelter while blasting in opencast mine :i) In an open cast working, the shot firer shall not charge or fire a shot

a) unless all persons other than his assistants has taken proper shelter. He shall also take suitable steps to prevent any person approaching the shot and shall himself take adequate shelter along-with his assistants. b) unless sufficient warning by efficient signals is given over the danger zone, i.e. within a radius of 300m from the place of firing.However, DGMS in statutory permission instructs the mine management to treat the danger zone for 500m in any direction from the place of firing.c) two persons are posted, one each in either direction at the two extreme points of public road / railway falling within danger zone to warn the passengers with efficient system of telecommunication or other approved means.

ii) If permanent building / structure not belonging to owner lies within the danger zone, the aggregate max. charge in all the holes fired at one time shall not exceed 2Kg. However DGMS may permit the charges to fired at a time in excess of 2 Kg.

If blasting is done with delay detonators and there is a delay of at least half a second between successive shots fired, a maximum charge of 2kg. can be used in each hole.

If there is surface structure within 50m of place of firing no blasting shall be done except with written permission from DGMS.

In case of big open cast mines, adherence of these provisions are nor practicable hence, is exemption required from DGMS.

iii) Adequate shelters shall be provided against flying fragments or missiles. In order to ensure adequate shelter when there are private hutments and public road within the danger zone, the following steps shall be taken:- i) Marking & identification of danger zone:-Before any blasting is done in Opencast workings the danger zone (a radius of 500 m) is marked on the surface plan of the mine and also identified on the ground.ii) System of warning & posting of guards:-Based on the features/structures within the danger zone, decide upon the scheme of warning people within the said zone and ensuring their safety. The number of guards to be deployed for the purpose may be decided on the needs of the situation.Guards must be posted at all points of entry into the danger zone so that no one can unknowingly enter the dangerous area.iii) Education:- Educating the people about danger zone, hazards from blasting and the need to take proper shelter at the time of blasting. Evolve a fool proof method of warning them about impending blast as well as that of informing them about cessation of danger from blasting. A powerful siren could be used for the purpose. But the difference between ‘Danger Signal and All Clear’ signal should be made clear to all concerned.

Persons working in the adjoining pits, either in the same mine or a neighboring mine must be adequately warned before commencing blasting operations.iv) Selection of spot for shot firing:-A suitable spot should be selected for firing shots. From this place the shot firer should be able to communicate with all the guards deployed for ensuring that no person remains within his danger zone without due protection from projectiles. A Walkie-Talkie communication between the shot firer and guards would be desirable.v) Taking shelter - The blasting in-charge must ensure that all those within the danger zone have taken proper shelter before the blast is initiated.vi) Use of substantially built shelters- All those who must remain within the danger zone at the time of blasting should take shelter in substantially built shelters. Buildings with thatched roofs, or asbestos or filed roofs, or wooden structures or mine tubs may not be able to withstand the force of projectiles. Shelters should be of strong construction to be effective. vii) Controlled Blasting: - The blast must be muffled in a manner that flying fragments cannot project beyond a distance of 10m; or shots should be fired by controlled blasting technique with nonels or electronic detonators.. viii) The above drill is necessary in addition to.a) careful planning of pattern and sequence of blast holesb) correct charging and stemming of holes.c) proper sequence of blasting using short delay detonators, where necessary.

Ans:b)- Action plan to deal with emergency arising out of possible explosion in a mechanized ug district: An exact procedure to be followed in such a situation is difficult to state as it will depend on the possible site of the explosion, the distance of my district from that site, the layout of the mine, the nature of ventilation system and the extent of explosion. Telephonic communications are invariably disrupted after an explosion and I cannot expect guidance from others.Normally a gas explosion is sometimes followed by a second one and keeping this in mind my line of action will be as follows:-

i) Sending word to all explosions in bye to come to my district.ii) Counting all the workers to see if any person is missing or still inbye.iii) Explaining to the workers, the gravity of the situation and the need to

keep cool without losing heart. To keep up their morale, I would quote examples of previous gas explosions in other mines where men had survived.

iv) Assuming that my district is ventilated by an independent split which is not affected by the products of explosion such as smoke, fumes, afterdamp coal dust-laden air current, I shall decide to escape by the intake air route. A level headed strong man should form the rear guard and all the men will travel together.

v) If en-route, there are signs of violence resulting in roof fall, jamming of the route with tubs, broken steel arches etc., I shall take another route to reach an unaffected seam or another district away from the possible site of explosion. The main idea is to avoid any route where after dump may be present and for this reason a return airway will be avoided.

vi) If my district happens to be on the return side of the explosion, smoke, fumes, coal dust laden air will enter my district with the ventilating air and I shall then have to escape via the return airway. Before escaping, the ventilation will be stopped by erecting brattice cloth to arrest travel of oncoming air mixed with after dump, smoke, fumes, dust etc.

vii) If the workers are provided with self rescuers, I shall ask them to wear the self rescuers before passing through a zone containing afterdamp. If self rescuers are not provided and the return route is also affected by after dump and roof falls, the only course for me will be to retreat in bye and stay in the air which is still unpolluted by after damp. The air will be conserved by erection of brattice / stoppings and by short- circuiting the ventilation. If compressed air pipes are available in the district, I would turn on the compressed air assuming the surface compressors to be still running. To conserve the cap lamp current, practically all the lamps will be switched off and if flame safety lamps are provided they will be dimmed. The air trapped in the district behind brattice stoppings will last a long time and perhaps for a few days.

The party then has to visit for the arrival of the rescue team.

Q.6. What could be the occupational health problems with increasing mechanization? What steps should be taken to guard against the same.

Ans: Occupational Health:- Occupational health is essential preventive medicine. According to the joint ILO/WHO Committee,” Occupational health should aim at the promotion and maintenance of the highest degree of physical, mental and social well-being of workers in all occupations, the prevention among workers of departures from health caused by their working condition, the protection of workers in their employment from risk resulting from factors adverse to health, the placing and maintenance of the worker in an occupational environment.In modern times Occupational Health may be defined as the state of physical, mental, social and spiritual well being of all workmen at all kind of workplaces and not merely absence of sickness and infirmity.The health of a worker not only depends on facilities of housing, water, sewage and waste disposal, nutrition and education but also on occupational environment.Need for Mechanization:-For sustainable development of our country, coal is to be produced to meet the energy demand. This could be possible only by increasing mechanization in both u/g as well as in open cast mines using high capacity equipment / machines.To ensure ever increasing production needs with safety standards, introduction of intense mechanization compatible to the geo-mining requirement is quite necessary.

Occupational Health Hazards- There is no profession which is free from occupational hazards. Out of the

accepted hazardous professions mining is considered to be one in the top list. Increasing mechanization in mines may lead to occupational health hazards to

the workmen. The occupational hazards in mining depend on:-

Mineral being worked Geological formation Technique employed Standards of health and sanitation Living environment

Following are the occupational health hazards /problems with increasing mechanization vis-à-vis preventive measures against the same:-1. Physical 2. Chemical3. Mechanical 1) Physical Hazards- a) Dust Hazards- Dust pollution is a predominant problem associated in mining operations. In coal as well as metalliferous mining activities involving drilling, blasting, crushing, transportation, dumping of Ore etc., are closely associated with high levels of air borne coal and other metal dust including asbestos and exposure to crystalline silica (free silica), Inhalation and retention in excessive amount of such dust over the length of time may lead to serious respiratory health problems including pneumoconiosis.Preventive measures- To guard against dangers of coal dust, the following precautions shall be taken:-

i) The concentration of airborne reparable dust shall not be more than 3 mg /m3

of air, when Si02 <5% & not more than 15 if Si02 > 5%. %of Si02

ii) Air borne dust survey shall be conducted in prescribed manner at prescribed interval and record shall be maintained.iii) If the concentration of dust in mine workings exceeds the permissible limit, immediate necessary steps shall be taken to minimize the emission of dust. If needed, the relevant operation(s) causing excessive dust shall cease.iv) Mine management shall provide dust respirators in sufficient number free of cost to concerned work person for use in dusty atmosphere.

v) Every working face and the floor, roof and sides of every roadway or airway within 50m shall be washed down to prevent accumulation of dust and shall be kept wetted.

vi) Water spraying arrangement shall be made and maintained within 90m of working faces.

vii) Complete set of picks with proper size shall be fitted in cutter head.viii) The speed of cutter head shall be maintained such as to prevent formation of dust.

ix) Water spray system shall be maintained in good working order to prevent formation and propagation of dust.

x) The spray nozzles shall be kept regularly cleaned. xi) Pyrite band of igneous rock shall be avoided to cut by machine. xii) Cutting of coal shall not be commenced until water spray starts with proper

pressure and quantity. xiii) Cutting of coal at the face by Coal Cutter shall not be commenced or carried out unless water spraying arrangement at the cutting picks is provided and maintained in good working order.xiv) Suitable mechanism to interlock the operation of water spraying and cutting shall be provided and maintained at all time in the Coal Cutter.xv) Screening and sorting plant should be located beyond 80m from down cast shaft, incline or other openings being used as intake.

xvi) Tubs and conveyors are to be maintained in good condition. xvii) Workers may be protected by remote operations, job rotation or by using

dust protectors.b) Noise Hazards- One of the important physical hazards which mining workers are exposed to, due to use of modern machinery is high intensity noise in different working areas of the mines. Continuous exposure to high intensity noise can cause a serious occupational illness called noise induced hearing loss (NIHL) which is due to irreversible damage to the highly sensitive internal auditory organ. It not only has a detrimental effect on auditory machinery and nervous system but it also affects other organ systems adversely. Preventive measures- These include: Providing enclosure or barriers to noisy machines/ attenuating screen. Damping by layers of soft or elastic materials. Fitting silencers and noise absorbers Isolating men from source by means of acoustic enclosures. Ensuring that machine is balanced. Proper mounting of machines/flexible mounting. Use of ear protection devices such as ear plugs, ear muffs, helmets and

other sophisticated ear-protectors. Selection of suitable machine

Proper maintenance of machine i.e. lubrications, spare parts managements.

Noise mapping of various work places in the mine premises based on the various machines being used in concerned mines along with personal noise dosimetry of individual, workmen exposed to noise level above 85 db(A).

c) Vibration- Workers using different machinery like pneumatic drills, excavators, dozers, dumpers, SDLs, LHD, surface miners, conveyor etc are exposed to high degree of whole body and segmental vibration during their entire shift of working, over a period of time. Exposure to whole body vibration can cause either permanent damage, or disturb both the central as well as peripheral nervous system. Daily exposure to hand arm vibration over a number of years can also cause permanent physical damage resulting in white finger syndrome. Preventive measures against vibration:- These include: Mounting of machine on sound foundation, if necessary on vibration isolators

or dampers. Installing the machine on inertia block with a damping sand-witch between it

and the building foundations. Vibration studies of various mining machinery.d) Heat & Humidity- The common physical hazard in our industry is high temperatures and the workers are often exposed to it. The direct effect of heat causes hyperpyrexia, heat exhaustion, syncope, cramps, burns, heat stroke etc. While the indirect effects are decreased efficiency, increased fatigue, enhanced accident rates.Preventive measures- To guard against the dangers from heat & humidity, sufficient quantity of fresh air should be ensured in the mine working as per statutory provisions in order to clear away smoke and steam, to dilute gases(inflammable or noxious) to harmless proportion, to provide air containing sufficiency or oxygen and to prevent excessive rise of temperature or humidity likely to be harmful to health of persons.e) Light – The workers may be exposed to the risk of poor illumination. The acute effects are eye strain, headache, eye ache, lachrymation, eye fatigue and conjection. The chronic effects lead to “Miner’s nystagmus”. Preventive measures- Adequate lighting arrangement shall be provided in order to prevent glare or eye strain.2) Chemical Hazards- The chemical hazards are on the increase with the introduction of newer and complex chemicals. The chemical agents act on three ways, direct contract / local action, gas poisoning / inhalation and metal poisoning. a) Direct contract / local action – It is usually in the form of dermatitis, ulcers, boils etc. The acidic water, machine oil or other chemical substances which come in direct contact with skin are the responsible factors.b) Gas poisoning/ inhalation- Gas exposure is a common hazards, noxious gasses like CO, CO2, Nitrous fumes are common sources of inhalation poisoning. These cause irritation to eyes, headache, giddiness, vomiting, broncho-spasm, dyspnoea, cynosis, hyposixa, pulmonary oedema and finally death depending upon severity and duration of exposure.c) Metal poisoning- Many metals such as Mn, Hg, Pb, Cr, Br etc. due to their harmful chemical properties cause tremendous adverse effects on miners health.Preventive measures- Adequate steps should be taken to guard against gas and metal poisoning. 3) Mechanical Hazards- The main cause of health hazards due to application of large scale high capacity Shovels, SDLS, LHDs, Drag Lines, Drills etc are:

Faulty structure of seats of the machinery. Wrong posture of the employees while handling the machinery. Faulty ways of lifting and handling heavy equipments.

Preventive measures- Ergonomic assessment of all latest machines, before their introduction into mining operation should be made.In addition to the above, the following additional measures should also be taken to guard against occupational health hazards due to increasing mechanization: 1) IME & PME of workmen as per provision of statute.2) IME should be made mandatory for all mining employees whether permanent, temporary or contractual, before they are engaged in any mining job. 3) The frequency of PME should be brought down from existing 5 yrs to 2 yrs for the mining employees above 45 yrs of age.4) Each mechanized mine should engage at least one qualified medical officer for every 500 employees and thereafter, one for every 1000 employees.5) One of the medical examinations of every person should be arranged within one year of his superannuation.6) Standards IME & PME shall be suitably modified in order to ensure early diagnosis of diseases caused due to employment in mines.7) Special tests should be included in the PME for employees exposed to specific health hazard.8) Setting up structured occupational health services.9) Potability test of drinking water supplied to the mine employees, to be made mandatory once in a year irrespective of its source, the sample of water to be collected from the points of consumption.10) Occupational health survey of workmen as per provision of statute.

Q.7. Write short notes on the following:a. Risk Management.b. Effectiveness of Safety Committee.c. Statutory provisions relating to Rescue Rooms.d. Condition for use of trolley wire locomotive below ground.

Ans:-a) Risk Management:- Risk management as a tool for development of good health and safety management system is a break through in the traditional strategy as it differs from the existing one by involving the entire staff in the realization of safety improvement programme with responsibility and accountability sharing proportionately with the decision making authority.As per recommendation of 9th conference on safety in mines, Risk management plans shall be prepared on the basis of risk assessment and implemented in the identified mines. Risk Management is a logical and systematic application of management policies, procedures and practices to the tasks of identifying, analyzing, assessing, treating and monitoring risk with any activity, process or equipment etc. It is the pro-active process, where a particular process or operation is examined in detail so as to identify potential hazards and threats, which if not addressed, could cause an accident or incident. Controls or combination of controls are identified, which if implemented, ensure safety. It aims to improve the understanding of the potential for the accidents, their possible consequences and the adequacy of controls.Objectives of risk management:- To reduce the likelihood and impact of mishaps of all kinds. To reduce the inherent potential for major accidents which could injure or

kill many people. To limit the damage to the environment To ensure desired production, productivity and profitability.Fundamentals of risk management :- Understanding of what could happen and how Real and visible commitment to managing the risks.Risk Management process/Elements of risk management - Risk management consists of following steps:- i) Establishment of context – It is important to clarify-a) the nature of risks which the organisation is concerned about (people,

equipment, environment, production etc.)b) resource limitations of the organisationc) the attitudes within the organisation.ii) Identification of hazards:- Hazard identification is a critical step of risk assessment, presuming what is not identified cannot be actively managed.iii) Analysis of risks: - Analysis of risks entails understanding the nature of the hazards which exist, the nature of the existing controls and barriers and assessing the likelyhood of occurrence of hazards and the severity of the consequences of those hazards.iv) Assessment and prioritization of risks:- It is the process used to determine risk management priorities by evaluating and comparing the level of risks against predetermined standards, forget risk levels or either criteria. All risks can not be totally eliminated at once. Ranking the major contributors and planing appropriate improvement on the principle of “do first things first and then move to the next” should be adopted.

v) Treatment of risk:- It is selection and implementation of appropriate options for dealing with risk. It consists of identification and evaluation of treatment options as well as preparation and implementation of treatment plans.vi) Monitoring and review:- An essential part of any rise management programme is monitoring of performance compared with the standards and the plans and review of the standards. The success of the programme needs to be reviewed periodically by consideration of : the degree of completion of the listed tasks (inputs) the performance of the mine in relation to the defined criteria (outputs)

Applicability / Need of risk management :- In principal, a systematic risk management/ assessment should be undertaken whenever there is:i) a mine which has not previously undertaken a formal risk management exercise.ii) a disaster/ dangerous occurrence has occurred and management wishes to act effectively to prevent a recurrence.iii) a modification in procedure is planned which could affect safety.iv) a new equipment/ extensively modified equipment is purchased or equipment/machine is to be modified.v) an established method or mining operation is to be modified. Ans: b) Effectiveness of Safety Committee- For improvement of functioning of the safety committee, the following steps may be taken:1) The members of the safety committee should be given orientation training on different aspects of mining as well as in communication skills etc.In order that the members of the safety committee discharge their functions meaningfully and become more relevant to the safety needs of the mining industry, a need based pre-designed training schedule should be developed for the members who are workmen or subordinate supervisory officials.The training programme may consist of 10 lectures/demonstrations, sessions of a not less than 2 hour duration each supplemented by visits to mines, workshop etc. A suitable syllabus should be drawn by the individual mine management to suit the local conditions and local work practices.2) For the safety committee meetings, 60% of the total membership should constitute a quorum provided that if a meeting is postponed due to lack of quorum, the next meeting may be held irrespective of quorum.3) Before a S/C meeting is held, a suitable agenda should be prepared by the secretary by soliciting information from workers and other members of the committee.4) During any meeting, the status of implementation of the recommendations of the previous meeting should be discussed first before taking up discussions on the prepared agenda.5) During discussions in a S/C meeting, the workers representatives should be encouraged to participate in the discussion. In fact discussions should not be dominated by officers of the company. The members should not only be encouraged to initiate the discussions but also to substantially participate in the discussions so that they feel themselves important with regard to safety management of the mine.6) A scheme may be initiated for making special award to any members who makes any constructive suggestions for improving safety in mines.

7) Senior officials of the company as well as officers from DGMS should attend some of the meetings so that the workers may appreciate the importance attached to such meetings.Once in a year the meeting of the safety committee should be attended by the senior officials of the Area. Such meetings should review the recommendations made during the year by the safety committee together with the status of implementations of the recommendations.8) At the area level annual review of the functioning of S/C of all the mines of Area should be made by the G.M. Such meetings should be attended by G.M.(Safety), W.I. (Mining). Workmen’s representatives of the S/C, the Secretary and the Chairman of S/C. An officer from the DGMS may also attend the review meeting.9) In order to prevent the S/C meeting becoming mere rituals, monitoring of the S/C should be done by officers of higher level of mine management.10) In order that the S/C can serve as a forum for communication of messages of safety & occupational health matters, based on the deliberations in the S/C meeting, the members of different categories of workers may be allowed to visit districts of the mine within a suitable time schedule prepared by the manager of the mine for communication messages to the workers in general.11) Occupational health physician should be a member of the S/C where he could contribute to the health education of the workers.12) Manager being the Chairman of the S/C does not have enough time to devote. Moreover, deliberation under him becomes difficult for the subordinate officers. Therefore, it is suggested that some other officials who is relatively free but smart enough to conduct such work, shall be given the responsibility.13) Some of the important officials of the adjoining mines should be included in the safety committee so that their opinions are also considered because safety of the mine has to do a lot with the condition of the adjoining mine.14) In the safety committee. Doctors, Welfare Officers and Surveyors should also be made a committee member.15) There should be provision for recording of the discussions taking place in the safety committee.16) The members of the safety committee should visit surface and underground workings on a fixed day in every month with a view to meet the workers on the spot and talk with them on the matters of safety, invites suggestions on the safety and check general safety standard.17) Examination and enquiry of all types of accident and incidents by S/C.18) Unit/department –wise safety committees to be constituted under overall control of the main safety committee.19) Action taken report on rectification of the deficiencies to be prepared by the official concerned within 7 days of the committee meeting and compilation of the status of rectification by the Area Safety Officer. 20) Status of rectification of deficiencies pointed out in the safety committee meeting to be assessed a day or two before the next safety committee meeting.21) Tenure of Safety Committee to be made 2 years.22) Training and refresher training of safety committee members..

Ans:c) Statutory provisions relating to Rescue Rooms:-Refer to Q.No.7(b)(2nd class 2005)

Ans:- (d) Condition for use of trolley were locomotive below ground- While using trolley-wire locomotives belowground, the following condition shall apply :

i. General- As far as practicable, the surface of every length of roadway shall be kept even, firm, well- drained and in a condition which is not conducive to skidding.

ii. Approval for use:- No trolley- wise locomotives shall be used below ground unless it is a type approved by CIM and equipped with a “ dead man control” The maximum voltage, the character of current and the electro-technical details of every installation shall be approved by electrical Inspector of Mines. Control levers of the locomotives shall be so arranged that the lever cannot be accidentally removed when the power is on.

iii. Gradient- No locomotives shall run on any length of roadway, the gradient of which exceeds 1 in 6.

iv. Transport rule:- The manager of a belowground mine shall frame transport rules for safe operation / movement of locomotives and submit a copy to DGMS for approval and enforce the same in the mine.

v. Clearance:- The following minimum clearance should be ensured:a) On the side of the track opposite to the manholes – 0.3m(b) Where there is total minimum clearance of less than 2m, safety stations shall be provided at intervals of 30m and they shall be clearly marked.

v. Height of trolley wires- The height of the trolley wire above the top of the rails shall not be less than 2.0 m

vii. Support & electrical protection of trolley wires and feeders:-(a) It shall be supported from efficient insulators at suitable spacing and doubly insulated from the anchorage of the suspension device.(b) It shall be protected collectively by an automatic circuit breaker.(c) Trolley wire shall be of adequate current carrying capacity and having x-sectional area not less than 0.53 cm2 and breaking load not less than 2000 kg.(d) All trolley lines shall be sectionalized every 800m by placing a switch in the line.(e) All branch trolley lines shall be provided with a frog and switch at a point where they leave the main line, by which the branch line can be disconnected.(f) At every shunting place, crossing and approach, conspicuous light signals shall be provided.

viii. Rail Track:- (a) It shall be of adequate X-sectional area & be so connected together by welding, fish plates and so efficiently bonded across all joints that electrical resistance of a joint between two successive rails does not exceed the resistance of one rail of normal length.

(b) Two rails of the same track shall be connected by cross-bonding of good conductance at intervals not exceeding 200m in approved manner by a conductor having X-sectional area not less than that of any trolley wire conductor over the track.(c) The negative track rails shall be electrically and mechanically continuous and be effectively connected to the negative terminal of the generator or converter by insulated copper conductors of adequate current carrying capacity.(d) Drawbars and axles of the locomotives shall be bonded.(e) Trolley wires and the rail return shall be so constructed and maintained that during the working of the system, sparking between the loco wheels and the rails is minimized.

ix. Safety devices:-Trolley wire locomotive shall be provided with (a) an efficient automatic braking system of non-inflammable material.(b) a suitable parking brake permitting satisfactory emergency braking

(c) a speedometer (d) an efficient distance indicator

(e) an efficient head light (f) an approved portable lamp for emergency

(g) a mechanically operated device like gong hammer capable of giving adequately audible warning signal.(h) at least two portable fire extinguishers(i) an ergonomically designed seat for the driver.

x. Examination & maintenance – For proper functioning & maintenance of the system, the following examination & maintenance scheme/schedule shall be prepared and ensured by manager:-(a) Shift-wise examination.(b) Daily examination(c) Weekly examination(d) Monthly examination

Q.8. The management of a large opencast mine has entrusted the work of removal of overburden to a contractor. Deployment of contractor’s trucks and workers for removal of overburden has led to increase of accidents. Discuss the reasons for increase in accidents and suggest preventive measures.

Ans:- Increased demand of coal has necessitated large amount of Coal /OB handling in the mine. The O/C activities have thus been under immense pressure to boost production and achieved required target and hence OBR jobs are being increasingly carried out by engaging contractors trucks and workers.Analysis of accidents in O/C reveals that: Approximately 33% of accidents take place while reversing vehicles in

dump yard / coal benches. 60-70% of the victims were either driver or Khalashi of the vehicles

deployed by the contractors. No basic or specialized training were imparted to the contractors

workers before engaging them in the mine.

Risk to contractors workers – Workers are purely temporary or migratory in nature and not well

conversant with mining activities or laws. In many cases, no formal or informal training is imparted as required.

Contractor’s workers are having more risk taking attitudes as earnings are directly connected with output.

Safety is considered as a cost components by the contractors. Contractors have little commitment for ensuring safety and health

condition of the work force.

Reasons for increase in accidents due to deployment of contractors trucks and workers for removal of OB & preventive measures to reduce such accidents:i) Unskilled, negligent and unauthorized driving / riding of trucks. Preventive measures- a) Contractors shall submit the list of drivers (whose antecedents he believes are good) along with their valid licenses for verification and record by Engineer and issue of authorization by Manager/PO(Agent). No such driver should be allowed without verification of license/authorization. b) No helper/any – unauthorized person shall be allowed to travel in tipping trucks. Trained trip man/helpers shall be provided at the loading and unloading point and for the miscellaneous jobs at key positions. Unauthorized riding in vehicles shall make both the driver and/or the unauthorized person traveling liable to punishment. c) Manager shall take all appropriate steps including his authority of punishment to ensure prohibition of unauthorized driving/riding. ii) Non road-worthiness of trucks and non-fitting of various safety devices in the trucks.

Preventive measures- a) All contractual/ hired machinery engaged in the mine shall be audited/inspected by a team consisting of mine officials and contractors technical personnel for their suitability before engaging in the mine.

b) Fitness of all the vehicle/machines including AVA shall be checked under the supervision of Colliery Engineer.c) Fitness certificates of all vehicles shall be checked by the Colliery Engineer and proper records shall be maintained.d) After the checking of the vehicles and fitness certificates the Engineer shall recommend for the issue of valid pass for vehicles/machines to the Manager/Project Officer.e) No contractors vehicle/machines shall be allowed inside mine premises without valid pass issued by Manager/Project Officer(Agent) of the Colliery.f) If any vehicle is found defective, the same shall not be allowed inside the mine, unless the defect has been rectified and vehicles certified to be fit by the Colliery Engineer in writing.g) The time of incoming and outgoing contractors vehicles in the command area should be recorded in a register at the check post.h) Contractors equipment are to be checked by a competent person of the mine periodically. i) Regular checking of braking systems of trucks including parking brakes. Fail safe brake should be used.j) An audiovisual back up alarm system which adjusts itself to the surrounding noise level maintaining minimum 5 dB(A) above the noise level may be used in the trucks, which should be actuated automatically during reversing.iii) Not following traffic rules and code of practice for movement of vehicles.Preventive measures- a) Code of traffic rules, dumping practices, signaling and communication shall be framed and implemented.b) Escape lane or escape road shall be provided wherever there are chances of over speeding or roll back of vehicles in motion.c) Separate roads/lanes for HEMMs and contractors tipping trucks and for pedestrians shall be provided.d) One way traffic should be adopted for movement of vehicles. iv) Uncontrolled fleeting and over crowding of vehicles.

Preventive measures- a) Sufficient dumping place shall be ensured by the Manager to avoid over crowding.b) Sufficient level space shall be provided on ramps close to unloading point for unloading, reversing and authorized parking.c) Dumping and manual loading shall not be allowed at the same place.d) No vehicle shall be parked along slope/gradient. If, it is unavoidable, hand brakes shall be applied firmly, engine stopped, the vehicle kept in gear and stop blocks against the wheels used.e) Adequate level parking place should be created near loading / unloading points.v) Improper open pit / dump slope design:Preventive measures- a) The height, width and slope of benches should be maintained as per statute and conditions imposed by DGMS.b) OB dump should be designed taking into consideration the natural angle of repose of dump materials.

vi) Inadequate illumination.Preventive measures- Proper illumination is a key to better and safe working environment. Adequate lighting arrangement as per provision of statute shall be provided and maintained for proper lighting of open cast workings.vii)Improper and unsafe haul road and dump yard. Preventive measures- Haul road & dump yard shall be designed properly taking into consideration the engineering parameters and shall also be maintained in good condition.viii) Lack of knowledge of mine lay out, mine working including system of working among the contractors workers.Preventive measures- a)All persons engaged at any work within the mines premises through contractors must receive relevant training and other job related briefings.b) Compulsory training programme on the basics of mining layout & system of working encompassing traffic rule should be arranged by management, proper vigilance should be observed, so that contractor could engage no one in the mine premises without imparting training. ix) Lack of training & frequent change of workers by contractor.Preventive measures- a) Before commencement of work against work order, contractor shall give to the manager a list of his workers/supervisors to be trained as per VT rules and new VT module.b) Persons required to be trained, shall be sent for training by Manager.c) A list of trained workers already available with the contractors shall be furnished to the Manager.d) Strict guidelines should be enforced by management to discourage & stop the frequent retrenchment of workers by contractors.x) Lack of competent supervision during loading and transportation of OB.Preventive measures- Statutory supervision of contractual operation by departmental competent persons to be ensured by Manager/Project Officer.xi) Deployment of workers on overtime.Preventive measures- Contractors workers should not be allowed to work beyond permitted hours without permission of management.The responsibility of contractors works safety is a shared one. Work can be contracted but risks can not. Under the circumstances, mine management, contractors and contractors workers have to play their active roles and to shoulder individual responsibilities for ensuring safety of contractors workers. As per recommendation of 10th safety conference, following measures should be taken for ensuring safety of contractors workers.

1. Managements responsibility - i) Ensuring that contractor’s arrangements for health & safety management are consistent with those of the principal employer.ii) Ensuring that contract shall preferably be for longer periods so that there is an adequate scope for management of safety by contractors.iii) Ensuring that contractor provides fit – for – purpose machinery, operators and other staffs and provided with written safe work procedures.iv) Monitoring of all activities of contractors to ensure that they are complying with all the requirements of the statutes and safety system.

2. Contractor’s responsibilities- i) Preparing written safe operating procedure for the work to be carried out, including risk assessment and safe method to deal with the risk and providing a copy of SOP to the person designated by mine owner who shall be supervising the contractor’s work.ii) Keeping the SOP up-to-date and providing a copy of changes to the designated person.iii) Ensuring that all work is carried out in accordance with the statute and SOP and deploy adequate qualified and competent persons for the jobs.iv) All persons deployed by contractors for working in the mines shall undergo vocational training, IME & PME. 3) Contractors workers responsibilities- i) An employee shall take reasonable care for health and safety of persons who are at his place of work or who may be affected by his acts and omissions.ii) An employee shall cooperate with his employer or other persons in supervision of his work to enable compliance with requirement of the statute.

Morning Session THE MINES ACT, 1952


SECOND CLASS



Answer any SIX Questions(All questions carry equal marks)

Q.1. Write provisions in respect of the following:-(a) Appointment of rescue trained persons in mines and their disposition etc.(b) Fresh air base(c) Duties of manager in emergency.Ans:-a) Appointment of rescue trained persons in mines and their disposition etc:-

Refer to Q.No.3 (b) (2nd Class 2007)Ans:-(b) Fresh air base- i) As soon as possible, fresh air base(s) shall be established in fresh air as near

to the irrespirable zone(s) as safety permits.ii) If F.A.B. is belowground, it shall be connected to surface by telephone or if

F.A.B. is on the surface it shall be connected to shaft bottom by telephone.iii) Except in emergency, rescue trained persons shall not proceed beyond any

place where FAB is to be established until there have been provided at such base. One qualified medical practitioner and one rescue trained person. A spare rescue team. One or more reviving apparatus, oxygen revivers etc. First aid box and stretcher CO detector A hygrometer and Two flame safety lamps.

iv) Whenever men are already at work beyond the FAB, there shall be provided at the base as soon as possible the persons, apparatus and equipment as mentioned in (iii) above It is recommended that telephone, O2 cylinder, mechanical resuscitators and food stuffs should also be provided at fresh air base. A good FAB underground should possess the following features:-

It should be located at a well ventilated place. There should be scope for quick advance / retreat. The roofs should be properly dressed and supported Sufficient space should be available for the rescue team to prepare/

moved about / retreat, and for the stocking of the first aid and medical facilities.

The following persons may also be made available at the FAB as early as possible:

In-charge of the affected area and his assistants. Mechanics & Helpers.

Ans:- c) Duties of manager in emergency:- Speed & efficiency are the main requirements for handling an emergency. This calls for a fast and efficient team working under able leadership. First few hours are vital after an emergency has set in, to contain loss of human lives and property.The following are the statutory provisions in Mines Rescue Rules 1985 in respect of duties of manager in emergency. i) On receiving information of any emergency, the manager shall immediately:

inform rescue station or rescue room serving the mine. summon rescue trained persons employed in the mine inform the management of adjacent mines for rescue/ help. inform the management of rescue station regarding the nature of

emergency. summon medical assistance: and send information to Regional Inspector of Mines.

ii) All rescue and recovery work shall be conducted under the control, supervision and direction of the manager. However, in case of major emergency, the manager shall take guidance from an expert group consisting of senior official of management, representative from D.G.M.S., concerned rescue station and recognized trade unions in taking decisions regarding rescue and recovery.

Q.2.Discuss problems of high-wall and spoil dump stability and the precautions to be taken in deep mechanized opencast mine using dragline.

Ans: - Problems of high-wall In an open cast mine deploying draglines, the height of benches may go beyond

50m but in Indian condition it is restricted within 40m. The common dragline bench height ranges from 30m for draglines having bucket capacity 24m3 with a boom length 96m. To manage such high walls in case of dragline benches is a very difficult task and some times becomes a potential hazard for safety due to failure of benches.

The angle of slope of bench plays a vital role in stability of benches. The angle of slope of bench should be either equal to or less than the angle of repose of bench rock. The angle of slope depends upon the plane of weakness, orientation of bedding plane, hydro-geological condition of the strata etc. The slope failure is due to mainly by a slow progress of rotational shear, mechanical properties of rock like cohesion, angle of internal friction, pore water pressure, seepage forces, tension crack etc. The bench slope may failed in following ways:

Plane failure Wedge failure Circular failure

Causes of bench slope failure- i) Dynamic loading caused by plying HEMM, heavy blasting, earthquakes

etc.ii) Presence of water in the rock mass iii) Decrease in cohesion & angle of internal friction of high wall materialiv) Floor sliding due to presence of aquifer.v) Improper bench geometry

Precautions to be taken against high wall:-

i) Bench Design: - Design of bench geometry on the basis of sound scientific technique.

ii) Supporting of slopes:- Supporting of high wall slopes may control the failure of slopes,. The high wall slopes may be supported by bolting, anchoring, shotcreting etc.

iii) Proper drainage system- Surface drainage arrangement, deep drainage system, vertical bore holes, horizontal toe drains, horizontal drainage adits etc. should be provided and maintained for stability of high wall slope.

iv) De-watering of slopes - Dewatering of slopes also called depressurization, reduces water- pressure components and also improves the properties of rock-mass.

v) Re-excavation/re-shaping- This method of slope stabilization removes extra material to form shorter benches. This ensures a stable slope. Such type of stabilization work is adopted when support measures are not likely to be effective.

By taking above pre-cautionary measures, the problems of high wall due to its slope failure may be tackled. Problems of spoil dump stability-

Safe, property designed and scientifically engineered slope is essential requirement for stability of spoil dump. The benefit of an open pit operation largely depends on the use of the steepest slopes possible which should not fail

during its life. However, excessive steeping may result into slope failure leading to loss of production, extra stripping costs to remove failed material, reforming of benches, rerouting of haul roads and production delays.

Factors influencing spoil dump stability are:- a) Soil dump geometry i) Height of spoil dump :- Slope stability generally decreases with increasing

height of spoil dump as the shear stresses within the spoil mass increases due to added weight and may exceed the shear strength of the spoil material.

ii) Slope of spoil dump :- Low slope angle minimizes the adverse effects of increasing spoil height. Long terms stability is achieved by re-sloping the face of piles between 26º-28º .

iii) Zonation in spoil dump :- The zonation of the spoil material results in different strength and density material results in different strength through the spoil pile which can control this failure surface and influence the nature and extent of spoil stability.

b) Presence of Water:- It adversely affects the dump stability by changing the material strength and influencing the pore water and seepage forces.

c) Climate :- The total precipitation, frequency of thunderstorms or heavy rainfall and seasonal precipitation affects the ground water conditions and drainage through spoil dump and reduces the stability of spoil dump.

d) Foundation of dump :- Nature of foundation strata and its slope angle is to be found very carefully as it affects the stability of dump. The maximum permissible foundation slope can be determined by the following relation:-

tan θ= tanβ/F, where θ = slope angle of foundation β = friction angle between the base of the

pile and its foundation. F = desired factor of safety.

e) Geotechnical Parameter:- Shear strength of foundation material should be greater than shear strength of material comprising soil dump.f) Mining equipment and mining method.g) Drainage :- It affects the ground water condition and pore water pressure and hence stability of dump. The surface water must be prevented from entering spoil dump and the foundation with the help of proper drainage.h) Blasting:- The fragmentation of O.B. rocks affects the initial particle size of spoil material. The well graded fragment size may allow a denser packing and thereby increases density and strength of spoil material.

Precautions to be taken against likely failure of spoil dump:-

To ensure stability of spoil dump, the following precautions should be taken i) Design of slope - The rock mass behind each slope is unique. To design proper slopes for each case of rock formation, the geological data, rock strength formation, ground water data and pressure is required.Slopes have to be designed by qualified and competent rock mechanics engineers after taking into consideration the factors influencing the slope stability.ii) Slope stabilization:- When safety factor of a slope is found to be inadequate, it needs to be stabilized. The method for this are:-a) External Supportb) Removal of water from the slopec) Removal of material which is likely to slip.

External support is given by retaining walls (in soil slopes) as a temporary measure, provided the wall is higher than the slope and its foundation is below the expected slip surface. Such walls are practicable only in case of short slopes.

Rock-bolding with pre-tensioning and with or without shotcreting is a fairly permanent measure, in rock slopes. The bolt must extend beyond the failure surface. Removal of water from the slopes reduces water pressure components and also improves the properties of rockmass. The third method of slope stabilization is removal of material to form shorter benches or re-grading the slope. This is adopted when support measures are not likely to be effective.

iii) Drainage- The excavated pit must be provided with an effective garland drain. The benches should have an effective toe drains. All the drains should be kept clear of debris and effective for the free flow of water.

iv) Controlled blasting:- Un-controlled blasting results in rough uneven contours, over breaks, overhangs and extension of tension cracks in the slope. Poor blasting causes opening between various weak planes, which result in loss of resultant cohesion between them. It also results into shattering of the slope mass well behind the desired location and consequently allowing earlier infiltration of surface water, which leads to un-favourable ground water pressures and related problems.These detrimental after effects, due to poor blasting, can be checked by one of the most experimented controlled blasting methods known as “ Pre-spliting Blasting Technique” in order to minimize the damage of the slope mass forming the ultimate pit slope.

v) Slope monitoring – It is essential to detect any instability well in advance so that any damage to men and animals can be avoided. If any instability is detected in the early stage then it can be stabilized by applying the suitable remedial measures. The active monitoring system permits early and confident decision making by management both for safety purpose and for optimum excavation sequencing.Tension cracks are the first sign of slope instability. The development of any tension cracks on the different benches formed in weak slope material should be observed. Tension cracks should be filled with weathered laterite and sealed with clay to prevent the entry of water, which may cause failure.

Q.3.An accident had occurred in an open cast mine due to run over by a dumper being driven in reverse. One worker received fatal injuries. Write a report of enquiry of the accident bringing out contraventions, responsibility and suggestions to prevent similar accident in future. Assume your own conditions.

Ans:- Enquiry Report

Ref.No……………………… Date………...

To,The Manager,“ A “ OCP

Sub:- Enquiry report in respect of fatal accident involving 1 worker in A-open cast working due to run over by a

dumper being driven in reverse.Dear Sir,

As desired vide your letter no………………… dt…………… I am enclosing herewith the detailed enquiry report in respect of fatal accident in A-O/C working due to run over by a dumper being driven in reverse indicating the cause and circumstances attending to the accident, contraventions of statutory provisions, responsibilities and suggestions to prevent similar accident in future in Annex.l . I am also enclosing the accident plan showing the site of accident along-with photo graphs.

Yours faithfully,Encl: As above.

( A.C.M. ) “A” OCP

Annexure - l

Detailed Enquiry Report

Assumption of Conditions:-

A OCP is being worked in lll seam 10m thick, dipping at 1 in 7 with shovel – dumper combination using deep hole blasting after obtaining statutory permission for extraction of pillars by OC method from DGMS.The seam is extensively developed in 2 sections in past on the pattern of B/P method of mining. The depth of working from the surface is about 50m. There are 3 benches in OB and 2 benches in Coal. The Coal & OB are being removed by hiring agency.

I _______________, ACM, A OCP inspected the place, where this accident occurred and enquired into the cause and circumstances connected with the same.

1) Introduction & information :- The accident occurred in A OCP of M/s……. on ……… at about 3.45 A.M. in 3rd / night shift causing death of 1 person working as maintenance helper of M/s. ……….. the hiring agency engaged for removal of Coal & OB. I received information about the accident at about 4.30 A.M. when I was in my residence.

2) Background information:- The depillaring permission was obtained for extraction of developed pillars by open cast method with shovel – dumper combination using deep hole blasting. The usual practice at A OCP was to expose the developed coal pillars by removing OB, extract the pillars and then Coal & OB transported to coal stock and OB dump respectively.

3) Occurrence of accident:- At about 3.45 A.M., one of the worker’s noticed that a person was slipping on the sand on OB bench & dumper operator was driving the dumper in reverse and the dumper run over the sleeping worker.

4) Cause of Accident:- After inspection of site of accident, recording of statements of co-workers and other officials it was revealed that accident occurred due to the following reasons:-i) Careless driving of dumper by dumper operator who was deployed on overtime.ii) Sleeping of person / maintenance helper while on duty.5) Contraventions of statutory provisions:- In my opinion, the following statutory provisions were contravened:i) Reg. 38(6) of CMR,1957 – The maintenance helper of M/s. …… engaged by hiring agency was sleeping on OB bench while he was on duty.ii) Reg. 95A of CMR,1957- Negligence on duty by dumper operator as he carelessly driven the dumper in reverse direction in contravention of conditions imposed by DGMS in statutory permission.

6)Responsibilities:- Enquiry into the accident revealed that if the dumper operator was operating the dumper carefully & maintenance helper was not sleeping, the accident could have been averted. The following persons are considered responsible for the accident:- i) ACM- In contravention of provisions of reg. 95A and 42 of CMR 1957, the ACM failed to effectively implement the conditions imposed by DGMS for safe driving of dumpers.ii) Overman- In contravention of provisions of reg. 95A and 43 of CMR 1957, the Overman failed to effectively implement the conditions imposed by DGMS for safe driving of dumpers as well as allowing the maintenance helper to sleep while on duty.iii) Dumper Operator- He failed to follow the instructions given by senior officials. iv) Maintenance Helper- He failed to obey the regulation 38(6) of CMR,1957 as well as instructions of his superiors.

7) Suggestions to prevent similar accident in future:- In my opinion, the following suggestions should be implemented in order to avoid repetition of similar accidents in future:i) Manpower -Adequate nos. of dumper operators should be appointed keeping in view factors like absenteeism, leave etc. in order to avoid deployment of dumper operator on overtime. ii) Avoidance of overtime duty.- Work on overtime should be avoided..iii) Selection of Operators- Operators should be selected from amongst persons possessing requisite qualifications. The selection process should comprise a test to check driving / operating skill, aptitude, health and oral examination of the candidate by a competent selection committee.viii) Training and re-training- Operators should be imparted proper training and retraining for their development and strict adherence of safety rules.

Q.4.Draw a code of practice for deployment of side discharge Loaders in a depillaring district in which a 5.0m thick seam is being extracted in two lifts in conjunction with hydraulic sand stowing.

Ans:- Refer to Q.No.7 (2nd class 2007)

Q.No.5.Discuss the various reasons for accident due to inundation. Suggest steps for prevention of such accidents.

Ans: The history of Coal Mining in India has witnessed several disasters / accidents due to inundation both from surface sources as well as u/g sources of water.

The following are the various reasons for accidents due inundation vis-à-vis preventive measures to avoid such accidents:-

Sl.No. Cause of accidents Preventive measuresA. Due to surface source of wateri Entry of water into mine workings through

openings of mine (shaft / incline/ goaf / borehole etc) which are at lower level than the HFL of any river/ nallah etc.

a) Ensuring mine opening above 3m of known HFL of the area.b)Diversion of river or provision of suitable embankment.c) Fixing warning level , danger level and withdrawal level at a suitable site.d) Checking of protective measures regularly.

2 Low cover and pot holing under river or low lying areas where water can accumulate.

a) Seeking and obtaining permission from CIM while making mine workings beneath and within 15m of bank of river, stream, nullah,lake,tank etc.b) Inspection and examination of protective measures envisaged and enforced to provide adeq uate protection against danger of inrush of water.

3 Collapse of unstable workings whether the cover is low or comparatively high but capable of producing wide cracks on the surface.

a) Supporting the roof by steel girders & stabilizing the workings by packing with incombustible materials.b) Providing dams out bye of the packing in appropriate case.

4 Subsidence under rivers, tanks, lakes or water accumulated in low lying areas.

a) No extraction of pillars under low lying areas by caving method.b) Providing drains around subsided areas.

5 Obstruction in the course of water and water entering through mine openings

a) Avoiding constricting the water course on the

which are apparently at higher level. downstream side or erecting dams across the course for pumping water.b) Avoiding choking of culverts etc by debris and checking water courses for ensuring unobstructed flow of water during rainy season.

6 Fault planes, fissures connected with river lake, canal etc. may cause inrush of water.

a) Leaving a barrier of at-least 7.5m against such fissures/disturbances and crossing at minimum number of essential points.b) Driving galleries with advance boreholes.c) Plugging boreholes effectively when in –flow of water cannot be stopped.

7 Failure of embankment a) The embankment should be of right dimension for streams.b) It should be such as to contain the water against features to be protected. Water should be not by pass the embankment at any point.c) The side facing water shall be pitched with stone and brick masonry set in cement mortar.d) It should be built with proper materials and well compacted to prevent leaking or breaches.

8 Water accumulated against stoppings/ deposits of quarry debris in galleries exposed in quarries.

Barriers against quarries shall be at least one pillar in thickness to avoid dangers. Otherwise accumulation of water against such barriers shall be avoided.

9. Where a mine threatened with danger of inundation is worked in rainy season without taking safety measures.

To guard against sudden release of large quantity of water from dams on the upstream side or due to heavy rains on the upper reaches of the river, effective liaison shall be

maintained with the dam authorities. Adequate advance warning arrange ments for monitoring rains in the upper reaches of the river and re-flashing warning sufficiently in advance shall also be provided.

B. Due to underground source of water- 1 Inundation from accumulation of water

in the same seam:a) Inadvertent connection of active workings with water body either due to unknown thickness of barrier or presence of thin barrier.b) Connection of active workings with water logged workings along a fault plane.

c) Failure of a dam holding a body of water.

d) Impounding of water against stoppings and their bursting.

a) Maintenance of correct water danger plan & surveyor’s report when water is 75m away.

b) Maintenance of Plans correctly showing geological disturbances & spot levels at the ends of workings.c) Ensuring design of water dam based on engineering parameters.d) All stoppings against which water can accumulate shall be provided with suitable drain pipes.

2 Inundation from waterlogged upeer seam or section:a) Boreholes, staple pits, drifts connected with water logged upper seam/section.

b) Collapse of roof under waterlogged workings.

c) Extracting pillars beneath waterlogged workings.

a) Maintenance of accurate plans, submission of AMPs and maintenance of surveyor’s report book.b) Dewatering the top seam workings and stabilization of unstable workings in the lower seam if possible.c) Dewatering of water body may be done by pumps, boreholes etc. The fact that the workings are free from water must be ascertained with reason able certainty.

3 Danger of water accumulated in a lower seam

a) 60m barrier shall be left against any borehole or staple connecting active workings in upper seam

with water logged lower seams.

4 Transference of dangera) Thin barrier on connection with a mine vulnerable to inundation from surface water.b) Non-superimposition of barriers between two mines.c) Intentional floodingUnder the circumstances mentioned above, transference of danger due to water may take place from one mine to another.

Statutory provisions stipulated in statute must be followed strictly.

Q.6 State provisions of IER 1956 regarding the following:-(a) Voltage limits.(b) Precautions where gas exits.(c) Care of flexible cable.Ans:- a) Voltage limits:- Energy shall not be transmitted into a mine at a voltage exceeding 11 KV and shall not be used therein at a voltage exceeding 6.6 KV.However, this shall be subjected to following limitations:-

Maximum Voltage(a) Hand- held portable apparatus- 125V(b) Electric lighting (i) u/g (phase to phase); - 125V (ii) o/c mines and surface of mines - 250V

(phase to phase)(Neutral point shall be connected with earth)

(c) Portable hand lamps u/g. 30V(d) Circuits for remote control or inter-locking of apparatus 30V(e) In fixed plants if bolt type plug is used 650V

Ans:- b) Precautions where gas exits Ref. to Q.No. 5(d) ( 2nd Class 2007)

Ans- c) Care of flexible cable: - Flexible trailing cables are highly vulnerable to damage. Manual handling should be avoided as far as possible by use of properly designed, installed and maintained cable reeling or handling devices. Where manual handling is unavoidable, the following precautions should be taken:1) Where flexible cable is not required to move, it should be effectively supported and protected against physical damage by roof/side fall, shot firing, crushing by moving machinery or tubs.2) Machine operators and cable men should be trained in safe operation and handling of trailing cables.3) Handling live trailing cables should be considered a specialized job to be done by competent persons. They should be properly trained and authorized.4) Where flexible cable is joined with the main cable, a switch shall be provided which is cable of entirely disconnecting supply from the flexible cable.5) Flexible cable shall be connected to the gate end box and the machine by suitable and properly constructed connectors. For HV machines, bolted type connectors shall be used. 6) Flexible cable shall be examined periodically by the person authorised to operate the machine. It shall be examined at least once in each shift by the competent person. Damaged or defective cable shall be replaced by good one immediately. No flexible cable with a temporary joint shall be used.7) Supply of energy shall be disconnected whenever the cable is not in use and it shall be removed from the face to a safe and secure place.8) Arrangements shall be made to prevent energizing of flexible cable by unauthorized persons. 9) Guidelines for repair and maintenance should be laid down considering manufacturers instructions, relevant BIS standards and skill of workmen incorporating the following :-

Provision of well equipped workshop in terms of manpower & equipment / appliances

Provision of procedure for location of puncture in the outer sheath, detection of faults between conductors, drying out of cable, check on insulation resistance during vulcanization.

Condition for replacement of cable. Periodical checking of insulation resistance and maintenance of records.

Q.7. Write short notes on:- (a) Nominated owner

(b) Compensatory day of rest(c) Pattern of holes while approaching waterlogged workings.(d) Support of freshly exposed roof.

Ans:- a)Nominated Owner:- Section 76 of Mines Act’1952 stipulates the provisions in respect of nominated owner and empowers a firm or an association of persons or a joint stock company to nominate any of its partners, members or directors, respectively or managers to assume the responsibility of the owner of the mine. In case of mine owned by Govt., officers authorised by the Govt. will be the nominated owner.The nominated person must be a resident of India, and must either be actually in charge of the management or hold the largest number of shares in such firm, association or company.

In large companies, all persons on the Board of Directors do not look after the day to day management of the company. Such persons should not be held guilty of contravening any provision of the law. Therefore the Act has made a provision for nominating an owner who can even be a manager of the firm or association or company.A notice to this effect is required to be sent to CIM in form l accompanied by a certified copy of the resolution of the Board of Directors of the company and a written consent of the concerned Director for acceptance of such nomination.In case of non-appointment of nominated owner, every Director / partner / member / manager of the company / firm / association is liable to the responsibilities / punishment of the owner of the mine.Such partner, member, director or manager nominated as owner shall so long as he continues to so reside and be in charge or holds the largest no of share be deemed to be the owner of the mine unless a notice in writing canceling his nomination or starting that he has ceased to a partner, member, director or manager is received by CIM. Hence, the person who is nominated by the management to take the responsibilities of provisions of statute as owner is known as nominated owner which is given below:-

Owner (Management) Nominated Owner (Provision)1. Firm or other association

of individual

2. Company

3.Government or local authority

any partners or members

any directors or managers

Any officers or person authorized by the Govt. or such local authority.

Ans:-(b) Compensatory day of rest..A Person can be deprived of his weekly days of rest either under one of following eventualities:i) an emergency involving serious risk to the safety of the mine or of person employed therein.

ii) an accident, whether actual or apprehended.iii) any act of God.iv) any urgent work to be done to machinery, plant or equipment.or, as a result of exemption granted by the Central Government in exercise of powers conferred by section 83(1). If a person is deprived of his weekly days of rest, he shall be given a compensatory day of rest, equal in number to the days of rest which he has been deprived off, within the same month or within the next two months. These compensatory days of rest shall be so spaced that in any one week not more than 2 such days shall be allowed to any one person.In the event of a person being discharged or dismissed, the number of compensatory days of rest due to him shall not be reckoned as part of any period of notice to which he is entitled under any rule, award, agreement or contract of service, and he shall be allowed such compensatory days of rest before the date of his discharge or dismissal.On or before the last day of every month a notice shall be displayed outside the office of the mine showing the list of all persons, who have not been allowed compensatory days of rest during that month and the dates on which the compensatory days of rest will be allowed to them in the following two months.A register of compensatory days of rest is also to be maintained in Form F of the mines rules 1955. Ans:- (c) Pattern of holes while approaching waterlogged workings.Pattern of holes commonly depends on:

condition of strata head of water in the old workings reliabilities of old plans

In order to approach a waterlogged area of a mine, which is not easily approachable, boring is practiced. Ordinary long hole boring is not of any help as the danger of inrush is imminent. The advance bore holes must be driven by safety boring machine/burnside boring machine. This machine achieves safe boring with water under control, and enables the water to be drained out under control when tapped.Reg.127 of CMR.1957 stipulates that CIM’s permission shall be obtained when a working is to be advanced within 60m (shortest distance) of any waterlogged workings. Workings shall be advanced strictly as per the approved plan, in approved method and as per the conditions laid down by DGMS in the permission letter. There shall be no variation from the approved method unless such variation is against approved by CIM. For getting permission, information regarding outline, depth of workings, proposed method and layout, presence of geological disturbances and other particulars shall be acquired and submitted to DGMS with two copies of plans and sections.The height & width of workings shall not exceed 2.4m and there shall be maintained at-least one central bore hole, sufficient flankholes on each side and bore holes above and below the working, at a maximum intervals of 5m.

All boreholes shall be drilled sufficiently close to each other to ensure that the advancing face will not accidentally hole through into water logged workings and shall be constantly maintained at a sufficient distance in advance of the workings and such distance shall not be less than 3m. The typical pattern of holes while approaching waterlogged workings have been shown in the adjacent figure.

The simplest arrangement is to bore two central boreholes driven in advance and the flank bore holes should be arranged to cross one and other by driving them alternatively at 22½º & 45º . To set off the flank boreholes accurately , a central line should be marked along the heading and the direction of the hole obtained with a triangular frame of wood giving the correct angle. The length of holes must be governed by condition such as nature of the seam, reliability of plans and the expected pressure of water.All these operations shall be carried out under direct supervision of competent person, who shall also maintain the record of bore holes alongwith its pattern. This record shall be countersigned by the manager every day.Also a plan and section of workings approaching waterlogged workings showing the above particulars, shall be prepared and maintenance and brought up to date at-least once in every 15 days. The advance of minimum 3m must be constantly maintained even after blasting, so depth of boreholes should take into consideration advance desired to be maintained. During drilling advance bore holes, the following precautions shall be taken:-

area near the face to be well supported before the starting of operation. machine to be supposed on timbers or steel girders to withstand the

weight when the machine is under pressure of water. proper ventilation & good lighting provision of safety lamps & automatic gas detectors to detect CH4, SO2

etc. provision of escape route.

Ans:-d) Support of freshly exposed roof: - A majority of roof fall accidents occur close to working faces, where the freshly exposed roof is not kept supported. The conventional roof supports are often dislodged during blasting and thus about 3m – 4m zone behind the advancing force practically remains unsupported. To control accidents in this vulnerable zone, some quick setting supports which will not be affected by blasting.The fifth Conference on Safety in Mines recommended that no worker shall be permitted to work under unsupported roof that has been freshly exposed.

As per Xth safety conference, suitable steps are to be taken by the mining company to inculcate a culture of no work at a face till the roof is supported by roof bolts upto at-least .6m from the face. The importance of support of freshly exposed roof arises because of the following:-i) The maximum percentage of accidents occur due to falls of roof.ii) A majority of the roof fall accidents occur close to the working face.iii) With each advance of the face, roof is exposed, the nature of which cannot by any means be assessed or foreseen.iv) Apart from exposure of week planes in the roof, bed separation commences as soon as the roof is exposed. Bed separation extends gradually upwards and causes roof falls in stages.v) Once bed separation takes place heavy supports will be necessary to hold the loose strata.In order to be effective the supports designed for freshly exposed roof shall have inter-alia the following characteristics:i) They should not be easily dislodged during blasting.ii) They should have adequate strength keeping in mind that the thickness of roof fall normally varies from 15 to 80 cms.iii) They shall be amenable to quick setting so that the roof can be secured before loading of coal commences after blasting. iv) They shall be portable and acceptable to the workmen.vi) The cost of such supports should not be prohibitive.As per regulation 108 of CMR 1957, freshly expose roof shall be supported systematically. Managers of every below ground mines shall frame and implement the SSR in their mines. Keeping the above in view, the following methods of supports may be adopted for the support of freshly exposed roof in development galleries and depillaring areas.A. Support of freshly exposed roof in development galleries. In development galleries the following methods of supports for freshly exposed roof may be adopted depending on the prevailing conditions at the faces:-1) Crossbar supports fixed on Clamps2) Screw type props with crossbars set over them3) Bamboo/Wooden Bolts.4) Recoverable Bolts.5) Hydraulic Props with link bars.6) Triangular Screw Type cogs.7) Rock bolting with quick setting cement.Pal committee/Expert group recommends that, in general, extended use of roof bolting as a method of support should be adopted for support of freshly exposed roof. The committee has recommended the following system supports for freshly exposed roof:Recommended support System for freshly exposed roof (upto 10m from the face)

Roof (Class) Description of bolding system Conventional Supports1. Very Poor Roof(Class V)

a) Yielding steel arches under high stress condition.b) Rigid steel arches under moderate stress condition.

2.Poor Roof ( Class (a) Point anchored (mechanical Cross bars on steel

IV) or grouted with quick setting resin) bolts for immediate ten-sion, to be fully grouted soon afterwards. W-straps where necessary.(b) Full column grouted bolts with quick setting grout.

chocks or hydraulic props with minimum 5te setting load.

3.Fair Roof(Class III)

(a)Combination bolts as at (a) above.(b) Full column grouted bolts with quick setting grout.(c) Recoverable bolts.

(a) Light duty hydraulic props.(b) Steel Props(c) Triangular shocks at junctions(d) Safari supports

4. Good Roof (Class ll)

(a) Recoverable bolts.(b) Full column grouted bolts.

(a) Steel props(b) Safari supports

5 Very Good Roof (Class l)

No support except for spot bolting in disturbed areas.

B. Support of freshly exposed roof in depillaring areas: Supports for the depillaring areas need special considerations so that they may be withdrawn safely and easily. Further, such supports should not interfere with the cavability of roof when extraction is being done with caving method. Keeping these points in mind, the following types of supports may be used for supporting the freshly exposed roof:

Screw type props Three legged screw type cogs Recoverable bolts

Q.8.Draw up a suitable scheme of training and facilities to be provided under Mines Vocational Training Rules 1966 for a large mechanized underground mine having Longwall Workings.

Ans:- Conditions assumed :- i. Mining parameters Mine Outlet : A pair of inclines Production : 1.0 mill. te/year Thickness of seam : 3.5 to 4.0m Height of extraction : 3 to 3.5 m Depth of working : 60 m Gradient of seam : 1 in 20 Mode of Coal getting : By highly mechanized longwall system. Panel length : 860 m Face length :120m Face span :4.5 m Roof : sandy shade & sand stone Floor : -do-ii. Face equipment Coal cutter- Shearer (double ended ranging drum) Face support – 4 legs hydraulic chock (Powered support) Face conveyor – Armored Flexible conveyor ( 760 tph.) Loader – Stage loader (760 tph) Power pack with feed pump Lump breaker, Gate belt, boost pump Deployment of manpower:-Assuming that the L/W face is operated in two shifts for production and one shift is kept for maintenance. Manpower are deployed on the concept of all men all job. The requirement of manpower in mechanized L/W working shall be as follows:-a. Mine officials Shifts Designation I II III Total

i)) Mining Sirdar/Overman 1 1 1 3 ii) Foreman/Foreman incharge 1 1 2 4 iii)Engineer 1 1 0 2 iv)ACM 2 1 1 4

5 4 4 13

b) Operators & Others- Shearer operators 2 2 2 6 Face crew 18 18 18 54 Mech. Fitter & helper 2 2 2 6 Elec. fitter & Helper 2 2 2 6 Gale belt operator 1 1 1 3 General mazdoor/ Others 2 2 2 6

Total 27 27 27 81 G.Total 32 31 31 94Training Scheme:-The training scheme for the persons mentioned above must incorporate the following:

Categorisation of workers - i) no. of batches ii) course content & its duration

Type of training to be imparted Type of training Centers Manpower Equipment Records

For imparting training to workmen, supervisors and officers, a full fledged training organisation ( Group training centre as well as Mechanized Long-wall training centre) must be available as per following details:-

Training Organisation

Manpower Building accommodation Training Aids Record maintenance with furniture* Principal Lecture hall Equipment * Suptt. Training gallery Appliances & tools * Training Officer GT Chamber Samples* Instructors Other Stores Supplies* Accountant Work shed * Stenographer Model Room* Clerks * Fitters/Electricians* Lab assistant* Scientific Asstt. Etc. For training of above persons, a well equipped & well furnished training centre having adequately trained, qualified and experienced training officers, as well as trainers from various aspects of operations is to be established. For this purpose, L/W mechanized training centre set-up as per recommendation of safety conference may be utilized for imparting training. The training centre should have adequate accommodation for model room, discussion hall, record room, canteen, model aids, equipments, video etc. The total training programme is divided as follows:-

Training Scheme↓

↓ ↓Statutory Non-Statutory

↓ ↓ ↓ ↓ Workers Supervisor Executives

i)Training for Longwall crew:- As per statutory provisions contained in MVTR’ 1996, all persons to be employed in u/g mine shall be imparted initial / basic training for 24 days including 12 days training under direct personal supervision of trainers. They shall also be imparted refresher training for 15 days within one month of re-employment after break of service of one year or more.However, as per recommendation of National tripartite workshop on Revised Modules for vocational training in Mines held in 1999, Longwall Crew, mine officials & other workman shall be imparted training as per the proposed new training modules given below:-

(a) Type & duration of training Type of training Duration of training

Initial Refresher Theoretical class room training 22 05 On the job practical training 24 06 Feed back training/oral test 02 01(b) Course Content:-Training to L/W face crew should include – Basic concept of L/W mining, different types of machines and statutory provisions, concept of ventilation, support of gate rods, different types of support and their use, support at face, roof bolting and anchorage testing, fundamental and maintenance of hydraulic machines, familiarization of tools used for maintenance of L/W machinery, concept of different types of pumps, precautions against inflammable and noxious gasses, concepts of power supports, chain and belt conveyors, examination of machinery & writing of statutory reports, salvaging of longwall equipment, procedure to support in case of cavity formation, dust & gas hazards (health & explosion) importance of leg-pressures, its monitoring and leakage.(ii) Training of mine offcials-a) Sub-ordinate Supervisory officials: Type of training Duration of training ( days) Course content/syllabus

Initial Refresher Mining & Geology, safety Theoretical 11 5 policy, ISO, causes of On Job 6 3 accident & preventive Feedback 1 1 measures, cost of accidents,

enquiry into the accidents, workman’s inspection S.C.-

role / function, duties and responsibilities of supervisors mining methods, exam. of workings, emergency plan,

mine plan etc.b) Electrical supervisor Type of training Duration of training ( days) Course content/syllabus

Initial Refresher Theoretical 11 5 Electrical layout, AC & DC, PF,

On Job 6 6 Ohm’s law, load calculation, Feed Back 1 1 voltage drop, transformer, circuit

breakers, isolators, Cables, method of earthing, capacitors & its use, reports and records maintenances of electrical plan, IR, resistance testing etc. FLP & intrinsically safe equipment, first aid, electric shock etc.

iii) Fitters/ Mechanics Initial Refresher Theoretical 24 5 various type of m,/c used in u/g, tools

On Job 28 6 and tackles, duties, maintenance

Feed Back 2 1 schedule & preventive maintenance, different types of FLP motors used

belowground, tensioning & alignment methods of chain conveyors and different types of rollers used with belt conveyor, statutory provision regarding use

of m/c, dangers from fires in hydraulic system in different m/c. and their maintenance, dangers from mine gas, action in case of emergency.. Electrician Type of training Duration of training ( days) Course content/syllabus

Initial RefresherTheoretical 24 5 Various types of electrical On Job 28 6 machine used in u/g, Feed Back 2 1 duties of electrician, provision of IER and its applicability in mines, dangers due to electricity and use of personnel protective equipment, testing & measuring instruments, LT & HT switchgears and panels common causes of faults &

repairs in electrical machines, earthing and earth pit maintenance, electrical signaling & telecommunication, cable lying, jointing & protection, electrical layout plan, FLP enclosure & intrinsically safe circuit, Testing of inflammable gas with flame safety lamp & maintenance, permit to work system etc.

Other facilities to be provided:- Training allowances Accommodation/fooding Reading materials Certificate of competency

Afternoon Session THE MINES ACT, 1952


FIRST CLASS




Q.1.What are the objectives of convening the National Safety Conferences? Briefly state major recommendations made by it till date and their impact on legislation and status of safety in mining industry?Ans – Safety in mines has remained as a vital necessity of our mineral development. Indian legislation related to mines safety remained as most comprehensive corpus encompassing every aspect of mining operations. One of the best forums at the national level for all those associated with mining operations has been mines safety conference.National Safety Conference:- National conference on safety in mines is a tripartite forum at the national level for deliberation on issues connected with safety and health in mines.In the conference, the employer’s representatives, the Trade Unions representatives, the Govt. represented by the Ministry of Labour and Employment/DGMS, various administrative ministries/ department and state Govt. and Associated Institutions, Professional bodies, Academic and Research Institute, Service Associations etc take part. This is an event of great importance which brings together the policy formulators, planners and experts in mining technology, officers of law enforcement machinery, representatives of mining industry, trade unions and workers.Objectives of convening the National Safety Conferences:-i) To discuss/ review the status of safety in mines.ii) To dwell upon the emerging safety issues in mines by different stake

holders of the country to identify the thrust areas for improvement in the safety standards in Indian mines.

ii) To review the status of safety in mining and adequacy of existing measures in improving working conditions in mines in a spirit of mutual co-operation.

iv) To suggest measures for further improvement in safety, welfare and health of mine workers.

v) To think, reflect and critically analyse as to how safe mining operations can be combined with production of minerals.

vi) To play vital role in shaping the safety and health policies of the mining industry.

Safety Conference was first started in the year 1958 following a disaster (explosion) in Chinakuri Colliery in Eastern India and subsequently eight more conferences were held in the years 1966, 1973,1978,1980,1986,1988,1993 & 2000.

Many of the recommendations of the safety conferences have been absorbed in statute by making suitable amendments and by the DGMS circulars where as some have been incorporated in management’s safety policies and practices.

The major recommendations of various safety conferences vis-a- vis its impact on legislation and status of safety in mining industry are tabulated below:-

Safety Conference

Major recommendation Impact on legislation & status of safety in mines.

i) 1st (1958) i) Detailed specification of standard of ventilation, illumination and tracks.ii) Specification of standards of accuracy of mine plans, carrying out of important surveys and preparation & maintenance of water danger plan.iii) Organisation for dust treatment

v) Appointment of safety officers in large and / or gassy mines.v) Provision of experienced manager in large mines. vi) All technical instructions should be routed through the manager and to enable him to devote more attention to the safety matters; he should be relieved of non-technical obligation.

vii) Constitution of Pit safety committee.

viii) Introduction of scheme for training of all new entrants to mining & re-refresher course for mine workers

Technical instructions have been issued by DGMS for strict compliance in order to ensure safety in mines. Some recommendations have been incorporated in statute.

CMRI’1957 amended in 1965 in which appointment / qualification of safety officer in mine were specifically defined. DGMS advised the mining industry that persons having experience more than 5 years after obtaining Managers certificate of competency should be appointed as Manager.

PSC constituted in each mine.

MVTR’s 1966 frammed incorporating provision of basic training to new entrants and refresher training to mine workers with a view to make them aware of the dangers of working in mines so that they can work safely.

2nd July (1966) to review a fresh the entire position regarding safety in mines.

i) Compulsory installation of mechanical ventilators in all mines, provision of safety lamps, conduction of gas survey.ii) Greater association of workers in safety matters.iii) Suitable vocational training, specially for the surveying and engineering staff.iv) Formation of more rescue station

CMR 1957 were amended in the year 1967,1971 and 1972 to provide the following:1967- To provide for use, supply and maintenance of footwear, helmets and other protective equipment.

1971 -i) Installation of fan

made compulsoryii)Lamp checker’s certificate introduced

iii)Appointment of V.O.iv) Duties of S.O.& V.O.v) Quantity and velocity of air specified.1972 –i) Procedure for classification of coal seems according to their degree of gassiness.ii)Appointment & Qualification of shot firers & fixing of max no. of shots in a round.

3rd (July 1973)

i) Treatment of workmen at the cost of management with full pay and provision of suitable alternative job, who is rendered unfit as a result of an occupational disease/injuryii) Issue of Identity cards to all mine workers.

Mines rules,1955 amended in 1978 to include a new chapter on medical exami nation of persons employed or to be employed in mines and to prescribe the medical standards of fitnessMines rule 1955 amended in 1980 to provide for issue of identity tokens to all persons employed in mine.For ensuing safety in mines, CMR1957 were further amended in 1978 regarding systematic supports and CIM’s approval for certain equipment and materials. AIso IER, were amended in 1980 for requirements regarding the use of FLP apparatus & intrinsically safe circuit.

4th(Dec’1978) No Recommendation5th Dec’ 1980 i) Well defined Safety Policy in the

fields of health & safety of its employees and establishment of institution of ISOii) Amendment of Mines Act 1952 to give statutory backing to the institution of PSC and Work-men’s Inspector.iii) No worker to be permitted to work under unsupported freshly exposed roof.

Incorporated in management policies and practices for ensuring safety in mines.Mines Act were thoroughly amended in 1983 in-corpora- ting following provisions::

i)Safety & occupational health survey by DGMS. ii)Duties & responsibilities of Owner, Agent & Manager.

iii)Constitution of committee at national level.

Mines rules 1955 amended for inclusion of a new chapter on P.S.C &.W.I.

CMR amended in 1985 incorporating provision for appointment of deemed

agent, fixed mine boundary , preparation of emergency plan, compulsory use of self rescuer in u/g mines.

6th (Jan’ 1986)

i) Formulation of support plan for support of roof, sides, back and hang wall in consultation with strata control cell, CMPDIL & Safety Committeeii) Conduction of fresh survey to connect the mines to national grid and check survey to ensure accuracy of mine plans.

iii) Preparation of ventilation scheme to achieve the stipulated standards w.r.t. mine environment and facilities of continuous monitoring of environment, conduction of dust survey at regular intervals.

iv) Selection, appointment and training of operators and drivers of HEMM as well as steps for preventing unauthorized riding on dumpers & trucks.

CMRI 1957 were amended in a major way in 1990. The important amendments are-i) SSR have been modified indicating the use of roof bolts, hydraulic chocks & powered supports.ii)Provision regarding setting and withdrawal of support have been detailed.iii)Requirement regarding the qualification and appointment of VO revised.iv)Permissible limit and sampling procedure for air borne respirable dust prescribed and precautions against dust elaborated.v)Coursing of air upto 4.5m of face.

Included in Management policies and practices.

7th (Dec’88 ) i) Framing of suitable code of traffic rules for regulating the movement of HEMM and suitable code of practice for the prevention of injuries to persons engaged in tipping, dumping and loading operations.

ii) Design & maintenance of haul roads.

iii) Creation of well equipped properly staffed department on O.H.S. in mining companies and for group of mines.iv) Infrastructure, scheme and functions of OHS

v) Training and education in first aid and OHS

Guidelines have been issued by DGMS in the form of technical circulars for framing and enforcement of traffic rules for movement of HEMM and code of procedure for prevention of injury to persons.

Incorporated in management policies and practices. For proper health care and detection of occupational diseases, PME centres have been established & is functi oning effectively

8th (May 1993)

i) Framing of SSR based on RMR, introduction of roof bolting as primary support system.ii) Establishment of adequate arrangement, organisation and

Roof bolting has been introduced as a means of integrated support system in u/g mines for securing roof and sides.

infrastructure facilities for carrying out dust survey.iii) Introduction of eudiometry as a part of mandatory medical exam for persons seeking employment and for persons engaged in operation where noise level exceeds 90 dB(A)iv) Training of work person, front line supervisors and member of safety committee.v) Evaluation of competency of drivers / operators of HEMM by a Board of experts.vi) Discontinuance of tractor trailer combination on haul roads.vii) Relevant training and other job related briefing to contractor’s works for safe operation. viii) Adequate facilities for X-rays and lung function test at PME centre & Training of medical officer for use of ILO classifications of pneumoconiosis.

Guideline has been issued by DGMS for conducting air bone dust survey.

By implementing these recommendations, safety status in mines has improved considerably and accident rate reduced.

9th (Feb,2000)

i) Critical examination and assessment of danger of inundation before onset of monsoon.ii) Embankment to be provided against river and jore to be designed on civil engineer parameters.iii) Filling of surface excavation.iv)Provision of alternative source of supply.v)Establishment of effective communi cation within the mines and between the mine as well as between mines and rescue station, hospitals, DGMS office.vi) Formation of tripartite committee to study the feasibility of establishing rescue room for storing oxygen type self rescuer for fiery mines.vii) Preparation of risk management plan on the basis of risk assessment & its implementation in the identified mines.viii) Computerization of records of medical & environmental surveillance.ix) Formulation of guide lines for referral, re-evaluation, classification of pneumoconiosis and necessary remedial actions by ODB.

For ensuring safety in mines, DGMS put forward these recommendations to the mining industries in the form of circulars for strict compliance.

DGMS advised mining industry to undertake a formal risk assessment process for preparation and implementation of RMP to reduce the hazards.Recommendations are being implemented by mining companies.

Q.No.2. Inundation continues to be a major hazard in below ground working. As a Manager, what action would you take to identify and eliminate this hazard from your mine? Draw an action plan for the same.

Ans:- The history of coal mining in India has witnessed several disasters due to inundation. Inundation has become one of the greatest killers in coal mines of our country. In spite of elaborate provisions in the statute as well as availability of guidelines in the form of DGMS Circulars & recommendation of various committees, court of inquiry & safety conferences, accidents due to inundation are taking place

. Essentials for prevention of dangers due to inundation:- i. Maintenance of accurate plans and a meaningful reading of the same.

ii. Identification of the causes of dangers due to inundation both from surface sources & underground sources.iii. Formulating the preventive measures and periodical review of the same for ensuring their sufficiency if there is any changes in the circumstances.iv. Strict enforcement of the preventive schedules once formulated.To guard against the hazards due to inundation in belowground mines, the following methodology shall be adopted systematically:-(i) Identification of dangers (ii) Elimination of dangers/ Protective measures to be taken.(iii) Regular precautionary measures to be observed.

Conditions assumed : Mine X is being worked by B/P method of mining. On surface, there are jore,

river, water tanks, rain catchment areas, low lying areas which can accommodate water, water logged quarries, dams on the up stream side. These sources in the vicinity of mine openings may pose a problem, specially during rainy seasons.

In underground, sources of dangers are disused/old abandoned water logged workings in the same seam, upper or lower seams including goaved out areas in the same mine or adjacent mine.As a manager, I shall take the following actions for identification & elimination of inundation hazards in my mine:-

1) Action for identification of hazards due to surface source

Possible steps / measures for elimination of hazards

i. In the case of mines worked in the neighborhood of rivers, jores, water courses, tanks, low-lying areas, water logged quarries, the following points should get special attention:

Position of Mine openings w.r.t. HFL of the Area.

Presence of subsidence cracks Pot holes over the workings or

goaf at shallow depth of cover consisting mainly of sand, aluminum or soft weathered rock

Openings formed due to dislodgement of strata on account of faults.

Bore holes connected with

a) Maintaining all mine entrances/ opening at a level at least 1.5m above HFL of a rising body of waterb) Properly designed and constructed embankment to be provided against river, nallah etc.All disused pits, potholes and subsidence cracks to be sealed by RCC.All pits proposed to be abandoned to be secured at the collar level.c) Seeking and obtaining permission from CIM while making mine workings beneath and within 15m of bank of river, stream, nallah, lake, tank etc.

water on surface, study of mine plan & physical inspection of sources of dangers.

Blockage of culvert, bridge or higher water level in the main river on the down stream side/ obstruction in the course of river.

Bursting of dam on the up stream side on uncontrolled release of water by the dam authorities.

Spot levels at the boilers, power sub-station, electric motors used for winders if any w.r.t. withdrawal level/ danger mark fixed and possibility of stoppage of winders in adverse weather conditions.

Whether or not the HFL line correctly drawn along entire length of the river, Jore etc.

Possibility of the HFL changing drastically due to excessive impoundment of water against dam and also due to abnormal release there from.

Open cast workings having connection with below ground workings either directly or through subsidence cracks/ fissures.

Possible impending heavy rains.

Effective signaling system between surface and belowground.

d) Provisions of captive generators in working condition to run the winders in case of emergency.

e) Provision of float alarm at strategic point(s) in addition to posting river guard and maintaining liaison with dam authorities to get timely intimation.

f) Reclamation of open cast working.

g) Linking of mine to the local meteorological deptt for timely dissemination of information.

h) Provision of effective communication system capable of functioning even with failure of power and in adverse conditions.

2. Underground workingi. Correctness of mine plansii. old water dams – specification not knowniii. Presence of disused / abandoned water logged workings in the same seam, upper or lower seams including goaved out area in the same mine or adjacent mine. Old working –a) Accessibleof same mine b) Inaccessible shown on plan not shown on plan (AMP not

Preparation of correct plans showing correct extent of workings, spot levels at ends of galleries and bringing the plans up to-date as per statute.Draining out water from water logged seam whether developed or goaved out by putting bore holes.

For measuring quantity of increase in seepage or water, v-notch shall be installed in roadways leading to faces within 120m of water logged working.

available/AMP incorrect /not up to-date.Water logged workings of adjoining mine

- Inadequate inter mine barrier

- Joint survey not done

- Check survey not done

iv) availability of water dams planv) Position of geological disturbances w.r.t. water bodies.vi) Accumulation of water against stoppings.

No working shall extend with 60 m of any water logged working without written prior permission from DGMS.

Vertical barriers between the mines shall be maintained as per statute In mines where the barriers have become ineffective due to inter connection or otherwise, the same may be restored by constructing suitable dams / explosion proof stoppings.Conducting check survey of workings at regular intervals particularly when the mine workings reached within 120 m of any adjoining mine which may contain water.Maintenance of correct water danger plan.All stoppings against which water can accumulate, shall be provided with suitable drain pipes.

Besides above, risk assessment & risk management / technical audit of mines before onset of monsoon to identify the sources of danger should be undertaken and preparatory work should be done as per the details given below:A) Surface preparation:- a) Pre-monsoon- Before on set of monsoon – Pre-monsoon joint inspection by team consisting of officials from DGMS and agent, manager, safety officer, surveyor for careful assessment of danger of inundation shall be made . During course of inspection apprehended dangers shall be pin-pointed, precautions clearly laid down and implemented. This will involve:i. Preparatory work on surface like strengthening of existing embankment, construction of Pucca Wall/ dams around shafts or inclines.ii. Cutting of drain to divert rain water from near mine openings, subsided areas or low-lying areas.iii. Clearing obstructions, widening and re-grading drainage channels before onset of monsoon, making new drains if needed.iv. Fixing danger mark and withdrawal level prominently after a thorough study and after evaluating various features, with a margin of safety.v. Providing float alarm in addition to river guards and an effective and speedy communication system capable of functioning independent of power and also in adverse condition.vi. Filling of subsidence cracks, low-lying area, plugging of bore holes etc to avoid rain water to percolate to u/g working. vii. Providing effective signaling between surface and u/g. viii. Framing and enforcing standing orders for safe withdrawal of persons in case of emergency. All persons shall be made familiar with the standing orders. Mock rehearsals shall also be held at regular intervals.

b) During monsoon:- Constant vigilance shall be exercised during rainy season. The manager or sr. most official present at the mine shall go round the surface

area of the mine during heavy rains and check vulnerable points and effectiveness of the safety measures. In case of doubt, persons shall be withdrawn to safety.

B. Underground Preparations:-a. Construction and / or repair of Pucca drain along the traveling and haulage roadway in order to divert the water to dip side sump of adequate size.b. Providing safety water pillars or barriers of adequate size to prevent water accumulations from suddenly breaking into mine openings.c. Providing adequate sump and pumping capacities at predetermined points for dealing with in-rush of water even where safety pillars are provided. Adequacy of the pumping arrangement should be checked, and if needed strengthening be done.d. Ensuring vertical inter-mine barrier of adequate thickness between two mines.e. Erecting water dams or hydraulic seals to seal abandoned sections of the mine. The condition of the existing dams shall be checked and if necessary, they must be strengthened.f. Cleaning of sumps should be ensured well before the breaking of monsoon.g. Erecting bulk head doors in mine workings when approaching within 60m of water logged workings.h. Providing additional lodgment capacity in worked out area(s) to which sudden inrushes of water may be directed in an emergency.i. De-watering of water logged working by in-seam pumping or through long bore holes.j. Preparing and maintaining water danger plan showing warning lines based on known extent of workings and caved areas in upper seams and presence of inter- connection through drifts, shafts, fault planes etc between the seams.C. Inventory & Stores:-

Ensuring adequate inventory of spare parts for pumping arrangement. Additional / spare pumps, cables, switchgears, transformer etc should be

kept ready for emergency. Sufficient store of cement, rods or other building materials should be kept

ready for emergency work in rainy reasons.

Q.3. Define the following in the context of statutory provisions:a. Hand-held portable apparatus. b. Transportable apparatus.

c. Portable apparatus. d. Voltage.e. Flame proof apparatus. f. Owner.g. Serious bodily injury. h. General body of air.i. Ordinarily employed. J. Person employed in a mine.

Ans:-a) Hand-Held portable apparatus:- means an apparatus which is so designed as to be capable of being held in the hands and moved while connected to a supply of electricity.

Ans:-b) Transportable apparatus:- means an apparatus which is operated as to be capable of being moved readily from one place to another., e.g. A face conveyor, auxiliary fan etc.

Ans:-c) Portable apparatus:- means an apparatus which is so designed as to be capable of being moved while in operation. i.e. C.C.M, Drill, SDL, LHD, Electric shovel etc.

Ans:-d) Voltage: - means the difference of electric potential between any two conductors or between any part of either conductor and the earth as measured by suitable voltmeter in volts.Low voltage - not exceeding 250VMedium voltage - not exceeding 650VHigh voltage - not exceeding 33 KVExtra high voltage - exceeding 33 KV

Ans:-e) Flame proof apparatus:- means an enclosure for electrical machinery or apparatus that will withstand, when the covers or other access doors are properly secured, an internal explosion of the inflammable gas or vapour which may be present in the surrounding atmosphere.

Ans:- f) Owner- means any person who is the immediate proprietor or lessee or occupier of the mine or part thereof. It includes liquidator or receiver but does not include a person who merely receives a royalty, rent or fine from the mine or merely the proprietor of the mine subject to any lease grant or license for the working of mine or is merely the owner of the soil and not interested in the minerals of the mine. It also includes any contractor or sub-lease for the working of the mine but not so as exempt owner from any liability.

Ans:-g) Serious bodily injury- means any injury which involves or in all probability will involve, the permanent loss of any part or section of a body, or the use of any part or section of a body, or the permanent physical incapacity or the fracture of any bone or one or more joints or bones of any phalanges of hand or foot.

Ans:- h) General body of air:- means the general atmosphere in a seam and includes the atmosphere in the roof cavities but does not include general atmosphere in the sealed off area or in any borehole drilled in coal or in the adjacent strata.

Ans:-i) Ordinary employed- means the average number of persons employed per day in the mine or part thereof during the preceding calendar year i.e. Ordinary employed =______________No. of man days worked______________

No.of working days excl. rest days and other non-working days.

Ans:-j) Person employed in a mine- a person who works as the manager or works under appointment by owner, agent or manager or with knowledge of manager whether for wages or not in

a) any mining operation (including the concomitant operations of handling and transport of minerals upto the point of despatch and of gathering sand and transport thereof to the mine.

b) Operations/services relating to the development of the mine including construction of plant but excluding construction of buildings, roads, wells and any building work not directly connected with any existing/future mining operations.

c) Operating, servicing, maintaining or repairing any part or any machinery in or about the mine.

d) loading operations for despatch of minerals within mine premises.

f) any office of the mine

g) any welfare, health, sanitary or conservancy services required or watch and ward within a mine premises excluding residential area or

h) any kind of work incidental to or connected with mining operations. (clue- m c r l o w a )

Q.4. a) What are the statutory provisions relating to Systematic Supports? Explain the factors that you will take into account while formulating Systematic Supports Rules for your mine?

b) What do you understand by the term “RMR”? What is its application in strata control?

Ans:-a) Systematic Support: - Roof support is one of the most important components of underground mining activity. Efficient roadway support while providing a safe working environment should minimize the cost of labour and material as well as down time.

The objective of providing support is to control deformation of roof by timely support reactions reducing the long term movement to a minimum and in general to help the rock mass to support itself.

Systematic support is the term used for erecting supports in such a manner that the distances between supports are according to a specified pattern based on rock load estimation as laid down by the Manager and approval by DGMS.Purpose of SSR: - Introduction of SSR serves the following important purposes:-1. It reposes the responsibility of studying the nature of the roof and designing the pattern of roof supports on the Manager of the mine and relieves the junior subordinate officials from exercising their discretion. Thus one important matter viz. support of roof is left with a person of high technical competence.2. This gives the Manager of the mine some relief amongst his multifarious work as he can rest content that with the systematic support rules enforced, work in the mine will proceed in a safe manner and on every occasion when a particular patch of bad roof is encountered his attention may not be called to be diverted from other work at hand.3. The systematic Support Rules once enforced, the junior subordinate officials will have to exercise their discretion only in limited areas not covered by the supports set according to the said rules.4. Introduction of the Systematic Support Rules provides safety against falls of roof, an integrated project for production of coal.5. Provision of Systematic Supports provides for greater safety and thereby has an effect on minimizing cost of production by avoiding accidents.

Statutory Provisions: - As per reg. 108 of CMR’1957, the following are the statutory provisions relating to systematic supports:-

1. Applicability: - The following places in belowground workings shall be supported systematically:-i) every depillaring districtii) every long-wall workingiii) every development working within 10m of face (green roof) and every junction of roadways immediately out-bye of a development face.iv) every working in a disturbed or crushed ground.v) any mine or part requiring artificial support as per instruction of DGMS.

2. Framing and Enforcement of SSR: -i) The manager of a belowground mine shall frame and enforce systematic support rules specifying in relation to each working place the type and specification of supports on roadways, each row of supports, adjacent rows of supports, last row of supports and the face, hydraulic chocks & powered support and the pack and face.

ii) The manager shall submit at-least 30days before the commencement of any mining operation, a copy of SSR to RIM who may require such modification in this rules as he may specify therein.iii) The manager shall also hand over copies of SSR together with illustrative sketches to all concerned supervisory officials including ACM and shall also paste such copies at all conspicuous places in the mine. iv) The manager and supervisory officials shall each be responsible for ensuring effective compliance with the provisions of SSR.

3. Formulation and Implementation of code of standing orders: - The Manager shall formulate and implement a code of standing orders specifying-i) The system and the organisation for procurement and supply of supports (quantity, quality and strength)ii) The method of handling and transportation of supports from the surface to the face and from the face line to their new site.iii) the system and the organisation for maintenance and checking of supports, dressing of roof and sides, erecting, examining and re-tightening of supports and re- erecting dislodged supports.iv) The panel of substitutes.v) The manner of making all concerned persons fully conversant with SSR and code of standing orders related to erection and maintenance of supports including withdrawal of supports.Factors taking into account while formulating SSR:-Assuming that coal seam (lll seam) is being developed along floor by Board & Pillar method of mining with SDL’s having thickness of seam 7m, width of gallery – 4.8m and height of working 3.0 m. The immediate roof consists of 4.0m coal overlain by sandstone. It is also proposed to adopt roof bolts as a primary means of support system in my mine. While formulating SSR of the IIl seam working as mentioned above, the following factors shall be taken into account:-i) Physico-mechanical properties of the roof rocks:- a. Nature and thickness of layers of different nature in the roof rock and their compressive strength. b. Slacking/swelling property, clay, if present will become unstable and provide poor anchorage to roof bolts.c. Joints pattern, type of filling material etc.ii) Local geological conditions: Such as presence of discontinuities like joints, faults, slips and sedimentary features like cross bedding, sandstone channels etc.iii) Rock weather-ability.:iv) Compressive strength of roof rock:v) Ground water seepage- presence of water & its pressure in the various discontinuities, its physical & chemical effect with the infilling materials of various joints can alter the cohesion; reduce the frictional and shearing resistance. In addition to above, system of work, level of mechanization and past experience shall also be taken into account white framing SSR besides gallery span, profile, virgin stress and induced stresses.Ans: b) RMR:- Rock mass rating is a rock parameter. It is a geo-mechanic system of rating of stability characteristics of roof rock in a coal mines.RMR is a number which is weighted sum total of ratings or marks given to five parameters of the immediate roof rocks out of a total maximum 100 as follows:

Parameter Maximum rating Layer thickness 30

Structural features 25Rock weatherability 20Strength of rock 15Ground water seepage 10 RMR = ∑f ( ) = 100

If there are more than one rock type then the combined RMR is obtained as:Combined RMR = ∑(RMR of each bed x bed thickness) ∑ thickness of each bed.

RMR so determined is further adjusted for various geo-mining conditions viz. depth.,lateral stress, influence of adjacent and overlying workings and mode of drivage. Finally roof is classified on the basis of adjusted / final RMR as given below:Sl.No. Range of RMR value Class of Roof Description of roof.1.. 0 -20 V Very Poor2. 20 -40 lV Poor3. 40 -60 lll Fair4. 60 -80 ll Good5. 80 -100 l Very GoodHigher the RMR, better is the roofRMR provides useful information for selection of support system and rock load values are used for optimum support design. Applications of RMR is Strata Control:-Following are the applications of RMR in Strata Control:-1) Classification of Roof – On the basis of final / adjusted RMR value, roof are classified as mentioned above.2) Estimation of rock load for support design in development district- For

designing of support of gallery and junction in B/P development working having maximum span 4.8m, the rock load is calculated by the formula given below:

For gallery Rock load, (Pg ) =B x D (1.7 – 0.037 x RMR + 0.0002 x RMR2

) t/m2

For Junction: Rock load(Pj ) = 5 x B 0.3 x D ( 1-RMR/100)2

t/m2

Where, B= roadway width/span(m) D= density of roof rock (t/m2)

RMR=final / adjusted RMR of roof rock.

3) Estimation of support load density in depillaring working- RMR also finds its application in the estimation of support load density for designing of support system in depillaring working as evident from the following empirical relation-

For slice junction, SLDJn = r.H 0.50 . K 0.64 . W 1.17 R0.90

Within Slice, SLDsL = r.H 0.67 . K 0.84 . W 1.74

R1.42

In the split gallery, SLDsp = r.H 0.52 . K 0.59 . W 1.12 R1.02

For goaf edge, SLDge = r.H 0.54 . K 0.49 . W 0.89 R0.79

Where, r = weighted average rock density of the immediate roof strata (t/m3 )

H= depth of cover (m) K= ratio of horizontal to vertical in-situ stresses

W=Width of split or slice (m) R= Weighted average RMR of the immediate roof rock.

SLDJn,, SLDsL , SLDsp and SLDge = required suppose density ( in t/m2) at the slice junction, within slice, in the split gallery and at the goaf edge respectively.

4. Monitoring of Strata/ Support :- RMR is also used in calculation of theoretical maximum convergence and convergence velocity for monitoring of strata/ support. The empirical relations are:

Cm = 40 x B x D 1/3 (1-RMR/100)3 (mm)

Cv = 0 .55 x B x D1.7 (1-RMR/100)5.6(mm/day) Symbols have their usual meanings.

Q.5. What are the statutory provision relating to “Emergency Plan”? Briefly explain the essential elements of a good Emergency Plan and their

rationale. How will you incorporate modern technology advancements into the emergency plan for a large colliery with belowground workings?

Ans:-Emergency Plan :- An emergency plan is a programme of action to be followed in emergency. It should clearly indicate the duties and responsibilities of each mine official and some other key persons like telephone operator, attendance clerk, cap lamp in-charge etc. This plan should be drawn up taking into consideration special features of mines, foreseeing every possible source of dangers and damages. It consists of programmes which provide for prior arrangements to be kept in readiness before emergency strikes and also operative part of the emergency plan to deal with the emergency as and when it strikes. Statutory Provision: - As per regulation 199A of CMR 1957, the following are the statutory provisions for framing and enforcement of emergency plan:

1. The manager of every belowground mine shall prepare an emergency plan outlining the duties and responsibilities of each mine officials and keymen including the telephone operators who shall be thoroughly instructed in their duties so as to avoid contradictory orders and confusion at the time when prompt and efficient action is required.

2. The emergency plan shall also provide for mock rehearsals at regular intervals. 3. The Manager shall submit a copy of emergency plan within 30 days of opening of mines to RIM, get it approved and enforce at the mine. 4. When any emergency occurs, manager /principal official shall immediately put the emergency plan into operation. This Plan should be updated from time to time.

Essential elements of a good emergency plan- Following are the salient points to be kept in mind while drawing an emergency plan:1. The first few hours immediately after any emergency are of vital importance. 2. Each member of the organisation should be given duties with which he is

generally familiar, so that he does not have to learn a new to play. 3. At the time of the actual occurrence, the Manager has to use his discretion in

adopting the plan according to the nature and scale of the emergency. 4. The officials in the pit at the time of the occurrence have to act according to

their own knowledge and initiative 5. Every person involved in the operations must clearly understand, in

advance, his particular role. 6. The possible causes and magnitude of emergency should be envisaged,The manager has to keep in mind the nature of expected emergency while drawing up the emergency plan. Various components of the plan would however, be the same irrespective of the nature of emergency. The various elements comprising a good emergency plan are:-A. Standing Consultative Committee- It should be a permanent committee and its member should be intimately acquainted with the mine. It should include:-

o Manager or senior most official present.o Safety Officer, Ventilation Officer, Surveyor, Medical Officer, Engineer.o Welfare Officer, Security Officer, Manager of adjoining mines.o A senior executive of management

o Representatives from DGMS and Rescue Stationo Two representatives from supervisory staff. o Two representatives from workers unions.

On being informed of an emergency the members will immediately proceed to the operation Control Room, confer and approve the action Plan. They would meet from time to time to review the progress of operations.B. Communication- An efficient communication system is essential for effective execution of emergency plan. The control telephone exchange should have telephone connections with all key personnel and key points in the mine and a list of their telephone numbers should be kept in the control room.C. Stores and Materials- The following materials should be kept ready at operation control room:-

o Emergency operation plans, list of key personnel, Telephone log books.o List of members of consultative committee, Operation Books, Authorisaion

Card.o Duty Cards of key personnel, Message forms (with duplicate pages)o The emergency plan should show all details of rescue plan, water

danger plan, fire fighting equipments belowground. D. Accommodation- Convenient accommodation shall be provided for –

o Operation control room, Manager’s office, Laboratory, Press, Securityo Rescue apparatus room, Rescue workers rest room.o Welfare Control and catering.o Walking casualties, Stretcher Casualties, Mortuary.

The locations shall be predetermined to avoid confusion during emergency: The existing emergency plans are deficient and some times not effective in dealing the emergency situation quickly and efficiently. Hence the chances of rescue of persons belowground may get reduced and an emergency may turn out to be a disaster. Reactive response through surface management control teams, rescue teams and emergency duty card systems have limited impact on survival rate of u/g personnel during the 1st few hours of emergency. To overcome the inherent drawbacks in the existing emergency plan, adoption of the doctrine of self escape which offers the best chance of survival to the underground personnel, when ably supported by an aided rescue strategy, should be considered. An integrated and well-rehearsed self escape strategy essentially pro-active in nature offers best chance of survival.Taking into the above concept and philosophy into consideration, the following modern technology advancements should be incorporated into the emergency plan for a large colliery with belowground workings: 1. Risk Assessment: A risk assessment exercise may be carried out and control measures formulated, specifying responsibilities of individual mine officials with a protocol of implementation, to obviate the possibilities of dangerous occurrence in a coal mine. 2. Preparation and prevention: Group discussions may be held with workmen/ officials/managerial personnel to consider various hypothetical scenarios of mine emergency and to chalk out hazard control measures Scenario planning and hypothesis testing sessions may be conducted to search for possible solutions / control of hazards and risks which may not have been identified.3. Introduction of gas chromatography: Provision of Gas Chromatographs for speedy and accurate analysis of air samples may be made in modern emergency plan.

4. Detection and classification:- Regular inspection be made as per the established protocol to identify remedial measures by activating mechanism of control / elimination. Present standing orders may be revised to incorporate specific trigger action points that will activate emergency action plan quickly. Competent persons should be trained and authorised to recognize emergency and act on those trigger points.5. Response and mitigation:- The twin philosophy of “ self rescue” and “ aided rescue” form the foundation of a response and mitigation scheme.a. Self rescue- All concerned may be trained in the process of self rescue rather than waiting for aided rescue by taking following steps:-i. Mine Officials may be trained in deciding the survival / escape actions with work persons at the time of emergency, including routes of travel, mode of travel, order of travel, use of link lines, communication, signaling etc. ii. All overmen and mining sirdars may be provided with updated mine plans, showing air circuits and primary and secondary emergency exit routes.iii. Primary and secondary escape routes may be established and may be fitted with guide ropes, clearly sign- posted with embossed to make them identifiable in conditions of poor visibility.iv. In each district, place may be identified where the workmen can gather in an emergency. Such places may be equipped with telephone, mine plans, link lines and blind man walking sticks.v. Effective telecommunication system may be established so that in an emergency, district officials can communicate with other districts and the surface. b. Aided rescue - Aided rescue is essential to provide external assistance to work persons unable to reach places of safety. Arrangements for getting external assistance should be pre-decided. Rescue station may be manned by a team of dedicated and competent personnel. c. Re-entry and Recovery:- Initiation of a process of hazard analysis and risk assessment is considered as an essential pre-requisite to the event of re-entry. Thereafter, barriers to re-entry may be critically examined and evaluated and recovery be effected as per devised rescue protocols and guidelines.6. Mock rehearsals- This may be conducted from time to time. Deficiency may be noted and emergency plan may be corrected and updated as and when required.

Q.6.(a) What are the causes of Pneumoconiosis? What are its symptoms? What precautions should be taken to prevent it?(b) State statutory provisions relating to periodical medical examinations and discuss its relevance to ILO classification of radiographs for detection of Pneumoconiosis.

Ans (a) - Dust pollution is a predominant problem associated in mining operations. Mining activities involving drilling, blasting, crushing, transportation, dumping of ore etc are closely associated with high levels of air borne coal and other metal dust including asbestos and exposure to crystalline silica (free silica). Inhalation and retention in excessive amount of such dust over the length of time may lead to serious respiratory health problems including pneumoconiosis.

Pneumoconiosis:- It refers to lung diseases produced by dusts of size range 0.25 – 3.0 microns.As per ILO “It is defined as the accumulation of dust in the lungs and tissue reactions to its presence resulting into lungs disease”Pneumoconiosis is a general term to cover all the dust disease of longs. It is now well established that all dusts are dangerous. It is only the degree of harmfulness in which they differ. All dusts, in-haled in large quantity, under suitable conditions, may give rise to some form of Pneumoconiosis.Pneumoconiosis is the term given to a group of diseases that result from the inhalation and deposition of dust in the lungs, characterized by a fibrotic reaction (microscopic scarring) around the small airways and air sacs of the lung. Usually these conditions are more accurately described in terms of the dust that actually causes the problem e.g. coal workers pneumoconiosis (CWP), silicosis, asbestosis, stannosis (from tin) etc. A pneumoconiosis may be either ‘simple’ or complicated.Causes of Pneumoconiosis:- It is caused due to inhalation of dust. It is now well established that the incidence of pneumoconiosis, silicosis, asbestosis etc depends upon:i) The period of exposes to dusty surroundingsii) Nature and concentration of the dust.Symptoms of Pneumoconiosis:-i) Simple pneumoconiosis is said to exist where the only abnormality found is the presence of typical small round opacities (shadows) on a chest x-ray, caused by dust particles being deposited in the air sacs of the lungs. It is generally considered not to cause any symptoms, like breathlessness and cough, or to affect the working of the lungs as demonstrated in breathing tests. ii) Complicated pneumoconiosis is used to describe a situation where a simple pneumoconiosis is associated with the presence of scarring in the lungs. This scarring may progress, causing damage to the lungs that may result in disability or death from respiratory or heart failure. Scarring of this type may be either diffuse or massive where it appears in one or more discreet patches, as in complicated CWP. Chest radiography is the most important tool for the diagnosis of Pneumoconiosis. There appears clear relationship between total dust exposure and severity of radiographic changesPrevention of Pneumoconiosis:- There is need for planning strategy for the prevention and control of pneumoconiosis. It should consist of two major components:-

1. Definition of magnitude of problem2. Implementation of actual control measures

1. Definition of magnitude of problems- To plan and execute the strategy for the prevention of Pneumoconiosis, the knowledge of total population at risk and number of people already affected is very essential. After estimation of population at risk and identification of major vulnerable groups the industrial and medical surveys should be carried out for measurement of “total” and respirable dust at work place and the quantitative analysis of dust samples and chest radiography of the person respectively2. Implementation of actual control measures:- i) Dust control measuresii) Medical measures. i) Dust control measure:- a) Engineering control use of appropriate technologies ventilation & local exhaust process enclosure wet techniquesb ) Legislative control enforcement of laws & regulations formation of dust steering committee strengthening of OHI training for inspectors to enable dust measurement & improve

knowledge on dust control solutions.c) Administrative control use of personal protective equipment work practices personnel hygiene awareness training maintaining dust exposure profile record of individual workers. computerization of environmental surveillance records. In addition to above, the following additional measures should also be taken: Prevention of production of dust, prevention of dust getting air

borne and dilution and suppression of air borne dust. Collecting the dust by suitable dust traps Examining the dust concentration at working places at regular

intervals by approved suitable apparatus and taking corrective steps.Statutory provisions have been for environmental surveillance to be exercised by the mine management in respect of airborne respirable dust e.g. location, frequency and manner of sampling. The manager of every mine has to formulate a scheme specifying locations for collection of dust, nature of sampling instrument to be used, laboratory facilities for analysis, organisation, re-establishment for dust monitoring and control measures and actions to be taken including use of respirators where the permissible dust limit is exceeded. Necessary training should be imparted to the persons engaged in airborne dust surveys and control measures.

ii) Medical Measures:- As per recommendation of WHO, the medical screening programme should be integrated and perused with the environmental surveillance programmes so that the results of both could be related for review of measures taken to control the environment. It should be confirmed, not as control method, but to verify the adequacy of dust control measures. It includes pre-employment and periodical examinations, incorporating chest X-ray, sputum examination and spirometery .

Ans:-6(b) Statutory provisions related to PME- Refer to Q.No.5 (i)(1stclass’ 2006)ILO Classification of radiographs for detection of pneumoconiosis – i) Dust retention and the changes of pneumoconiosis show up on chest x-ray, x-ray changes are apparent early on in the disease process and provide a method of detecting the disease in its early stages.. The ILO classification categorises three things: the size, shape and profusion of opacities on the x-ray of the lungs and these parameters are converted into a series of codes.ii) The profusion or amount of opacities is defined by four numbers, categories 0,1,2 and 3 where profusion increases from 0 to 3. Because the four point profusion scale (0-3) was found to be insufficiently sensitive to assess progression for some purposes, it is often subdivided and converted to a 12-point scale. Thus 0/-, 0/0, 0/1, 1/0, 1/1, 1/2, 2/0, 2/2, 2/3, 3/2, 3/3 and 3/+ are categories often reported.iii) The shape and size of small (< 10 mm) opacities is indicated by lower case letters. Codes p, q and r are ‘round’ as they are in CWP, s, t and u are ‘irregular’ or elongated as they are in asbestos; p and s are the smallest; r and u are the largest. The zones of the lung in which the opacities are seen are also recorded- the right (R) and the left (L) thorax each divided into three zones; upper (U), middle (M) and lower (L). iv) The large opacities associated with PME are defined in terms of their dimensions and given upper case letters; A,B or C. Category A is an opacity having its greatest diameter exceeding 10mm and up to 50 mm or several opacities each greater than 10mm, the sum of whose greatest diameters does not exceed 50mm . Categories B and C, which are more ‘severe’ than category A, relate the combined area of the opacities to the area of the right upper lobe.v) It should be noted that the large PME opacities can be associated with any of the categories of simple pneumoconiosis. Thus category A2 would describe a case of PME where a category A large opacity is found against a background of small opacities typical of a category 2 simple pneumoconiosis. PME vis a vis ILO Classification for detection of pneumoconiosis: Rule 29 F and 29 L of mines rules’1955 lays down the manner & criteria for conducting medical examination which are given below:A full size postero-anterior chest radiograph (large enough to include thoracic inlet and both costophrenic angles) obtained by an x-ray machine of at least 300 ma (milliampere) strength shall be evaluated in the manner specified by the Chief Inspector and lung function test (spirometery) to record Forced Vital Capacity ( FVC ) and Forced Expiratory Volume in one second (FEVI ) shall be made. There should not be any evidence of active pulmonary tuberculosis, he may be permitted to work if his sputum is negative on repeated examination and on production of a certificate that he is taking treatment from a qualified medical practitioner/hospital.The pneumoconiosis can be detected at an early on chest x-ray and its effect on functional capacity can be assessed with the help of lung functions tests.

Q.7. A Large open cast mine is approaching a village hutments that can not be vacated. What actions would you take to fulfill production targets with due regard to safety. Draw a detailed plan of action for the same.

Ans:- In a large open cast mine approaching village hutments, the under mentioned methodology may be adopted in order to fulfill production target with due regard to safety:-

i) Using deep hole blasting both in coal & OB ii)Deploying surface minor in softer strata & coal and practicing deep hole

blasting in harder strata. In a big open cast mine, use of relatively huge quantity of explosive could not be

ruled out which may lead to various socio-environmental impacts such as: Ground vibration Noise/air over pressure Fly rocksHence, in order to fulfill production target with due regard to safety, the following actions should be taken:1) Statutory actions:- i)Seeking permission for controlled deep hole blasting- Prior permission should be obtained from DGMS specifying the limiting charge weight per delay, total charge in a blast hole and total charge in a round of blast along-with provision of muffling of shot holes with screens and sand bags to limit the travel of flying fragments to within 10m from the site of blast.ii) Seeking exemption under regulation 170 (1A & 1B)/ Taking shelters- Since in a big open cast mine, the observance of provisions contained in regulation 170 of CMR’1957 in respect of removal of people from danger zone, posting of guards, limit of 2kg charge in all the holes fired at one time etc are not reasonably practicable and hence exemption has to be obtained from DGMS. 2) Non-statutory / other actions:- Apart from the statutory actions mentioned above, the following actions should also be taken:

i)Training:- Blasting operation shall be carried out by a team of qualified and experienced persons and special training for his purpose shall be given to them.ii)Supervision:- Every blasting operation shall be performed under the supervision of experienced overman and Asstt. Manager possessing FCC.iii)Safety flag:- Safety flags shall be pasted at a minimum distance of 50m from the site of blasting, all along the danger periphery.iv)Blasting time:- Shots shall be fired only during day light and particularly between two shifts or during rest interval.

v)Use of explosive:- Charge per delay, charge per hole & charge per round of blast shall not be more than permissible limit.

vi)Posting of Guards:- Sufficient numbers of trained guards with efficient communication systems shall be posted near the village.

vii)Blasting shelter:- A substantially constructed blasting shelters shall be provided near the village hutment and also for the shot firer.

viii)Siren:- Ten minutes before firing, a siren installed for the purpose shall be blown three times for one minute each at one minute interval and no blasting shall be done unless the shot-firer has ensured that all persons have taken proper shelters.

Detailed action plan for fulfilling production targets with due regard to safety :-With the use of controlled blasting method, the socio-environmental impacts can be minimized to acceptable limits. Before introducing controlled blasting technique, a scientific study shall be carried out in consultation with blasting experts from organizations like CIMFR, CMPDIL etc. much before the hutments fall within the blasting danger zone. For this purpose, the following action shall be taken:i) DGMS permission:- When the working has approached the village hutments, the permission of CIM shall be taken for further working (within danger zone of 500m)ii) Taking help of scientific agency- Help of scientific institution such as CIMFR, CMPDIL, ISMU etc should be sought for designing proper blasting pattern and taking valuable guidance on control measures for safe working. Experimental blasting shall be carried out by the scientific agency in presence of management personnel for the training purpose.The following scientific studies shall be carried out to formulate safe blasting practices:-a) Study/observations:- Study of ground vibration, air-blast over pressure, peak particle velocity etc, shall be carried by the scientific agency in the hutments area, by using modern instruments, and a safe and suitable blasting pattern shall be designed.b) Preparation of Plan:- A plan showing structures belonging to the owner and not belonging to the owner in different prominent shades shall be prepared. The plan shall incorporate details of construction of the structures in a tabular form. The plan should also show 50m, 100m, 200m, 300m & 500m zones from the structures, the place of experimental study and the limit upto which blasting is proposed to continue.c) Structural response:- During the study, the response of the structures assuming different natural frequencies should be calculated and plotted.d) Monitoring:- In order to ensure effective control over the vibration and related damages there is a need of regular inhouse monitoring and the management should train the blasting personnel during the experimental study and start observations on their own during the regular blasting operations. 3) Control of ground vibration/fly rock/air-blast over pressure-a) Limited /Safe charge per delay, and per round of blast.b) Use of nonels and electronic detonator.c) Muffling of shot-holes.4) Warning & Communication systems:- Modern warning & Communication systems approved by CIM should be

used. 5) Shelter:- Substantial shelters shall be constructed near hutment area and

near the public roads lying within the danger zone.6) Competent Supervision:- The blasting activities shall be performed by the

experienced and trained personnel under competent supervision. The overall blasting process shall be controlled by an Asstt. Manager having FCC.

7) Educating villagers about dangers of blasting in open cast mine.8) Preparation and implementation of Environment Management Plan for

control and reclamation of environmental damages.9) Providing compensations to villagers for their damages.

10) Rehabilitation of villagers, if necessary. The above mentioned detailed action plan may be summarized in the following manner:-

Action Plan

↓ ↓

↓

↓

↓

↓

↓

↓

↓

Pre-blast survey & permission

Experimental/trial blasting

Record & monitoring with seismograph

Permissible limits

Permission for regular blasting

Code of practices for conducting controlled blasting

Regular in house monitoring

Preparatin & Implementation of EMP

Educating, compensating and rehabilitating villagers

Q.8. (a) In an underground coal mine three persons of shot firing crew including shot-firer, several hours after returning home, complain of chest pain and breathing difficulty and have to be hospitalized. One of them dies next day. What may be the possible causes of this episode? How would you enquire into it? Discuss possible causes and statutory contraventions.

(b) At the end of a working shift, the assistant manager is informed that one underground worker is missing. What actions should be taken?

Ans: - Since the effected persons are sort-firing crew and having complaint of chest pain and breathing difficulty, they might have been exposed to excessive blasting fumes ( beyond permissible limit ) present in working faces just after blasting operation.

Under the circumstances, the following may be the possible causes for this episode:- i) Inhalation of ‘Nitrous Fumes’:- Exposure to high concentrations of nitrous fumes may lead to chest pain or even death from bronchospasm and respiratory failure. Nitrous fumes are very poisonous, the maximum tolerable concentration for Indian Mines is taken as 0.0005%(5 PPM). Men affected by nitrous fumes show immediate symptoms of cough, nausea, choking, perspiration bronchial troubles such as bronchitis and bronchopneumonia which may prove fatal within 48 hours.Nitrous fumes are usually generated when explosives undergo combustion instead of detonation as may sometimes occur in case of weak detonation. Hence, when explosives are blasted in confined space in U/G , nitrous fumes are produced in dangerous concentration after blast. Short firing crew are encountered with deadly concentration of nitrous fumes, when they return early at blasting place after blasting. This might be the possible cause for the accident of short firing crew.ii) Inhalation of Carbon Monoxide:- CO is also a very poisonous gas, but less dangerous than nitrous fumes. When explosive is blasted in confined space like in a drill hole, it produces an appreciable amount of CO which may affect health of person.But as in question the short firing crew several hours after returning home complain of chest pain and breathing difficulty and one of them died the next day is clear indication of ‘ Nitrous Fumes’ poisoning.Hence it can be concluded that the possible cause of episode is inhalation of nitrous fumes in high concentration i.e. in excess of permissible limit.Enquiry of Accident:- I would make enquiry about the accident in the following ways:-i) Background information- ll seam of A mine is being developed by B/P method with SDLs. The seam thickness, pillar size and galleries width are 2.5m, 25mx25m and 4.8m respectively. The galleries are driven by blasting off-the-solid using P-5 explosives and CDD.ii) Event prior to the accident- After drilling and charging of blast holes, blasting was done by shot firing crew under the supervision of mining Sirdar and Overman. iii) Occurrence of the accident:- On ……………. at about 9.30PM ( ll Shift) a last round of shots were fired at face no. …….. (20m blind level heading) by shot fires and his two helpers. They rushed at the face immediately after blasting ( without waiting a couple of minutes) to check the condition of the face and to

leave the distt. as early as possible as it was last round of fired shots. As soon as shot firer and his two helpers reached at blasting fumes face they got 2-3 misfire of shots. They stopped at the face for a longer period to detect the misfired shots in blasting fumes environment. They entered at the face repeatedly to check and fire the misfired shots one by one. Thus they got exposed to high concentration of blasting fumes environment for a longer period and suffered with their toxic effect. iv) Inspection and inquiry:- On next day, I met with the shot firer and his one living helper and recorded the statement of both of them. Subsequently I also inspected the place of accident in llnd shift alongwith co-workers of deceased and asked them to describe the incidents. Thereafter, I also asked mining sirdar, overman and ACM who were on duty at the time of accident to give their written statements separately.During the course of inspection, ventilation measurement, quantity of air was also measured at the blind end face and also at immediate outbye ventilation connection from the face. v) Possible causes of the accident:- Following are causes of accidents:a) Use of explosives in excess of permissible limit: - One of the cause of accident may be use of permitted explosives in excess of permissible limit as permitted by DGMS for given degree of gassiness producing more nitrous fumes.b) Inspection of face by Shot firer without waiting for clearance of fumes: The shot firer alongwith his helpers had entered the face without waiting for clearing of blasting fumes. Even, shot firer did not wait for at least five minutes after blasting.c) Ventilation requirement –Quantity of fresh air was not adequate at the face resulting into high concentration of nitrous fumes in air at face. d) Coursing of air- Blind heading was not ventilated by coursing of air upto 4.5m from the face.In my view, all the above factors collectively were responsible for such type of accidents.vi) Contraventions of statutory provisions:- The following provisions of the statute have been contravened in this case.a) CMR 176 : After shots have been fired, shot firer or any other person shall not enter the place until the atmosphere in the area is free from smokes & fumes.b) CMR 177 : Shot firer and blasting crew entered or re-entered the blasted face until waiting for 5 minutes ( for clearing of fumes ), thus the shot firer contravened the regulation 177 of CMR 1957. c) CMR 130: Quantity of air was not adequate at the faces for clearing the blast fumes. d) CMR 136A: Velocity of air shall be at least 30m/ min at immediate outbye ventilation connection from the face and at 4.5m from the face on the intake side of the brattice or partition.e) CMR 146: Air current shall be coursed upto a point within 4.5m of the face by means of brattices or other materials.f) DGMS Cir.Tech.30/1973: Adequate arrangement should be made to circulate such quantity of air upto the site of blasting as to ensure after every round of blasting, dilution of ‘CO’ and ‘NOx’ in the blasting fumes to less than 50 PPM & 5 PPM respectively within a period of 5 minutes.Ans: (b) Assumptions of conditions:- Availability of telephonic communication between surface & underground.

Prevailing general practice regarding assembling of all workers including pump khalasi at rest shelter half an hour before end of shift and then coming out of mine under supervision of mining sirdar.

Contrary to the daily practice, till the end of shirt one pump khalasi has not reported to the Distt. Mining Sirdar and subsequently information sent to ACM regarding missing of one pump khalasi.

Under the above assumed conditions, I being an ACM, should take following actions:-.i) Checking of attendance & cap lamp issue register- For this purpose, I shall

ask time keeper to check form ‘C’ and cap lamp issuer to check cap lamp issue-return register to ensure any possibility of his coming outside.

ii) Organising Rescue work- Rescue work shall be undertaken for missing persons and instruction will be sent that no further person should go in as the person might have been overcome by noxious gases. iii) Improving ventilation - Instruction would be sent to improve ventilation by coursing of air and arranging the materials (brattice, timber) for coursing of air to the pump site.iv) I would inform/arrange to inform manager and other senior officials, rescue station/ rescue room, doctor.v) I would arrange to send u/g – Flame safety lamps, Brattices, Tube apparatus, Co-detectors, Self rescuer- O2 type.vi) I would not rush down the mine without making proper arrangements. However, after another officer is present on surface, I would go down the mine.vii) Withdrawal of person from return side would be arranged.viii) I would improve the ventilation to dilute the noxious gases at pump site by coursing of air.xi) If victim is within reach of the tube apparatus, the same would be used to bring out the victim.x) Application of artificial respiration to the victim is done till the life is pronounced by a doctor.xi) If the place is difficult to ventilate, and also ‘O’2 type self rescuer are not available, there is no alternative but to wait for the rescue team with breathing apparatus.xii) Only after threat from noxious gases is removed, work in the mine will be resumed.xiii) Investigation is needed to establish the sources of noxious gases.



SECOND CLASS




1. What are the provisions of Mines Act, 1952 for the following:- (a) Hours of works belowground.

(b) Extra wages for overtime(c) Leave with wages.

Ans:-a) Hours of works belowground- i) No adult shall work belowground in the mine for more than 48 hours in a week or normally for more than 8 hours in any day , however the daily maximum hours may be exceeded to facilitate the change of shifts subject to previous approval of the Chief Inspector. ii) Work below ground must be carried on by a system of shifts which should be so arranged that the period of work of each shift is not spread out for more than the daily maximum of 8 hours. iii) No person employee in a mine shall be allowed to be present in any part of a mine belowground except during the period of work shown in respect of him in form C.iv) The manager of every mine shall cause to be posed outside the office of the mine a notice in form ‘A’ not less than 7 days before the commencement of the work stating the time of commencement and of the end of the work at the mine and if the mine is to work by a system of relays, the time of commencement and the end of work for each relay. Ans:- b) Extra wages for overtimei) When a person works for more than 9 hours in any day above ground or more than 8 hours in any day belowground or more than 48 hours in any week above ground / below ground, he is entitled to overtime wages at twice the ordinary date of wages. ii) The period of overtime work shall be calculated on a daily basis or weekly basis, whichever is more favourable to him. In the case of a person paid on piece rate basis, the time rate shall be equivalent to the average of his full time earnings (excluding any overtime) during the preceding week.iii) Persons holding positions of supervision or management or employed in confidential capacity are not entitled to overtime wages. iv) The time spent by any person during examination related to safety & occupational health survey shall be counted towards his workings time, so however that any overtime shall be paid at the ordinary rate of wages.Ans:- c) Leave with wagesRefer to Q.No. 6 (iii) ( 1st class 2006 )

2 An accident had occurred in a depillaring due to fall of roof in slice, in which one person was killed. Write an enquiry report assuming your own conditions clearly bringing out contraventions of the statues and persons responsible.

Ans:-

From : _____________, Safety Officer, _____________, Colliery,

Dated, ______________ToThe Manager,_____________________Colliery,

Sir,

Ref. Your letter No._______ dated ______________

I submitted herewith a report on the roof fall accident that occurred on ________ at about 10 p.m. in the depillaring district in __________________seam at __________Colliery and resulted in the death of two loaders namely,___________ and ____________________________

Yours faithfully,

(Signed)Encl. Inquiry Report.

Inquiry Report

i) Description of mine and its workings.

l Seam, which is about 6.0m in thickness and having gradient 1 in 10 and depth of working 140m has been extensively developed along sand stone roof with 2.2m height by Bord and Pillar method. Presently depillaring with caving is being done.

ii) Events prior to the accident:Panel no. 46B was started on 17-07-2005 with conventional depillaring by caving method. The area of goaf was around 4720 m2 on 16-10-2005. Induced blasting was regularly done to bring down the hanging goaf as per the existing practice. The first fall in the goaf had taken place in 3rd shift on 14-10-2005. The extent of fall was 1750 m2

. The 2nd fall had taken place in 3rd shift on 15-10-2005 and the area of fall was 1470 m2. The area of exposure left in the goaf was around 1500 m2

at the time of accident.

iii) Occurrence of the accident:

On 16.10.2005 during lll-shift at 00.50hrs(early hours of 17-10-2005) in panel no. 46B depillaring district in l seam at 1st slice of 55 ½ L.S. / 9 dip, a massive stone measuring 11m x 7.25m instantaneously caved in. One person succumbed to fatal injury and two persons sustained serious bodily injuries.

iv)Rescue & Recovery:- Trained manpower were deployed immediately for removal of the debris. One dead body & two seriously injured persons were removed after 2 hours of the accident. v)Inspection & Enquiry: - On receiving information about the accident, I immediately inspected the place of accident along with the other supervisory staff and workmen. I made detailed observations and some measurements at the place of accident and prepared a sketch of the place of accident giving leading dimensions. Photographs of the place of accidents were also taken. The sketch and photograph is attached with the report. I also examined witnesses and recorded their statements.vi) Analysis of evidence and findings:From the inspection of place of accident, careful study of DGMS permission and analysis of evidence collected, the following were revealed:-

The total area of exposure of the hanging goaf since 17.07.2005 upto 14.10.2005 was 5480 m2

On 14.10.05 in 3rd shift 1750 m2 ( 1st fall)

On 15.10.05 in 3rd shift 1450 m2 (2nd fall) The accumulated stresses within the strata were neither released fully nor

settled and it could be concluded that goaf was active. Roof strata load was transferred on the supports erected around the working

face. In between 2nd shift of 16.10.05 and 3rd shift of 17.10.2005 further bed

separation might have taken place and parted roof might be resting on the supports as well on the coal rib.

The hanging stone which partly resting on the coal rib had fallen along with the supports erected underneath the strata, as the support density was not adequate to take the load of hanging strata.

As per the evidence gathered the full was so sudden that the hanging roof has fallen suddenly without giving any indication of sound due to which no time left to the workmen to escape for safely.

vii) Cause of the accident:Speed of extraction is essential in the caving system of depillaring. Induced caving for bringing down the roof at regular interval in order to relieve the strata pressure is necessary. A large area remain exposed for considerable period causing dangerous conditions resulting in the crushing of the think stook and premature collapse of roof in the working area. Symptoms of the build up of pressure, if any, went unnoticed by the supervisory staff. These combined factors are responsible for occurrence of such type of accident.

viii)Contraventions of statutory provisions:- Regulation 108 of CMR 1957 read with DGMS permission letter for extraction of pillars by caving method were contravened in respect of the following:-a) Support of split galleries & slices - SSR framed by manager were not fully implemented.b) Induced caving- Induced caving for bringing down the roof at regular interval in order to relieve the strata pressure was not done.c) Installation of convergence recorder- As per condition laid down in statutory permission letter, sufficient nos of convergence recorders were not installed for giving symptoms of roof weighting.

ix)Responsibilities:- Enquiry into the accident revealed that if the workings were supported as per SSR, roof weighting noticed in time & safety precautions taken by officials as required under statute, the accident could have been averted. Under the circumstances, the following persons are considered responsible for the accident:-

a. Agent- In contravention of provisions of section 18(1) and 18(4) of Mines Act 1952 read with regulation 190 of CMR 1957, agent of mine failed to effectively implement that all operations carried on in connection with the mine are conducted in accordance with the provision of mines act and regulation made their under.

b. ii)Manager- In contravention of provisions of reg. 108 and 41 of CMR 1957 read with sec. 18(4) of mines act 1952, the manager failed to effectively implement the conditions imposed by DGMS for supporting of splits, goaf edge etc.

b) ACM- In contravention of provisions of reg. 108 and 42 of CMR 1957, the ACM failed to effectively implement the conditions imposed by DGMS for supporting of splits, goaf edge etc.

c) Overman-In contravention of provisions of reg. 108 and 43 of CMR 1957, the Overman failed to effectively implement the conditions imposed by DGMS for supporting of splits, goaf edge etc. and also failed to notice the roof weighting.

x) Recommendations for prevention of similar accidents:In all depillaring districts where extraction is done with caving, special vigilance is required. The Overman and Mining Sirdar must be told about the likely dangers and should be advised to watch carefully for signs of roof weighting. If any indications of roof movement are observed, they should immediately withdraw the workers. The Asstt. Manager should inspect such districts more frequently and with greater care.

Q.3. State the provisions on Indian Electricity Rules, 1956 regarding the following:-(a) Precautions where gas exists.

(b) Flexible cables(c) Sundry Precautions(d) Voltage LimitsAns:- (a) Precautions where gas exists- Refer to Q.No.5(d) ( 2nd Class 2007 )Ans:- (b) Flexible cables i) It shall be of two core or multi-core and shall be covered with insulating material efficiently protected from mechanical injury. Even if the mechanical protection component is used as earth conductor, it must have a separate earth conducting core. ii)Where flexible cable is not required to more, it should be effectively supported and protected against physical damage by roof/side fall, shot firing, crushing by moving machinery or tubs.iii) Machine operators and cable men should be trained in safe operation and handling of trailing cables.iv) Where flexible cable is joined with the main cable, a switch shall be provided which is cable of entirely disconnecting supply from the flexible cable.v) Flexible cable shall be connected to the gate end box and the machine by suitable and properly constructed connectors. For HV machines, bolted type connectors shall be used. vi) Flexible cable shall be examined periodically by the person authorised to operate the machine. It shall be examined at least once in each shift by the competent person. Damaged or defective cable shall be replaced by good one immediately. No flexible cable with a temporary joint shall be used.vii) Supply of energy shall be disconnected whenever the cable is not in use and it shall be removed from the face to a safe and secure place.viii) Arrangements shall be made to prevent energizing of flexible cable by unauthorized persons.ix) Joining of flexible cable to the main cable shall be through a circuit breaker capable of disconnecting supply automatically.x) If voltage of the circuit exceeds low voltage:-

flexible cable for transportable apparatus shall be provided with metallic screening or pliable armoring

flexible cables for portable apparatus shall have flexible metallic screening on all the power and pilot cores.

However, this will not apply to flexible cables attached to any transportable apparatus used in opencast mines if reeling and unreeling of such cable is necessary as per design features of the equipment.

xi) In case of separately screened flexible cable, conductance of each screen shall be not less than 25% of that of the power conductor and the combined conductance of all screens, shall be not less than 0.15 sq. cm. copper conductor.xii) Length of flexible cable with any portable or transportable apparatus shall not exceed 90m. But it may be upto-250m when used for long-wall operation, with coal cutting machine or cutter-loader or armoured face conveyor or with shuttle car or LHD or cutter loader or all alike equipment for development and depillaring operations.350m with electrically operated HEMM in opencast mines, and 1000m with bucket wheel excavator at 11kv.xiii) Flexible cable shall not be used with apparatus other than portable or transportable apparatus.

Ans:- (c) Sundry Precautionsi) All apparatus shall be maintained reasonably free from dust, dirt and moisture, and shall be kept clear of obstruction.ii) All apparatus other than portable and transportable apparatus shall be housed in a room, compartment or box so constructed as to protect the contents from damage by falling material or passing traffic.iii) Inflammable or explosive material shall not be stored in any such place.iv) In case of any fault in any circuit, that part of the circuit shall be made dead without delay and it shall remain dead until the fault is rectified.v) While lamps are being changed, the supply shall be disconnected.vi) No lamp holder shall be in metallic contact with the guard or metal part of a portable hand-lamp.vii) The following notices in Hindi and local language of the district, so designed and protected as to be easily seen and read at all times, shall be exhibited:

at all places where electrical apparatus is in use, a notice “unauthorized persons not to operate or interfere”.

where a telephone or other means of communication is provided, a notice giving full instructions to persons authorized to effect the disconnection, at the surface of the mine, of the supply of energy to the mine.

viii) All apparatus, including portable and transportable apparatus shall be operated only by persons authorised for the purpose.ix) When a plug and socket coupling is used with flexible cable, an electrical interlock or other approved device shall be provided to prevent opening of the coupling while conductors are live. Ans:-( d) Voltage LimitsRefer to Q.No.6(a) (2nd class 2004)

Q.4. Write short notes on any three the following:-(a) Risk assessment as a tool to improve safety.(b) Haul road gradient in opencast mine

(c) Noise pollution in mines.(d) Angle of draw and its relevanceAns:- a) Risk assessment as a tool to improve safety:- Refer to Q. No. 6(b) ( 1st Class 2008 ) Ans:-b) Haul road gradient in opencast mine- Good haul roads are a necessity for successful mining operations. Poorly designed, constructed and maintained haul roads are major contributors to high cost and pose safety hazards. Haul roads in O/C mines need to be properly designed, constructed and maintained for:-i) Ensuring operational safety.ii) Achieving operational efficiency with high dumper speeds and minimum cycle time.iii) Reducing breakdowns, maintenance work and consumption of tyres and spare parts.iv) Minimizing fuel consumption.The haul road geometry plays an important part in the safety of operation of moving vehicles, their productivity as well as cost of construction. Guidelines provided by DGMS for mechanized OC mines deals with the gradient, width, visibility at bends and parapet walls of haul roads.The grade line for a haul road is the profile taken along the centerline of the road and is a series of straight lines connected by parabolic vertical curves to which the straight grades are tangent. All roads for trucks, dumpers or other mobile machinery shall be maintained in such conditions as to be fit for their use. No haul road should have gradient steeper than 1 in 14 at any place except for haul road ramps (going from one bench to another) over a small stretchers where a gradient upto 1 in 10 may be permitted. Where this condition can not be fulfilled, prior written permission of CIM should be obtained and the condition specified must be followed. In case of operational difficulty due to limited property and adverse topographical consideration, it is necessary to have steeper gradient/slopes. For this purpose, special permission shall be obtained from DGMS.It is advisable from safety and engine life considerations to keep a small stretch (say 50m length) of lesser gradient after every 500m of steep gradient. A number of rules of thumb regarding haul road gradients have been provided by Couzens (1979). These are given below:-i) In a pit where there is a considerable vertical component to the haulage requirement, the grade will have to be fairly steep to reduce the length of the road and the extra material necessary to provide the road length. The practical maximum grade is considered to be is 10%. A number of pits operate quite well at 10% grades both favourable and un-favourable to loads. ii) An 8% road grade is probably preferred providing that it does not cause too much extra stripping or unduly complicate the road layout. This grade provides more latitude in (a) building the road (b) fitting in bench entries without creating some locally over-steep places, than do steeper grades.iii) There is normally nothing to be gained by flattening the road below 8% unless there is a long distance to travel without regarding much lift.iv) Pit geometry is the prime consideration and roads are designed to fit particular situation. Thus there often will be number of different grade segments in haul roads. Haul road should be maintained smooth, free from fallen rocks and sprinkled with water to prevent raising of dust and well drained. To ensure this,

road maintenance equipment and personnel should be separately earmarked depending on size of the mine. Ans:c) Noise Pollution in mines-A sound without agreeable musical quality is :-Noise:- Any unwanted or undesired sound is called noise. Human ear can defect sound in the frequency range 05 16HZIt is an abrupt sound of complete chamber with an irregular period and amplitude originating from a source in a non-periodic motion.Nose Pollution:- This is a common hazard associated with mining. Almost all mining operations generate noise. It has got a detrimental effect on the health of persons working in a mine:1. Pathological effect- Hearing loss Reduction of speech intelligibility Acoustic traumas Auditory fatigue2. Physiological effect- Changes in blood pressure Changes in pulse rate Constriction of blood vessels Dilation of the pupil of eye Changes in blood cholesterol contents3. Psycological effect. Feeling of discomforts Sleeping interference Reduced intellectual performance Fatigue Vexation Irritation distress Mental disorderThe degree of injury from exposures to noise depends upon a no. of factors such as intensity and frequency range, duration of exposures and individual simplicity Noise level standards:- i) Warning level – 85dBA( for eight hours daily exposure)ii) Danger level – 90dBA (Unprotected for 8hrs daily exposure)iii)Compulsory wearing of ear protection limit- 115 dBA ( for 8 hrs daily exposure)iv)Impulse noise of short duration – 130 dBA (Single outburst)vi) No work limit – 140 dBA.

Measures for noise control and reduction of noise exposure.a) Engineering Measures (noise control)-

For new machinery, laying down noise levels in specifications of machinery to be purchased. Acceptance level could be 85-90-dB (A) in normal operation of the machine at the operator’s position.

In case of existing machinery, conducting noise zone survey, reducing noise at source.

Interrupting the noise path by putting acoustics noise barriers or enclosures, isolating men from the source by acoustic cabins & using remote control equipment.

b) Administrative measures (reducing noise exposure)- Noise exposure can be reduced by:

reduction of exposure time at noisy operation. job rotation during a shift or on a day to day basis.

c) Hearing protection:When all engineering and administrative measures fail to reduce noise to acceptable levels or as a short term measure, hearing may be protected by ear protectors.Regular audiometry as a part of periodic medical examination of workers will show to what extent the measures have been successful.

Ans:- d) Angle of draw and its relevance:- Refer to Q. No.6(a) ( 1st class 2008)

Q.5. What are the causes of damage to buildings and structures due to blasting in opencast mines. What precaution should be taken to prevent such damages.Ans:- When commercial explosives are detonated in blast holes, huge amount of energy is liberated, both useful and waste energy. While useful energy (shock energy and gas energy) is capable is doing work, the waste energy can not be used in a constructive way and it creates some environmental problems and

annoyance including damage to buildings and surface structures due to ground vibrations (seismic energy). When blasting is done in Open Cast Mines, ground vibrations are generated outward from the blast areas which cause damage to surrounding surface structures. The vibrations radiating from the blast holes while passing through surface structures induce vibration on the structures causing resonance. The components of ground motion can affect the structures through compression and tension and also through vertical and horizontal shearing effects. In a properly designed and executed blast, only 20-30% of energy of commercial explosives used in the mines is utilized for fragmenting the rock, the rest of energy is transmitted through the earth in the form of ground vibrations resulting in damage to the surrounding structures.As per rough estimation, distribution of energy of commercial explosives in a surface mine blast is as follows:

Sl.No. Parameters % Util. of energyi. Fracture in situ 1ii. Rock Breakage 15iii. Rock displacement 4iv. Crushing in the

vicinity of hole1.5-2

v. Fly rock 1vi. Deformation of solid

rock behind the shot1

vii. Ground Vibration 40viii. Air blast 38-39

Cause of damages to buildings and structures due to open cast blasting:-When blasting takes place in an open cast mine, the incoming blast- induced ground vibrations transmitted through the ground create a dynamic response in buildings and surface structures. The response depends on various factors, such as: Type and characteristics of the vibration, duration of seismic pulse,

frequency of propagating waves, transmitted energy etc. Type of transmitting medium on which the building & surface structure

stands, and Type of structure and its vibratory character as well as non-structural

entity of the structure.Damage to any buildings and surface structure due to blast vibration can best be explained in terms of its response to the passing vibrations. One of the critical response factors is the amount of differential movement that occurs between structural members causing strains, which in turn, produce cracking. Investigation into cause of damage to buildings & surface structure due to O/C blasting showed that the structural resonance responded to low frequency ground vibrations, resulting into increased displacement & strain. Experimentally, it has been verified that if the wave length of the transmitting wave is long enough compared to the size of the structure (low phase angle) the entire structure tend to move generally as one.In India, peak particle velocity (PPV) and frequency of wave has been considered as the best criterion for evaluating blast vibration in terms of its potential to cause damage.

Following are the causes of damages to buildings & surface structure due to O/C blasting:- i. High magnitude, long duration and low frequency of vibration waves.ii. Primary or compressional or P-wave produced due to blasting propagating through the ground materials alternatively producing compressions and dilations, with particle movement in the direction of wave propagation.iii.Transverse or shear or S-waves moving the particles in a direction perpendicular to the wave propagation transmitting through the ground materials.iv. Surface waves or ray Leigh or R-waves and Love or L-waves propagating through the soft rock / soil over hard and competent material.v. Differential movements of structure due to ground vibration.vi. Deformation of buildings & structure due to resonance effect i.e. coincidence of natural frequency of structure with low frequency ground vibration.v. Compression, tension and shears produced in structure due to ground movement. Precautions to be taken to prevent damage to buildings & structures:i. As far as practicable, buildings & structures should be constructed away from the blasting zone.ii. For buildings of historical importance and multistoried structure, permissible PPV should be lowest to ensure low level of ground vibration.iii. For ensuring low PPV as well as permissible / safe ground vibration, blasting operation should be conducted by observing following precautions:-a. Charge weight per delay should be less for less intensity of ground vibration as the later increases with the former.b. Delay interval between rows should be so arranged that the wave fronts emanating from corresponding charges are separated avoiding superimposition.c. As the bottom initiation generates less vibration as compared to top initiation, the former system should be adopted.d. Blast design parameters such as burden, spacing, stemming charge, bench height, sub-grade drilling, charge length etc. should be optimum in order to have low level of ground vibration.e. Charge per delay and charge per round should be restricted for low ground vibrations.f. Delay time should be fixed compatible with the type of rocks, the acoustic properties and period of oscillation of waves.iv. Practicing controlled blasting techniques-a. Qualified Mining Engineer possessing 1st class certificate holders should be appointed for conducting control blasting.b. Sufficient nos. of technical assistance such as blasting over-man, mining sirdar as well as other person having good knowledge of blasting should also be appointed for the purposes. c. Adequate training should be imparted to the persons engaged in control blasting operation. d. Controlled blasting technique such as use of nonels, electronic detonators, muffle blasting, deck charging etc should be practiced to control ground vibration.v. Direction of initiation- To have low level of Seismic / ground vibrations, direction of initiation of blast should be decided after trial and error method.

vi. Charge confinement- Confinement of explosives has significant influence on generation of vibration. For similar scaled distance, deeper holes generate less vibration as compared to shorter blast holes. vii. Duration of blast- It should be less for low level of ground vibration.

In order to ensure effective control over the vibration and related damages there is a need of regular in house monitoring and the managements should train the blasting personnel during the experimental study and start observations on their own during the regular blasting operations.

Q.6. Write short notes on any three of the following:-(a) Life of winding rope.(b) RMR and its application in strata control.(c) Obligations on manager in case of serious bodily injury.

(d) Illumination in opencast mine.

Ans:- (a) Life of winding rope- Winding rope built to withstand severe conditions are made of quality steel. Maintenance plays an important role to get proper life of a rope. Deteriorations such as wear, corrosion, fatigue, corrosion-fatigue, distortion and plastic deformation badly affects the life of winding rope.Reg. 80(4) of CMR’1957 stipulates the max statutory life of winding rope which is 3½ Yrs. Hence, no winding rope, which has been in use for more than 3½yrs shall be used for winding purposes. However, RIM may allow/permit use of winding rope for longer period ( i.e. over and above statutory life) if he is satisfied that due to sparing use any such rope is in good condition.For seeking permission for extended use of winding rope, mine management has to submit application accompanied by a copy of certificate containing details such as breaking load, quality, construction, diameter etc and also by a certificate as to the strength of the rope. The aforesaid certificate shall relate to a piece of the rope cut off not more than 3 months prior to the date of application.Extension of life of rope may be generally given upto a period of 6 months at a time if the rope condition is found satisfactory from the test reports, statutory examination reports and visual examination. In case where there is any doubt, the winding conditions are adverse, winding duty is heavy and involves large number by men being wound, the period may be shortened. In case, where complete test report of the rope sample drawn in accordance with regulation is not submitted in time with the application, provisional extension may be given upto a maximum period of 3 months, provided the condition of rope is found otherwise satisfactory.

RIM may also prohibit the use of winding rope for winding purposes before expiry of statutory life of 3½ yrs if he is of opinion that the rope has become unsafe for use in a shaft.However, in case of kope winder, extension of life of rope is not possible because of testing of rope samples can not be done due to non provision of recapping of rope. Ans-(b) RMR and its application in strata control.Refer to Q.No.4(b) ( 1st Class -2005)Ans-(c) Obligations on manager in case of serious bodily injury.Refer to Q. No.5(b) ( 2nd Class – 2007)Ans-(d) Illumination in opencast mine.Refer to Q. No.5(a) (2nd Class – 2007)

Q. 7. Write statutory provisions in respect of the following:- (a) Duties and responsibilities of Rescue Superintendent

(b) Rescue Room(c) Appointment of rescue trained persons in mines their disposition and accommodation.

(d) Duties of the training officer. Ans:- a) Duties and responsibilities of Rescue Superintendent- Rule 12 of Mines Rescue Rules,1985 stipulates the statutory provisions in respect of duties and responsibilities of Rescue Superintendent as mentioned below :-i) The rescue superintendent shall be in overall control of rescue station and rescue rooms served by such rescue station.ii) He shall ensure that

a) all the rescue equipment & apparatus kept at the rescue station, rescue room & at the entrance of the below ground mines under his control are

maintained in perfect order inspected by instructors at specified intervals and passed fit after tests are conducted and adjustments are made

b) adequate stock of spare parts and supplies are kept for maintaining rescue equipments and apparatus in perfect orderc) persons selected for initial training and those undergoing refresher training receive the prescribed course of instructions and practices and are issued the certificates for the same.

iii) He shall a) countersign the records maintained by the instructors

b) make periodical inspection of rescue rooms and apparatus and equipments under his control.

c) perform such rescue and recovery work as may be assigned to him by the manager/ principal official in the event of an emergency.

d) within 3 days of completion of rescue or recovery work send a report of the same to RIM or CIM.

e) maintain in a bound paged book a diary and record of results of each of his inspection and also the action taken by him to the rectify the defects observed during inspection.

f) submit annual return to CIM & RIM indicating detailed report on the functioning of rescue station & rescue room under his control with particular reference to

type and number of equipment and apparatus provided & maintained.

superintendent, instructors, rescue room in-charge and rescue brigade in position as on 31st December.

number of rescue trained persons at each mine served by rescue station and number of such persons given refresher practices and medically examined with results thereof.

particulars of emergency attended any other relevant matter

It is suggested that a copy of annual return / report submitted by rescue superintendent is sent to the owner of the mine or the report is routed through the owner. Apart from the above statutory provisions, he shall ensure that his rescue station has an effective rescue cover for all the mines under his station. Such cover must also ensure that when any station is on a call to one mine, there must be effective back up arrangements in case of an incident at any other mine under the same rescue station.

b) Rescue Room- i) The owner of every below ground mine ordinarily employing more than

100 person belowground and where there is no rescue station within a

radius of 35 km, is required to establish and maintain a rescue room either exclusively for one mine or for group of mines belonging to the same owner.

ii) A rescue room may serve group of mines belonging to the same owner if the total number of persons ordinarily employed in all such belowground workings is not more than 5000 and all mines are situated within a radius of 35 km from rescue room and connected by road with the rescue room.

iii) CIM may require the owner to establish and maintain a rescue room irrespective of the number of person ordinarily employed below ground in case of belowground coal mines having a fiery seam or gassy seam of second or third degree.

iv) At each rescue room, there shall be appointed one rescue room in-charge and sufficient number of rescue trained persons as per statute.

v) At-least one rescue trained person shall always be in attendance at rescue room.

vi) At every rescue room, there shall be provided and maintained for immediate use, apparatus and equipment as specified in schedule Il of Mines Rescue Rule 1985.

vii) Self contained breathing apparatus provided at rescue room shall be of the same type and make.

viii) Every mine shall be connected telephonically with the rescue room serving the mine. Wherever practicable, wireless or other approved communication shall also be provided.

Functions of rescue room:-1. A rescue room shall provide for the storage, assembly, testing and adjustments of breathing apparatus and other rescue equipment and apparatus and for their speedy transport to mines.2. A rescue room may function as rescue station (if permitted by CIM) for group of mines having the total number of persons ordinary employed belowground in excess of 5000, except imparting initial training in rescue work, if such rescue room is:

a. equipped with requisite additional rescue apparatus including at least 5 extra sets of two hour self-contained breathing apparatus and

b. placed under the charge of an instructor and minimum five no. of rescue trained persons including one rescue room in-charge are posted.

Ans. (c) Appointment of rescue trained persons in mines their disposition and accommodation.

Please refer to Q.No. 3(b)(2nd Class 2007)Ans:- ( d) Duties of training officer- i) Training Officer shall :-a) organize and supervise the training of every person undergoing training

under MVTR 1966.b) maintain records of the training given to every person and to furnish weekly

reports to the Manager on the progress of persons undergoing training. c) maintain records of the supervision in respect of practical training on actual

operation specified in schedule l, ll & lll of MVTR,1966.d) discharge such other duties as may be necessary for the proper compliance

of these rules.ii) Every training officer shall keep a record of his work and shall, at the end of

every year, forward to the CIM through owner, agent or manager of the mine a summary of the report of his work during the year.

iii) He has to send regularly the following reports to DGMS and other authorities as directed from time to time: quarterly programme of trainings quarterly progress report of trainees. monthly performance report of trainees.

iv) He shall plan and prepare schemes for training of workers etc and executed the same.

v) He shall also ascertain the need of training for each category / class or trades, prepare with his assistants lesson plans, supervise the training and finally shall test the trainees and award them certificate if they are found upto the required standard. He should also follow up the trainees.

Training Officer should not be a reject from production or physically / mentally

handicapped. He must have received training for working as training officer. Qualities of Training Officers:-

Good academic record Technical knowledge and varied experience Aptitude & ability to teach, demonstrate & give good guidance Rationality, adaptability, organizing capacity, safety and discipline

mindedness, creativity and motivation to training.

Q. 8.What are the reasons for low productivity in underground coal mines of our country. Suggest different measures required to improve the productivity. Ans:- Productivity is conventionally defined as the ratio of output and input . The term input is not merely confined to manpower alone rather encompasses a wide domain of resources such as capital, labour, machinery

and materials including raw materials. It is in-fact an index representing the effective utilization of all the resources used in the process of mineral production. As per ILO “Productivity is the ratio of output of wealth produced and input of resources in the process of production.i) Productivity measurement in u/g : Different industry uses different indices for measurement of Productivity. In

Coal industry, the index for computing productivity is OMS (output per man- shift)

OMS = Coal Production Man shift

For calculation of OMS, the manpower deployed in welfare activities, civil constriction, water supply, health care, recreational facilities, plantation and security are not considered. OMS of different mines are not comparable under dissimilar geo-mining environment and unequal level of mechanization.

ii) Productivity measurement in O/C:- In O/C mine, both coal & OB are taken into account white calculating OMS. As

the recommendation of Banerjee Committee, overall OMS in O/C is measures by the following formula-

OMS = P + d . x M(1 + d.S)

Where P = Coal Production (te) d = density of coal (te/m3)

x = OBR (m 3 )M= Man-shift (nos.)S= Striping ratio (m3/te)

However, as per modern concept, productivity of any Organisation is define by the following formula:-

Output ( Production) Productivity = Input (5M)

5M: Men, Money, Material, Manpower & Management.

Reasons for low productivity- The reasons for low/ poor productivity in Indian u/g mines are listed below:-i) Difficult geo-mining condition- presence of geological disturbances, presence of fire and water, steeply inclined seams, old mines (rate hole and unscientific mining in past)ii) Defective/ wrong planning – system deficiencies and mis- match of planning & mechanization. iii) Poor technology selection – lack of mechanization, modernization and standardization.iv)Irrational manpower- excessive manpower, improper manpower planning, defective as well as misuse of men/machine, wrong selection of men/machine for particular job.v) Lack of planned & preventive maintenance schedule – routine maintenance, corrective maintenance and preventive maintenance schedules are not planned & implemented.

vi) Poor availability and utilization of machines – downtime losses with respect of use of machine arising out of various reasons.vii) Improper training & retraining:- resulting into loss of efficiency of men & machine.viii) Bad work culture – lack of discipline, lack of attitude and motivation.ix) Non- availability of working faces – insufficient blasted materials.x) Improper utilization of resources.xi) Defective communication system.xii) Socio- economic condition of workmen – Job dissatisfaction/ non-reasonable workload.xiii) Dis-regard of safety laws- resulting into accident/ incident causing loss of production, improper detective and incompetent supervision.xiv) Disparity in wage earnings among of piece rate, time rate and monthly rated workmen.Steps for improvements of productivities:-For improving productivity in ug mine, the following points should receive attentions:-1) Planning of the mine should be done by fixing the targets for productivity in different stages of development and depillaring throughout the life of the mine.During planning itself, the inputs with regards to the selection of technology and machines should be oriented to the needs of productivity.2) During planning human elements will be eliminated in circumstances where the jobs can be performed by machines and as far as practicable emphasis should be put on automation of different process and operations.3) To achieve the needs for improved productivity, it is necessary to concentrate on 3E’s

Education Engineering Enforcement

a) Education- Training programmes for Officers, Supervisors and persons engaged in production activity should include the following:-i) Intimate knowledge about the methods of work for assessing the defects and inefficiencies affecting productivity and taking corrective measures for overcoming the same.ii) Knowledge for selection and maintenance of machine as well as selection of personnel for different jobs.iii) Science and art of communication of directives for production to the front line supervisions and other persons involved in the process of productivity.iv) Training for motivation of workers for developing a sense of belongingness to the organisation.v) Training for identifying unsafe conditions and also to avoid unsafe practices in performance of their duties.b) Engineering – Engineering plays a vital role in production management. The areas covered under the heading may include the following-i) Adoption of a sound mining technology which must foresee the impact of the methods on aspects such as ventilation, fire hazards, risks of explosion & inundation, strata behavior and strata control techniques, environmental pollution, system of transport, lighting etc.ii) While importing technology from foreign countries, correct choice of the technology keeping in view the geological conditions, physico-mechanical properties of the strata and the local laws should be made. The technology

should be preferably be imported as a complete package and not in a piece meal manner.iii) For purpose of improving productivity, standardization of different machines should receive attention.iv) Development of diagnostic and preventive techniques by proper maintenance of machine shall be encouraged.c) Enforcement – Enforcement of the formulated measures to secure productivity is probably the largest area where the officials of the top management have got to get full involvement for effective management. These includes:i) Providing effective organisation for production management ii) Clean allocation of responsibility within the management structure.iii) Keeping the work force continued and improving their general and social condition and job- satisfaction – one important tool for management of productivity.In addition to above, the following suggestions would go a long way to help improve productivity in u/g coal mines.i) Creation of productivity board/ council for coal industry as a whole and productivity cell at area / subsidiary level.ii) Standardization of manpower requirement and material consumption through work and time study.iii) Cost reduction through inventory control and materials management. iv) Modernization of plant and machinery along with improvement in system and procedure. v) Creating basic welfare amenities like housing, school, hospital, community centre be etc should be considered as essential ingredients for an improved performance.vi) Innovative maintenance management vis-à-vis equipment utilization.

Afternoon Session THE MINES ACT, 1952

Examination for Mine Manager’s Certificate of Competency under the Coal Mines Regulation , 1957

FIRST CLASS


Sunday, the 17th December, 2006 Full Marks: 100Time : 3 Hours


Q.1.There has been considerable increase in mechanization of underground and opencast mines. Discuss the adequacy of the provisions of Coal Mines Regulations, 1957 in respect of qualifications and appointment of Safety Officers. First Class and Second Class Managers and Engineers in mines. Assume your own condition.

Ans:- Introduction of large scale mechanization in u/g and o/c mines has become necessity in recent years because of the following reasons:-i. In u/g mines multifarious activities at faces after introduction of face mechanization are minimized as most of the operations are carried out with the machines in a sequential manner in order to ensure safety in mines besides meeting the growing demand of coal.ii. Availability of huge coal reserve at greater depth, u/g mechanization is a must for ensuring ever increasing production needs with high safety standards.iii. The current upsurge in mineral demand has also resulted in massive mechanization of various mining operation in O/C mines with State of the art technologies by way of introducing high capacity shovels, dumpers, draglines etc.CMR 1957 was framed log back and last amended in 1990. The statutory provisions in respect of qualification and appointment of safety officers, 1st class & 2nd class Managers and Engineers contained in Coal Mines Regulation 1957 are not adequate and needs some amendment. We are appending below in the table the existing statutory provision vis-à-vis necessary proposed changes in the present day context of increasing mechanization in U/G and O/C mines:-A. Qualification & appointment of safety officers:- Existing Statutory Provisions Adequacy / Proposed changed in

Existing Provisioni) In all coal mines, having an average monthly output 5000te, safety officers are appointed for promoting safe practices in the mine, on the basis of output, holding the following qualifications:Av. Out put( te/month) Mini. Qualificationa. More than 15,000 1st class Mgr’s Certft.b. 10,000 - 15,000 1st & 2nd -do-c. 5,000 - 10,000 1st or 2nd Class or deg. or dip.in min.engg.

The existing provisions in respect of appointment of safety officers is not adequate. The following additional provisions should be incorporated in the statute:-i) in case of fiery seam or gassy seam of 3rd degree, an ACM possessing 1s class Manager’s certificate of competency should be appointed as safety officer

ii) Where special condition – exists, CIM maypermit or require appointment of safety officer in variation of above provision.iii) When the CIM is of the opinion that due to the large size of a mine or other condition existing at the mine, it is not possible for the safety officer to attend his duty himself, he may require the appointment of such number of persons to assist the safety officer by an order stating the reasons and qualifications.

irrespective of monthly output.ii) In every mine, the manager shall be assisted in the work of promoting safety practices in the mine by a safety officer who will be senior most ACM next to the Manager, possessing a 1st class Mine Manger’s certificate. However, in case of a mine having an average output in excess of 5,000 te but not exceeding 10,000 te, the safety officer shall posses a first class or 2nd

class manager’s certificate. iii) In highly mechanized U/G mines , safety officer shall be assisted by Environment officer possessing 1st

or 2nd class Manager’s certificate for control of dust, noise and environment.

B. 1st Class & 2nd Class Managers.i) Every mine has to be opened, worked or reopened only under the control, supervision management & direction of a manager having been duly appointed by the owner or the agent having requisite qualification.ii) In all coal mines, managers are appointed on the basis of average output, holding the following qualifications:- Av. Out put( te/month) Mini. Qualificationa. More than 2500 1st class Mgr’s Certfb. 600-2500 1st & 2nd -do-c. less than 600 1st or 2nd Class or

or Manager’s permit iii) When special condition exists, CIM may direct that the manager of a mine in clause (b) above to be a 1st Class manager’s certificate holder and the manager of a mine in clause (c) above to be a 2nd class manager’s certificate holder.iv) The scale of appointment of manager as mentioned at point no.(i) shall remain unchanged for the succeeding 12 months even when there is any reduction in the average output.v) No person shall act or be appointed as the manager of more than one mine, except with prior written permission of CIM. Such a permission shall be valid for a period not exceeding 12 months unless renewed.vi) A person holding an overman’s certificate may be permitted to work as a manager of any mine having production less than 600te

The provisions contained in the statute in respect of appointment of 1st class and 2nd class managers are inadequate and hence following additional provisions should be made:-i) In every mine where only pumping or other preparatory / protective work is going on belowground and all other operations have been suspended, the mine shall be in charge of a 1st class manager, particularly in case of fiery mine or degree lll gassy mine.ii) A person holding 2nd class manager’s certificate may not be allowed to work as manager of more than one mine if the output of any mine exceeds 1500 te/ month.iii) A person holding 1st class manager’s certificate may be allowed to work as manager of more than one mine if-a) the combined output of the mines does not exceed 7000 te/month.b) the output of the any one mines does not exceed 4000 te/ month and c) he is assisted by an assistant manager at the mine other than this one where he resides, it the output of that mine exceeds 2500 te/ month.

by CIM for a maximum period of 12 months unless renewed at an interval of 12 months. vii) In every mine the average output of which exceeds 7000te, the under-manager or assistant manager shall be appointed on the basis of average output to assist the manager on the following scale-Av. Output (te/month) No of ACM’sa. 7,000 – 10,000 Oneb. More than 10,000 One additional ACM for every 5,000 te output Or part thereof in excess of 10,000 te.Where the average output exceeds 20,000te atleast one of the ACM’s appointed as above, shall hold a 1st class manager’s certificate.CIM may permit or require the appointment of ACM’s in variation with the above provisions.

iv) In case of highly mechanized o/c mines, atleast one 2nd class ACM in each production shift shall be appointed besides the appointment of 1st class ACM in general shift for blasting operation and its instrumentation. v) In case of highly mechanized u/g mines, such as power support L/W working, use of continuous miner etc, in each shift one 2nd class ACM shall be appointed. In addition, one 1st

class ACM shall be appointed for strata control and ground movement monitoring in general shift as overall in-charge.

C. Qualification & appointment of Engineersi. At every mine, where machinery is used, an engineer, not less than 23 yrs of age, shall be appointed to hold the general charge of such machinery and be responsible for its installation, maintenance and safe working. A notice of every such appointment, giving the name and full particulars of the qualification and experience of the persons shall be sent to the RIM within 7 days of the appointment.ii. In every mine, engineer shall be appointed on the basis of hp used in the mine holding the following qualifications:-Type of Mine Minimum Qualificationsa.O/C mine worked A deg. or equi.by HEMM having qualification in mining aggregate hp of Engineering from recog all the machinery nised institution follow exceeding 750 or ed by an orientation in other case exce course in mining machieding 500. nery and not less than 1 yrs experience in the installation and mainte nance of machinery used in mine. Or A degree or equ. Qualif ication in electrical and/ mechanical engineering

In present context of mining operation both in u/g and o/c mines, the aggregate hp of all machinery is very large due to introduction of high mechanization. Under the circums tances, the following statutory provision should be incorporated in the statute:-i) Scale of appointment of engineers in highly mechanized o/c mine shall be as per the following table:a. 10m3 /5m3/3.5m3 For every two shovels shovels- one engineer.b. Drills For every four drills- one engineer.c. 85T/35T dumpers For every 20 dumps – One engineer.d. Where input cru A minimum of shing and conve 5 engineers yor technology is shall be provi implemented in ded. any project.ii) Scale of appointment of engineer in highly mechanized u/g mines shall be as follows:-

from recognised institu tion and not less than 2 Yrs experience. In case of diploma holder, 7 yrs experience is required.

b) Any other mine A degree on equivalentin which the qualification in miningaggregate hp of engineering from recothe all the machin gnised institution follo-ery used exceeds wed by an orientation 150 course in mining mach inery. A degree or equ. Qualif ication in electrical and/ or mech. engineering from recognised institu tion and not less than 6 months experience in similar job.

In case of diploma holder,2 yrs experience is required.

iii. No person shall undertake the duties of an engineer of more than one mine without prior written permission of RIM.

a. L/W face - One engineer per face per shift.b. LHD, CM or - Two engineers/ Other mecha shift. nised operation.iii) In open cast mines, a person holding degree in automobile engineering may be appointed as an engineer.iv) Persons appointed as an engineer should not be permitted to perform additional duties of electrical supervisors except in case of small mines for which prior permission of RIM is necessary.v) Where mine tips, dams or other structures, requiring the services of a civil engineer, are erected at a mine, they should be designed, erected, and maintained under the supervision of a qualified Civil engineer, who shall be responsible to the manager for their safe operation.vi) At large mechanized mines, Chief Engineer should be appointed to co-ordinate the activities of the electrical and mechanical engineering department. Also a deputy engineer(maintenance) may be appointment to (a) administer and examine the effectiveness of the managers PPM scheme.b) examine the new methods of routine condition monitoring and assess their suitability for implementation in the managers PPM scheme.c) Correlate and analyse the information available and monitor the failure of equipment, design failure and subsequent remedial actions to reduce the machine down – time.

Q.2.(i) What is meant by remote operation of coal face apparatus with pilot core protection? Discuss the associated voltage and current limits.

(ii) Describe a trans-witch unit used belowground. What area (a) its special features and (b) the protective devices incorporated in it?

Ans:- i) Remote control circuit with pilot core protection- In u/g mines at almost every face there are electric motors, coal cutting

machines, ventilating local fans, compressors, pump sets etc. All these coal face apparatus are switched on and off by means of a remote control circuit known as pilot circuit. In system of remote control, all switching operations of the power circuit for starting and stopping the motor are performed not at the motor but at the circuit breaker which is placed at the safe distance from the face. The operating switch on the motor operators only low voltage pilot circuit.

The pilot circuit is completed through the trailing cable which supplies power to the face apparatus. The trailing cables have five cores/conductors, three power conductors, a pilot circuit conductor and an earth conductor which serves both to maintain continuity and also to complete the pilot circuit. A transformer in the gate end box gives supply to the pilot circuit. The typical values for pilot circuit voltages are 7.5 volts and 12volts.

When the operator operates the pilot switch located in the machine, the pilot circuit is completed and it energizes the operating coil in the gate end box placed away from the face at a comparatively safer place well ventilated which closes the main contactor of the gate end box. Thus the machine operates on remote control. The pilot circuit is intrinsically safe.

The pilot circuit in the GEB has the following additional features which ensures protection to pilot core and hence known as pilot core protection.

An earth leakage trip switch – Preventing power supply to the apparatus in case of earth leakage.

An overload trip switch – Cutting off power in case of overload beyond the designed limit

A no volt coil – not allowing automatic power supply to the machine when the power is resumed after interruption.

As per rule 124 of IER 1956, all portable and transportable apparatus used in underground mines shall operate on remote control from the concerned switch gear with pilot core protection.Advantages for use of remote circuit the pilot core protective :- Training cable becomes dead when the machine is not running. Machine can not self start when the power supply is restored after its

failure. Machine will not start if earth continuity is interrupted. Pilot circuit itself fails if it becomes faulty. In case of emergency the pilot switch is near at hand to switch off the

circuit The circuit is made lead before the live parts are exposed, if the plug

attached to the electrical cable is withdrawn from the socket, the circuit breaker will automatically trip.

High voltage arcing during switching on or off the machine at the main contracts is shifted from the coal face site to the GEB site.

Machine controller’s function is transferred to the gate end circuit breaker. Economy in the machine size. Pilot core protection is an additional safe guards in a remote control

circuit. A pilot circuit is designed as an intrinsically safe circuit.

Associated voltage and curved limits :- Voltage limits-i) Pilot Circuits shall operate in the start position at voltage down to 75% of the declared voltage.ii) In the run position it shall continue to operate down to 60% of declared voltage.iii) With the remote switch in the run position and with a restoration of supply after failure, the pilot circuit shall not operate at less than 120% of the declared voltage.Current limitsThe pilot circuit current in the start condition is 125 mA d.c. This is the minimum current required to energise relay.Ans:-ii) Trans-switch unit used belowground: - With the introduction of coal face mechanization, the number and size of coal face machines increased tremendously and it became necessary to have large transformers installed close to the coal face in order to keep the voltage drop between the transformer and motor to a minimum. Trans switch unit is used for this purpose. Virtually all coal face equipment get supply from the FLP transformers used for supplying intrinsically safe circuits. They are specially constructed with an earthed screen between the primary and secondary windings to ensure that the primary voltage can not be connected to the secondary circuit even if there is a complete failure of insulation.Trans-switch unit is basically a dry type transformer provided with incoming and outgoing circuit breakers. It is mobile / portable transformer sub-station mounted on wheels which moves as the face progress.It consists of a step down transformer with high and medium tension circuit breakers attached- all mounted on flanged wheel. An isolator is provided to permit work on the TSU.a) Special features of TSU- Following are the special features of TSU used belowground:-

Dry type / air cooled Certified flame proof Built to operate at high temperature using class “C” insulation. Capable of withstanding short time overload. Fitted with integrated switchgear in the H.V. incoming side and L.V

protection chamber with circuit breakers. Robust construction.

b) Protective devices incorporated in TSU- For ensuring safety, the following protective devices are incorporated in TSU:-

i. Earth leakage and short circuit protection- The LV ends of transformer houses the earth leakage and short circuit protection devices. On detection of a fault on the LV circuit, the protective devices automatically trip the HV Switches.ii. Overload and earth fault protection- The HV switch also provides overload and earth fault protection for the transformer.

Q.3. (a) What are bye-laws? How are they framed? (b) Frame a set of bye-laws for use of continuous miner in a degree-l seam. Ans:-a) Bye-laws:-

Bye laws are laws framed by the owner, agent or manager of the mine for a particular set of conditions, governing the use of any particular machinery or the adoption of a particular method of working in the mine, when so required by the Chief Inspector or Inspector, for the prevention of accidents and for the safety, convenience, and discipline of the persons employed in the mine.These are complimentary laws which are applicable in a particular situation for a particular mine to handle the situation by the authority of the mine.Procedure for framing bye laws:- 1. The owner, agent or manager of a mine, either on his own initiative or when asked by the Chief Inspector or an inspector, shall frame draft bye- laws and submit them to the Chief Inspector.2. If the drafts bye-laws are not submitted within 2 months of being asked or having been submitted are considered insufficient, the Chief Inspector or the inspector may himself propose draft bye-laws or propose such amendments in the bye-laws submitted as will render them sufficient and send them to the owner, agent or manager for consideration.3. If the owner, agent or manager and the Chief Inspector or inspector is unable to agree as to the terms of the draft bye-laws within two months, the Chief Inspector or the Inspector shall refer them to the Committee for settlement.4. When the owner, agent or manager and the Chief Inspector or inspector have agreed to the draft bye-laws or the differences have been settled by the Committee, the Chief Inspector or the Inspector shall send a copy of the draft bye-laws to the Central Government for approval. The Government may make such modification in the draft bye-laws as it thinks fit.5. Before approving the draft bye-laws, the Government shall publish them suitably for informing the persons affected and shall set a time of at least 30 days within which objections may be sent to the Government. The Government shall consider the objections and approve the bye-laws with or without any amendments.6. The bye-laws when so approved shall have effect as if enacted in this Act.7. The bye- laws so made shall be laid before each House of Parliament while it is in session for a total period of 30 days (comprising one or more successive sessions). The parliament can modify or annual the said by laws in the session(s) in which the 30 days period is completed or in the next following session. Thereafter the by laws have effect only in such modified form or be of no effect, as the case may be. Ans:b) Bye-laws for use of continuous miner in a degree-l seam.- A. Machine Operations:- 1. Continuous Miner shall be operated only by competent person, who has been properly trained and duly authorised by the manager in writing.2. A competent person shall examine the Continuous Miner at the beginning of every shift as per check list provided by the manufacturer for that purpose.3. Before starting the machine it shall be ensured that no person or any other obstacles are within the working place of the machine and a pre-start warning signal shall also be given to warn all the people in the area including operator/ helper.

4. Wherever any inspection is to be made or maintenance are to be done in job/boom in raised position, a proper support shall be provided under the job/boom.5. If power shut off, the supply of every motor shall be shut off immediately.6. No work shall be done by standing on job/boom.7. Machine shall be fixed by jacks while cutting operation is going on.8. Head lights of machine shall be kept on during operation of machine.9. A log book shall be maintained by the operator and charge shall be given /taken in writing by the operators.10. Operator shall keep watch on roof condition also. If any changes noticed, he shall stop he machine and inform immediately to Mining Sirdar.B. Precautions against dust:-1. Complete set of picks with proper size shall be fitted in cutter head.2. The speed of cutter head shall be maintained such as to prevent formation of dust.3. Water spray system shall be maintained in good working order to prevent formation and propagation of dust.4. The spray nozzles shall be kept regularly cleaned.5. Pyrite band of igneous rock shall be avoided to cut by machine.6. Cutting of coal shall not be commenced until water spray starts with proper pressure and quantity.C. Ventilation:-1. At least 284 m3 of air shall be conducted upto 4.5m at every face where Continuous Miner is being operated.2. Minimum 0.5m/sec air velocity shall be maintained over the Continuous Miner.3. Test of inflammable gas shall be made at the face before and during the operation of Continuous Miner with an approved type of methanometer.4. Inflammable gas content in the general body of air shall not be 0.5% or more where Continuous Miner is being operated.D. Precautions against fire:-1. Fire resistant hydraulic oil shall be used as recommended by manufacturer.2. Sufficient fire fighting arrangement and sufficient number of fire extinguishers shall be kept near the face.E. Service and maintenance:1. Continuous Miner shall be maintained in accordance with the schedule

prescribed by the manufacturer.2. Before the Continuous Miner is put to work after maintenance, it shall be

thoroughly inspected by the Engineer. A report of every such inspection shall be recorded in a register kept for the purpose.

F. Electrical:-1. Cable shall be connected with motor with suitable connector with interlock

system.2. Trailing cable shall be handled properly to avoid damage.3. Continuous Miner operator shall check the trailing cable in beginning of every

shift, if it is found damaged, it shall be replaced by good one.G. Supervision:-

1. Every shift shall be run directly under the supervision by an Assistant Manager.

2. Mechanical foreman shall be posted in each shift for looking after the Continuous miner.

Q.4.An exploration has occurred in a Degree- lll mine in a depillaring district with stowing. How will you determine the cause of the explosion and its point of origin. How would you ascertain whether the explosion has occurred due to inflammable gas or coal dust or both. Assume your own conditions.

Ans:-Condition assumed- Seam being worked – X bottom seamDepth of working - 100mPanel being worked – 18 ( depillaring with sand stowing )Status of stowing – Void more than permissible limit.Status of gas detector- LMD installed but not functioning.Status of ventilation – Generally poor

The basic purpose of an investigation after an explosion is to be ascertain the real causes of such explosion to prevent its recurrence, revealing unexpected hazards and combating the same. All the explosion evidences shall be carefully collected. Some of the evidences may be conflicting in nature due to the effect of backlash.While determining the cause of explosion and its point of origin, the following factors shall be taken into account:

evidence of survivors. history of affected district. kind of work being done at the time of explosion. evidence gathered in inspection after explosion.

I shall follow the following procedure for explosion investigation :1) It will be ensured that during rescues operations, evidence not to be disturbed except for actual rescue work. 2) Observations made during rescues operations shall also be kept noted. Methods of investigation:-There are two complimentary methods of approach for making investigation after an explosion:a) Intuitive approach – This is based on experience and knowledge of the mine

and the mining operation in progress. This is theoretical approach. For this purpose, I shall talk to Manager of the mine and gather information from them.

b) Analytical approach – This is required to be done for a perfect investigation, practical and scientific, which relies mainly on the observation made for violence, evidence of burning, fires, coked dust etc. This is based on dispassionate survey of all the evidence recoverable.

A. Seat of Origin of Explosion:- I shall try to locate the area from which explosion violence appears to have radiated. For this purpose, evidence of violence, evidence of burning, evidence of coked coal dust, evidence of presence of fire damp, position of equipment and victims, collection & analysis of air samples & examination of roadway dust shall be studied and evidences collected.

The following investigation shall be made in underground affected district:

i) Evidence of violence – Violence caused by the explosion and the direction of travel of the force of the explosion are observed from the movement of the heavy objects and bending of fixed weak objects.Violence may appear to radiate from a zone. All evidences of motion and bending are separately recorded on a plan for analysis in light of other information Generally, violence is less near the site of origin of explosion and damage is greatest far away. ii) Evidence of burning – Evidence of burning is studied and the max. burning effects will be observed at places where the flames of an explosion have lingered. As flame passes very rapidly, evidence of burning is not available on heavy materials. The most sensitive materials are fibrous edges of papers, hairs on human skin etc. Charring of timbers are found only where the flame had lingered. This is done with good magnifying glass and under microscope to find scorching. Doubtful specimen is examined in the laboratory.iii) Evidence of coked coal dust- Samples of coal dust collected within and beyond the suspected limits of explosion and examined under microscope to find signs of exposure to heat confirm direction and passage of flame travel. Some dust is coked in situ, others carried forward by the blast is impacted on surfaces facing the origin and coked there, whilst yet other dust, originally raised as a cloud, is coked and thrown back by the flame so that it is deposited on surface facing away from the origin.iv) Evidence of presence of fire damp- Continued issue of CH4 after an explosion may be due to disturbance of strata by the explosion. They however, indicate that gas was near at hand and may have been present.v) Position of equipment and victims - Position of the victims and equipment in relation to their normal or probable working place might suggest operation being carried out, such as coal cutting, shot-firing, repair of drill, switch or other machinery. Posture, nature of injuries and cause of death, whether by burning, violence or CO poisoning, may give evidence of the course and nature of explosion. Burning is usually heavy near the origin, violent injuries farther away, poisoning by CO off the direct path of explosion.vi) Collection & analysis of air samples – Analysis of samples of atmosphere taken immediately after explosion is helpful to establish extent and nature of explosion. Occurrence of firedamp in after damp is not a proof of its presence prior to explosion, but it is a proof that gas was near at hand. Presence of dead ends, unventilated headings, goaf edges, disused workings, and examination of adjacent areas and holes drilled in adjacent strata may reveal source of firedamp or feeders of gas. This is examined in the light of immediate past history. vii) Examination of roadway dust- Evidence as to the composition of roadway dust, the result is compared with those which were analyzed before the explosion.All the evidences / data obtained during the investigation are plotted on a large scale plan. On this plan reduction of evidence is examined.Such examination gives a general idea about the origin of the explosion but the exact seat/origin of the explosion will not be known until the cause of ignition is found.Source / Cause of ignition-In the area narrowed down for the origin of the explosion by study of the plan, searches are made for all possible causes of ignition. While making such searches, considerations are made regarding the causes which might be associated with the particular work which was being done in that area at the time of explosion.

All lamps and electrical equipment are withdrawn for examination/extensive tests and if it is too heavy, examined on the spot by a scientific agency. All the causes namely naked light, shot firing, electrical spark including static spark, frictional spark, defective safety lamp, spontaneous heating, blown-out shot, tampered FLP apparatus, tampered protective device in electrical switch gear, defective machinery like drill, opened drill & meggar etc. are considered before making any final conclusion.After collection of results of examination, a formal unbiased enquiry are made in light of full evidence.It is usually a firedamp explosion or an explosion in which firedamp and coal dust have taken part. For coal dust explosion, by far the commonest source is a firedamp explosion and the result is a mixed explosion. Explosion involving only coal dust is rate- it requires simultaneous formation of coal dust cloud and striking of ignition source such as blown-out shot, breakdown of electrical apparatus or cable burst by run-away tubs.

Difference between coal dust and firedamp explosioni) Examination of Trickett’s Ratio -

From analysis of samples of after damp, Trickett’s Ratio are calculated by the following relation:

TR= CO2 % +.75 CO % - .25 H2 % O2 % used

T.R. < 0.5 indicates firedamp explosion > 0.85 indicates coal dust explosion 0.5 to 0.85 indicates mixed explosion.

2) Extent of affected area:A gas explosion is localized. It takes place in a district or a gallery, where blowers or out bursts or other type of gas emission occur. But a coal dust explosion travels through whole mine, especially through dusty intake roadway embracing fresh O2.

3) Presence of CO: In methane explosion, CO2 is found entirely but in coal dust explosion a large amount of CO is almost always present.

4) A purely gas explosion leaves no traces distinctive of CH4 but a coal dust explosion leaves coked coal dust.

5) In a gas explosion, worker dies due to burning or due to suffocation on account of O2 deficiency. But in case of coal dust explosion, workers die due to CO poisoning and violence. They are bodily thrown out from one place to another.

Q.5. Write short notes on : (i) Initial and periodical medical examination

(ii) Workmen’s Inspectors and their duties.(iii) Medical attention in case of injury.(iv) Disability allowance and compensation for occupational disease.

Ans:- i) Initial and periodical medical examination-

1) Type of examination and frequency. Mine management shall arrange for -a) IME of every new person seeking employment in the mine unless he has undergone a similar examination in another mine in previous 5 Yrs.b) IME of all persons employed in the mine. One-fifth of the persons are to undergo such examination every year so that all such employees are covered within 5 Yrs..c) PME of all persons employed in the mine at intervals of not more than 5 Yrs. For persons engaged in mining and milling of asbestos Ore, the PME shall be done at least once in every 12 months.2)Procedure of Examination- a) Notice : The Manager of the mine shall give at least 20 days notice to the employee (in Form M). For new recruits the period may be shortened. A copy of the notice shall be sent to the examining authority (MO of the mine/ MO employed by the owner/state of central govt. medical officer not below the rank of Asst. Civil Surgeon). In case of PME, the previous medical certificate shall be sent to such authority. If the person fails to report for a reasonable cause, the manager shall give him another chance by serving a notice (in Form N) 10 days in advance.b) If the person fails to turn up for examination even after second notice, he shall be issued a show cause notice by the manager. If the explanation is satisfactory, he will be given a third chance, if explanation is unsatisfactory, his service shall be terminated.c) Identity: The candidate shall submit 3 copies of passport size photograph for identity at the time of examination.d) Women Candidate: They shall not be examined by a make medical practitioner without her consent, except in the presence of another woman.e) Standard: The medical examination shall be as per the standard laid down in form P and P1 of the Mines Rules.f) Certificate: The examining authority shall send or deliver two copies of certificate to the manager/the employee, and retain third copy with him.g) Retention of certificate: The medical certificate including all medical exam records with medical history and job details to depict the occupational dust exposure profile shall be retained by the manager upto 10 years after employment ceases. If the employee joins another mine, its manager can request and get the certificate from the manager of previous mine.h) Persons found unfit shall not be employed after 30 days after the medical examination unless he has filed an appeal to manager. A person found unfit can appeal to appellate medical board for re-examination( to be arranged by manager with 30 days). i) Re-examination: 2 notices of 15 days time but no 3rd notice shall be given. Fee shall be paid by appellant if found unfit. After re-examination, if found unfit- no employment after 30days.j) Cost of medical examination, shall be borne by the owner of the mine.

As per recommendation of 10th conference on safety in mines, the following additional provisions should be made for IME &PME:

IME should be made mandatory for all mining employees whether permanent, temporary or contractual, before they are engaged in any mining job.

The frequency of PME should be brought down from existing 5 yrs to 2 yrs for the mining employees above 45 yrs of age.

Each mechanized mine should engage at least one qualified medical officer for every 500 employees and thereafter, one for every 1000 employees.

One of the medical examinations of every person should be arranged within one year of his superannuation.

Standards IME & PME shall be suitably modified in order to ensure early diagnosis of diseases caused due to employment in mines.

Special tests should be included in the PME for employees exposed to specific health hazard.

Mining companies having mechanized mines are required to computerize records of the PME.

Ans: ii) Workmen’s Inspectors and their duties-A workmen’s inspector is a qualified representative of workmen of the mine so designated by the owner, agent or manager in consultation with the registered trade union of the mine to carry out inspection of the mine on behalf of the workmen.There shall be provision of 3 workmen inspectors ( one each of mining operation, electrical installations and mechanical installations) in every mine where 500 or more person are ordinarily employed. When the number of person employed in the mine exceeds 1500, one additional workmen’s Inspector (mining) shall be provided for every additional 1000 persons or part thereof. There has to be a panel of substitutes 3 persons also. As per recommendation of 9th safety conference, all mechanized mines and mines using HEMM for exploitation of mineral’s where 100 or more workers are employed, should appoint workmen’s inspectors.Qualifications:- (1) Holder of Overman’s certificate in case of mining, an Electrical Supervisor’s certificate holder for electrical aspect and a person of equal rank for mechanical installations/equipment. He should have minimum of 5 year’s experience in mines including atleast 2years experience in that particular mine, and he should have undergone an orientation course as per the syllabus approved by the DGMS ( 30 lectures of 2 hrs. duration)Role. (a) To supplement efforts of DGMS (b) To correct attitude of all.Duties of Workmen’s Inspector:-(1) To inspect all shafts, inclines, roads, work-places and equipment, including equipment for conveyance and transport of men. (2) To inform the manager and the Inspector and to suggest remedial measures in case he notices any urgent and immediate danger.(3) To accompany the inspector in his complete Inspection of mine, and also during such other inspections as may be considered necessary by the inspector.(4) To investigate into accident and dangerous occurrences in or about the mine/ to be informed forthwith by management in case of such incidence.(5) To act as a member of the Pit Safety Committee.

(6) To record results of his inspections and furnish the same to the manager. Manager, agent or owner has to put remarks within 15 days on his inspection report.Ans. iii) Medical attention in case of injury: Mining, being the hazardous industry poses threat to the safety of workmen. Rendering first aid in time to the persons receiving injury in mining operation is vital in saving life. First aid is the first assistance or treatment given to a casualty for any injury or sudden illness before the arrival of an ambulance or qualified medical expert. It may involve improvising with facilities and materials available at the time. First aid treatment is given to a casualty:

To preserve life To prevent the worsening of the condition To promote recovery

Rule 45 A of mines rules,1955 elaborates the following provisions related to medical attention in case of injury: a) Every person receiving an injury in the course of his duty shall, as soon as possible, report the same to an official. If he is not in a position to report the same to an official, it shall be the duty of the person who first comes to know of it to report the same to an official. The official shall make such arrangements for rending first aid to the injured as may be required. If in the opinion of the official the injure is of such a nature as to require immediate attention by the medical practitioner, he shall arrange for the medical practitioner to be called.b) If an official who is required to carry a first aid outfit receives information about injury to a work person, he shall himself attend to the injured person.c) It shall be duty of the person in charge of the nearest first aid station to render necessary first aid to injured person.

Ans:iv) Disability allowance and compensation for occupational disease- If during occupational health survey authorized by the Chief Inspector or an Inspector or an Inspector a workman is found to be medically unfit, he shall be entitled to medical treatment at the cost of the owner, agent and manager with full wages. If after treatment also he is declared medically unfit to discharge the duty which he was discharging in a mine immediately before presenting himself for such examination and such fitness is directly ascribable to his employment in the mine, he shall be given an alternative employment. If no such alternative employment is immediately available, such person shall be paid ‘disability allowance’ at the rate of 50% of the monthly wages that he was in receipt of immediately before presenting himself for the medical examination.Disability Compensation: If a person as above decides to leave his employment in the mine, he shall be entitled to compensation as may be admissible under the provisions of the Workmen’s Compensation Act, 1923, as contracting of such diseases is deemed to be an injury by accident under the Act. In case the disease is not covered under schedule III of that Act, he shall be paid by way of disability compensation at the same rates as provided that Act as if it is an injury.

Q.6. Describe the provisions of the Mines Act 1952 in respect of the following: (i) Duties & responsibilities of owners, agents and managers.

(ii) Powers of inspectors of mines.(iii) Annual leave with wages.

Ans: i) Duties & responsibilities of owners, agents and managers- a) The owner and agent of every mine shall each be responsible for making

financial and other provisions and for taking such other steps necessary for compliance of statutory provisions. They shall also be responsible for proper provision and maintenance of crèche, canteen & pit head bath.

b) The owner, agent and manager shall be responsible to see that all operations carried on in connection with the mine are conducted in accordance with the statutory provisions.

c) In the event of any contravention by any person whosoever of any statutory provision, except those which specifically require any person to do any act / thing or prohibit any person from doing any act/ thing, besides the person who contravenes, the owner agent and manager shall be deemed to be guilty of such contravention unless he proves that he had used due diligence to secure compliance with the provisions and had taken reasonable means to prevent such contravention.The above mentioned persons may not be proceeded against if it appears on enquiry and investigation that he is not prima facie liable.

d) Every owner, agent and manager shall afford the CIM, RIM, IM and every person authorised by inspectorate all

reasonable facilities for making any entry, inspection, survey, measurement, examination/enquiry under the statute.

provide / afford all necessary facilities for OHS. borne cost of medical treatment with full wages during the period of

such treatment of any person found medically unfit and also provide alternative employment if declared medically unfit.

Ans:-ii) Powers of Inspectors of Mines- The powers vested with Inspectors of Mines are given below:-a) The Chief Inspector and Inspector of mines may

make examination and inquiry to ascertain whether the statutory provisions are observed in the mines.

enter, inspect and examine any mine at any time by day or night. examination into and make inquiry with respect to state and condition of

any mine, the ventilation of the mine, sufficiency of bye-laws and matters relating to health, safety and welfare of the persons and may take statements of any person.

exercise powers as may be prescribed by regulations.b) They may search any place and take possession of any material or plan, section, register/record if they believe that offence has been or being committed.c) They may undertake safety and occupational health survey in a mine at any time after giving notice in writing to the manager of the mine.d) Powers of Inspectors under section 22 –

For any matter for which no express provision is made in statute and it appears to the CIM or Inspector that such matter, thing or practice is dangerous to human life or safety or defective so as to threaten the bodily injury of any person in a mine, he may give notice stating the particulars of danger and requiring the same to be remedied in a manner and within the time frame as specified in the notice.

If mine management fails to comply with the terms of notice, the inspector may be order in writing prohibit employment of persons except those whose presence is necessary for securing compliance with the terms of the notice.

If depillaring or stopping operations are likely to cause crushing of pillars or premature collapse of any part of the workings or if adequate provisions have not been made against fire or flooding, the inspector may prohibit the extraction or reduction of pillars or blocks of minerals in any mine.

If the CIM or inspector authorized by CIM is of opinion that there is urgent and immediate danger to the life and safety of person, he may, by order in writing containing a statement of the grounds of his opinion prohibit employment of person in any mine till the removal of dangers.

(e) Power to prohibit employment in certain cases under section 22A. For any matter relating to safety for which express provision is made in

the statute and mine management fails to comply with such provisions, the CIM may give notice requiring the same to be complied with within such time or within such extended time as may be specified.

If mine management fails to comply with the terms of a notice, the CIM may order prohibition of employment of persons in the mine.

Ans- (ii) Annual leave with wages- Section 52 to Section 56 of mines act,1952 stipulates detailed provisions in respect of annual leave with wages popularly known as earned leave which are appended below: 1) Entitlement and quantum of leave- a) Every person employed in a mine who has completed a calendar year’s service shall be allowed, during the subsequent calendar year, leave with wages, calculated at the rate of –

for persons employed belowground, 1 day for every 15 days of work belowground.

for other persons, 1 day for every 20 days of work performed by him.b) A calendar year’s service shall mean in case of a person employed belowground 190 attendances and in case of other persons a minimum of 240 attendances.c) A person, whose service commences otherwise that on 1st January shall be entitled to leave with wages in the subsequent calendar year at the rates specified above if -i) in case of a person employed belowground, he has put in attendance for not less than half of the total number of days during the remainder of the calendar year, andii) in any other case, he has put in attendances for not less than two-thirds of the total of days during the remainder of the calendar year.2) Accumulation of leave- The leave, not taken by any person to which he is entitled in any calendar year, shall be added to the leave to be allowed to him during the next calendar year. However, total leave accumulated any time, shall not exceed 30 days. At the same time, if any person has applied for leave with wages but has not been given such leave by the granting authority due to exigencies of the situation, the un-availed leave shall be carried forward without any limit.3) Application for leave- Written application for leave with wages earned or accumulated should be made to the manager at least 15 days before the date from which leave is required. A person can take earned leave maximum three

times in a calendar year. An application made for leave with wages 15 days in advance shall not be refused unless the granting authority is of the opinion that owing to the exigencies of the situation the leave should be refused.If a person wants to avail himself of the leave with wages, due to him, to cover a period of illness, he shall be granted such leave even if the application for leave is not made 15 days in advance.4) Wages for the leave period- Wages for the earned leave period shall be paid at a rate equal to the daily average of his total full-time earnings for the days on which he was employed during the month immediately preceding his leave, exclusive of any overtime wages and bonus, but inclusive of any dearness allowance and the compensation in cash, including such compensation, if any accruing through the free issue of food grains and other articles, as the employee may be entitled to for the time being. If no such average earnings are available, then the average shall be computed on the basis of the daily average of the total full-time earnings of all persons similarly employed for the same month.5) Payment of leave wages in advance- Any person who has been allowed leave for more than 4 days, shall be paid the wages for the period of the leave allowed before his leave begins.6) Leave wages at termination of service etc- i.) If the employment of a person is terminated before he has taken the entire leave to which he is entitled upto the day of termination of his employments or if such person, having applied for having not been granted such leave quits his employment, before he has taken the leave, the owner, agent or manager shall pay him his due leave wages.ii) The un-availed leave of an employee shall not be taken into account for computing the period of any notice required to be given before the termination of his employment.iii)Where a person employed in a mine (a) is discharged or dismissed from service or (b) quits his employment or (c) is superannuated, or (d) dies while in service, he or his heirs or nominee, as the case may be shall be entitled to wages in lieu of leave due to him, if - in the case of a person employed belowground in a mine, he has put in

attendance for not less than one half of the total number of days from the date of his employment to the date of his discharge or dismissal or quitting of employment or superannuation or death and

in any other case, he has put in attendance for not less than two- third of the total number of days from the date of his employment to the date of his discharge or dismissal or quitting of employment or superannuation or death.

Payment of such wages shall be made by the owner, agent or manager of the mine, at the rate specified above, where the person is discharged/dismissed/quits employment/superannuated, before the expiry of the second working day after such discharge/ dismissal quitting of employment / superannuation, as the case may be and where the person dies while in service, within a period of two months of his death.7. Register of leave with wages and notice of leave due- A record of leave with wages shall be maintained in respect of every employment in Forms G and H of the Mines Rules 1955. On or before 20th February every year, the owner, agent or manager shall exhibit a notice at the office of the mine ( in Form L of Mines Rules) showing leave with wages due to each person employed in the mine calculated upto 31st January.

Q.7. What are statutory provisions in respect of : (i) Precautions after a fire has broken out. (ii) Danger from underground inundation.

(iii) Splits and airways.Ans:- (i) Precautions after a fire has broken out.Reg.119 of CMR,1957 makes detailed provisions regarding precautions to be taken after a fire has broken out, which are appended below:-(1) (a) When there is any indication that fire has broken out, effective steps shall be taken, without delay, to deal with the fire and all persons shall be withdrawn from the mine excepts those who are required to deal with the fire.No person, except those required for dealing with fire, shall be readmitted in the mine until the fire has been extinguished or effectively sealed off and examination has been made by Manager or ACM and the mine has been declared to be safe. Such examination, after the area has been sealed off, should include the collection and analysis of air samples from behind the sealed off area. A report of such examination shall be maintained in the register kelp for the purpose. However, RIM may permit the employment of other persons also.(b) The above examination shall be made with approved flame safety lamp and a cage containing suitable birds or approved apparatus. Only approved safety lamp or torch shall be used.2) During fire dealing or sealing of fire area :a) a competent shall be present on the spot throughout.b) adequate precautions shall be taken to prevent danger to persons from any noxious, asphyxiating or inflammable gases, flame, steam and ejected or rolling down hot material, explosion of water gas and falling into crevices or potholes that may occur in the area on fire.c) there shall be kept available at or near all places belowground-

(i) adequate number of self rescuers and atleast two smoke helmets or other suitable apparatus for use in emergency.(ii) a cage containing suitable birds or other means of detecting carbon monoxide gas approved by the Chief Inspector and (iii) a flame safety lamp or other means of detecting carbon dioxide gas and oxygen deficiency, approved by the Chief Inspector.

3) The manager of every mine shall prepare and establish a detailed scheme for the provision and maintenance of suitable fire fighting arrangements for the prevention, detection, dealing and control of any heating or fire; for the examination and maintenance of the protective measures taken to control or isolate a fire or heating and for ensuring safety of persons engaged in the said operations.

The scheme shall be suitably modified and kept updated as the situation warrants:

The scheme may contain: (a) Organisation plan clearly stating the line of command and the

responsibilities of each person in cases of emergency situations, (b) equipment plan clearly stipulating the equipments make and type,

capacity, location, correct operation and field of operations.(c ) action plan clearly stipulating alarm & communication system, system of notifying the authorities, the duties of each person involved, when and how the equipment shall be used and when how the action shall be carried out.(d) Plan for training of persons & for drills.

Ans:-(ii) Danger from underground inundation- Reg.127 of CMR’1957 makes the following statutory provisions to guard against dangers from underground inundation:-

1) Proper provisions shall be made in every mine to prevent irruption of water other liquid matter/wet material likely to flow from the workings of the same mine or adjoining mine and to prevent accidents while drilling bore holes for probe or release of water / wet material. 2) A scheme of working shall be prepared and implemented when workings are to be made-a) (i) below an upper seam or section (ii) at a place which is at a lower level than a body of water in the lower seam

or section. (iii)advancing towards a fault which passes through an upper seam or section

which contains or may contain an accumulation of water.b) any water bearing strata.3) CIM’s permission shall be obtained when a working is to be advanced within

60m (shortest distance) of any other working (excluding that which has been physically examined and found to be free from accumulation of water etc.). Workings shall be advanced strictly as per the approved plan, in approved method and as per the conditions laid down.

For getting the permission, information regarding outline, depth of workings, proposed method and layout, presence of geological disturbances and other particulars shall be acquired and submitted to the DGMS with plans and sections.

4) If at any place in the mine (even outside the restricted area), seepage of water, not normal to the seam , is noticed or there is suspicion or doubt of such seepage, work shall be stopped forthwith and intimation sent to the CIM/RIM. For resumption or work permission of CIM is necessary.

5) Workings done within 60m of accumulation of water or done after noticing seepage of water, shall have height and width not exceeding 2.4m and there shall be maintained at least one bore hole near the centre of the working face and sufficient flank bore holes on each side where necessary, bore holes above and below the workings at intervals of not more than 5m. All such bore holes shall be drilled sufficiently close to each other to ensure that the advancing face will not accidentally hole through into a working containing water or liquid matter or any material that is likely to flow when wet and shall be maintained and shall be constantly maintained at sufficient distance in advance of the working and such distance shall in no case be less than 3m. These precautions shall be carried out under the direct supervision of an official, having Manager’s or Overman’s Certificate specially authorised for the purpose This actual dimension/details of holes shall be recorded and plans maintained.

Ans:-(iii) Splits and airways- The purpose of adequate ventilation is to clear away smoke and steam, to dilute gasses, to harmless proportion, to provide air containing sufficiency of oxygen and to prevent excessive rise of temperature or humidity likely to be harmful to health of persons. To fulfill this, Reg.135 of CMR’1957 makes the following provisions:i) Every mine shall be divided into such no of districts/splits as to ensure

that separate current of fresh/intake air is made available in every such district/split. This means that every ventilation district must have separate intake & separate return airways.

ii) The intake air shall be so arranged as to travel away from all stagnant water.

iii) For fiery seam or gassy seam of 2nd / 3rd degree, there shall be provided two main intake airways for every ventilating district. One of the two intake airways shall be used as traveling roadway. However, the RIM may grant exemption from the provision if situation permits.

iv) Every connection between a main intake airway and a main return airway shall be provided with at-least two doors so spaced that whenever one door is opened, the other door can be kept closed. Steps shall be taken to ensure that at least one of the doors is always closed. Any such connection which has ceased to be required shall be effectively sealed.

It has been observed that additional airways result in savings & increased intake air. In one case when the number of splits at the shaft bottom was increased to three, the increase in intake air was found 20%.

Q.8. A thick coal seam that was developed in two sections was being extracted by opencast mining. There was active fire on a coal face and a shovel was

under operation at a distance of 50m on a lower coal bench of the same seam. Suddenly, water gas explosion occurred and the shovel was covered by hot ash/dust etc. causing instantaneous death of the shovel operator. Write an enquiry report of the accident suggesting out contraventions, responsibilities and suggestions to prevent similar accidents in future. Assume you own conditions.Ans:- Enquiry Report

Ref.No……………………… Date………...

To,The Manager,“ X “ OCP.

Sub:- Enquiry report in respect of fatal accident involving one shovel operator in X-open cast working due to water

gas explosion.

Dear Sir,

As desired vide your letter no………………… dt…………… I am enclosing herewith the detailed enquiry report in respect of fatal accident in X-O/C working due to water gas explosion indicating the cause and circumstances attending to the accident, contraventions of statutory provisions, responsibilities and suggestions to prevent similar accident in future as an annex.l . I am also enclosing the accident plan showing the site of accident along-with photo graphs.


( A.C.M. ) “X” OCP

Annexure - l


Assumption of Conditions:-________Colliery had two OCPs namely, the pilot OCP(X –OCP) and main OCP.(Y – OCP). The accident occurred in pilot OCP which was located in the trough of two strike faults running east-west. The strata dipped at 4º to 5º in northerly direction. No. 3 seam was 9m thick and occurred at depth of about 12m. No. 2 seam was about 35m thick and occurred 6m below no. 3 seam. The quarry was worked with shovel and dumpers and was 52m depth .The coal benches in the south side of the pilot quarry (which was close to a major fault) almost always had problems of fire since long. At the time of accident the south side face was on fire in patches over a length of 270m.

I _______________, ACM, X OCP inspected the place, where this accident occurred and enquired into the cause and circumstances connected with the same.i)Introduction & information :- The accident occurred in X OCP of M/s……. on ……… at about 3.00 P.M. in 2nd shift when 14 persons under the supervision of an overman and two mining sirdars were engaged at the floor of the 2nd lower coal bench in various activities at a distance of 50m from the south quarry face of 1st coal bench. I received information about the accident at about 4 P.M. when I was in my residence.ii)Background information:- The depillaring permission was obtained for extraction of developed pillars by open cast method with shovel dumper combination using deep hole blasting. The usual practice at X OCP was to expose the developed coal pillars by removing OB, extract the pillars and then cover up the exposed area by dumping the OB material to control heating. iii)Occurrence of accident:- At about 3.50 PM, one of the worker’s noticed that large quantity of hot ash and dust ejecting from the coal face of southern side of the quarry spreading over a wide area including lower coal bench at a distance of 50m from coal face of top bench. All the persons at lower coal bench escaped safely but shovel operator buried under ejecting hot ash and dust etc.iv)Rescue & Recovery:- Machines were deployed immediately for removal of the debris. The dead body of shovel operator could be removed after 5 hours.v)Inspection & Enquiry: - On receiving information about the accident, I

immediately inspected the place of accident along with the other supervisory staff and workmen. I made detailed observations and some measurements at the place of accident and prepared a sketch of the place of accident giving leading dimensions. Photographs of the place of accidents were also taken. The sketch and photograph is attached with the report. I also examined witnesses and recorded their statements.

vi)Analysis of evidence/ Observations: - From the inspection of place of accident, careful study of DGMS permission and analysis of evidence collected, the following were revealed:-

a) Prior to accident there was heavy rainfall for 4 days. b)There was a slide of material in which huge quantity of material came down

along the south side over a width of about 20m. This slide might have been caused by fire, heavy rain, presence of fault, plane, water entering through wide cracks on the surface etc.

c)Active fire was noticed in the exposed u/g galleries as well as in the pillars on all sides.

d) The entire fire area was not covered / blanketed with 1m thick alluvium as advised by DGMS in permission letter.

vii)Cause of Accident:- The water gas explosion occurred due to formation of explosive mixture in the fire affected area.

There was a possibility of generation of superheated steam at high pressure. The heavy rain on 4 days prior to the accident would have clogged the cleavage planes and other natural fissures in the coal and associated rocks and steam superheated to high temperature could be entrapped at high pressures in interstices of ash and strata. Probably high pressure steam confirmed within the fire zone played the main role in the ejection of hot ash and dust etc.

The water gas must have formed in the void created by the burning of the coal seam and air entering the fire area must have rendered the mixture explosive which was ignited by the burning of coal thus causing water gas explosion.

viii)Contraventions of statutory provisions:- Regulation 119, 120 & 122 of CMR 1957 read with DGMS permission letter for extraction of pillars by open cast method were contravened in respect of the following:-

a) The fire area was not covered / blanketed with 1m thick alluvium and suitably compacted to prevent breathing of air.

b) Adequate precautions was not taken against explosion of water gas as required.

c) Sufficient supply of sand of incombustible material was not provided. d) Adequate precautions was not taken prevent the passage of air from the

surface into the fire area through any broken strata.ix)Responsibilities:- Enquiry into the accident revealed that if the statutory

provisions for precautions against fire were taken and DGMS conditions were fully comply, the accident could have been averted.

The following persons are considered responsible for the accident:- a)Agent- In contravention of provisions of section 18(1) and 18(4) of Mines Act

1952 read with regulation 190 of CMR 1957, agent of mine failed to effectively implement that all operations carried on in connection with the mine are conducted in accordance with the provision of mines act and regulation made their under.

b)Manager- In contravention of provisions of reg. 119,120, 122 and 41 of CMR 1957 read with sec. 18(4) of mines act 1952, the manager failed to effectively implement the conditions imposed by DGMS for blanketing of fire area.

c)ACM- In contravention of provisions of reg. 119,120, 122 and 42 of CMR 1957, the ACM failed to effectively implement the conditions imposed by DGMS for blanketing of fire area..

x) Suggestions to prevent similar accident in future:- In my opinion, the following steps should be taken to avoid recurrence of

similar accidents in future: i) The conditions specified by the DGMS in statutory permission letter should be

strictly followed.ii) In an open cast mine as soon as a fire is notice, it should be dug out and

quenched. Alternatively, measures should be taken to prevent its spread by not allowing access of air to the fire i.e blanketing.



SECOND CLASS




Q.1. What are the provisions of Mines Act, 1952 for the following:- (a) Hours of work belowground (b) Employment of woman.

(c) Extra wages for overtime. Ans:- (a) - Hours of work belowground. Please refer to Q.No. 1(a) ( 2nd Class – 2005) Ans:- (b) Employment of women.

i) No women can be employed belowground. However, women employed in health and welfare services and who in course of their duties, occasionally have to enter the workings belowground for purposes other than manual work, have exempted from the provision. Every such woman before entering belowground shall be in possession of a pass granted by the manager showing the day(s) and hours between which she is permitted to be present belowground.ii) No women shall descend/ ascend a shaft/winze, in a cage etc. unless accompanied by one or more adult males.iii) Women can be employed aboveground or in opencast workings only between 6 am and 7pm. However, this does not apply to women employed in pithead baths, crèches and canteens, and midwives and nurses employed in hospitals and dispensaries.The central Govt. may vary these hours but no women shall be employed between 10 pm and 5 am.iv) The women employees shall be allowed an interval of rest not less than 11 hours between the terminations of employment on any one day and the commencement of next period of employment.v) In any mine workshop coming under the purview of Factories Act. no women shall be allowed to clean, lubricate or adjust any part of a prime mover or of any transmission machinery, which is in motion or to clean, lubricate or adjust any part of any machine if in doing so she would be exposed to risk of injury from any moving part of either that machine or an adjacent machine.

Ans:- c) Extra Wages for overtime Please refer to Q.No. 1(b) ( 2nd Class 2005)

Q.2. What is ‘Occupational Health Survey”? What facilities are to be provided by mine management for Occupational Health Survey in accordance with Mines Act, 1952.

Ans:- Occupational Health Survey Mining is a hazardous industry. Occupational health hazards in mining are

dust, noise, radiation, heat and humidity, vibration, mine gases etc. To protect the mine workers from occupational health hazards as well as to know the safety and health status of a workman, occupational health survey is necessary.

Occupational Health Survey is defined as the survey which is conducted to know the status of health of mine workers and associated health problems due to mining environment. Generally, the following occupational health survey each conducted both were mine management and DGMS:

i) Medical and Biological Survey(IME & PME)- monitoring of diseases for detection at an early stage and monitoring to prevent further deterioration in health of the worker by

control measures rehabilitative methods

ii) Environmental Survey- monitoring of work environment such as dust survey at specified intervals, noise mapping of work places and personal noise dosimetry of workmen exposed to noise levels above 85dB(A), vibration studies, portability test of drinking water etc.Under Section 25 of Mines Act the mine management is required to report occurrence of cases of diseases notified by Central Govt. to competent authority.Research and academic institutions conduct surveys from time to time to identify incidence of occupational diseases. DGMS also undertakes surveys of occupational diseases in priority area or investigate specific complaints about occurrence of occupational diseases.Facilities are to be provided by mine management for Occupational Health Survey:i) Section 9A of Mines act 1952 empowers DGMS to undertake safety and occupational health survey in a mine at any time after giving notice in writing to the manager of the mine. Mine management shall afford all necessary facilities for this purpose.

ii) Every person chosen for occupational health survey shall present himself for examination and furnish all information regarding his work and health in connection with the said survey.

iii) The time spent by any person chosen for examination in such survey shall be counted towards his working time. So however that any overtime shall be paid at the ordinary rate of wages.

iv) If such person is found medically unfit on such survey, he shall be entitled to medical treatment at the cost of the owner, agent or manager with full wages during the period of such treatment.

v) If after such treatment he is declared unfit to discharge the duty which he has discharging and such unfitness is directly ascribable to his employment, he is entitled for an alternative employment in the mine for which he is medically fit or for payment of disability allowance at the rate of 50% of monthly wages that he was receiving before such survey.

Provided that where such persons decide to leave his employment in the mine, he shall be paid a lump sum amount by the way of disability compensation.

Type of surveys & studies to be undertaken:- Epidemiological studies for prevention of occupational diseases. Evaluation of chest radiographs for pneumoconiosis opacities. Assessment of hearing impairment due to exposes to noise. Assessment of physiological stress due to hot and humid working

conditions. Assessment of physiological and metabolic capacities of workers.

Facilities available at DGMS Electrocardiography(ECG) ILO international classification of Chest Radiographs of

Pneumoconiosis Audiometer Portable laboratory models of lung function tests machine. Heart rate monitors Necessary equipments for general medical examination. Oxycon-5 Metabolic Cart with Bicycle Ergometer.

Q.3. State the provisions of Indian Electricity Rules, 1956 regarding the following:-

(a) Isolation and fixing of transformer, switchgear etc. (b) Flexible cables.

(c) Precautions where gas exists. Ans:- a) Isolation & fixing of transformer, switchgear etc-

1. Where necessary, to prevent danger of mechanical damage, transformers and switchgears shall be placed in a separate room, compartment or box.

2. No inflammable material shall be used in construction of the room, compartment or box or fittings therein containing the apparatus, unless the apparatus is so constructed, protected and worked as to obviate risk of fire.

3. The room, compartment or box shall be:o substantially constructedo kept dryo well illuminatedo efficiently ventilated for all apparatus installed therein.

4. Adequate working space and means of access, clear of obstructions and free from danger, shall be provided for all apparatus. Operating handles shall be conveniently placed.

5. Properly constructed switchgear for disconnecting supply of energy to the mine shall be provided at the surface at a point approved by the Inspector. During the time any cable supplying energy from this switchgear is live, a person authorised to operate the said switchgear shall be available within easy reach thereof.

6. Every motor shall be controlled by switchgear arranged to disconnect supply from the motor and all apparatus connected thereto. Such switchgear shall be so placed as to be easily operated by person authorised to operate the motor.

7. Whenever required by the Inspector, the switchgear shall be arranged to disconnect the supply in the even of over current, over voltage and single phasing.

Ans:-(b) Flexible cables. Refer to Q. No.3(b) (2nd Class 2005) Ans:- (c) Precautions where gas exists. Refer to Q.No.5(d) (2nd Class 2007)

Q.4. Write short notes on any three of the following:-

(a) Noise (b) Angle of draw and its relevance (c) Support of freshly exposed roof (d) Illumination in opencast mine.

Ans:-(a) Noise Please refer to Q.No.4(c ) (2nd Class-2005)

Ans:- (b) Angle of draw and its relevance. Please refer to Q.No.6(a)(1st Class 2008)

Ans:-(c) Support of freshly exposed roof. Please refer to Q.No.7(d)(2nd Class– 2004)

Ans:-(d) Illumination in opencast mine. Please refer to Q.No.5(a)(2nd Class-2007)

Q.5. An accident had occurred in an opencast mine due to run over by a dumper being driven in reverse. One worker received fatal injuries. Write a report of enquiry of the accident bringing the contraventions, responsibility and also suggestions to prevent similar accidents in further. Assume your own condition.

Ans:- Refer to Q. No. 3(2nd class 2004)

Q.6. Draw up a suitable scheme of training and facilities to be provided under Mines Vocational training Rules, 1966 for a large mechanized underground mine.

Ans:- Refer to Q. No. 8(2nd Class 2004)

Q.7. What is the procedure to frame Traffic Rules for a large opencast mine? Frame model ‘Traffic Rules for a mine producing about 6 Milton tonnes of coal per annum with a stripping ration of 1:5.

Ans:- Please refer to Q.No. 1(2nd Class-2007)

Q.8. Write any three of the following:- (a) Risk assessment as a tool to improve safety (b) Applicability, merits and limitations of Long wall mining (c) Support resistance in a longwall face (d) Safety in “Contiguous Workings”.

Ans:-(a) Risk assessment as a tool to improve safety. Please refer to Q.No.6(b)(1st Class-2008)Ans:-(b) Applicability, merits and limitations of Long wall mining

Applicability of L/W system:- The long wall method of mining is applicable to almost any set of geological

conditions, shallow to very deep-seated seams, thin to very thick seams, level to steeply inclined seams, non gassy to very gassy seam, seams prone to self heating, outbursts and bumps, hard and massive to fragile roofs, hard and stable to soft and heaving floors, contiguous seams and mining below the aquifers, water bodies and important surface features.

However, being the universal method of mining, the long wall mining is best suited under the following conditions: Seam thickness varying from 0.4 to 6m in single slice where thick seam is

to be worked mainly either by multi-slicing system or integral or sub-level caving system. However, the system is more productive in seam whose thickness varies from 2m to 3m.

Flat and moderately inclined seams are best for this method. Coal of moderate hardness is suitable for this method. However, very

friable and soft coal or very hard coal are less suitable for this system. Uniform seam thickness, free from geological disturbances like faults,

folds, highly fractured are best suitable. Immediate roof not too hard or not too weak. Strong floor condition.

Merits of L/W system of mining:- In L/W method of mining, the extraction front–the long wall face-is 90 –

200m long and continuous. The face is generally straight (but, some time stepped, notched or even curved). The through air current sweeps the face. This all leads to the significantly enhanced concentration of production, supervision, control and safety – resulting in increased production and productivity. In long wall mining, the following advantages are also claimed: Concentration of mine operation. Continuity of operation. Higher % of extraction. Better subsidence control. Improved safety & easier ventilation with simple & direct air

routs. Greater feasibility of winding operation at greater depth. Reduction of number of L/W districts.

Better mining method for thin and thick seam and also for multiple seams. Means of easier ventilation and environmental control. Enhances % of extraction with the help of Pump

Packing System.

Seams liable to spontaneous heating can be satisfactorily worked.

It lends to mechanization with the least capital cost per te of annual output.

It provides the most successful methods of working beneath another workout seam.

Floor likely to creep may be controlled easily. Limitations of Long wall mining – Generally unsuitable in case of shallow depth mining due to subsidence

problem and hard roof. Not suitable for steeply inclined seams. Strata control problem. Demands high capital investment. In case of geological disturbed area the method does not yield good

results. In long wall advancing method roadways are to be maintained in worked

out areas and entail substantial recurring maintenance costs. Sometimes there is convergence of roof in the roadways which are required to stand for long.

In the case of long wall advancing with caving a large expanse of goaf left behind constitutes a vast reservoir of firedamp a potential source of danger.

In the case of long wall advancing with strip packing, if roadway packs are not well maintained against leakage, ventilation current may short circuit through the goat, which is both wasteful and dangerous ( as it may cause incipient heating of small coal left in the goat).

(c) Support resistance in a long wall face Ans:- The first desirable criterion for a support system is its ability to develop

the needed resistance to keep convergence and there fore roof degradation within acceptable limit (max. convergence should not exceed 60mm/m in case of sand stone roof and not more than 45mm/m in case of coal and fragile shale).This resistance can be manipulated within certain limits by varying support spacing in case of individual supports but such adjustment is very limited with mechanized support.The time weighted average resistance developed by the supports per unit are known as support resistance or load density.The determination of capacity of powered support involves the determination of likely load coming on the supports under a particular geo-mining situation.Once the desired support resistance necessary in particular geo-mining situation is known, the support capacity may be decided by the following empirical relationship:

Support capacity ( c) = R.A.K1 . K2 K3

rlWhere R = desired mean support resistance (MLD) in t/m2

A = area supported by a support. K1 = factor of take care for leakage in hydraulic system and leg circuits.

K 2 = factor to take care of setting load deficiency.K3 = factor to take care of other imperfections like premature leakage and

deviations from nominal span.R1= efficiency to take care of inclination of legs vis-à-vis vertical

resistance.

It is now well established that if the immediate roof consists of strong(high compressive strength) and massive rocks(high RQD), caving of roof would be more difficult. There will be more overhangs in the goaf leading to more weighting at the face and this in then would require higher support resistance.

A support system is to be considered adequate if it provides sufficient resistance to strata movement to keep convergence within limit during the life of the face including the periods of weightings so that undue deterioration of roof condition does not take place. There should neither be any roof fall or undue roof fracturing at the face.

The first line of defense against roof falls during periods of weighting is adequate supports and higher rate of advance is beneficial.

It is not possible to vary the system of support during day to day operations of a face advance, the support system would have to be planned to effectively support the maximum load associated with periodic weights.

With thicker cavable bed immediately above the coal seam, the degree of filling in the goaf is improved and maximum convergence during weighting is reduced. One way to increase the thickness of cavable bed is to resort of blasting the immediate roof in the goaf. But such blasting is not possible in case of shield support and may be unsafe in gassy seam. Support resistance for long wall workings deploying power support may be calculated by the following empirical formula:-

R={h/(K-1)}.ρ.k1.k2.k3 where, R = support resistance(t/m2) h = working thickness of seam(m)

k = bulking factor ρ = specific weight of roof rock(t./m3)

k1 = factor for type of support k2 = factor for goaf treatmentk3 = factor for delayed caving.

(d) Safety in “Contiguous Workings”.

Ans:- Legal provisions: No contiguous seams / sections shall be worked without obtaining

prior permission in writing from CIM. For obtaining statutory permission, applications shall be accompanied

by two copies of plan showing the proposed layout of workings, section of the seam (s), depth (s) , rate & direction of dip, proposed dimensions of pillars and galleries in each seam / section and thickness of parting between seam / section.

Coincidence verticality shall be maintained in seams / sections. The minimum parting between any two seams / sections shall be 3m.

Following precautions shall be taken during extraction of pillars by caving method in two sections of a seam or in two seams which are contiguous to each other:-1. The extraction of pillar i.e. drivage of split gallery and the extraction of slices in two sections/ seams shall be done simultaneously such that the line of extraction in both the section/seams are superimposed.2. The workings in each of the sections/seams shall be under the supervision of a separate mining Sirdar.3. The working of both the sections/seams will be placed under the charge of same overman for better co-ordination of the workings.

4. The overman shall be furnished with an offset plan showing the workings in both the sections/seams in different colors showing there on the sequence of extraction of pillars.5. The overman in each shift shall bring the hand plans upto date by showing there on the progress of splits and slices in each of the sections/seams.6. For easy access from one section/seam to the other for supervision, drift or staple pits with ladders shall be provided at every alternate junction of galleries.7. Suitable arrangements for communication between the two sections/ seams shall be provided by provision of signaling devices or telephones.8. If at any time, any danger is noticed in any of the sections/seams, persons shall be withdrawn from both the sections/seams.9. When shot-firing is being done in any of the sections/seams persons should be withdrawn from other section/seam also if the parting between the seam is 4.5m or less.10. Supports should be erected in both the sections/ seams as per SSR and they shall be as far as practicable vertically one above the another in the two sections/seams.11. Withdrawal of supports from both the sections/seams should be done simultaneously.

Afternoon SessionTHE MINES ACT, 1952

Examination for Mine Manager’s Certificate of Competency under the Coal Mines Regulation , 1957

FIRST CLASS



(Question No.1 is compulsory and carries 20 marks. Answer any five Questions from the rest and these carry equal marks)

---------------

Q.1. You are the manager of a mine which uses continuous miners and shuttle cars for extraction of pillars at a depth of about 400 m. The seam dips at 1 in 5 and has a thickness of 4.0 m. Immediate roof is hand sandstone.a. List what would you consider the five major risks in such an operation which are needed to be managed.b. List and describe control measures for the three highest ranked risks.c . Who would you involve in the risk assessment process.

Ans:- a) Conditions given Conditions assumed Depth of working – 400 m Method of work – Depillaring with caving Gradient of seam – 1 in 5 Gassiness - Degree l Thickness of seam – 4 m Size of pillars – 35 m x35 m (centre to centre) Immediate roof – Hard sand stone Floor - Sand stone/shale/coal Machinery used- Continuous miner Make of water - Normal seepage shuttle car combination.

Followings are the five major risks in extraction of pillars with caving method using continuous miner shuttle car combination under the condition mentioned above:-1) Risk / Danger of air blast 2) Risk / Danger of spontaneous heating or fire 3) Risk / Danger of coal dust. (Health & Explosion Hazard) 4) Risk / Danger of roof / side falls5) Risk / Danger of subsidence

b. Control measures for the three highest ranked risks- 1) Control measures against any risk of air blast:-

i) Depillaring operations shall be conducted in such a way as to leave as small an area of un-collapsed roof as possible with due regard to danger from an air blast or weighting on pillars. ii) Where possible suitable means shall be adopted to bring down any over hang goaf at regular intervals. In case any overhang goaf not normal to the strata is observed, extraction shall be stopped.iii) The manner of extraction such as splitting and slicing of pillars, its width and height and no. of pillars to be extracted at a time shall be strictly in accordance with the conditions imposed by DGMS in depillaring permission.iv) Strata control and ground movement monitoring shall be kept under the supervision of experienced lst Class Assistant Manager who shall be provided with adequate number of trained manpower and facilities.

v) Scientific body having expertise and infrastructure shall be engaged for monitoring of strata behaviour including caving characteristics, convergence, load on supports and stress developed over the pillars during extraction and corrective measures shall be taken.vi) Strata management plan including a detailed scheme of strata monitoring using suitable instrument such as rotary tell tales, convergence indicator, strain gauge, stress capsules, bore hole extensometer shall be drawn out in consultation with RMT and the scientific body. vii) Monitoring of strata movements and indications thereof shall be carried out in every shift by experienced officer. Warning and withdrawal limits in terms of convergence (mm), convergence velocity (mm/day or shift) and./ or strata dilation(mm) shall be fixed for the safety of work persons. If there is an unusual or abnormal deformation/ convergence, persons shall be withdrawn to safe place.Additionally, following precautionary measures shall also be taken to minimize dangers from air blast due to sudden collapse of overhanging roof in goaf:-A. Construction of Isolation/ Preparatory stopping:- i) Initially 1.5 m x 1.5m openings shall be left in sufficient number of isolation stoppings and covered with approved fire-resistant plastic sheeting to serve as safety valve in the event of an air blast which shall be subsequently closed permanently. ii) Doors meant for closing the preparatory stoppings in emergency shall be taken off and kept laid flat on the ground in the vicinity.B. Provision of Shelters:- i) Shelters shall be provided at suitable locations away from the probable path of air blast where workmen way take refuge in emergency. ii) Shelters and approaches there to shall be kept free of any obstructions by ensuring support of roof at the shelters using crossbars / roof bolts.C. Warning System:- District overman and mining Sirdar shall be provided with whistles and whenever any danger from air blast is apprehended, they shall repeatedly blow the whistle to warn persons.D. Withdrawal of persons:- i) Obligation of work persons:-

On hearing the sound of whistle, all persons shall take refuge in the shelters.

If a person is caught in the air blast, he shall immediately lie flat on the ground, preferably in a gallery not in direct path of air blast.

ii) Obligation of overman and mining Sirdar:- He shall, in addition to giving warnings, see that all persons take refuge in the shelters.

E. MOCK- drills etc.i) Manager shall ensure that only supervisory officials experienced in extraction by caving method are deployed in the district.ii) Regular mock-drills shall be held so that every person remains alert to perform his duty during an impending air blast.

2. Control measures against risk of Spontaneous heating/fire-A. Formation of panel(s)/sub-panel(s) –

i) Formation of panel(s)/sub-panel(s) and size of panels shall be done keeping in mind the incubation period of the coal seam. Panels should have independent ventilation in such a manner that it is possible to isolate one from another easily, if necessary.

ii) No depillaring operation shall be commenced until fire dams or isolation stoppings/preparatory stopping have been provided around panel(s)/sub-panel(s).

B. Sealing of panel(s)/sub-panel(s) i. Every panel(s)/sub-panel(s) shall be isolated by constructing adequate nos of stoppoings immediately after it has been goaved out.ii. Where the extraction of pillars is discontinued which would preclude the completion of extraction in the panel(s)/sub-panel(s) within the incubation period of the seam, the goaved out part of the panel(s)/ sub-panel(s) shall be sealed off.

C. Detection of spontaneous heating:- i. In order to detect spontaneous heating at early stage, % of carbon monoxide shall be tested in the return air way at least once in a shift with an approved automatic detector.

ii. The air in the return airway shall be completely analyzed once at-least in every 7 days with a view to determine the ratio of CO formed/ O2

consumed.iii. In case of detection of heating/fire, suitable arrangements shall be made

for dealing the same.iv) The quantity of air current at the face shall be measured at least once

in every 7 days and appropriate action shall be taken, if velocity drops below 30m/min.

D. Inspection of depillaring district and isolation stoppings:-i. Every depillaring district shall be inspected on every idle day and all

unsealed and unused workings, shall be inspected once at least in every 7 days by a competent person for any fire risk and record shall be kept maintained,

ii. The isolation stoppings built up around goaved out areas and unused workings shall be inspected by a competent persons at similar intervals as mentioned at point no.(i)The inspection should also include the isolation stoppings built around the goaved out areas in the panel(s)/sub-panel(s) still under extraction. The records of the isolation stoppings shall be maintained stopping wise.

E. Filling of surface cracks:- Surface crakes formed as a result of extraction of pillars shall be filled up

expeditiously and the filling material shall be well rammed into the cracks and kept topped-up as often as necessary thereafter to prevent leakage of air into the goaf.

3. Control measures against risk of coal dust:- In Coal Mines, the two most important hazards arising out of dust are :-i) Explosion Hazard and ii) Health Hazard

To guard against dangers of coal dust, the following pre-cautions shall be taken:-

i) The concentration of airborne respirable dust shall not be more than 3 mg /m3 of air, when Si02 <5% & not more than 15 if Si02 > 5%. %of Si02

ii) Air borne dust survey shall be conducted in prescribed manner at prescribed interval and record shall be maintained.

iii) If the concentration of dust in mine workings exceeds the permissible limit, immediate necessary steps shall be taken to minimize the emission

of dust. If needed, the relevant operation(s) causing excessive dust shall cease.

iv) Mine management shall provide dust respirators in sufficient number free of cost to concerned work person for use in dusty atmosphere, if needed.

v) Every working face and the floor, roof and sides of every roadway or airway within 50m shall be washed down to prevent accumulation of dust and shall be kept wetted.

vi) Water spraying arrangement shall be made and maintained within 90m of working faces.

vii) Stone dust barrier of such design & at such place as approved by DGMS shall be provided and maintained in order to prevent effect of explosion extending from one part of the mine to the other.

Apart from the above, the following additional precautions shall also be taken:i) Complete set of picks with proper size shall be fitted in cutter head.

ii) The speed of cutter head shall be maintained such as to prevent formation of dust.

iii) Water spray system shall be maintained in good working order to prevent formation and propagation of dust.

iv) The spray nozzles shall be kept regularly cleaned. v) Pyrite band of igneous rock shall be avoided to cut by machine. vi) Cutting of coal shall not be commenced until water spray starts with

proper pressure and quantity. vii) Cutting of coal at the face by CM shall not be commenced or carried out

unless water spraying arrangement at the cutting picks is provided and maintained in good working order.

Viii)Suitable mechanism to interlock the operation of water spraying and cutting shall be provided and maintained at all time in the CM.

ix) Monitoring of air borne dust concentration at the face and 30m out bye of the face in return airway shall be done at least once in a month.

C. Involvement of persons in risk assessment process:- As a manager of mine, I would involve following persons in risk assessment process including myself- Project Officer/Agent Manager, Engineer, Safety Officer, Ventilation Officer, Surveyor Overman, Mining sirdar and short firer, Electrical/Mechanical

foreman Electrical supervisors, Workmen’s inspector, members of safety

committee Workmen from different areas of operation Officials from area and ISO. Expert from original equipment manufacturer Retired officials, if needed.Besides above, assistance may be taken from experts of other organisation such as CMRI, ISM, CMPDIL etc.Risk assessment shall be performed on regular basis by the team as mentioned above. The members of the team shall be varied from session to session to gain a broad perspective of the hazards across a site. The goal for each risk assessment session is to identify hazards, determine risk ratings and controls and to review the implementation of risk controls from previous risk assessment sessions.

Q.2. A 6.0 m thick coal seam was being extracted by opencast method deploying HEMMS. The overburden consisted of a 25 m thick cover of soft soil followed by shale and sandstone. A sudden failure of benches for length of about 400 m. and part of a dump lying near the edge of the quarry occurred burying two shovels and four dumpers resulting in death of six operators and an overman. Write an enquiry report of the accident bringing out contraventions, responsibilities and suggestions to prevent similar accident in future. Assume your own conditions.


Ref.No……………………… Date………...

To,The Manager,“ X “ OCP.

Sub:- Enquiry report in respect of fatal accident involving 7 persons in X-open cast working due to sudden

failure of benches & OB Dump .

Dear Sir,

As desired vide your letter no………………… dt…………… I am enclosing herewith the detailed enquiry report in respect of fatal accident in X-O/C working due to sudden failure of benches and OB dump indicating the cause and circumstances attending to the accident, contraventions of statutory provisions, responsibilities and suggestions to prevent similar accident in future as an annex.l . I am also enclosing the accident plan showing the site of accident along-with photo graphs.


( A.C.M. ) “X” OCP

Annexure - l


Assumption of Conditions:-The present X OCP was earlier part of the Z u/g mine having workings in local seam about 6m thick and dipping at 1 in 4.5 developed extensively on B/P system in past through inclines. The property has a major fault with a throw varying from 10 to 30 m. Two O/C mines were started in the property to extract the developed local seam with barrier between the two mines being along this fault plane.

The X OCP is on the dip side of the fault whereas the property lying on the rise side of the fault has been allocated to Y OCP. The overburden consists of 25m thick soft soil including 10m black cotton soil at the top underlain by 15m to 25m shale and sand stone. Fire was also noticed in the exposed galleries 2 years back and had extended on all sides. I _______________, ACM, X OCP inspected the place, where this accident occurred and enquired into the cause and circumstances connected with the same.1)Introduction & information :- The accident occurred in X OCP of M/s……. on

……… at about 3.50 P.M. in 2nd shift when 13 persons under the supervision of an overman and two mining sirdars were engaged at the floor of the coal bench in various activities including loading of coal by shovels into dumpers. I received information about the accident at about 4 P.M. when I was in my residence.

2)Background information:- The depillaring permission was obtained for extraction of developed pillars by open cast method with shovel dumper combination using deep hole blasting. The usual practice at X OCP was to expose the developed coal pillars by removing OB, extract the pillars and then cover up the exposed area by dumping the OB material to control heating. Some OB material were also being dumped near the edge of the quarry.

3)Occurrence of accident:- At about 3.50 PM, one of the worker’s noticed loose debris falling from the top of the benches on rise side all along the strike. By the time, he could raise an alarm, loose debris and boulders started sliding down rapidly into the quarry. 5 Persons tried to runaway while 7 persons i.e. 6 operators and one overman took shelter behind the HEMM. One person left the area earlier.The huge quantity / volume of OB material slid down into the quarry. All the 7 persons, who had taken shelter behind the HEMM were completely buried under the debris. The 5 persons who had tried to runway were partially trapped but could escape with minor injuries.

4)Rescue & Recovery:- Machines were deployed immediately for removal of the debris. All the 7 dead bodies could be removed by 5 AM on next day.

5)Inspection & Enquiry: - On receiving information about the accident, I immediately inspected the place of accident along with the other supervisory staff and workmen. I made detailed observations and some measurements at the place of accident and prepared a sketch of the place of accident giving leading dimensions. Photographs of the place of accidents were also taken. The sketch and photograph is attached with the report. I also examined witnesses and recorded their statements.

6)Analysis of evidence/ Observations: - From the inspection of place of accident, careful study of DGMS permission and analysis of evidence collected, the following were revealed:-

i) Height of benches in black cotton soil was as much as 12m (against permitted height of 5m) & width of only 4 to 8m . The next two benches in shale/ sandstone were 12m to 15m height (against permitted height of 10m) and had width of less than 5 m.

ii)The coal bench was 6m high and was almost flush with the sandstone bench above, the combined height at the place of accident was 40m.

iii)The strata had sets of geological discontinuities, parallel as well as at an angle to the fault plane.

iv)Active fire was noticed in the exposed u/g galleries as well as in the pillars on all sides.

7)Cause of Accident:- The benches failed because of their excessive height and very small width. The following are considered to be the technical reasons for the accident:-

i)The main technical reason for the collapse/slide is the gross deviation of the height & width configuration of benches at the place of accident w.r.t. stipulated conditions of DGMS.

ii)The Shape of the barrier in relation to the bench height and width was such that it was near to limiting equilibrium having a factor of safety around one.

iii)A change in the lithology particularly increase in the thickness of top soil contributed in reduction in the factor of safety near the site of slide.

iv)The existence of fire in the mouth of the galleries near the accident site probably reduced the cohesive strength of sandstone. A possible collapse of underground galleries/junction after fire in association with the weakened strata acted as de-stabilizing factors to initiate the slide.

8)Contraventions of statutory provisions:- Regulation 98 of CMR 1957 read with DGMS permission letter for extraction of pillars by open cast method were contravened in respect of the following:-

i) Formation of benches/ Design of pit slope - The height, width and slope of benches were not maintained as per statute and conditions imposed by DGMS.

ii)Design of Dump Slope- OB Dump near the edge of quarry were made without taking into consideration the natural angle of repose of materials. As the height of the OB dump was more than 30m, its should have been properly benched with height not exceeding 30m and general slope not exceeding 1 in 1.5.

9)Responsibilities:- Enquiry into the accident revealed that if the workings were made properly benched and special care taken while working near the fault plane and coal benches affected by fire as required under statute, the accident could have been averted.

The following persons are considered responsible for the accident:- i)General Manager/ deemed agent and agent- In contravention of provisions

of section 18(1) and 18(4) of Mines Act 1952 read with regulation 190 of CMR 1957, the General Manager/ deemed agent and agent of mine failed to effectively implement that all operations carried on in connection with the mine are conducted in accordance with the provision of mines act and regulation made their under.

ii)Manager- In contravention of provisions of reg. 98 and 41 of CMR 1957 read with sec. 18(4) of mines act 1952, the manager failed to effectively implement the conditions imposed by DGMS for formation of benches and design of OB dump.

iii) ACM- In contravention of provisions of reg. 98 and 42 of CMR 1957, the ACM failed to effectively implement the conditions imposed by DGMS for formation of benches and design of OB dump.

iv) Overman-In contravention of provisions of reg. 98 and 43 of CMR 1957, the Overman failed to effectively implement the conditions imposed by DGMS for formation of benches and design of OB dump.

10) Suggestions to prevent similar accident in future:- In my opinion, the following steps should be taken to avoid recurrence of

similar accidents in future: i) The conditions specified by the DGMS in relation to width and height of

benches should be strictly followed.ii) If any change has to be done, it must be supported with scientific analysis

on slope stability and necessary permission should be obtained from the competent authority.

iii) Slope in the direction of gradient of rocks is more risky, due to gravity helping the slope failures. Therefore, benches in the in-crop side need extra precautions.

iv) Existence of fire in the u/g galleries contributes in the weakening of overlying strata and reduction in factor of safety. Therefore, a higher factor of safety should be planned in such cases e.g. by increasing the width of bench.v) Wherever benches are formed near a fault, a detailed examination should be conducted and it should be ensured that likely sliding mass is removed or is stabilized properly.vi) Growth of plants in specific cases may help in stabilizing the soft rocks.vii) A system should be created in each opencast mine to draw cross sections of all the sides every month. These cross sections will be signed by Surveyor, Manager, Agent and countersigned by Chief General Manager of the Area.viii) Technology using laser profiling system/ computer processed videography/ high resolution satellite imagery should be used for survey and section preparation etc.

Q.No.3. In the present day context of heavy mechanization and outsourcing, give your views on adequacy of the provisions of Mines Vocational Training Rules. Suggest improvements and steps to be taken make vocational training effective.Ans:- Mines vocational training Rules, 1966 were framed long back to impart vocational training to mine workers, which includes:

Initial/basic training to new entrants followed by further training at the place of work under close supervision of experienced workmen.

Refresher training for persons already employed and also for persons who return to work after absence of 1 year.

Additional initial training for U/G workers. Special training of support gang, shot – firer etc.

Subsequently, MVTR 1966 were revised with a view to make these need-based and job oriented for improvement of knowledge, skill and correct job procedures.However, there has been considerable changes in mining technology in U/G, Surface and O/C in the form of fast and rapid mechanization and outsourcing activities. The existing statutory provisions contained in MVTR1966 are not adequate to fulfill the present day need.

In the present day context of heavy mechanization( in U/G, Surface and O/C) and increase in outsourcing activities particularly in open cast, the following are the flaws/ inadequacies in the existing MVTR:-1. Duration of training:- The present duration of trainings of 12 days for

surface/opencast/U/G works are not adequate.2. Course content- The course content designed for the purpose is very old

and inadequate and also does cover all aspects of mining technology:3. Type of training – In the present rule, there is provision only for theory and

practical training. Training modules are too general in nature and oriented towards departmental employees.

4. Applicability- MVTR is applicable only for limited categories of workers debarring officials, supervisors and officers ,office staffs & rescue persons.

5. Training for contractors workers - No provision exists in this regard.6. Appointment of training officer- Provision in respect of Qualification,

experience, nos. of training officers at training centre is not adequate.7. Staffing -Provisions in respect of qualified training staff, instructors and their

qualifications are not prescribed adequately in the statute.8. Training of trainers:- There are no provisions for training of trainers.9. Training aids & course material:- Existing provisions lacks of modern

amenities like films documentary, video, literature, models etc. at VTC10. No provision of training on occupational health safety.11. No provision of special orientation training for female workers.12. No provision of training for workmen and supervisors in respect of

environmental protection. 13. Training allowance- Allowances paid to trainers and trainees are not

adequate.Suggestions/ steps to be taken for improvements of MVTR:-Suggestions for improvements:- MVTR 1966 has become out of date and irrelevant and needs to be repealed and replaced by a new set of rules incorporating the revised modules for basic training, modules for refreshing training, provision for different types of VT centers, building accommodations, furniture, training aids etc.

In view of many changes sweeping the mining industry in the form of new technologies, changed mining conditions etc, an acute need has been felt to recast the existing statutory provisions contained in MVTR.1966.Following are the suggestions/ steps to be taken for improvements in MVTR 1966 in order to make it effective in the present day context of heavy mechanization and outsourcing in Indian mines:-i. Duration of training:- Keeping in mind the increasing mechanization and outsourcing activities in Indian mines the duration of training should be increased. The duration should be fixed based on type of organisation, type of mine and category of workmen. The suggested duration should be as follows:

Sr.No. Categories of workers Duration of training ( days)Initial

trainingRefresher training

1. Surface workers 12 062. Open cast workers 18 063. Underground workers 48 124. Additional training for specific categories open cast workers/ supervisors

a. Drillers, blasting crew 36 12b. operators dumper, shovel,dozer 54 12c.Dragline operators,fitters,mechanics 72 12d.Electricians 96 12e.Auto Electricians 72 12f.Electrical supervisors 18 9

5. Additional training for specific categories U/G workers/ supervisors a.Tramm., W.E.drivers, Banksmen, Onsetter, fan attendants

18 09

b. Track layers, ventilation gang,shot firing gang

24 12

c. Support gang 30 12d. Machine drivers/ longwall crew 48 12e. Fitters, electricians, mechanics 54 12f. Electrical supervisors 18 09

Refresher training period has been kept 50% of the initial training period but not exceeding 12 days. In the initial and refresher training, the last 1 – 2 days has been kept for feedback/test. 2. Course content- For effective training, the syllabus needs to be organisation specific, mine specific and cadre specific. A standard write-up should be prepared covering theoretical aspect of syllabus circulated in the form of text book in local language to all instructors and trainees. 3. Applicability - It should be applicable for all workers, supervisors and officers, staff and rescue persons. 4. Training of contractors workers- Separate modules should be drawn for contractors workers as the present modules are too oriented towards departmental employees. 5. Appointment, duties and responsibilities of training officers – The rule should provide for appointment of a training officer in each mine employing more than 500 persons besides instructors. The qualification of the training officer, and the no and qualification of instructor’s should be prescribed.

All training centers shall be adequately staffed as per following details:- 1st class Manager - Overall in-charge Adequate nos. of training officer and /or Asstt. Training officers having degree

in Mining/Mechanical/ Electrical Engineering Adequate nos of trained instructors at least diploma in Mining /Electrical/

Mechanical Engineering. Adequate nos of experienced and safety minded trainers for each specialized

or skilled jobs. Adequate sub-ordinate staffs.

6. Training of trainers, instructors & training officers should be given statutory backing.7. Training aids:- All training centres should be provided with computers with required software, overhead projectors, slide projectors & TV + VCP/VCD player etc.8. Special orientation training for female workings should be included in the training programme.9. Considerable damage is occurring to environment due to various mining activities. Training on Environmental protection to workmen and supervisors should be made mandatory.10. Provision of training in respect of occupational health and hygiene should be made in the statute.11. In view of the new Information Technology (IT) waves sweeping the globe, mining industry has to keep pace with it and accordingly the very nature/kind of vocations done by our workmen change. Such IT application to industry should be anticipated and accordingly such training should be included in Mines Vocational Training Rules Till the existing MVT Rules are thoroughly revised and amended incorporating the above mentioned suggestions, the following additional steps should be taken:-a) Each mining company should draw up model training schedules for different categories of work persons. Such schedule should be got vetted by the tripartite review committee.b) All front line supervisory officials like sirdars, overmen, surveyors, foreman, electrical/ mechanical supervisors as well as persons supervising other surface operation should be imparted structured training in safety management for at least 2 weeks once in every 5 years covering about 20% strength every year.c) Specialized training courses should be arranged for the development of skilled operators required for HEMM, L/W face equipment etc including contractor’s workers.d) All persons engaged at any work within the mine premises through the contractors should be imparted relevant training and other job oriented briefings and the drivers of vehicles belonging to contractors entering the mine premises should be explained the salient provisions of traffic rules framed by manager of mine . Each mining company should draw up appropriate training schedules and modalities in this regard and implement the same.

Q.No..4. Design an emergency plan of a belowground mine with dangers from spontaneous heating and inflammable gas. How can you make it effective?

Ans:- Emergency Plan :- An emergency plan is a programme of action to be followed in emergency. It should clearly indicate the duties and responsibilities of each mine official and some other key persons like telephone operator, attendance clerk, cap lamp in-charge etc. This plan should be drawn up taking into consideration special features of mines, foreseeing every possible source of dangers and damages. It consists of programs which provide for prior arrangements to be kept in readiness before emergency strikes and also operative part of the emergency plan to deal with the emergency as and when it strikes.Necessity of Emergency Plan: - An emergency plan is required to be kept prepared specially for the following reasons:-

i) To avoid chaotic condition which develops after an emergency / disaster.

ii) To keep the persons trained before hand with details as to what to do and what not to do, whenever an emergency arises.

iii) To save human lives who might get isolated due to emergency.iv) To save the mine by taking action to deal with the emergency as early as

possible. Statutory obligation :- As per regulation 199A of CMR 1957, manager of every belowground mine has to prepare and submit emergency plan clearly indicating the duties and responsibilities of key persons within 30 days of opening of mines to RIM, get it approved and enforce at the mine. When any emergency occurs, manager/principal official should immediately put the emergency plan into operation. This Plan should be updated from time to time.Emergency plan of a belowground mine with dangers from spontaneous heating and inflammable gas:- Components of emergency plan –A) Prior arrangementsB) Framing and operation of emergency organisation / standing orderC) Operation control room.D) Enforcement of standing order.

A. Prior arrangements- A no. of buildings as detailed below shall be kept earmarked for use during emergency.

Emergency Control Room Two rooms for rescue organisation. One room to be used as laboratories Three room for welfare departments used for control, catering and visitors. Three rooms for medical appliances – For stretcher casualties, walking

casualties and mortuary. Rooms for Trade unions, police personnel and media persons.

B. Framing and operation of emergency organisation / standing order. Standing order for emergency plan should clearly show the duties and responsibilities of workmen/person noticing danger, mine official and other key persons besides actions to be taken for withdrawal, re-admittance of persons and resumption of work as detailed below: 1) System of giving warning/ Action to be taken by any person / official

Action by Action to be takeni. Any Person

i. Any person who notices smoke/fire and detects the presence of inflammable gas, shall immediately withdraw himself from the place and fenced off the area. He shall take steps by the fastest means to inform nearest supervisory officials and also give warning to on-setter, if he is near the pit bottom.

ii. Mining Sirdar/ Overmen/Other mine Official

On receiving information, he shall verify the correctness of information and send information by special messenger/telephone to :-i. other part of the mine so that persons may be withdrawn to safe place. ii. any senior official present in the underground.iii. manager/principal official present on the surface. He shall try to with draw all persons safely through escape route with the help of self rescuer

iii. On setter

On receiving information, he shall inform the banks-man on surface by telephone/signaling 10 raps and confirm the same by a special messenger.

iv. Banks-man

On getting information about the detection of spontaneous heating and inflammable gas, immediately inform-a) Manager / principal official present on surfaceb) Attendance clerkc) Not allowing anybody to proceed belowground without written permission of manager / official.

v. Attend-ance Clerk.

He shall –a) Inform telephone operator and managerb) sound emergency siren continuously for one minute and repeat the same twice at interval of five seconds.c) Prepare a statement of persons present in different parts of the mine and send a list to operation control room. The list should be updated time to time.d) Not allowing anybody to proceed belowground without written permission of manager/official.

vi. Fire fighting & rescue personnel

On being informed, the fire fighting and rescue team shall immediately assemble at operation control room and obey the order of manager/ principal official.

vii. Mana gers

On getting information about spontaneous heating and inflammable gas, the manager/principal official shall either himself inform or take suitable action to inform the Agent and other senior officers of the company, the rescue station and DGMS. He shall also inform the management of neighboring mines.

2) Withdrawal of Persons:- a) Duty of Mining Sirdar and Overman:- i. They shall forthwith withdraw all persons under their control from the mines

except those persons whose presence in the mine is considered necessary for dealing with the spontaneous heating and inflammable gas.

ii. Persons shall be withdrawn in an orderly manner and without creating any panic.

iii. Persons shall normally be withdrawn via intake roadways and down cast shaft or intake incline.

b ) Duty of mine officials:- Mine Officials superior to Mining Sirdar and overman shall exercise general supervision over the withdrawal of persons for u/g workers.

3) Admittance of persons Restriction on employment of persons below ground:-

i. Only authorized persons shall be allowed to remain in or to enter the mine for dealing of spontaneous heating and removal of inflammable gas.

ii. Attendance clerk shall record in his register, the entry to and exit from the mine of every authorised person.

iii. Banksman shall not allow any un-authorised person to go under ground.

4) Conduct of fire fighting operation & removal of inflammable gas- i. All work of fire dealing shall be conducted in accordance with statutory

provision and recommendation of DGMS contained in various circulars under the supervision of specially trained persons and under rescue cover, if necessary.

ii. During removal of gas, only trained and experienced persons shall be engaged under competent supervision and in accordance with statutory provision.

5) Resumption Work- Normal work shall not be resumed u/g except with the prior permission of the manager and unless all working places have been thoroughly examined by a competent person and declared safe.

C) Operations Control roomAll the persons summoned to the mine under the emergency scheme shall sign a log book kept at the control room. At the operation control room the following actions shall be taken without delay:-

(a) Making a list of missing persons & casualties. (b) Making chart of roster duty. (c) Formation of rescue team. (d) Recording of events in operation record book in cronical orders.

Items to be kept at operational control room- Copies of emergency action plan Ventilation plan Underground working plan Duty cards of diff. Categories of workmen. Telephone directory Authorisation cards for U/G visits Message form in duplicate Rescue plans & trainings Fire fighting plan.

D) Enforcement of standing order- i. A copy of orders shall be posted at the mine office, the attendance room

and every entrance to the mine. It shall be the duty of all mine official and other concerned persons to make themselves thoroughly familiar with their duties in case of danger of (i) spontaneous heating & (ii) Inflammable gas.

ii. Mock rehearsals shall be held once at least in every quarter.Effectiveness of emergency plan:Even the most carefully prepared plans will developed flaws when put into practice and only rehearsals can so them up for necessary correction. Following steps shall be taken to make emergency plan effective:-

1) Mock rehearsals shall be conducted once in every quarter religiously and if practicable, at shorter intervals so as to check emergency arrangement including the communication system, alertness and comprehension of allotted duties on the part of the key personals so as to make sure that the action plan will work under emergency condition. 2) Simulation exercise shall be done once at-least in every year in order to check the emergency preparedness and deficiencies, if any.3) Emergency plan shall be reviewed once in a year by ISO and DGMS and plan shall be updated as per suggestions.4) Training & retraining shall be imparted to all key persons to deal with emergent situations defining their duties and responsibilities during emergency.5) Emergency escape route and sign board should be marked belowground right upto face by fluorescent paint.

. 6) Training & retraining of all rescue trained persons for use of rescue & other life saving apparatus.7) Establishment & implementation of occupational health inputs into emergency plan. 8) To make the emergency plan really effective and meaningful, duties and responsibilities of some other important key persons and officials such as store keeper, lamp room in-charge, surveyor, doctor, welfare officer, canteen in-charge and security staffs should be included in the standing order in order to make them accountable.9) The emergency plan including the action plan (s) and the duty cards should be kept constantly updated.10)The standing consultative committee as well as the key personnel should meet at regular intervals to keep themselves abreast with the mine workings including any changes therein an the action plans and also to review the plan and preparedness.11)The emergency duties allotted to individual key personnel should not be very much different from the work normally done by them.

Q.No.5. Describe different type of man-riding systems available and their limitations. Discuss safety provisions of each system.

Ans: - In case of large extensive and steeply inclined U/G mines, installation of man riding system becomes essential in order to avoid arduous traveling, eliminate chanceas of accidents and to ensure effective utilization of available shift hours.Man riding system should be induced in the Indian u/g mines under following conditions:-a) Where seam gradient is more than 1 in 4 and traveling distance is more than 1.5 KM, b) Where seam gradient is less than 1 in 4 but the traveling distance is more than 3 KM. It may be kept in mind that no man riding system shall be used U/G unless it is of a type approved by the Chief Inspector of Mines. All equipment used for man riding system shall be:(a) of sound construction (b) inspected at regular intervals and (c) maintained in good and safe condition.Different types of man riding system available, their limitations and safety provisions:- Commonly used man riding system are:-

1) Haulage . 2) Belt conveyor 3) Locomotives 4) Chairlift 5) Telepher 1) Haulage system: - This system shall be considered where the steep gradient

is required to be negotiated. The maximum operating gradients for direct and endless rope haulages are 1 to 10 and 1 in 12 respectively. The factor of safety of haulage rope shall not be less than 10 end the life of rope shall not be more than 1½ Yrs. The system requires a high standard of installation and maintenance of tracks and safety provision including signaling and automatic braking system in case of rope breakage or trolley over speeding and used for transport of men in the beginning and the end of shift, in long-wall and continuous miner mines in India.

Limitation:- This system cannot be used where gradient of roadway is more than 1 in 10 for direct haulage & 1 in 12 for endless rope haulage.

Safety Provisions in man-riding haulage system: a) Safety devices -

Over speed tripping device Position indicator and rope speed indicator Run- over indicator Dead man’s handle – to stop the haulage in the event of collapse of or incapacity

of driver Service brake – having restraining torque capable of holding 1.5to 2.0 times the

torque resulting from the rope pull. Emergency brakes Track limit switch – to be provided at in- bye and out - bye end of journey.

b) Clearance :- Below the roof - 0.3 m

On that side of track on which manholes are provided– 0.6 m On that side of track opposite to the man-holes when there are not more than

two tracks - 0.3 m In any other case – 0.6 mc) Effective signaling system – suitable code of signaling to be specified by

manager for strict enforcement.d) Electrical – All Electrical equipment & fittings – Flame proof construction in gassy mines,

Voltage - not more than 250 V All conductors should be properly insulated, protected & maintained to prevent

leakage or sparking. Proper earthing of metallic parts.e) Notices:- * Rope speed limit notice in the engine room. * Notice at each stations prohibiting travel beyond specified point. * Notice specifying max. no of persons to be carried.f) Operation, Installation, maintenance, inspection and testing- Manager shall

frame and enforce a scheme of operation, installation, maintenance, inspection and testing of the whole system specifying the manner, interval and responsibility.

2. Belt Conveyor System:- Top or bottom belt is used in mechanized mines abroad for man-riding. Using belt conveyor exclusively for transport of men is economically not viable. The system is provided with several protective features including stations for getting on or off, pulls wire signaling system and limit switch. Such a system is not used in any Indian Mines at present.

Limitations of use:- (a) The speed of man- riding conveyor shall not be more the 2 m/s and the

gradient not more than 1 in 4.(b) Where mineral and /or material are being conveyed at the same as men, there

shall be neither mineral nor material on the length of the belt being used for man-riding and for not less then 5 m in front of and behind this length.

(c) Where subsidiary conveyors feed on to the man-riding conveyor, neither mineral nor material shall be placed on the man-riding belt within 5 m of any person riding on the belt.

(d)No other form of mechanical haulage apparatus shall be in operation in the same roadway as a man-riding belt conveyor, while persons are being transported.

Safety Provisions in man-riding belt conveyor system:- (a) Safety devices:-

Safety gate & Overriding switch Automatic indicator showing fully engaged safety gate Belt slipping preventer to prevent danger arising due to belt slip. Belt alignment device to ensure that belts do not move out of line in

excess of 75mm Belt breakage detection device Belt tear detection device Chute blockage detection device Pull cord system to stop the conveyor from any point along with its length

by any one riding over the belt during emergency. b) Clearance:- Conveyor road shall be so made and conveyor shall be so located

that the clearance shall be as given below:-

i) 1.65 m. for top belt and 1.40 m for bottom belt at any boarding platform and same clearance shall be maintained for a minimum distance of 9 m beyond the boarding platform in the direction of travel.

ii) 1.65 m. for top belt and 1.40 m for bottom belt at any alighting platform and for a minimum distance of 3 m beyond each end of alighting platform.

iii) .9 m clearance elsewhere along conveyor for both the system where men were conveyed and for a minimum distance of 9 m. beyond the safety gate.

c) Other provisions such as signaling, communication, notices, lighting, white washing etc shall be made.

d) Scheme for operation, installation, maintenance, inspection and testing for belt conveyor shall be made and enforced by manager.

3)Locomotives system:- This system consists of man-riding cars attached to a locomotive. The cars are equipped with braking system which can be operated by passengers. When not required, man-riding cars can be stabled at one end of journey. These can be used for transport of large manpower, but, only between limits of loco haulage, in a mine were locomotives are used for coal transport and the mine is extensive.

Limitation:- No locomotives shall be used where the gradient of the track exceeds 1 in 15.

Safety Provisions in man-riding locomotive system :- i )Service and parking brake and also a dead man control ii) Ergonomically designed seat for driver

iii) Speedometer, distance indicator, head lights and rear lights iv) At least two portable fire extinguisher’s of appropriate type and signaling

arrangement. v) An approved portable lamp for emergency. vi) Other provisions:

Pressure and temperature gauge Exhaust conditioner An exhaust gas cooling box Suitable air filter Suitable flame arresters/traps

4&5) Chair lift system & Telepher system:- Chairlift system:- Chairlift system consists of an endless rope running

near the roof of the roadway. A no. of chair lifts are kept stacked at either end of journey. Any one who wants to travel takes a chair lift, hangs it on the traveling rope at specially designed stations & rides on the seat. It is similar to an aerial ropeway station to put ropeway buckets on or off. Carrying capacity of the system is high and it can be used both for upward and downward journeys. It is one of the commonly used systems in India.

Telepher System: - This is a simple system consisting of an endless rope in a steeply inclined roadway. Each person traveling has a hook attached to his cap-lamp belt, the other end of which can be put on or off the upward traveling rope for pulling the person who is traveling. This system is useful for short distance and helps walking up the inclines only. It is a cheap and simple system used in some mines in India.

Limitations :-1. Gradient of roadways should not be more than 25 degree. 2. This system should not foul with other transport system.

3. No material shall be transported by the telepher system, and while men are being conveyed by the chairlift system.

4. Rope speed shall not exceedChairlift – 1.75 m/sTelepher – 0.8 m/s

5. Minimum factor of safety of rope – 10

Safety Provisions:- For both systems, safety requirements are similar which are given below:-

(a) Safety devices:- i) Over speed device and device to prevent backward movement of

the system.ii) Over travel limit switch at either end of the journey to stop the

system in the event of over riding of persons.iii) Over stretch switch to stop the system in the event of the rope

stretch beyond a pre set limit or rope snaps.iv) Rope speed indicatorv) Pull cord to stop the system from any point

(b) Clearance:- Chair lift Telepher

Top of chair seat to floor – 1.0 m From sides - 0.3m From sides - 0.8 m Walking free space Centre to centre of chairs – 1.2 m from end of telepher rope rollers-

1.00m (c) Efficient & Effective signaling system . (d) Provision of notices at appropriate places. (c) Installation operation, maintenance, inspection & testing – scheme to

be prepared and enforced by manager.

Q.6) what are the notified diseases? Which of other diseases you would like to be included in notified diseases. Discuss the system of “Occupational Health Surveillance” in your organisation, its short comings and suggest improvement.Ans:- Notified diseases:-These are those diseases which have been notified by the central Government in the official Gazette as diseases connected with mining operations. These includes

Silicosis Coal miner’s pneumoconiosis Manganese – poising nervous type Asbestosis Pneumoconiosis Cancer of lung or the stomach or the pleura and peritoneum.

Under factory Act, Noise induced hearing loss has been notified by Central government as notified disease.Under section 25 of mines act 1952, it has been specified that where any person employed in a mine contracts any notified disease, mine management shall send notice to CIM, DM, RIM, Inspector of Mines (Medical) within three days. In addition to the existing notified disease, the following additional (other) occupational diseases should be included in the list of notified diseases:-

i. Siderosis and Berillyosis.ii. Noise induced hearing lossiii. Carbon monoxide poisoningiv. Contact dermatitis caused by contact with chemicals.v. Pathological manifestations due to radium or radio active substances.

System of “Occupational Health Surveillance” in our organisation - The following comprehensive occupational health services are available in our organisation:-1) Central Hospital- At central hospital, initial medical examination of every persons to be employed in a mine is done. Besides this, referral cases and chronic diseases are also taken care of at Central Hospital. 2) Regional Hospital – In addition to central hospital, sufficient nos of regional hospitals have been set up in the organisation to take care the employees posted in different parts of the organisation.3) Empanelled Hospitals- Patients needing specialized treatment and health care are generally referred to empanelled hospitals across the Country. 4) Periodic medical examination centers with full time medical officer.5) PME centre equipped with X-ray facilities, facilities for lung function test, Audiometry and Classification of Chest Radiographs as per ILO classification.6) Occupational health physician suitably trained in use of ILO classification7) Provision of approved type of personal or environmental sampling instruments for conducting airborne respirable dust surveys with facilities for determination of free respirable silica. 8) Noise survey instruments are available for conducting Noise surveys.9) Mechanism for monitoring progress of medical examinations, classification of chest radiographs, detection of occupational diseases, progress of dust and noise surveys etc.Short comings of existing system of occupational health services:

Following are the short comings of occupational health services in Indian mines:-

1. Lack of adequate of infrastructure facilities for conducting medical examinations in PME centres.2. Failure to conduct initial and periodic medical examinations of all persons employed in mines as per provision of statute.3. Failure to evaluate chest radiographs as per ILO classification.4. Non-reporting of cases of notified diseases.5. Lack of adequate infrastructure facility for conducting dust and noise

surveys.6. Failure to conduct dust and noise surveys at prescribed intervals as per provision of statute.7. Lack of trained manpower in occupational health and hygiene.8. Lack of organizational framework on occupational health and hygiene.9. Poor quality of medical surveillance and use of non uniform subjective diagnostic criteria.Suggestion for improvement of system of occupational health services:-Suggestions to improve status of occupational health and hygiene in our organisation are given below:-1) Setting up structured occupational health services.2) Regular short term training programmes on occupational health and hygiene with special reference to dust and noise monitoring and diagnosis of occupational diseases and use of ILO classification need to be organized. 3) Identification and assessment of health hazards in workplace.4) Control of working environment by elimination or minimization of occupational health hazards5) Establishment of effective First-Aid machinery.6) Establishment of necessary arrangement for subsequent Medical emergency.7) Proper maintenance of Health records and relevant statistics.8) Putting in place an effective policy for rehabilitation of sick and injured person.9) Development of Health promotional activities including Health education.

. 10) Noise mapping of various work places in the mine premises based on the various machines being used in concerned mines along with personal noise dosimetry of individual workmen exposed to noise level above 85 dbA.11) Vibration studies of various mining machinery including drills, SDLs, LHDs, excavators, motor graders, dumpers, etc.12) Ergonomic assessment of all latest machines, before their introduction into mining operation. Ergonomical assessment should include:

Assessment of work process Assessment of working aids/tools Assessment of working posture

13) Potability test of drinking water supplied to the mine employees, to be made mandatory once in a year irrespective of its source, the sample of water to be collected from the points of consumption.14) IME should be made mandatory for all mining employees whether permanent, temporary or contractual, before they are engaged in any mining job. 15) The frequency of PME should be brought down from existing 5 yrs to 2 yrs for the mining employees above 45 yrs of age.16) Each mechanized mine should engage at least one qualified medical officer for every 500 employees and thereafter, one for every 1000 employees.17) One of the medical examinations of every person should be arranged within one year of his superannuation.

(18) Standards IME & PME shall be suitably modified in order to ensure early diagnosis of diseases caused due to employment in mines.(19) Special tests should be included in the PME for employees exposed to specific health hazard.

Q.7) Discuss the following:

a. Information Technology in mine safetyb. Development of communication systems in minesc. Use of site mixed slurry explosives with special reference to safetyd. Electronic detonators.

Ans:- (a) Information Technology in mine safety – Quick and accurate information is vital to any decision making process in mining operational environment where numerous technical parameters need to be synthesized and evaluated. IT specialists design and implement systems to match requirements. Information technology has become a major resource next only to men, money and machine to shape and operate an organisation. It can readily affect the structure of an organisation. Although, industry has recognized the importance of information technology, its application is still in a stage of infancy. A corporate information technology network will have to be developed so that it enables platform for individual and knowledge sharing.

Information Technology is defined as the convergence of electronics, computing and tele-communication. Large scale use of computers in combination with modern communication facilities is generally referred to as IT. It has unleashed a tidal wave of technological innovation in the collection, storing, processing, transmission and presentation of information.In the mineral industry, it will have to play a major role in the areas like

Planning and design of mines Exploration and production of minerals Safety Accurate mine surveying CGPS,CIS, Total Station. Computer aided blast design. Spotting of hot spots/fire. Inventory control Capacity utilization Optimization of inputs

The following are the major thrust areas where introduction of information technology in synchronization with management objectives will yield the tangible results in terms of production, productivity, safety and utilization.

1. Remote control and monitoring system for accurate management information2. Management of project implementation through compute- based software packages.3. Introduction of atmospheric monitoring system to improve safety standard in u / g mines.4. Introduction of radio – communication in u / g mines in place of cable –communication.5. Integrated communication network for voice and data transmission right from work sites to the corporate level.6. Computerized maintenance technology like routine condition monitoring of the health of the equipment for better utilization and taking corrective measures in time.

7. Quality forecasting by continuous computerized monitoring of coal samples for online ash monitoring and also removal of shale / stone from coal.8. Introduction of integrated mine management system in large o/c mines enabling mine management to ensure optimal utilization of system capacity. Ans-(b). Development of communication systems in mines- In case of serious bodily injuries, fatal accidents, mine disaster and dangerous occurrence such as outbreak of fire, collapse of workings, presence of noxious gases etc, speedy information of such accidents / dangers occurrence will not only help in rescue and recovery operations but also limit the consequences of danger. This can be achieved through effective communication system from the wok site in the mines to all concerned.As per reg. 87 (4) (b) of CMR’1957, in any mine below ground, if a system of haulage roadways and conveyors extends to a distance of more than 600 m from the shaft or the entrance to the mine, efficient telephonic communication shall be provided and maintained between the end of every such system and the bottom and the top of the shaft or entrance to the mine.Rule 113(2) of IER 1956 also requires that efficient means of communication shall be provided and maintained between surface switch room (where switch gear for distribution of power supply is provided) and shaft bottom or other distributing centers in the mine.Although statutory provisions have been made in the statute as mentioned above for communication system in below ground mine and also between surface switch room and the shaft bottom but these are not sufficient because existing communication system has its limitation owing to wired transmission and the need for a person reach the place, where the set for communication is provided to communicate any message.Communication system available in O/C mines and at surface of a mine in the firm of wireless communication through microwave line and mobile phone may be considered sufficient.In case of belowground mines, CDS (central dispatcher system) connecting working place, mine site offices and residence of the mine officials is available, in addition to point to point telephone connection. With this communication system, trapped miner could not located precisely and hence they could not be rescued at right time without wasting the valuable time.Hence the need for reliable communication between the miners inside the mine and the outside has been felt.The following are the communication systems that have been developed and permitted by DGMS in India. (i) Mobile Radio Communication System using base station and DECT (Digital Enhance Cordless Telecommunication hand sets( manufactured by M/s. HCL Info system Ltd.) :- This system provides communication between working district to surface and belowground to belowground workings with the system, voice communication is possible through wireless handsets at a distance of 90 mtr. from the base station. A miner having the handset can communicate his location if he is alive when trapped under debris. This system do’not have tracking facility.(ii) Mine Radio system using leakage feeder cable (manufactured by M/s. Mine Radio System Canada);- Leaking feeder is the technology used to provide communication services in u/g mines and tunnels using a special Co-axial / radiating cable which is partially shielded. This allows radio signals propagating inside the cable to leak out and radiate into the immediate vicinity. These leaked

radio signals are received by conventional VHF two away radio equipment (portable radio). This system has been field tried only for voice communication purpose and the portable radio can cover a radius of 20 mtr. from the nearest amplifier station.(iii) Detection system (manufactured by M/s.CMRI, Dhanbad):- It is a wireless transmission system having two different devices working in conjunction with each other. The two devices are:-a) transmitter unit attached with the mine worker, and b) receiver unit carried by rescue team.The transmitter unit can be incorporated with cap lamp to derive supply for operation. The LF radio wave transmitted by the transmitter is capable of transmitting through rock strata and coal debris. The receiver unit to be carried by rescue team is designed to catch the said frequency and amplify it several times before input to the final alarm circuit. As soon as the receiver system finds a signal, the rescue team, member will turn the antenna associated with the receiver in order to find the direction where the loudness of alarm is maximum. In this way the rescue member will be able to reach the trapped miner quickly. If the trap miner could not switch on his transmitter, than the system will not be able to locate him. (iv) Central Electronics Engineering Research Institute, Pilani, India is developing a system which shall be capable of transmitting data from UG to Surface where it can be analysed to locate place of roof fall/wall collapse and shall be cable of detecting the trapped miners and determining whether the miner is alive under the debris. To introduce the above mentioned communication system in Indian mines, the existing rules & regulations under IER,1956 and CMR 1957 regarding telecommunication system for belowground mines should be suitably amended.Ans. ( c ) :-Use of site mixed slurry explosives with special reference to safety- The following safety precautions shall be taken in using SMS in opencast mines:-i) Statutory obligation - Mine management shall obtain prior written permission from DGMS for:- Use of explosives in other than cartridge form. Use of more than one type of explosives in the same hole.ii) Compatibility of booster and the column charge to be ensured by the management.iii) All conditions stipulated by the Chief Controller of Explosive granting approval for SMS regarding manufacturing, storage, transportation and handling shall be strictly followed. iv) The operations of mixing of the SMS, loading, charging etc. shall be carried out under the guidance of the technical service engineer of the explosive manufacturer and pump truck carrying the explosive constituents shall be approved by CCE and shall be in safe operating condition and driven by competent licensed driver. v) The mine management shall frame a suitable code of practice to be observed by the blasting crew for handling the SMS in consultation of the explosive manufacturer. A copy of the same shall be submitted to DGMS.vi) Loaded pump truck not to be kept at isolated place.vll) No smoking / open flame to be allowed within a radius of 60m of the pump truck

vlll) Area within 10m radius of pump truck to be kept free of rubbish, dry grass or other combustible materials.ix) (a) Only necessary minimum persons to be allowed during charging and firing operation.

(b) No spillage of explosive during charging operation. (c) Ensuring continuity of explosive charge in the hole (d) Hose pipe used for loading of SMS shall have anti static properties and a

diameter less than critical diameter of explosives and pump truck shall be properly earthed with chain link where loading.

(e) Charging and firing of holes only in day light hours. (f) Preventing un-authorized and inadvertent entry of persons in the area of

loaded holes. (g) Maintaining proper record of blast geometry as well as post firing data related

to ground vibration, fly rocks, fragmentation etc by authorised competent person.x) No sleeping of holes without prior written permission of DGMS.xi) Adequate precautions to be taken in case of misfire.xii) In case of hot strata, no blasting to be done without obtaining prior permission from DGMS in writing.xiii) The entire operation of transportation of explosives to the sites of its use, charging and blasting shall be placed under the charge of asstt. manager. xiv) The mine management and manufacturer shall prepare a scheme of training covering all accepts of operation involving SMS blasting method. The persons engaged in operation shall be trained as per the scheme at regular intervals. Ans.(d) Electronic detonators- It is basically a device, which stores electrical energy for a certain time and then delivers that energy as a sharp pulse at a precise time to a conventional fuse head. It is based on microchip technology. A miniature timing circuit replaced the chemical delay element in conventional electric detonators.The conventional delay detonators are pyrotechnic based which suffers the disadvantages of cap scattering. The cap scattering causes inefficient blasting, poor fragmentation, more ground vibration and other associated problems The electronic detonator provides the accurate delay of the order of 1 ms, Each electronic detonator has a unique identification no.(ID No.)Components of electronic detonators:- Usually the electronic detonator system consists of three key components:-i) Programmable digital detonator.ii) Loggeriii) Blaster

i) Digital detonator- The programmable digital detonator contains a micro clip, energy store capacitor, safety components and conventional explosive components. The strength is equivalent to detonator No.8. The micro clip circuitry includes an oscillator for timing, memory for retaining its programmed delay and communication functions to receive and deliver messages to and from the central unit. The capacitor can store sufficient energy to run the micro clip independent of external power for 14 Sec. with enough energy remaining after the time period has elapsed to fire the fuse head. Protection against electrostatic discharges, stray current and radio frequencies are provided through detonator design, chip design and protective component on the input side of the detonator. Shock protection is provided both internally and externally. Each detonator has a connector which allows easy connection

to the harnesses wire when hooking up. Each detonator is programmable between 1 ms to 1500 ms.

ii) Logger – It is used to communicate and assign the desired delay times to the individual detonators. Operating at an intrinsically safe voltage, it recognizes and tests each detonator. During the check of the ID No. of the detonator to be logged, the logger also checks the correct contact between detonator and twin wire as well as the functioning of the detonator and check the wire of short circuit or current leakages. One logger can manage maximum of 200 detonators.

iii) Blaster:- It is a unit which controls the programming and triggering of blast. It is used to fire the blast and only deployed from the firing position once the operation is clear of persons. It contains the required voltages and codes capable of firing the detonators.It communicates to each detonator in turn via the logger. One blaster can manage upto 8 loggers. Thus the firing system can operate a maximum of 1600 detonators in one go.

Benefits/Advantages:- i) High level of protection against stray currents, static and

electromagnetic radiation.ii) Ensuring high diagnostic safety, security and complete system integrity

in the field.iii) Very much effective in containing ground vibration level.iv) Improved rock fragmentation, increased production and productivity.v) Accuracy, programmability and Testability vi) Noise free (as DF is completely removed from surface connection.)vii) Reduced overall cost.viii) Eco-friendly.

Disadvantage:- i) Misuse by antisocial elements ii) High Cost.

The accuracy, simplicity and safety of electronic detonator will lead to total control of fragmentation, vibration and fly rock in blasting operation. It is expected that these products would help the mining industry to maintain its sustainable growth keeping in view the increased human sensitivity and safety consciousness.

Q.8.Write detailed note on the following as per IER, 1956.a. Overhead lines in open cast minesb. Precautions to be taken in use of electricity in degree lll gassy mines.

Ans. a. Overhead lines in open cast mines- Rule 118 of IER 1956 stipulates that energy shall not be transmitted into a mine ( U/G or O/C) at a voltage exceeding 11 KV and shall not be used therein at a voltage exceeding 6.6 KV. In Indian OC mines, energy is generally transmitted at a voltage of 11 KV from 132 KV central substation and small electrical shovels use 3.3 KV but bigger shovels, draglines and drills use 6.6 KV In addition to the above, the following statutory precautions shall be taken in respect of O/H lines in OC Mines:-i) Clearance above ground of O/H line in opencast mine- The minimum clearance of the lowest conductor of the O/H line above ground in the mine should be 4.6m but if the line is to cross a haul road, the clearance of the lowest conductor above the raised body of maximum size of dumper plying in the circuit shall not be less than 3m, but in no case shall the clearance from the ground be less than 12m. ii) Precautions to be taken if the O/H line has to cross a road- If the O/H line has to cross a road (public road), the following precautions will be taken:a) Clearance above ground: 6.1m b) Guarding Cradle guard will be provided below the portion of the O/H line crossing

the road to provide safety against a fallen live conductor. Cradle guard shall be earthed. Breaking strength of wires used for making cradle guard shall not be less

than 635 Kg. and the wires shall be made of galvanized iron or steel. Guard wires used shall be of sufficient current carrying capacity so that in

case a live conductor breaks, there is no risk of fusing of the guard wire until the line is rendered dead.

iii) Stay wire: Stay wires shall be provided for the poles erected on either side of the road. These wires shall be earthed.iv) Anti climbing device and danger notice: If the supports/poles are such as can be easily climbed upon, anti climbing devices shall be provided on them to the satisfaction of inspector to prevent an unauthorized persons climbing it.v) Protective Device- The O/H line shall be protected with a device approved by the Inspector for rendering the line harmless in case it breaks.vi) Protection against lightning- O/H line shall be provided with lightning arrestors – both at the sending and the receiving end.vii) Blasting operation- No blasting shall be done within 300m of O/H without consultation of the owner of electric supply lines and in case of mining lease hold area, without written permission of CIM or Electrical Inspector of mines. viii) Service Line:- No service line shall be taken off an O/H line except at a point of support. ix)Earthing ;Each Support and its metallic fittings of O/H line shall be permanently and efficiently earthed.Ans. D. Precautions to be taken in use of electricity in degree lll gassy mines- Under mentioned precautions are required to be taken in use of electricity in degree lll gassy mines as per rule 126 of IER 1956 in respect of the following:-

1) Cables:- All cables at every place shall be constructed, installed, protected, operated and maintained ( CIPOM) in such a manner as to prevent risk of open sparking.2) Intrinsically safe circuit:- Signaling, telecommunication or remote control circuits at all places shall be so constructed, installed, protected, operated and maintained ( CIPOM) as to be intrinsically safe.3) FLP apparatus and enclosures:- i) All apparatus shall be flameproof within 270m from nearest face or goaf or in-bye of last ventilation connection or in a return airway. ii) All electric lamps shall be enclosed in flameproof enclosures at all places.4) Disconnection & re-connection of supply in general:- i) Supply shall be disconnected:- Immediately, if open sparking occurs During the period of examination or adjustment of the apparatus which

requires exposing of any part liable to open sparking.iii) Supply shall not be re-connected until the apparatus has been examined

by the Electrical Supervisor or one of his duly appointed assistants and until the defect, if any, has been remedied or necessary adjustment made.

5) Provision of flame safety lamp and automatic gas detector :- i) A flame safety lamp shall be kept burning near an apparatus ( including portable or transportable apparatus) which remains energized, and if the safety lamp indicates presence of inflammable gas, supply to all apparatus in the vicinity shall be immediately disconnected and the incident reported forthwith to an official of the mine.ii) Where apparatus for automatic detection of inflammable gas or vapour is employed in addition to the flame safety lamps, such apparatus shall be approved by the Inspector of Mines and maintained in perfect order. The apparatus shall be interlocked with the controlling switch in such a manner as to disconnect the power supply automatically if inflammable gas exceeds 1.25% in that particular district. 6 ) Disconnection & re-connection of supply in case of detection of gas :- i) If inflammable gas in the general body of air exceeds 1.25%, power shall be immediately disconnected from all cables and apparatus in the area. Re-connection shall not be made till the gas remains in excess of 1.25%Provided that such disconnection shall not apply to intrinsically safe environmental monitoring scientific instruments.ii) Such disconnection and re-connection shall be noted in the Daily Log Book and reported to the Inspector of Mines. 7) i) Only DGMS approved FLP equipment and intrinsically safe equipment shall be used in u/g mines. ii) Cables shall be as per BIS specifications. iii) Only intrinsically safe testers/ meggers shall be used.



SECOND CLASS




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Q.No.1. What is the procedure to frame Traffic Rules for a large opencast mine? Frame model Traffic Rules for an opencast mine producing 10 million tonne of coal per annum with a stripping ration of 1:5.

Ans:- Conditions given:- Coal production – 10 mte. OBR – 50 mm3, S.R. – 1:5,Composite volume- 57 mm3, density of coal – 1.4 te/m3 Condition assumed- HEMM & other machinery to be deployed.a) Heavy Vehicles:-Electric rope shovel (10 m3) – 12 Nos.,Dumpers ( 85te) – 50 NosDozers – 10 Nos.,Drills (250mm) - 10 Nos., Road Graders- 03 Nos.Explosive Pump trucks- 03 Nos., Buses – 02 Nos., Water Tankers- 04 Nos., Pay loaders – 10 Nos.b) Light Vehicles- Jeeps, land rovers, maruti gypsys etc.Need of traffic rules:-As per recommendation of 7th Safety conference on safety in mines, each mining company should frame suitable code of traffic rules for regulating the movement of HEMM commensurate with the capacity, size and type of machines used in mechanized open cast mines for enforcement in each mine.

Procedure for framing traffic rules:-The following rules are designed for the safe operation of vehicles in and around the mine. Operators of vehicles shall observe these rules and any other special instructions given by the Mine Manager. The Mine Manager and Officials appointed by him shall ensure that all persons in the mine comply with these Rules.

Following are the procedures for framing traffic rules:- (a) Only persons authorized by Manager shall drive or operate vehicle in or

about the mine.(b) A private vehicle shall not be driven within the mine premises unless

authorized by the Mine Manager or the official in charge of the office.(c) Any driver, not regularly working in or about the mine shall request and

receive permission to enter the mine premises from Mine Manager or an authorized official, prior to driving a vehicle within the mine premises.

Model Traffic Rules for a large opencast mine:-

1) Speed Limits:- (a) Speed limits fixed by the Mine Manager for class of vehicles shall be strictly

followed.(b) In case of poor visibility or poor road conditions, speed shall be reduced to

the extent necessary to maintain effective control.

2) Right of way:-(a) At inter-sections , all drivers should give way to the vehicle on the right,

except below:-(i) All drivers shall give way to emergency vehicles showing a

flashing red light.(ii) Vehicles being used for grading, rolling, watering and repair of

roads have right of way over all vehicles except in emergency vehicle. These vehicles will show an amber flashing light.

(iii) Light vehicles shall at all times give way to haul trucks and other heavy vehicles.

(b) The driver of a vehicle having right of way over another vehicle shall not endanger himself or other through insistence on that right if this is likely to cause a collision.

3) Parking and Standing: - Following precautions shall be taken by the drivers(a) No parking / standing of vehicles in a position endangering other traffic on

the mine premises.(b) No parking / standing of vehicles opposite another vehicle on a haul road.(c) No parking/ standing vehicles within 30 m of the working area of mobile

equipment and within the area of swing of the dragline without permission from the operator.

(d) Ensuring the effective parking of vehicle by applying parking brakes and lowering implements.

(e) Ensuring that while moving from a parked position his path is free of any obstruction and /or personnel.

(f) While parking the light vehicles, the following rules to be obeyed:- Engine to be stopped.- Leavening vehicle in first / reverse gear:- Hand brake to be applied.- No parking in front of or behind a heavy vehicle;- Chocking the wheels, if parked facing up or down a slope.

4) General:(a) No driving of vehicle over electric cables, air hoses or water lines.(b) Wearing of seat belt by the operator’s during operation of vehicles.(c) No unauthorized riding of vehicles by the passengers.(d) For break down vehicles, a caution sign or hazard lights are to be

placed at the front and rear. (e) Cleaning, oiling and checking of water, tyres and fuel of machines

to be ensured by operators.(f) Ensuring that vehicle is correctly illuminated during hours of

darkness.(g) Dipping of head lights of vehicle while approaching other traffic or

mobile equipment in working areas.

(h) Sounding one blast on horn for all HEMM before moving off from parked position.

(i) No permission of smoking or use of naked lights during re-fueling and checking of batteries.

(j) Loading of trucks in such a manner that spillage is minimized. Loads should be centralized to maximize stability. Loads which have an overhang in excess of 1.2 m shall be clearly marked by a red flag during day and red light at night.

(k) Ensuring that the vehicle has adequate clearance, particularly, when reversing, parking, passing other vehicles moving / stationary.

5) Overtaking:(a) During overtaking of vehicles, the following shall be ensured: (i) The speed limit is not exceeded.

(ii) There is sufficient visibility of the road ahead.(iii)The vehicles are clear of any road intersection or junction.

(b) The driver of a heavy vehicle may not overtake another vehicle on an incline unless the overtaken vehicle is traveling at a speed less than 10 km/hour and there is adequate visibility of the road ahead.(c) No overtaking is permitted in the vicinity of road dividers.(d) While driving behind a haul truck, the driver shall ensure that he is visible in the rear view mirror until he pulls out to overtake.

6) Signs:(a) All signs are to be obeyed. (b) Temporary signs to be removed after need ceases to exist.(c) Warning signs are to be noted at all times.

7) Examination of vehicles:-(a) Daily examination of heavy vehicles ensuring its safe working and

record of the results of examination to be maintained.(b) In case of any defect in the vehicle as well as damage to the vehicle

or injury to drivers or passengers, the driver shall report the incident to supervisor.

8) Implementation – (a) The manager shall specify the name(s) of the officer(s) who shall be responsible for enforcing the Traffic Rules.(b) A copy of the traffic rules shall be handed over to every driver/ operator and every supervisor.

The above detailed traffic rules governing the movement of all types of vehicles including contractors vehicle within mine premises should be strictly followed in order to ensure safety in open cast mining operation.

Q.No.2.What are the categories of persons employed in mines, who are not covered under the Mines Vocational Training Rules? What are the provisions regarding training of these special category of employees?

Ans:- Following are the categories of persons employed in mines, who are not covered under MVTR’1966 amended time to time:-1) Persons employed for saving life or property, dealing with circumstances arising out of an accident (Rescue persons).2) Persons employed in a position of supervision or management or in a confidential capacity as specified i.e. officers, officials, and supervisors. 3) Shotfirer, blasters & Timber mistries.4) Clerks, accountants and register keepers5) Persons who have undergone a course of training at an approved institution.6) Mining apprentices working under personal supervision of a mine official.

7) Apprentice mechanics or apprentice electricians, if they have undergone an approved course of training at mine mechanization centre.Provided the persons at (4) to (7) shall undergo refresher training as per rule 8.

Provisions of training of special categories of employees:-1) Training of persons employed for saving life or property dealing with circumstances arising out of an accident:-

As per provisions contained in rule 4 of the Mines Rescue Rule,1985, Special categories of employees engaged for saving life or property, dealing with circumstances arising out of an accident , should undergo for the following types of training at mines Rescue Station:-(a) Initial training in rescue and recovery work: - Under this heading both theoretical and practical training shall be imparted. Theoretical training includes study on-

General methods of dealing with fires U/G and recovery of mines after fires and explosions.

Construction, use, repair, maintenance and testing of various types of rescue apparatus.

Properties and methods of detection of noxious and inflammable gases.

Collection of gas samples in irrespirable atmosphere Reading of mine plans.In practical training, not less than 12 practices with breathing apparatus

and not less than 2 practices with smoke helmet shall be carried out under conditions devised to resemble those likely to be encountered in operations U/G and requiring the use of rescue apparatus. Each practice shall be of at-least 2 hours.(b) Refresher training to rescue trained persons:- Theoretical courses for refresher training to rescue trained persons shall be same as mentioned in (a) above. However for practical purposes, at least 8 practices with breathing apparatus in every calendar year of which at least 4 practices shall take place in mines and 4 practices in hot and irrespirable atmosphere in the training gallery at Rescue Station.However, persons employed in rescue services should be imparted refresher training time to time and also specialized training for use of modern and sophisticated rescue apparatus.(2) Training of persons employed in a position of supervision or management or in a confidential capacity:-

Under these categories, the persons specified to be deployed in a position of supervision or management or employed in confidential capacity and provision for their training are given below:-a) Officers – Manager, Asstt. Manager, Ventilation Officer, Safety officer, Mining / Electrical / Mechanical Engineer, Medical Officer, Welfare or Personnel Officers.Training Provisions for officers:-(i) Induction/ Orientation training – Such type of training is imparted to newly recruited officers in order to make them familiar with the organisation and its structure, service conditions, duties, responsibilities and rights, career growth, social security, medical facilities etc. The duration of course is generally one week and the training is generally in-house.(ii) Medical Officer associated with PME should be imparted proper training in occupational health and use of ILO classification.(iii) Supervision & Management Course – One month extensive training is imparted at Central Staff training College for developing officers through inter company management development programme as a continuous process.iv) Special training facilities: - Special training related to introduction of special mining techniques and methods such as longwall mining, scraper mining, continuous mining, surface mining etc is imparted to officers engaged in mining operation. The duration of training is generally one week.v) External training facilities:- In-house training facilities are not adequate to meet all the training needs of the industry. Following external training facilities are given to officers:-

- Refresher and improved courses in technology at technical institution.- Management courses at administrative Staff training College.- Specialized technical skills and advanced management courses outside the

country.- Seminars and workshops organized by professional bodies like institution of

Engineers, Mine Managers association, educational institution etc.The course content and time duration for above mentioned courses are different for different types of training.(b) Supervisors and officials:- Overman, mining sirdar, mechanical/electrical foreman, electrical supervisors, Surveyors and assistant surveyors.

Training provision:- (i) As per new training modules, Supervisors and mine officials shall be imparted training as per details given below:-

Category Initial training( in no of days) Refresher training( in no of days)Theory

On the job

Feed back

Total Theory On the job

Feed back

Total

Supervisory Officials

11 06 01 18 05 06 01 12

Electrical Supervisiors.

11 06 01 18 05 03 01 09

The training shall be imparted strictly as per the syllabus/ modules designed for the purpose.

(ii)As per recommendation of 8th conference on safety in Mines:- All front line supervisory officials like Sirdars, Overman/ foreman,

Surveyors, Electrical/ Mechanical supervisors as well as persons supervising surface operations should be imparted structured training in safety management for at least two week, once in a five years covering 20% strength every year.

Properly designed class room training should be provided to candidates for Sirdars examination.

Members of safety committee should be given training to prepare them to discharge their assigned functions effectively and efficiently. The training programme should be for one week & should comprise lecture and demonstration sessions as well as field visits as per approved syllabus.

(iii) Each mine official should be trained in first aid and should see that his first aid certificate is re-validated whenever necessary and refresher training to all first aid certificate holders by qualified medical practitioner. (iv) All workmen’s inspector have to undergo an orientation training course consisting of not less than 30 lectures and demonstrations of not less than 2 hours duration each, in accordance with the syllabus specified by and at a centre approved by CIM.(v) Necessary training should be organized with the help of experts, both national and international, for optimal adoptions of the safety management system. (vi) Special courses for supervisors and officials should to be imparted to acquaint them with the special objectives necessary for immediate or future needs.(vii) Training in gas testing should be imparted to all mining sirdars, overman and other supervisors in VTC at least once in every year.(3). Training for short firers/ blasters and timber mistries:- All short firers/ blasters and timber mistries should be imparted training on development course as per following details:-

Categories of persons No of lectures /

days

Remarks

i) Short firer/ blasters :-a) All potential shot firers/ blasters before appearing for competency exam as newly appointed shot firers who have not undergone the course of training or with a break of service for more than six months

12 lectures Training to be completed within one month of employment / re-employment.

b) Training in gas testing for competency certificate holders & candidates intending to appear in gas testing exam within next 3 years

6 lectures Instruction course to be covered every year

ii) Timber Mistries:- a) To be newly employed from the categories of timber man.b) To be re-employed after a break of service exceeding 6 months.

6 days Training to be completed before appointment as Timber Mistry.

For clerks, accountants, register keepers, persons undergone training at approved institutions and apprentice’s mechanics or apprentices electricians should be imparted refresh training in their field of work from time to time.

Q.No.3. Enumerate the provisions of Mines Rescue Rules, 1985 regarding – (a) Establishment and location of rescue stations.

(b) Appointment of rescue trained persons in mines, their disposition and accommodation.

Ans:- (a) Establishment and location of rescue stations- i) CIM may permit or require the owner of belowground mine or ground of belowground mines to establish and maintain rescue station(s) with such design and specifications and at such place(s) as may be considered necessary in consultation with the owner. CIM may permit or require two or more owners to jointly establish a common rescue station(ii)At every rescue station, there shall be appointed one superintendent, at least two instructors and also there shall be maintained a rescue brigade of at least 18 rescue trained persons.(iii)The owner shall appoint another superintendent in case the period of absence of superintendent at rescue station exceeds 60 days.(iv)The owner shall within 7 days from the date of assumption or relinquishment of charge by the superintendent inform CIM & RIM.(v) At every rescue station, there shall be provided and maintained for immediate use apparatus and equipment as specified in schedule –l of Mines rescue rule 1985vi) Self – contained breathing apparatus provided at rescue station shall be of same type and make.vii) Every mine shall be connected telephonically with the rescue station serving the mine. Where ever practicable, wireless communication shall also provided.

Ans.3 (b) Appointment of rescue trained persons in mines, their disposition and accommodation-i) At every belowground mine where more than 100 persons are ordinarily employed belowground, at least 5 rescue trained persons shall be readily available at surface at any time.ii) When more than 500 persons are ordinarily employed belowground,

there shall be appointed one rescue trained person for every 100 persons or apart thereof.

iii) All rescue trained person shall be provided suitable accommodation close to their work place by the owner.

iv) There shall be provided at belowground mine effective bell or other approved arrangement for immediate summoning of rescue trained persons.

v) A rescue trained person may be suspended or debarred from undertaking any rescue and recovery work if found in-competent or guilty of negligence/misconduct in the performance of his duties by owner, agent, manager or an inspector.

vi) Every rescue trained person shall be re-examined once at least in every 12 months by a qualified medical practitioner and if declared medically unfit, he shall cease to a rescue trained persons from the date of such declaration.

vii) Every rescue trained person shall undergo practices and receive instruction as per the provision of Mines Rescue Rule 1985.

Q.No.4. An accident had occurred in an opencast mine due to fall of dumper from haul road to lower bench. One worker received fatal injuries. Write a report of enquiry of the accident bringing out contraventions, responsibility and suggestions to prevent similar accidents in future. Assume your own conditions.


Ref.No……………………… Date………...

To,The Manager,“ A “ OCP

Sub:- Enquiry report in respect of fatal accident involving 1 worker in A-open cast working due to fall of dumper

from haul road to lower bench.

Dear Sir,

As desired vide your letter no………………… dt…………… I am enclosing herewith the detailed enquiry report in respect of fatal accident in A-O/C working due to fall of dumper from haul road to lower bench indicating the cause and circumstances attending to the accident, contraventions of statutory provisions, responsibilities and suggestions to prevent similar accident in future in Annex.l . I am also enclosing the accident plan showing the site of accident along-with photo graphs.


( A.C.M. ) “A” OCP

Annexure - l


Assumption of Conditions:-A OCP is being worked in V,Vl,Vll,Vlll combined seam 18m thick, dipping

at 1 in 7 with shovel – dumper combination using deep hole blasting after obtaining statutory permission for extraction of pillars by OC method from DGMS. The strata above coal seam is hot due to fire. The seam is extensively developed in 3 sections in past on the pattern of B/P method of mining. The depth of working from the surface is about 100m. There are 5 benches in OB and 3 benches in Coal. I _______________, ACM, A OCP inspected the place, where this accident occurred and enquired into the cause and circumstances connected with the same.

1) Introduction & information :- The accident occurred in A OCP of M/s……. on ……… at about 5.00 P.M. in 2nd shift when 10 persons under the supervision of an overman and two mining sirdars were engaged at first OB bench in various activities including loading of OB by shovels into dumpers. I received information about the accident at about 5.30 P.M. when I was in my residence.

2) Background information:- The depillaring permission was obtained for extraction of developed pillars by open cast method with shovel dumper combination using deep hole blasting. The usual practice at A OCP was to expose the developed coal pillars by removing OB, extract the pillars and then Coal & OB transported to coal stock and OB dump respectively.

3) Occurrence of accident:- At about 5.00 PM, one of the worker’s noticed the falling of dumper from haul road to top bench on rise side. By the time, he could raise on alarm, dumper started sliding down rapidly into the quarry. 9 Persons tried to runaway while 1 worker could not escaped and buried under the dumper.

4) Rescue & Recovery:- Machines were deployed immediately & the body of the deceased could be removed by 10.00 PM on same day.

5) Inspection & Enquiry: - On receiving information about the accident, I immediately inspected the place of accident along with the other supervisory staff and workmen. I made detained observations and some measurements at the place of accident and prepared a sketch of the place of accident giving leading dimensions. Photographs of the place of accidents were also taken. The sketch and photograph is attached with the report. I also examined witnesses and recorded their statements.

6) Analysis of evidence/ Observations: - From the inspection of place of accident, careful study of DGMS permission and analysis of evidence collected, the following were revealed:- i) Dumper operator was operating the dumper carelessly and over speeding. During investigation, it was also revealed that dumper operator was on overtime. ii) The gradient of existing haul road was limited to 1 in 10.

iii)The dumper operator was wearing safety belt.iv) No berms and parapet wall was provided in the haul road.

7) Cause of Accident:- Enquiry into the accident revealed that accident occurred due to the following reasons:-i) Careless driving of dumper by dumper operator who was deployed on overtime.ii) Absence of berms and parapet wall in the haul road.iii)Unsafe haul road – high gradient.

8) Contraventions of statutory provisions:- Regulation 95A of CMR 1957 read with DGMS permission letter for extraction of pillars by open cast method were contravened in respect of the following:-i) Gradient of haul road - Gradient of haul road was not maintained properly. No haul road shall have a gradient steeper than 1 in 14. ii) Provision of berms & parapet wall – As per condition stipulated by DGMS, no berms and parapet wall was provided in the haul road.iii) Negligence on duty by dumper operator.

9) Responsibilities:- Enquiry into the accident revealed that if the haul road were made properly and care taken while operating the dumper by operator as required under statute, the accident could have been averted. The following persons are considered responsible for the accident:- i) Manager- In contravention of provisions of reg. 95A and 41 of CMR 1957 read with sec. 18(4) of mines act 1952, the manager failed to effectively implement the conditions imposed by DGMS for design, construction and maintenance of haul road and arrange adequate no. of dumper operators in all the shifts in order to avoid deployment of operator on overtime. ii) ACM- In contravention of provisions of reg. 95A and 42 of CMR 1957, the ACM failed to effectively implement the conditions imposed by DGMS for design, construction and maintenance of haul road. iii) Overman-In contravention of provisions of reg. 95A and 43 of CMR 1957, the Overman failed to effectively implement the conditions imposed by DGMS for formation of benches and design of OB dump.iv) Dumper Operator- He failed to follow the instructions given by senior officials.

10) Suggestions to prevent similar accident in future:- In my opinion, the following suggestions should be implemented in order to avoid repetition of similar accidents in future:i) Design, gradient and maintenance of haul road- a) No road shall have a gradient steeper than 1 in 16 at any place.. For any deviation, written permission of CIM should be obtained and the conditions specified must be followed. b) Width – The minimum standard road width should be three times the width of largest vehicle unless definite turnouts and waiting points are designated. As far as practical, all roads from the open cast workings shall be arranged to provide one way traffic and separate road for light vehicle. c) Stopping sight distance/ visibility at corners – All corners and bends in roads shall be made in such a way that the drivers of vehicles have a clear view for a distance not less that 30m away the road. Where it is not possible to

ensure a visibility for a distance of 30m, there shall be provided two roads for up and down traffic. d) Parapet walls – Where any road exists above the level of the surrounding area it shall be provided with strong parapet wall or embankments not less than 1 in height to present any vehicle from getting off the road. e) Design of berms- The size of berm should be at-least half the tyre height of the largest vehicle plying on the road. The side slopes of a berm should be graded at 450

to horizontal which stabilizes the side slope and enhances the impact absorbing quality of the berm.ii) Haul road lighting : Haul roads should be adequately lighted during dark hours. It should have a minimum standard of illuminations 0.5 to 3.0 lux.iii) Manpower -Adequate nos. of dumper operators should be appointed keeping in view factors like absenteeism, leave etc. . iv) Avoidance of overtime duty.- Work on overtime should be avoided..v) Provision of seat belt - For providing adequate safety to the operators in the event of overturning; a seat belt should be provided.vi) Selection of Operators- Operators should be selected from amongst persons possessing requisite qualifications. The selection process should comprise a test to check driving / operating skill, aptitude, health and oral examination of the candidate by a competent selection committee.viii) Training and re-training- Operators should be imparted proper training and retraining for their development and strict adherence of safety rules.

Q.No.5. Write short notes on any three of the following: (State statutory provisions wherever necessary)

a. Illumination in opencast mine.b. Obligation of manager in case of serious bodily injury.c. Intrinsically safe circuits and equipment.d. Provisions of Indian Electricity Rules, 1956 regarding “ Precautions

where gas exists”

Ans:-5(a) Illumination in Open mines- As per regulation 151 of CMR-1957 i) Adequate general lighting arrangements shall be provided during working hours at every opencast working..ii) The lighting provided in a mine shall be so arranged to prevent glare or eye strain.iii) Where electrical energy is available at the mine, the lighting arrangement shall be by electrical means.Standards of illuminations:- The standards of lighting to be provided in opencast mines during working hours at different places or area where natural light is insufficient., have been recommended by DGMS as per following details:-

Sl.No. Location Minimum Illumination Level /plane of illumination (Lux) (Horizontal /Vertical)

1. Operational area 5 H Of draglines & shovels, 10 V

2. Operational area of drills 20 V3. Operator’s cabin of Shovel, 30 H

Dragline, drill etc4. Dumper haul road 0.5 – 3.0 H5. OB and coal dumps 3 H6. Roadways and footpath

from bench to bench 3 H7. CHP, workshop and

service buildings As per BlS specification

Lighting near the faces and haul road may be arranged by clusters of high pressure sodium vapour lamps located on the top of an adjustable telescopic mast, mounted on a platform with rubber tyred wheels or skids and having a portable DG Set

Ans.b) Obligation of manager in case of serious bodily injury- Following are the statutory obligation of manager in case of serious bodily injury to a person employed in a mine:-i. Information & Notice of accident:- Manager shall forthwith inform the RIM about the occurrence by telephone or express telegram or by special messenger. He shall also give notice in form IVA to District Magistrate CIM, RIM and Coal Mines Labour welfare Commissioner within 24 hr of serious bodily injury to any person and shall simultaneously exhibit a copy of notice on special notice board at the office of mine and shall ensure that the notice is kept on the board in a legible condition for not less than 14 days from the date of such exhibition. If any injury already reported as serious bodily injury turns to fatal, a notice shall be given to above mentioned authorities within 24 hours of being informed of the death by the Manager.

Manager shall also within 7 days send to CIM, detailed information of persons injured in form lVB . He shall also send particulars of injured persons returning to duty within 15 days of return to DGMS in Form IVC.ii. Inspection and Enquiry: - Manager shall inspect the site of accident as soon as possible and shall also either himself or through an ACM have an enquiry made into the cause of and circumstances attending the accident. The result of every such enquiry and a plan and sections and wherever practicable a photograph(s) of the site of accident showing details, shall be recorded and a copy shall be sent to CIM and RIM within 15 days of accident.iii. Place of accident not be disturbed- The place of accident shall not be disturbed or altered before arrival or without consent of DGMS, unless such disturbance or alteration is necessary:- To prevent any further accident. To remove bodies of the deceased To rescue any person from danger To avoid discontinuance of work at the place of accident seriously impending the working of the mine.

In case of failure by DGMS to inspect the place of accident within 72 hrs of occurrence of accident, work may be resumed. However, before disturbing or altering the place of accident, accident plan shall be prepared ( in duplicate) and duly signed by manager or ACM, Safety Officer, Surveyor and workmen’s inspector / workmen and a copy of the same shall be sent to DGMS.

Ans.5(c) Intrinsically safe circuits and equipment-In every gassy seam of ll and lll degree, only flameproof or intrinsically safe

apparatus and equipment can be used belowground. An intrinsically safe apparatus is an apparatus which is safe in itself.Intrinsically safe as applied to apparatus or associated circuits shall denote that any sparking that may occur in normal working is incapable of causing explosion of inflammable gas or vapor. In other words – Intrinsically safe apparatus means an apparatus which is so constructed that when connected and used under the prescribed conditions, any sparking that may occur in normal working, either in the apparatus or in the circuit associated therewith, is incapable of causing an explosion of the prescribed inflammable gas or vapour. Electrical equipments are to be designed with great care due to sparking caused by the discharge of energy from the reactive parts of the circuit at the moment when the circuit is broken. Therefore, in most electric circuits used in mines, the energy which causes the spark is stored in the magnetic fields created by electromagnetic apparatus.Some times a single small spark is capable of igniting air firedamp mixture. Special type of circuits can be designed so that the discharge of reactive energy is controlled and does not produce an incendive spark when the circuit is broken. Hence to control the re-active energy, an electrical circuit is made intrinsically safe.Intrinsic safety can be obtained in circuits with a low power consumption i.e. both the voltage of the system and the current flowing in the circuit must be limited. In practice, intrinsic safety is confirmed to circuits for signaling, telephone, remote control and monitoring.

Requirement of intrinsic safety:-

The power obtainable from the source of supply must be limited so that the reactive energy in the circuit does not any time exceed the limit of safety. There must be a means of absorbing the reactive energy which is released when the circuit is broken. Use of Intrinsically safe circuits and equipment- i) In Deg. I gassy mine, at any place in-bye of the last ventilation connection, Signaling, telecommunication or remote control be intrinsically safe.ii) In degree ll or degree lll gassy mines, Signaling, telecommunication or remote control circuits at all places shall be intrinsically safe.Ans.5(d) Precautions where gas exists –

The following precautions shall be taken in respect of various u/g gassy mines where gas exists:A. In Deg. I gassy mine- 1) Cables:- All cables at every place shall be constructed, installed, protected, operated and maintained ( CIPOM) in such a manner as to prevent risk of open sparking.2) Intrinsically safe circuit:- At any place in-bye of the last ventilation connection, Signaling, telecommunication or remote control be intrinsically safe.

3) FLP apparatus and enclosures:- i) All electrical apparatus (including portable and transportable apparatus & light fittings) in- bye of the last ventilation connection shall be flameproof Provided that electrically operated or battery operated transportable apparatus such as shuttle car, men and materials transporting equipment of Increased safety type ‘e’ shall be permitted at any place with suitable monitoring devices for detection of gasses.B) In degree ll or degree lll gassy mines :-1) Cables:- All cables at every place shall be constructed, installed, protected, operated and maintained ( CIPOM) in such a manner as to prevent risk of open sparking.2) Intrinsically safe circuit:- Signaling, telecommunication or remote control circuits at all places shall be intrinsically safe.3) FLP apparatus and enclosures:- i) All apparatus shall be flameproof within the range given below :-Deg. II – 90m from nearest face or goaf or in bye of last ventilation connection or in a return airway.Deg.III - 270m from nearest face or goaf or in-bye of last ventilation connection or in a return airway. ii) All electric lamps (anywhere in the mine) shall be enclosed in flameproof enclosures.4) Disconnection & re-connection of supply in general:- i) Supply shall be disconnected:- Immediately, if open sparking occurs During the period of examination or adjustment of the apparatus which

requires exposing of any part liable to open sparking.ii) Supply shall not be re-connected until the apparatus has been examined by the Electrical Supervisor or one of his duly appointed assistants and until the defect, if any, has been remedied or necessary adjustment made.

5) Provision of flame safety lamp and automatic gas detector:- i) A flame safety lamp shall be kept burning near an apparatus ( including portable or transportable apparatus) which remains energized, and if the safety

lamp indicates presence of inflammable gas, supply to all apparatus in the vicinity shall be immediately disconnected and the incident reported forthwith to an official of the mine.ii) Where apparatus for automatic detection of inflammable gas or vapour is employed in addition to the flame safety lamps, such apparatus shall be approved by the Inspector of Mines and maintained in perfect order. The apparatus shall be interlocked with the controlling switch in such a manner as to disconnect the power supply automatically if inflammable gas exceeds 1.25% in that particular district. C ) Disconnection & re-connection of supply in case of detection of gas :- i) In coal seam of any degree of gassiness, if inflammable gas in the general body of air exceeds 1.25%, power shall be immediately disconnected from all cables and apparatus in the area. Re-connection shall not be made till the gas remains in excess of 1.25% except intrinsically safe environmental monitoring scientific instruments. ii) Such disconnection and re-connection shall be noted in the Daily Log Book and reported to the Inspector of Mines.(D) (i) Only DGMS approved FLP equipment and intrinsically safe equipment shall be used in u/g mines. (ii) Cables shall be as per BIS specifications. (iii) Only intrinsically safe insulation testers/meggers shall be used.

Q.No.6. What is workers participation in safety management? How can this help to attain high safety standards? Suggest suitable measures to improve safety performance of unsafe workers.

Ans:-Workers participation in safety management:- Safety in mines is the responsibility of everyone connected with the mine.

Since in almost all the accidents, workers are main victims, it was felt long ago that workers should also be associated with the management of safety.

Mine safety in general means safety of mine as well as the persons employed therein. Hence, if the mine is safe, the persons or the workers are safe. It indicates that while the mine safety depends on planning, equipping and devising appropriate technology on one hand, it is very much dependent on the human factor on the other hand.

Those human factors include selection of right person for right job & proper training.

For prevention of accidents, caused due to human failure, it is necessary to involve all those persons whose safety is to be ensured in this process of safety. This process may include:-

i. Safety promotionii. Accident prevention and iii. Safety audit

This means that workers should be given the right of participating in the safety management.

“Workers participation in safety management is the forum for workers through which their trade unions, organizations or their representatives and workmen himself play an important and active role by contributing to the implementation of safety instructions, framing and implementation of codes of practices and in accident investigation” Workers meaningful participation would mean a conscious effort by them to see that safe and healthy working conditions are established at the first instance and there after every effort is made by all concerned to maintain the safety system and curb the unsafe acts.

Workers participation in safety management forms a small but an essential part of the total concept of workers participation. Re-cognising the importance and fruitfulness of workers participation in safety management in shaping safe behaviour at work, the mining industry and DGMS has taken several measures to encourage the same. Over the years, this system is functioning and gradually developing into an effective tool for enhancing safety.At the national level, workers participation is ensured through participation of trade unions in various committee and forums.At various international forums also workers participation is provided in framing policies where workers are stake holders. ILO, Geneva provides for participation of workers representatives in formulating various instruments aimed at providing equality and for workers health, safety, and welfare.

Following are the forums of workers participation in safety & management:-a) Statutory forums:-1. Safety Committee:- Under Mines Rules, a safety committee shall be Constituted where 100 or more persons are ordinary employed. In this committee, workmen, officials and competent persons etc. are nominated. In large mines, sectional/departmental safety committees under the main safety committee may be constituted for specific area of operation as per recommendation of 9th safety conference.

2. Workmen’s Inspectors:- As per Mines rule, workmen’s inspector shall be appointed in all mines where 500 or more persons are ordinarily employed.

As per recommendation of 9” safety conference, all mechanized mines and mines using H.E.M.M. for exploitation of minerals, where 100 or more persons employed, should appoint workmen’s inspectors.

3. Committee:- Under section 12 of Mines Act, a committee shall be constituted by central govt. in which two persons representing the interest of workers shall also be appointed by central govt.

4. Works Committee:- The Industrial dispute Act requires the employer of a mine where 100 or more persons are employed to constitute a works committee in the prescribed manner consisting of the representative of the workmen and the employer.

5. Rights of the worker’s representative to inspect the register maintained under the Mines Rules,1955– The register maintained in Form ‘B’ under the Mines Rules, 1955 shall be available for inspection to a workers representative authorised by the person employed in the mine on an application made by him in this half.

6. Court of enquiry.- Under section 24 of mines act 1952, Central Govt. is empowered to constitute court of enquiry in which representatives of workmen may be appointed an assessor(s).

7. Right of work’s inspector or workmen to inspect the site of accident and to put his signature on sketch plan of site of accident

8. Signatures of WMI on Accident Plan b) Non- Statutory forms: 1. Tripartite safety committee constituted at company level and consisting of

representatives of DGMS, management and workmen. 2. Safety Board headed by Chief Executive of the Company and having

MD’s , Central trade union representatives, DGMS and a representative of the ministry as its members

3. Representation of Central Trade Union leaders in standing committee on safety.

4. Representation of workers organisation in National Conference on Safety in mines.

5. Formation of Quality Circles. 6. As a members of Emergency organisation. 7. Member in risk assessment and risk management process Workmen’s participation in safety management can help to attain high safety

standards in mine in following manners:-i) Inspection of mine workings, safety equipment and machinery to

identify hazardous conditions and defects and to check observance of statutory safeguards. Proper inspection made at frequent intervals help rectify unsafe conditions well in time and perhaps with lesser effort.

ii) Drawing attention of mine officials responsible for taking suitable remedial measures in case of urgent and immediate dangers.

iii) Involving themselves in company’s decision-making process relating to safety and health and then accepting their portion of responsibility for the results.

iv) Playing useful role in accident enquiries by helping to bringing out the real facts or root cause of the accidents for taking corrective actions.

v) Enabling the higher officers of the management to suitability access and appreciate the status of implementation of safety polices dictated from corporate level.

Suitable measures to improve safety performance of unsafe workers:-

Safety performance of unsafe workers may be improved by taking following suitable measures:-

i. Establishment and enforcement of stringent safety regulation, bye- laws and code of practices governing use of new mining machinery and adoption of new mining technology.

ii. Elimination or control of physical hazards such as designing and developing machines and systems incorporating automatic safety devices that could function independent of human behavior.

iii Imparting training & education to the unsafe workers for their overall development. Imparting initial training- theory, on the job & feedback training Refresher training at an interval of 5 years. Development training for enhancement of knowledge & skill.

iv) Motivation: - Where as machines and equipment can be controlled, men must be motivated towards safety to such an extent that they voluntarily improve this performance and realize the intrinsic value of such effort.

v) Eliminating unsafe conditions, unsafe acts & unsafe practices prevailing in the mines.

vi) Involving in Risk Management Process & preparation of safety management plan.

vii) Making a compulsory member of safety committee. viii) Involving in safety audit of mine, if deemed necessary. ix) Involving in general inspection by DGMS

ix) Making a member in emergency plan. Suggested deterrents for habitual unsafe workers:- In addition to above suitable measures for unsafe workers, the following deterrents are suggested:i) Punishment for habitual unsafe workers in terms of issuing warning letter, issuing charge sheets, suspension from the works and even removal from the service.ii) Trial in the court of law as per provisions contained in Mines Act for contravention of statutory provisions and for deviation from safe practices and safe acts.

Q.NO.7.Draw a ‘Code of Practice’ for deployment of Side Discharge Loaders in a depillaring district in which a 5.0m thick seam is being extracted in two lifts in conjunction with hydraulic sand showing.

Ans:- Conditions given :- Thickness of seam – 5.0 mtr. Method of work – depillaring by sand stowing in two lifts with SDL Condition assumed Depth of working – 100 mtr. Support – Roof bolting as per approved SSR. Make of water – Normal Gradient of seam – 1 in 0 Condition of floor – Hard Degree of gassiness- ll Since any depillaring operation is risky, a suitable code of practice for safe operation for SDLs should be framed, got vetted by tripartite safety committee and implemented. The code of practice shall be as follows:- 1) Fittings of SDL- The SDL should be provided with safety & other protective devices are mentioned below :- dump lever with key/push bottom switch foot brake temperature switch oil level switch adequate front and rear light audio-visual alarm Portable fire extinguisher Dead man’s control where by power will be cut off automatically when the driver leaves his seat.2) Operation:- i. SDL shall be operated only by competent person authorized by the manager. He shall not permit any other person to ride on SDL or interfere with its operation. However during test and examination, it may be operated by an authorized competent person other than the driver.ii. Before putting the machine in operation, the operator shall ensure that the machine and its accessories have been checked against a checklist and found in proper working order. iii. Operator shall give a pre-start warning before starting the machine and give sufficient time to persons in the vicinity to move away. iv. Trailing cable shall be protected from external damage during operation. Helper will use insulated gloves for handling the cable. He shall maintain safe distance from SDL in motion.v. During blasting, machine shall be parked at a safe place.vi. When leaving the working place, the operator shall keep the machine in a safe position which does not endanger any person, lower the bucket to the floor, turn and lock levers to neutral position and cut off energy supply from gate end box. The same procedure will be followed at end of the shift.vii. No person other than the operator shall be on the SDL when it is in motion unless permission has been taken from the manager.viii. No person should be allowed to stand besides the machine while the machine is running. ix. Control valve should not be used as a hand hold while climbing on to the machine.

3. Ventilation:- Minimum requirements:- Quantity of air- At least 284 m 3/min upto 4.5m from the face, Velocity- not less than 30m/min; Inflammable gas in general body of air- not more than 0.5%. SDL shall not be used out-bye of last ventilation connection.4. Dust Suppression: - Water spraying upto 90 m from the face of blasting. 5. Other safety precautions:- (i) Only approved type of hydraulic fluid shall be used.(ii) SDL shall not be operated at a gradient more than 1 in 4, Roads shall be kept clean and free from hindrance. Vertical supports shall be avoided as far as possible.(iii) No person shall cross the SDL during its movement.(iv) It should be ensured that FLP features of SDL electricals/ gate end box are in proper order, trailing cable is connected with suitable connector and the machine is controlled by pilot circuit.(v) For operation of SDLs with coal tubs, seam thickness should be min. 2.4m(vi)There should be 1 m clear space on either side of the machine where it works so that vertical support, if any used are not dislodged.6. Examination and maintenance:- SDL shall be examined in each working shift by competent person and once in 7 days by the engineer. It shall be maintained as per recommendations of the manufacturer. Records shall be maintained.7. Code of standing order for supports:- Manager of the mine shall frame SSR and formulate and implement a code of standing orders for supports of mine workings specifying the method of erection, monitoring and withdrawal of supports.

Q. No.8.Based on RMR value, design a support plan for support of weak roof for a Continuous miner to be deployed in a development district.Ans:- As the roof is weak and the development is to be done with continuous miner, the width of the gallery is required to be kept minimum. For this purpose, low height and low capacity continuous miner will be used for development.Assumption:- a) Machine details C.M. to be deployed – 12CM12B series Cutting width – 3302 mm Cutting height- 1270mm to 3683 mmb) Mining Parameters- Thickness of seam – 3.0 m (Working height) Depth of working – 120 m Width of gallery, B – 4.2 m Size of pillars – 30m x 30m (centre to centre)

Nature of roof rock – 1.2m intercalated shale/ sand stone (with two intermediate thin bands of clay), 0.6m thick coal overlain by sand stone.

RMR (Intercalated shale/clay/sst),R1 -38 RMR (Coal),R2 -51Density of parting between two seams, D – 1.6 t/m3

Design of support system-i) Calculation of combined RMR & Categorization of roof: Combined RMR = (R 1 x t 1 + R 2 x t 2 ) =(38x1.2 + 51x0.6)

t1 + t2 1.2 + 0.6 =42.34 = 42(Say)

Adjustment of RMR: RMR is further adjusted for various geo-mining conditions i.e. mode of drivage, lateral stress etc.

a) Method of excavation – Continuous miner(10% increase in RMR. Adjusted for continuous miner (+10%) = 42x1.1 = 46.2

b) Again adjusted for lateral stresses (-20%) RMR =46.2x0.80=36.96 =37 (Say)

:. Adjusted / final RMR = 37, Hence the immediate roof is classified as category lV, type – poor roof

ii) Estimation of rock load and support distance:Rock load in gallery and at junction is calculated by the empirical formula of geo-mechanics classifications developed by CMRI – ISM:a) For gallery

Rock load, (Pr) =B x D (1.7 – 0.037 x RMR + 0.0002 x RMR2 )

=4.2 x 1.60 ( 1.7 – 0.037 x 37 + 0.0002 x 37 2 )

=6.72 ( 1.7 – 1.369 + 0.2738 ) =6.72 x 0.6048 = 4.06 t/m2 = 4 t/m2

Support Resistance - Considering the anchorage strength/ holding capacity of 1.5m long bolt (22mm dia) made of M.S. ribbed steel to be grouted to full length using resin capsules as 12 te after full setting, support resistance/ bolt density/ bolt spacing will be calculated as follows:

AS = Pr x a2 x F Where as = Anchorage strength of bolt (12 te )

Pr = rock load ( 4 te/m2 ) a2 = area supported by each bolt in m2 F = factor of safety ( 2- say)

:. a2 = As = 12 = 1.5 Pr .F 4 x 2

:. a = (1.5) .5 = 1.22 m = 1.2 m ( Say ) b) For Junction: Rock load = 5 x B 0.3 x D ( 1-RMR/100)2

(Pj) = 5 x 4.2 0.3 x 1.6 x (1-37/100) 2

= 8.0 x 4.2 0.3 x 1(0.63) 2

= 3.1752 x 4.2 0.3

= 4. 80 t/m2 Similarly, spacing of bolts may be calculated as a2 = 12 4.80 x 2.25

a2 = As

PjxF Taking F = 2.25

:. a = 1.02 = 1.0m (say)

iii)Support plan:-(a) For galleries: - Galleries shall be supported with 4 resin grouted bolts of 1.5 m length. Spacing between the bolts in a row will be 1.2m and bolts will be supplemented by bearing plates and w-straps.The two side bolts could be inclined at 600 towards the pillars and 0.3m away from the pillar on either side whereas, the central bolts would be vertical. (b) For junctions:- Junction will be supported using four bolts in a row at 1.2m row interval with 1.2m row spacing . Thus 6 rows ( 6 x 4 = 24 bolts ) would be required to support the junctions. The support plan has been showed in fig.1 iv)Monitoring of support systems:-(a) Anchorage testing of installed roof bolts – 9 % bolts should be tested upto designed capacity and 1% may be subjected to destructive testing at random under the direct supervision of Asstt. Manager. (b) Monitoring of Strata behavior- Measurement of roof- floor convergence and load on support would be done with the help of convergence recorder & load cells respectively. Theoretically, maximum convergence and convergence velocity shall be determined with the help of following empirical formula.Max convergence, Cm = 40 x B 0.3 x D ( 1-RMR/100)3

(mm) = 40 x 4.2 0.3

x 1.6 x (1-37/100) 3

= 64.0 x 4.2 0.3 x 0.25

= 24.61 mm

Convergence velocity, Cv = .55 x B 1.7 x D ( 1-RMR/100)5.6(mm/day) = .55 x 4.2 1.7

x 1.6 x (1-37/100) 5.6

= .88 x 4.2 1.7 x .0752

= 0.76 mm/dayThe actual value of max. convergence & convergence velocity should be compared with the calculated theoretical value & support plan should be reviewed from time to time, if deemed necessary.

Afternoon SessionTHE MINES ACT, 1952


FIRST CLASS



Answer any SIX Question(All questions carry equal marks)

---------------

Q.1.In the present day context of large demand of coal, what are the recommendations of 10th Conference for safety in mines with respect to:(a) Mechanization with a view to phase-out manual loading & to improve

standards.(b) Reduction of risk from roof and side falls in coal mine.Ans:-a) Mechanization with a view to phase-out manual loading & to improve standards:- Limited potential of opencast reserves coupled with environmental considerations, land acquisition issues and availability of better grade coal at depth forced mining industry to extract coal from deeper horizons by underground methods. At these mining depths, the only course left for ensuring ever increasing production needs with high safety standards is to introduce intense mechanization compatible to the geo-mining requirements. Therefore, for the mining industry to gear up for such daunting situations ahead, it is imperative that the present and manual mining situation be totally phased out and a carefully designed mechanization era be introduced.With the introduction of appropriate face mechanization, accident in mines have shown positive downward trend due to reduced exposure/concentration of workmen at active coal faces. The gravity of the problem of continuing with manual work at bulk production fronts would be too intense for the mining operators and therefore, calls for an immediate switch over in the production policy towards face mechanization and reducing conventional crowded work-force at the production fronts.

Taking into consideration the above facts, 10th National Conference on Safety in Mines made the following recommendations:-

i) Identification & Introduction of appropriate technology:-Keeping in view the objectives of phasing out manual loading, all coal companies should identify appropriate technology suitable for the prevailing geo-mining conditions and introduce the same in phased manner to phase out manual loading operations completely within a period of next five years in coal seams with gradient of 1 in 5 or less and in 7 years in coal seams with gradient steeper than 1 in 5ii) Compatible back-up facilities: - While formulating the strategies for face mechanization in underground workings, this is to be ensured that back up facilities like coal excavation, support system, ventilation arrangements etc, are compatible with face mechanization.

iii) Scientific investigation for mechanization:- The scheme of face mechanization should be based on proper scientific investigation. The scheme should also include arrangements for monitoring strata behavior and environmental conditions.

iv) Deployment of multi-skilled miners:- Possibility of deployment of multi-skilled miners in the face shall be explored to reduce the exposure in hazardous area without affecting employment.

v) Training:- Suitable training for efficient and safe operation of machinery shall be imparted to all concerned.

vi) Long term sustainable technology: - While planning for face mechanization due considerations should be given for long term sustainability of the technology.

vii) Framing of Policy documents: - A policy document shall be framed by each coal mining company within 6 months to address implementations issues. It shall also be ensured that safety features are inbuilt into the system.

Ans:-b) Reduction of risk from roof and side falls in coal mine : - Owing to continuous efforts by mining companies, research institutions, academicians and DGMS, the accident caused by fall of roof and fall of sides have shown a down ward trend. Still fall of roof and fall of sides are the major causes of accident in u/g coal mines. An in-depth study of roof and side fall accidents in coal mines during 1997-2006 by DGMS officials revealed the following:

Fall of roof has been responsible for 42% of u.g. accidents and fall of sides for 16%. There has been a downward trend. These figures falling to 30% and 9% respectively in 2006

In development workings, area of freshly exposed roof upto 10m from the faces continues to be critical.

In order to ensure safety in mines and also ensure reduction in roof fall and side fall accidents in coal mines, 10th National Conference on Safety in Mines made the following recommendations:-

i) Setting up of strata control cell- In every coal mining company, strata control cell shall be established at corporate and area levels within 1 year to assist mine managers in formulation of Systematic Support Rules and for its implementation. Such cells shall be manned by adequate number of technical personnel headed by a senior official not below the rank of Chief General Manager at Corporate level and Dy.Chief Mining Engineer at Area level.

ii) Roof bolting as primary support- Roof bolting shall be used as a primary means of support for freshly exposed roof in development as well as depillaring districts. For the roof category “Poor” having value of RMR of 40 or less or where there is excessive seepage of water from the roof strata, roof bolts exclusively with resin capsules should be used to ensure adequate and immediate reinforcement of strata.iii) Side supports- Due emphasis should also be given to support the sides while framing systematic support Rules.

iv) No work below unsupported roof- Suitable steps shall be taken by the mining companies to inculcate the culture of no work at face other than support work, till the roof is supported by roof bolts right upto 0.6m from the face.

v) Use of suitable roof bolting machine- To ensure proper drilling for roof bolting in all types of roof strata, suitable, fit for use roof bolting machines should be introduced in all mines within a period of one year. Such machines should be capable of being operated from a distance or be provided with suitable canopy to protect the drillers/roof bolters during drilling or bolting operations.

vi) Risk assessment- Risk assessment shall be carried out for assessing the risk from hazards of roof and side falls and for identifying control mechanisms with specific responsibility for implementation. This exercise shall be reviewed at regular intervals not exceeding one year.

vii) Structured training- Each company shall take steps to impart structured training to officers, supervisors and support personnel on roof bolting.

Q.2.What are the various problems of safety when a part of the work in an opencast mine is outsourced? How will you ensure enforcement of Mines Act, Rules and Regulations by the workers of the hired contractor?Ans:- There is an increasing trend of contractual work in coal and non-coal mines in India in recent years. This is due to need of introduction of modern mining, access to specialized expertise and need to continually improve efficiency in the face of strong national and international competition, especially in view of entry of private entrepreneurs and multinational companies.

Mining industry, particularly the coal mining industry has in recent times been open to the private entrepreneurs and many mines are being opened and operated by private operators. Multinational Companies are also entering in to the Indian Mining Industry for extraction of minerals. Out sourcing of certain operations and equipment is also becoming quite common in the large public sector or Pvt. Mines. But this is also adding some new dimension to the health and safety aspects of mining industry.Various problems of safety when a part of the work in an opencast mine is outsourced:- i) In many cases, the existing mine management structure is not suitable and effective to control the interfaces with contractors.ii) Big contractors award parts of the job to petty contractors not having adequate capacity or concern for safety.iii) Employees are purely temporary or migratory in nature and not conversant with mining activities or laws.iv) Employees are not given required training.v) Contractors workers have more risk taking attitude as their earnings are directly connected with output.vi) Workers are put to extended hours of work and equipment used in many cases is not fit for the purpose.vii) There are hardly any medical surveillance and welfare amenities for workers.viii) Contractors consider safety as a cost component only ignoring work conditions.ix) Deployment of in-experienced, unskilled and ill health persons because of their cheap availability.x) Contractors having hiring and firing policy causing influx of unskilled persons.xi) ill maintenance of machines.xii) Over loading of truck & dumpers.xiii) Unauthorized driving and unauthorized riding Ensuring enforcement of Mines Act, Rules and Regulations by the workers of the hired contractor:For ensuring enforcement of statutory provision by the workers of the hired contractors, the code of practice for safety of contractor workers and machinery shall be made by the mine management for the adoption in contractual operations. The code of practice shall be as follows:

A) Code of Practice for adoption in contractual operations:Sl.No. Item Practice to be followed1 Training: All

contractors’ workers engaged on surface & OC

(i) Before commencement of work against work order contractor shall give to the manager a list of his workers /supervisor to be trained as per VTl Rules and new VT module.

mines to be trained.

(ii) Persons required to be trained, shall be sent for training by Manager.(iii) A list of trained workers already available with the contractors shall be furnished to be Manager.

2 Record in “B” Form

Manager shall ensure that records of contractors workers are maintained in Form – ‘B’ as per stature.

3 Supervision Statutory supervision of contractual operation by departmental competent persons to be ensured by Manager/Project Officer.

4 Issue of Identity Cards

(i)Contractors shall issue identity card to all workers under him.(ii) Contractor shall be bound not to employee any persons whom the Manager/Agent has reason to believe that the person’s actions are unsafe to the mining operations or who contravenes the provisions of Mines Act, Rules and Regulations framed there under.

5 Attendance/ Working hours/ rest day

Manager to ensure:(i) Attendance of contractors workers shall be recorded in the Form-D/E as per Mines Rules.(ii) Working time on every day shall be limited to 8 hours spread over to a maximum of 12 hours working shift. Weekly days of rest shall be ensured.

6 Rest Shelters Contractors shall arrange for rest shelter with drinking water facility to be provided near the place of work failure which the Manager shall do the same.

7 Safety Appliances

Manager shall ensure that all contractors’ workers are provided with helmet, shoes & other safety gadgets. In case of non-provision, the safety guards shall be provided by him and the amount spent on the guards deducted from the contractors bill. Contractors shall ensure the use of helmets and shoes by his workers.

8 Fitness Certificate and road worthless of vehicle.

(i) Before the start of transportation, the contractor shall submit a list of vehicle/machines to be deployed at the mine to the Manager/Project Officer(Agent)(ii) Fitness of all the vehicle/machines including AVA shall be checked under the supervision of Colliery Engineer.(iii) Fitness Certificate of all vehicles shall be checked by the Colliery Engineer and proper records shall be maintained and in case of O/C with more than 5000 tpd coal transport a separate engineer with Foreman and mechanic having automobile engineering back ground to be posted for checking the vehicle.(iv) After the checking of the vehicle and fitness certificates, the Engineer shall recommend for the issue of valid pass for vehicle/machines to the

Manager/Project Officer(Agent)(v) No’ contractors’ vehicle/ machines shall be allowed inside mine premises without valid pass issued by Manager/Project Officer(Agent) of the Colliery.(vi) A qualified engineer to have overall responsibility for daily/weekly checking and maintenance of contractors’ vehicle. Contractors shall authorize his engineer /foreman or mechanic as competent person for daily/ weekly checking and maintenance of vehicle/machines. Manager/Colliery engineer shall confirm the competency of such authorized person and ensure that the daily / weekly checking of vehicles is as per standards.(vii)Random check shall be made by Engineer/Safety Officer as regards fitness certificates, brakes, lights, horns, AVA’S etc.(viii) If any vehicle is found defective, the same shall not be allowed inside the mine, unless the defect has been rectified and vehicle certified to be fit by the Colliery Engineer in writing.(ix) The time of incoming and outgoing of contractors vehicles in the command area should be recorded in a register at the check post.(x) Fail Safe Brake should be used in tippler.

9 Unauthorized, driving / riding

(i) Contractors shall submit the list of drivers (whose antecedents he believes are good) along-with their valid licenses for verification and record by Engineer and issue of authorization by Manager/PO(Agent). No such drivers should be allowed without verification of license/authorization. (ii) No helper/ any-unauthorized persons shall be allowed to travel in tipping trucks.Trained trip man/helpers shall be provided at the loading and unloading point and for the miscellaneous jobs at key positions. Unauthorized ridding in vehicles shall make both the driver and /or the unauthorized person traveling liable to punishment.(iii) Manager shall take all appropriate steps including his authority of punishment to ensure prohibition of un-authorized driving as well as unauthorized riding.

10 Loading areas , Face supervisors : Under Manager / Overman / Mining Sirdar.

They shall ensure that:-(i) Pay loader operation Zones and the parking sites of trippers for loading and waiting are well defined and marked to avoid unnecessary movement/reversal of vehicles and pay loader at the face and also for unauthorized parking.(ii) No unauthorized persons shall be allowed in pay loaders operation zone and tippers loading/ waiting zone while loading and transportation are being carried on at the face.

(iii) Safe distance shall be determined and maintained. (a) Between pay loader and tipper stationed for loading(b) Between two trippers on movement(c) From the toe of the benches.(d) From the edge of the benches.

11 Roads/Transport (i) A parking area for contractors vehicles/ machines shall be fixed by Colliery Engineer in consultation with PO/Agent of the mine.(ii) The number of vehicles allowed to enter the mine premises at a time should be fixed by PO(Agent)/Manager of Mine.(iii) The rest shelter for drivers/operators should be made outside the barrier.(iv) Manager shall ensure that all provisions of the condition of the use of HEMM issued by DGMS are complied .(v) One way traffic should be adopted for movement of vehicles. However, in extreme case whenever it is not possible to make one way traffic, alternative may be used only after approval of Agent of the Mine.(vi) Separate roads/lanes of HEMMs and contractors tripping trucks and for pedestrians shall be provided.(vii) Ramps and curved sections of the haul roads shall have adequate curvature and super elevation designed in accordance with the speed and height of vehicle plying on them.(viii) Escape lane or escape road shall be provided where there are chances of over speeding or roll back of vehicles in motion.(ix) Code of Traffic Rules, dumping practices, signaling and communication shall be framed and implemented.

12 Dumping Place (i) Sufficient dumping place shall be ensured by the Manager to avoid over crowding.(ii) Sufficient level space shall be provided on ramps close to unloading point for unloading, reversing and authorized parking.(iii) Dumping and manual loading shall not be allowed at the same place.

13 Parking i) No vehicle shall be parked on slope/gradient. If it is unavoidable, hand brakes shall be applied firmly, engine stopped, vehicle kept in gear and stop blocks against the wheels used.ii) The engineer shall ensure that adequate numbers of stop blocks are always kept in the vehicle. In addition, he will also ensure that tow start vehicles are not allowed on the road.

iii) Adequate level parking place should be created near loading point, CHP/Feeder Breaker/ Weigh Bridge, dumping place etc for incoming tippers.

14 Surface Electrical Jobs

i)Jobs shall be done under the supervision of Engineer/Supervisors.ii) The Engineer/Supervisors shall ensure that proper shut down procedures for working on live lines are followed.iii) Code of Safe Practices shall be framed by Colliery Engineer for implementation on such jobs.

B) In addition to above code of practice, the following role and responsibilities should be played and shouldered by mine owner & contractors for enforcement of statutory provisions in outsourcing activities as recommended by 10th Safety Conference:.a. Managements responsibility - i) Inclusion of suitable clauses in the tender document stating how risks arising from contractual work will be managed

ii) Ensuring that contractors are familiar with relevant statutes, health & safety management system and are provided with copies of such documents prior to commencement of work.iii) Ensuring that contractor’s arrangements for health & safety management are consistent with those of the principal employer.iv) Ensuring that contract shall preferably be for longer periods so that there is an adequate scope for management of safety by contractors.v) Ensuring that contractor provides fit – for – purpose machinery, operators and other staffs are provided with written safe work procedures.vi) Monitoring of all activities of contractors to ensure that they are complying with all the requirements of the statutes and safety system, in case of non compliance contractors should be suitably penalized. b. Contractor’s responsibilities- i) Preparing written safe operating procedure for the work to be carried out, including risk assessment and safe method to deal with the risk and providing a copy of SOP to the person designated by mine owner who shall be supervising the contractor’s work.ii) Keeping the SOP up-to-date and providing a copy of changes to the designated person.iii) Ensuring that all work is carried out in accordance with the statue and SOP and deploy adequate qualified and competent persons for the jobs.iv) Developing and providing site specific code of practice for specified work to mine owner.v) All persons deployed by contractors for working in the mines shall undergo vocational training, IME & PME. vi) Every person employed by contractors shall wear safety gadgets either provided by contractor or by mine managementvii) Contractors shall submit quarterly or monthly return indicating details of contracts, persons engaged, training and medical facilities provided etc to DGMS for contracts more than one year or less than one year respectively.

Q.3. What is workers participation in safety management? How can this help attain high safety standards? Suggest some deterrents for habitual unsafe workers.

Ans:- Refer to Q. No. 6(2nd Class-2007)

Q.4.Enumerate various types of instruments (along with the objective, principle and functioning of each) which are used for monitoring ground movement in a deep underground mine.Ans:- Monitoring of the ground movement and stress build up around the excavation through systematic instrumentation helps to evaluate the stability of the openings. Instrumentation can help in design verification. With suitable instrumentation programme, one can work with a safety factor near unity. Under such conditions, monitoring would provide warning of potential problems for advance action.The essential features of instrumentation are:-a) Proper layout – location of instruments, type and number are determined in advance according to the requirement of the Project. b)Accuracy- a good instrumentation programme should have reliable instruments with the required accuracy.c) Recording- frequency and duration of the monitoring scheme should be strictly followed as decided during layout stage.Monitoring Ground Movement – Excavation of u/g openings results in movement of the roof and wall rocks. Ground movement monitoring would provide useful information to evaluate the stability of these openings.

Various types of instruments used for monitoring ground movement in a deep u/g mines:1. Closure meter or convergence recorder:- Objective:- To measure the relative ground movements, between two exposed rock surfaces of an excavation, usually the opposite ones, like roof and floor, hang wall and footwall etc. If one of the two reference surfaces is free from any movement, closure measurements give the absolute movement of the other surface.Principle:- Working principles of closure meter are as follows : Mechanical closure meters- Works on mechanical including hydraulic

principles and have the advantages of robust construction and simplicity of design.

Electrical closure meters- It works on electrical & electronics principles and have the advantage of versatility and flexibility and are easily adopted for continuous and automatic monitoring and recording and remote control.

Seismic closure meters- Works on the principle of seismology and are very sensitive and accurate and helps in certain measurements which are otherwise impossible.

Functioning:- Telescopic closure meter or convergence indicator is a very simple instruments consisting of a graduated rod ( with a least-count of 0.5 – 1 mm) fitted in a pipe for telescopic movement over a length of 2 to 4 m. The measuring points are metal rods grouted in the rock at the desired locations. Measurements are taken by simply stretching the telescopic rod between the reference points and reading the graduations on the rod.To measure closure at inaccessible locations, electrical closure meter can be used. In this instrument, a rheostat is fixed to the telescopic portion of the rod and a pointer is attached to the pipe in which the telescopic rod moves over a high tension spring. The instrument is permanently fixed between the reference points and measurements can be taken from a distance.

2. Borehole extensometers: - Extensometers are one of the principal instruments used to measure rock deformation.Objective: - To directly measure/monitor relative or absolute movements in un-exposed rock mass as well as bed separation.a. Tape extensometer- To measure changes in distance between two reference points in any direction.b. Multipoint borehole extensometer- To measure relative displacement of bore hole anchors which are fixed to rock mass units along the axis of the drill hole.c. Sonic multiple point extensometer- To monitor horizontal pillar expansion and the growth of the yield zone in a chain pillars.d. Wire extensometer- To measure axial displacement between a numbers of reference points on the same measurement axis.Principle:- Depending on the type of instruments, extensometer works on mechanical, magnetic and electromagnetic system, seismic and micro seismic principles as explained earlier.Functioning:- Tape extensometer can be used to measure closure between points upto 30m apart with accuracy of 0.05-2m. It is made of precision invar steel measuring tape with punched holes. For taking the readings, the free end of the steel tape is hooked to the remote reference point and the instrument is hooked to the nearest point. The steel tape is pulled taut and tension applied to the tape. The dial gauge reading after tensioning indicates the reading for the site.

For measuring the extent of movement inside the wall rocks (or in the pillars), at grater depth, multipoint extensometer are used. It consists of a transducer head, usually installed at the collar of a drill hole and a number of in-hole anchors, each of which is fixed in place at a known depth in the drill hole. As the rock adjacent to the drill hole is deformed, the distances between adjacent in hole anchors change, as do the distances between the individual in-hole anchors and the transducer head. These changes are measured, and the resulting data are used to compute the distribution, magnitude, rate and acceleration of deformation in the rock intersected by the extensometer drill hole.In the wire type multi point extensometer, expansion shells are used as anchors. A stainless steel wire of 1-2 mm diameter is attached to the anchor. The free end of the steel wire hangs through a collar station, to which a portable readout unit can be easily attached. The readout consists of a micrometer head and a dial gauge that serve both as tensioning and measuring devices.Sonic multiple point extensometers consists of a 7.6m long probe which is inserted inside a guide tube located along the borehole axis passing through all 20 or so snap-ring borehole anchors. A magnet is located within each anchor. The position of each magnet relative to either the head of the extensometer or to a neighboring anchor is measured and displayed directly on the readout unit.Tell Tale systems are simple wire extensometers which give a visual wearing of rock deformation through movement of an indicator, anchored in a small diameter borehole. It is now possible to integrate about 400 telltales into a mine wide monitoring system with the use of computer plus software development. The standard display provides information on the current reading and recent history of all the connected telltales. Individual warning and action levels can be set for each telltale, both as absolute levels and rates of change.

3. Stress meters, Earth pressure cells and Micro seismic geophones:-

Stress meters in use at present are electrical ones, either vibrating wise based or resistance strain gauge based. Generally, vibrating wire type instruments are more reliable for long term monitoring than strain gauge based instrument. Objective:- To measure/monitor changes in in-situ stresses in rock as the excavation continues and to predict the stability of the openings.Principle:- The basic principle of the vibrating wire stress meter is that the change in natural frequency of a stretched wire is proportional to the change of tension in the wire.Functioning- The vibrating wire stress meter can be installed with the help of installation tool in a bore hole; with its ring-wedge tightened across the diameter. A vibrating wire is put under tension across the diameter. Changes in rock stress distort the ring-wedge, thus changing the resonant frequency of vibration of tensioned wire. The square of the vibration frequency is directly proportional to the change in the diameter of the gauge and is calibrated, to the change in the stress of the rock. In other variation, the coil / magnet are used to vibrate the wire at its natural frequency in the pre-loaded condition. Stress changes in the surrounding rock cause small change in the diameter of the hollow cylinder.Pneumatic Earth pressure Cells can be installed in slots at shallow depth (maximum 2m) from the excavation surface. The pneumatic cell may be grouted in boreholes at much greater depth, the reach of grouting system, the capacity of drilling facility available and the length of cable being the limiting factors.Micro seismic geophones record the level of emission of micro seismic waves from the rock mass under stress. Re-distribution of in-situ stresses at or in the vicinity of the site of monitoring is clearly indicated by the anomaly in frequency and magnitude of emission of these waves. These may be used to predict rock burst/ coal bumps and roof falls in coal mines. 4. Strain gauged roof bolt:-Objective- To measure the strains developed in the bolt at up to mine locations along the length of the bolt.Principle: It works on the principle of wheat stone bridge. The gauges are photo etched resistive elements which, when affixed to a material to which a stress is applied, changes their resistance in proportion to the strain in the material. If the gauge is in one arm of a wheat stone bridge circuit, the resistance change will be seen as bridge unbalance which creates a voltage differential between opposing corners of the bridge and it is this voltage which is amplified and measured by the strain Bridge Monitor. Functioning:- This is a strain- gauged mild steel 1.5 m / 1.8 m long bolt with 9 pairs of gauges bonded into two long slots along the bolt. The strain values measured for each of the gauges are processed by a computer programme to calculate the axial force, the bending moments, the axial strains and the bending strains generated in the bolt.Instrumental bolts are connected via a cable to read out locations, 10-15 m away from the installation site. This enables the instruments to be monitored safety during mining operations and without causing delays to production.

(5) Australian New Zealand Inflatable(ANZI)Cell:-

Objective:- To measure in-situ stresses and stress changes in rock strata.Principle:- It works on electrical principles. Functioning:- The ANZI cells are essentially an inflatable membrane type of low modulus polyurethane material with strain gauges on its outer surface. It has a pressure meter design that enables 18 electrical résistance strain gauges to be pressure bonded directly to the rock of a bore hole wall. To install the ANZI Cell, the surface of the membrane and the strain gauge are coated with low slump epoxy cement. The instrument is inserted into a bore hole and pneumatically inflated at the location where the measurement is to be made. Once the cement has cured, a pressure test is conducted using ANZI Cell as a bore hole dilatometer or pressure meter. The configuration of strain gauges carried on the instrument can be varied to suit rock conditions.6) Load Cells/ Dynamometers- Objective- To measure the load on active supports, evaluate effectiveness of support system and monitor the support performance.Principle- It works on mechanical & hydraulic as well as electrical and photo-elastic principle.Functioning- While mechanical and photo-elastic devices measure the support load directly, in electrical devices, load is estimated indirectly from the resultant strain occurring in them due to loading.Loads cells are mechanical, hydraulic or electrical. Of these, electrical load cells give precise readings. This could be strain gauge or vibrating wire type. In strain gauge load cells, electrical resistance strain gauges are bonded to the periphery of a spool of heat treated steel or aluminum cell. The gauges are mounted in a full bridge configuration that compensates for unevenly distributed loads. They can be remotely read.In case of hydraulic load cells, a cell is first placed in a proper bore hole and then pressurized hydraulically with the use of hand pump suitably connected to the flexible tubing. Uni-axial stress change can be monitored at that localized position where the cell is placed in the bore hole. The flat jack is connected to a hydraulic diaphragm transducer that in turn is connected by flexible tubing to a dial gauge showing the stress change.Rock bolt load cells are used to measure the variation in bolt load. In case of full column bolts, strain gauges are fixed on the bolt at different intervals so that the stress transfer from the ground to the bolt at different horizons could be monitored.

Q.5.Enumerate the provisions of Mines Rescue Rules, 1985 regarding any two of the following:

(a) Establishment and location of rescue stations.(b)Appointment of rescue trained persons in mines, their disposition and accommodation.

(c)Apparatus and equipment to be provided in a belowground mine where no rescue room is located.

Ans:- 5(a) Establishment and location of rescue stations- Refer to Q. No. 3(a) (2nd Class-2007)

Ans.5 (b) Appointment of rescue trained persons in mines, their disposition and accommodation-

Refer to Q. No. 3(b) (2nd Class-2007)

Ans.5 (c)Apparatus and equipment to be provided in a belowground mine where no rescue room is located.As required under rule 11(3) of the Mines Rescue Mines 1985, at a belowground mine, where no rescue room is located, the following minimum apparatus and equipment shall be kept available in perfect working order at the surface of mine:-Type of apparatus & equipment Min.Nos. Requid. Remarks Pressure type tube apparatus with bellows 1 Flame safety lamp with maintenance tool kit 1 DGMS approved (i) CO detector 1 DGMS

approved(ii) CO tube 10

Whirling hygrometer 10 Safety belt 1 Resuscitating apparatus 1 First aid box 1 Blankets 1 Folding stretcher 2 Self rescuers 1 DGMS approved.However in case of belowground coal mines having a fiery seam or gassy seams of second or third degree, the Rescue room shall be established and maintained and the rescue apparatus & equipment as specified in schedule II of Mines Rescue Rule’1985 shall be kept available in perfect working order if required by CIM by written specific order stating the reason for the same.

Q..6.Write short notes on any four of the following:-

(a) Angle of draw and its relevance in longwall mining.(b) Risk assessment as a tool to improve safety.

(c)Vocational training as an effective tool in improving safety & productivity.(d) Role of Internal safety organisation in reducing accidents.(e) Direct & indirect costs of accidents.(f) Use of diesel locomotives.Ans:- a) Angle of draw and its relevance:- Subsidence is the downward settlement of ground due to an u/g excavation. It occurs as a symmetrical trough which is always larger than the excavation. Vertical movement less than 5 mm are neglected, so that the limit of subsidence is defined by all points which subsides by 5 mm.

It is a manifestation of the action of gravity on strata which have been rendered unstable by the withdrawal of their natural support over a sufficiently large area. All the strata from the coal seam to the surface sink slowly at different rates, until in the course of time with the development of opposing forces, equilibrium is restored at the lower level. Apart from vertical subsidence, lateral movement and change in slope occur at the surface.Angles of draw – It indicates the limit upto which subsidence takes place. It is used to determine the extent of subsidence trough over the surface in reference to the extraction perimeter underground. The angle of draw is the angle subtended by the line joining the limit of subsidence and the edge of excavation with the vertical.” It is also called the limit angle. Nowadays it is also defined as the angle between the horizontal and the edge of the subsidence through from the edge of u/g working Angle of draw depends upon the following factors:-(i) Nature of overlying strata- In soft strata, the draw is greater while it is less in brittle hard rock. Harder is the strata, smaller is the angle of draw and vice-versa.Higher proportion of shale in strata increases the draw. Indian strata have 0-36% shale and a lower draw than UK, where shale is higher. European coal fields have higher draw (250-430) because of softer strata where as Indian coal fields have lower draw (40-210 ).ii) Existence of faults and their location- The faults tend to arrest and also extends the subsidence trough depending upon the direction of the working face in relation to the strike of the fault. iii) Cleavage / Natural joints of rocks - If the line of advance is parallel to the natural joints, it will tend to reduce the angle of draw but at right angle, the effect will be minimum.iv) Dept. of seam: - The angle of draw depends upon angle of dip. The influence of the dip of the seam is to reduce the angle of draw on rise side of the working and to increase it on the dip side of the working.

Mathematically, βr = βh – K.Sin 2 α where, βr = angle of draw in rise side βd = βh + K.Sin 2 α βd = angle of draw in dip side

α = angle of dip βh = angle of draw in horizontal workings.

K = a constant.v)Thickness of seam – Thick seams when worked by slicing in descending order with caving may result in more subsidence and also in increased angle of draw.

Significance of angle of draw in longwall as well as in B/P workings- For assessment of boundary conditions in order to predict subsidence, slope and strain profiles in depillaring operations, the knowledge of angle of draw is essential. The angle of draw gives a true picture about the extent and magnitude of surface subsidence in different strata conditions. Hence it is very much relevant in managing and controlling the effect of subsidence. Ground subsidence causes damage to surface structures. The maximum damage occurs where the curvature is maximum and not necessarily where the maximum subsidence occurs. The ground straining occurs as a result of differential movement which may be in tension or in compression and causes damage to surface structures. It may also cause damage to upper level workings and also to roads and shaft linings if they are crossed by the limit plane. The gradient of the floor of the top seam workings may change and roadway pillars may develop fractures. The ground surface within the subsidence through is subjected to displacement ( horizontal and vertical), tilt, sag ( change in gradient per unit length) and strain, which must be kept within the permissible limits for the safety of this surface structures (building, plants, rail tracks etc) and sometimes the mine workings themselves:-Angle of draw & angle of slide are the main factors used to determine the extent of subsidence as mentioned below: i) Ground displacement can be estimated from this value of angle of draw by the following formula-v= k.h.(tan β)i where, v = ground displacement h = depth for working β = angle of draw K = a contant. i = ground slope.ii) Radium of shaft pillar: R = K1 + h1 tan 45º + h2 Tan β (m) Where K1 = a constant h1 = thickness of soft cover h2 = thickness of hard cover β = angle draw

β = 25º for flat seams of gradient less then 15º 40º on the rise side of the shaft for steep seam (up-to 35º)

20º on the dip side of the shaft for steep seam (up-to 35º)In B/P method of working, partial extraction system of workings is adopted to extract as much of the coal as possible while providing permanent support with an acceptable factor of safety to prevent subsidence. The concept of angle of draw is used for determination of size and distribution of coal pillars to provide permanent support of the surface structure and is given by SA = 2[(tan β.h) + Sz] + L + (SL.h)

Where SA = length of the side of the support area β = angle of draw

h = depth of cover Sz = safety zone/ additional protection zone L = length of structure

SL =slope of the ground surface away from the protected structure.

Ans:- b) Risk assessment as a tool to improve safety:- Risk assessment is a process whereby risk management priorities are evaluated. The objectives of risk assessment are:- Identification of risks which need to be reduced and options for risk

reduction. Identification of risks which need careful ongoing management and the

nature of ongoing controls. Identification of risks which can be tolerated. Considering the accident scenario in Indian Mining Industry, it has now become essential that risk assessment be undertaken of all hazardous operations, equipment and machinery taking account of the procedures used, maintenance, supervision and management. The process involves the entire staff in the realization of safety improvement programme with responsibility and accountability sharing proportionate to the decision making authority. It is now widely accepted world over that the various techniques of risk assessment and risk management contribute greatly toward improvement in the safety of mining operation. It aims to improve the understanding of the potential for accidents, their possible consequences and the adequacy (or inadequacy) of the various safeguards.Risk assessment plays a vital role in hazard identification in mines. It proves a potent tool in improving safety standards because of the following reasons:-

i) It helps management in preparation of mine specific action plan to mitigate the risks.

ii) It helps in preparation of safety management plan for its implementation in potential mines.

iii) A well laid emergency preparedness plan / pre-monsoon action plan can be prepared for every mine every year to take care of any emergency situation.

iv) It helps in preparation of documents related to:

Code of traffic rules for regulation of movement of machine. Code of practice for safe operation of mining machinery. Formation of safe work practices.

v) It helps in elimination of unsafe condition, unsafe acts & unsafe practices.vi) It helps in obtaining certification for mines in respect of:

Quality management system ISO 9001 : 2000 Environment management system ISO 14001 : 2004 Occupation health & safety – OSHAS 18001 : 1999

Ans:-6(c) Vocational training as an effective tool in improving safety & productivity- The vocational training and the safety as well as productivity are inter-related. Training helps in improved quality of work and high morale. Systematic training efforts are reflected in higher productivity and committed work force. An effective training to the work personnel of mining industry will reduce the overall accident and the cost involved in it. Mine workers are imparted training suitable to their respective vocations with a view to achieve improved knowledge, skill and correct job procedure which in turn improves productivity and safety standards in the mining industry. It is an apt to effect considerable changes in attitudes, behavior and thought process of human being. It can bring forth:

Consciousness and awareness of the problems and situations. Change of behavior in the positive direction. Improvement in skills in operation and maintenance and better

understanding of individual action, new conditions and changed environment.

General improvement in living conditions which can reduce mental stress. Change of attitude to achieve a unified and unidirectional approach of the

groups to achieve the desired goal. An effective, scientific and modern vocational training programme provides the following outputs:-i. improves knowledge on operation, maintenance, management, safety and

others.ii. improves skill of the worker.iii . improves safety standard of the mine and hence reduces mine accidents.iv. gives guidelines on correct job procedure.v. improves efficiency of the workers.vi. imparts knowledge on handling of machine, tools and method of workings.vii. enhances the team spirit, fellow feeling and makes the workers more social.viii. enhances high morality, job satisfaction, strong national feelings, etc.ix. enhances efficient use of material.x. reduces much of supervision, wastage of time and also reduce the production cost. xi. enhances motivation, grows self realization and responsibilities.xii. improves the quality and makes ease of management by the mine official since workers are also trained on the policy of mine management.xiii. assists better development and growth of the mine organisations and companies as a whole.All the above mentioned outcomes cause an outstanding performance by human and ultimately improve the production, productivity and safety of the mine.Ans:-6(d)- Role of Internal safety organisation in reducing accidents- As per recommendation of Gugnani Committee, in each mining company ISO was set up. ISO is a channel for transmitting the guide lines on the safety

policy of the company including short term and long term objectives into action programmes and for feed back on the state of its implementation. It is a basic ingredient of self regulation which is based on the sound premise that internal safety promotion can be more effective than external enforcement. The major functions of the ISO are contained within the following four basic areas:-i) Identification and appraisal of accident producing conditions and practices and evaluation of the severity of the accident problem.ii) Development of accident prevention methods, procedures and programme.iii) Communication of accident control information to those directly involved.iv) Measurement and evaluation of the effectiveness of the accident control system and the modifications needed to achieve optimum results.ISO plays active roles in reduction of accidents by taking following measures/actions:- Risk assessment & risk management exercise for various mines within

the organisation to ensure safety of mines and reduction in accidents. Inspection by senior officials of ISO in back shift to improve the

supervision level. Arranging for safety audit of mine of the organisation. Regular monitoring of safety status in mines. Ensuring supply of safety materials, safety appliances & apparatus. Conducting mock rehearsal for checking of emergency preparedness. Conducting safety drives in mines time to time involving key officials in

inspection team. Organising workshop for various safety aspects of mining. Organizing orientation training for mine managers & other statutory

officials. Co-ordination meeting & brain storming session on safety at different

levels of company for critical analysis of accidents and incidents. Vetting of plans and applications for seeking permission, relaxation and

exemption from statute to statutory authority. Issuance of safety clearance for opening a new mine / district. Enforcing the statutory provisions in mines by regular inspection. Enquiring into all fatal accidents and studying the cause of accidents and

making necessary recommendation for improving safety. Helping company in formulating safety policy. Monitoring the implementation of recommendation of various safety

conferences, recommendation of court of enquiry and committee on safety in mines.

Ensuring implementation of directives issued by corporate safety Board in the Mines.

Keeping liaison with DGMS and other organization for implementation of safety provisions.

Channelising the research in safety matters in close collaboration with research and scientific institution.

Formation and functioning of the safety research and standardization wings in the organisation.

Scrutiny of Abandoned Mine Plans before submission to statutory authority.

Reviewing functioning of safety committee and workmens inspector and giving suggestions for improvement.

Ans:-6(e)- Direct & indirect costs of accidents- Accident in no way causes gain or benefit to an individual, firm or company but always remains a damager, painful and loss maker. Accident does not happen but it is caused. There will be no interruption of production and productivity if the firm or company is free from accident. There will be neither loss of man-shift nor psychological upsetting in co-workers and friends. Mine executives are responsible for running their business profitably. Reliable and detailed cost information is essential for determining the efficiency and profitability of the business. Hence it is logical to compute the cost of accident and cost of expenditure on programme listed for accident prevention so as to estimate the savings made through expenditure for accident prevention. It is considered useful to prepare monthly reports showing the cost of accident per tonne of coal raised. The reduction in such costs by good accident records will work as a motivating factor for the mine executive concerned with overall cost and profitability for attention towards safe work procedures.

The employer, the state as well as the community at large have all considerable financial interest in preventing accident in mines. Elements of cost of accidents:-i) Cost to Employer.ii) Cost to Employee.iii) Cost to State.iv) Cost to community at large.

Direct Cost Indirect Costi)Cost to Employer-a. Medical treatment and ex-gratia payment.b. Compensation paid under WCA.c. Pension paidd. Employee pro-rata plant increasede. First aidf. Loss of production due to temporary stoppage of workg. Plant damage / loss and cost for repairs / replacement.h. Cost due to loss of time of co-workers.i. Extra cost due to OT work.

a. Loss of Employee’s scheme. b. Loss of uniform and / or estim ated production.c. Investigation of accident an preparation of accident reports.d. Increase in labour tension.e. Lessened goodwill in public & employees relation.f. Breaking in new men.g. Damage to the tools &equipment h. Loss of time for the period, the damaged equipment was out of order.i. Spoiled jobs.j. Failure to fill orders.k. Loss of revenue for loosing contracts and even markets due to fall in production.l. Overhead cost while wok was interrupted.

ii) Cost to Employeea. Decrease income.b. Financial Loss attributable to decrease income.c. Loss or decrease in future earning power.

a. Personal Pain & Mental concernb. Inability to enjoy normal relations.c. Increased difficulties in matters of family life.

d. Deterioration in morale.e. Economic Loss to the family of injured.f. Loss of time of the fellow workmen.

iii) Cost to Statea. Ex-gratia payment if any made under welfare scheme.b. Cost of medical arrangement including rehabilitation and retraining provided by Govt. organisation.c. Loss of tax due to decreased profitability of the mine undertaken consequent upon the accident.d. Loss of state owned insurance Company with whom the victim of accident was insured.

a. Cost of Establishment maintained for making payment.b. Cost of public services for making investigation into the accident and maintaining law & order in certain cases.

iv) Cost to community at large.a. Cost incurred by benevolent funds etc.b. Cost on the injured persons himself for making arrangements for looking after him.c. Loss of earning capacity of the partially disabled workers.

a) Cost of investigation into accident.b) Cost of procedure entailed the claiming damages/ compensation.c) Loss of services and other material gain provided by the victims of accident.

An objective analysis of elements of cost of accident will indicate that the needs of safety are not in conflict with needs of production. On the contrary, it may be seen that economizing on safety is counter productive. Statistics reveal that the indirect cost due to accident may be as low as 1: 1 and as high as 20: 1 as compared to direct cost. An average figure may be taken as 4: 1 Realisation of the enormous cost of accidents, both injury and non injury type, has led to the development of a new approach to safety i.e.:

Damage control Total accident control Total Loss control

The philosophy behind the approach is that the emphasis has to be on “accident prevention” rather than injury prevention. As a matter of fact, majority of accidents/ incidents are precisely those which do not involve physical injury. Ans: 6(f) Use of diesel locomotives- 1) Statutory Provision- As per Reg. 95 of CMR, 1957, following are the statutory provisions in respect of use of diesel locomotives: i. No locomotives shall be used belowground without prior written permission of CIM. ii. No locomotives shall be used where the gradient of the track exceeds 1 in 15iii. No person other than the driver shall ride on any locomotive unless authorised in writing to do so by the manager.iv. Except during shunting operations, the locomotive shall lead the tubs or set of train of tubs.

2. Construction of locomotives-

i. Locomotives and its accessories shall be of non-inflammable material.ii. No engine other than that worked by liquid fuel of flash point not less than 68ºC shall be used. The engine will be of compression – ignition type.3. Locomotives tracks, roads and roadways- i. Track shall be ballasted and where necessary drained and rail joints secured by suitable fish plates.ii. Weight of rail per meter shall not be less than that permissible limit. iii. Distance between the centers of adjacent slippers shall not exceed 1m.iv. Ventilation-

Velocity of air current not less than 30 m / min. Inflammable gas in the general body of air not more than 0.5 % at any

point in the roadway. Carbon monoxide in general body of air not more than 0.01% Oxides of nitrogen in general body of air not more than 0.001%

Where more than one locomotives are used in any road or roadway in common ventilation circuit, such additional quantity of air shall be supplied in the road or roadway as will be necessary to satisfy the above requirements.v. Clearance from roof and sides- Locomotive shall not be used in any road or roadway where there is not after

allowing for the swing of the locomotives and the tubs and trolleys, clear space not less than the following:

a. below the roof of its supports: i. if the locomotive is fitted with covered cab-0.3 m from the top of the cover; ii. in any other case – 1.8 m from the floor of the driver’s cab; b. on that side of the track on which manholes are provided – 0.6m c. on the side of the track opposite to the manholes:- i. where there are not more than two tracks – 0.3m ii. in any other case -0.6m d. between any two adjacent tracks so much as to afford a clearance of at least

0.3m between any locomotive or tub or trolley on track and any locomotive, tub or trolley on the other.

vi. Electricals- Equipment and fittings on the locomotives shall be of flameproof

construction. Voltage not more than 250volt. All conductors properly insulated, protected and maintained so as to

prevent leakage or sparking.vii. Precautions against coal dust- The locomotive shall not be used on any roadway / part thereof unless the % of incombustible matter(including moisture) in dust samples which shall be taken from that roadway or part once at least in every seven days, is less than 85% or the working are naturally wet. A record of every such analysis of sample shall be recorded in a bound paged book kept for the purpose.4. Safety Provisions in locomotive system :- i ) Service and parking brake and also a dead man control ii) Ergonomically designed seat for driver

iii) Speedometer, distance indicator, head lights and rear lights iv) At least two portable fire extinguisher’s of appropriate type and signaling

arrangement. v) An approved portable lamp for emergency. vi) Other provisions:

Pressure and temperature gauge

Exhaust conditioner An exhaust gas cooling box Suitable air filter Suitable flame arresters/traps

5. Examination of locomotives - The following examinations shall by made by a competent person appointed in writing by the manager and the results of the examination shall be maintained in a bound paged book kept for the purpose.

a) daily examination b) weekly examination c) monthly examination In case, defect is noticed either during examination or while in use, the

locomotive shall be stopped and shall not be put into use before the defect is rectified.

Q.7.What are the provisions of Electricity Rules with respect to:

(a) Portable & transportable apparatus.(b) Switch gears.(c) Appointment and duties of electrical supervisors.Ans:- 7(a) Portable & transportable apparatus- i) Definition :- Portable apparatus means apparatus capable of being moved while in

operation, e.g. coal cutting machine, electric shovel, continuous miner etc.Transportable apparatus means apparatus which is operated in a fixed position but is capable of being moved readily from one place to another, i.e. pumps, conveyors, auxiliary fans etc.

ii) Operation:-All portable and transportable apparatus shall be operated only by authorised persons.iii) Disconnection of supply:- The person authorised to operate an electrically driven coal cutter, or other portable or transportable machine, shall not leave the machine while it is in operation and before leaving the area in which such machine is operating shall ensure that the supply is disconnected from the cable. When any such machine is in operation, the operator shall ensure that the flexible cable is not dragged along by the machine.iv) Safety devices:-All portable and transportable machines used in underground shall operate on remote control from the concerned switchgear with Pilot Core Protection.v) Length of flexible cable, with any portable or transportable apparatus shall not exceed 90m, but it may be upto-250m when used with coal cutting machine or cutter or loader or armoured face conveyor for long-wall operation, or with shuttle car or load haul dumper or cutter loader or alike equipment for development and depillaring operations.300m with electrically operated heavy earth moving machinery in opencast mines and 1000m with bucket wheel excavator at 11 KV.vi) Permissible Voltage Limits- Hand held portable apparatus- 125Vvii)Flame proofing -All portable and transportable apparatus shall be flameproof as detailed below:-

Deg l - At any place in bye of LVC. Deg ll – 90m from nearest face or goaf

or in-bye of LVC or in a return airway. Deg lll – 270m from nearest face or goaf

or in-bye of LVC or in a return airway.

(Provided that electrically operated or battery operated transportable apparatus such as shuttle car, men and material transporting equipment of increased safety type e shall be permitted at any place with suitable monitoring devices for detection of gasses)viii) Detection of gas -A flame safety lamp shall be kept burning near portable and transportable apparatus which remains energized, and if the safety lamp indicates presence of inflammable gas, supply to all apparatus in the vicinity shall be immediately disconnected and the incident reported forthwith to an official of the mine. Where apparatus for automatic detection of inflammable gas or vapour is employed in addition to the flame safety lamps, such apparatus shall

be approved by the Inspector of Mines and maintained in perfect order. The apparatus shall be interlocked with the controlling switch in such a manner as to disconnect the power supply automatically if inflammable gas exceeds 1.25% in that particular district.

ix) All portable and transportable apparatus shall be maintained reasonably free from dust, dirt and moisture and shall be kept clear of obstruction. x) If the voltage of the circuit exceeds low voltage, all flexible cables attached to any transportable apparatus shall be provided with metallic screening or pliable armouring.Ans :- (b) Switch Gears:-

i) Definition - Switchgear denotes switches, circuit breakers, cut outs and other apparatus used for operation, regulation and control of circuits

ii) Construction- Every switchgear shall be so constructed as to be capable of opening the circuit it controls, and dealing with any short- circuit without danger.iii) Disconnection of supply:-

a) Properly constructed switchgear for disconnecting supply of energy to the mine shall be provided at the surface at a point approved by the Inspector. During the time any cable supplying energy from this switchgear is live, a person authorised to operate the said switchgear shall be available within easy reach thereof.b) Every motor shall be controlled by switchgear arranged to disconnect supply from the motor and all apparatus connected thereto. Such switchgear shall be so placed as to be easily operated by person authorised to operate the motor.c) Whenever required by the Inspector, the switchgear shall be arranged to disconnect the supply in the event of over current, over voltage and single phasing. iv) Protection- a) Where necessary to prevent danger of mechanical damage, switchgears shall be placed in a separate room, compartment or box.b) No inflammable material shall be used in construction of the room, compartment or box or fittings therein containing the apparatus, unless the apparatus is so constructed, protected and worked as to obviate risk of fire.c) The room, compartment or box shall be:-

substantially constructed kept dry well illuminated efficiently ventilated for all apparatus installed therein.

d) Adequate working space and means of access, clear of obstruction and free from danger, shall be provided. Operating handles shall be conveniently placed. If the voltage of the circuit is low voltage, all flexible cables attached to any transportable apparatus shall be provided with metallic screening or pliable armouring ( except in opencast equipment fitted with cable reel as its design feature)v) No switch gear shall be located within 60m of an U/G magazine or reserve station. vi) The switchgear should be so designed that it cannot be accidentally closed by gravity, impact, or any other cause.vii) Where the switchgear can be electrically charged from a duplicate source of supply, means should be provided to isolate the switchgear from both sources.Ans :- (C) Appointment and duties of electrical supervisor:- Appointment of electrical supervisor-

1. Under IER, an electrician holding the electrical supervisors certificate, covering mining installations, issued or re-cognised by the state govt. shall be appointed by the mine management. 2. The notice of the appointment containing the name of the electrical supervisor and the full particulars of the certificate held by him, shall be forthwith sent by the mine management to the electrical inspector of mines.3. The notice shall be duly countersigned by the person authorised.4. An engineer shall not be permitted to perform the duties of electrical supervisors, in addition to his own duties, except in case of small mines and with the prior approval of the concerned regional inspector.5. If necessary, for the proper fulfillment of the duties under the IER, one or more assistants to the electrical supervisor shall be appointed by the mine management.6. In the absence of the authorised electrical supervisor, no electrical installation work will be carried out within the premises of the mine. If the period of absence extends, or is likely to extent more than 7 days, immediate notice to this effect shall be sent to the electrical inspector of mines.7.Adequate number of authorised electrical supervisors shall be on duty in every mine while energy is being used therein.Duties of Electrical Supervisor:-1. Supervision-a) The authorised electrical supervisor shall not undertake the duties of supervision of electrical installations at more than one mine without prior written permission from the electrical inspector of mines.b) He shall supervise – (a) new installations, and (b) additions and alternation to existing installation.2. Sending of notices - He shall :-a. apply/ arrange to apply for approval for the installation of HT apparatus and shall not energise it until approval is obtained. b. carry out necessary insulation and continuity tests before energizing.c. give / arrange to give notices of all electrical installation.d. ensure correct maintenance of flexible cables and flameproof and intrinsically safe characteristics of such equipment.e. ensure proper earthing of all electrical equipments and apparatus and efficacy of earth fault relays.3.Testing- He shall carry out the following tests:-a. tests of earth fault relays.b. tests of earth electrode resistance at-least once a year and c. tests of oil of the oil immersed apparatus for di-electric strength and acidity.4. Maintenance of plans and records-He shall maintain the following plans and records:-i. log books ii. record of testing of earth fault relaysiii.record of earth fault resistance.iv. record of testing of di-electric strength and acidity of the oil immersed apparatus.v. register of maintenance of the flameproof and intrinsically safe apparatus and of flexible cables.vi. schematic diagram of the electrical installation of the mine.vii.electrical plan of mine.5. Maintenance of fire extinguishers:- He shall ensure proper maintenance of the fire extinguishers and keep records of their testing.

Q.8.Spontaneous heating in advanced stage has been detected in a caving

district.i. How could you deal with the situation, andii.What are the statutory obligations that should be fulfilled.

Ans:- i) Dealing with spontaneous heating detected in advanced stage in a caving district :

It may be appreciated that the course of action of mine officials below ground at the time of occurrence of fire/spontaneous heating in advanced stage can not be laid down in any details. They would have to act largely according to their initiative and knowledge of the mine and situation. However, in instant situation, the following actions should be taken to deal with the spontaneous heating detected in advance stage in caving district:-

a) Prompt action to control the situation ( e.g. to combat the fire) by those on the spot may prevent a minor emergency from becoming major disaster. This should include testing of noxious and inflammable gasses, cutting off electricity, control of ventilation, care for fire fighting men and mobilising all available resources (fire fighting equipment and material) to the site.

b) Immediate steps must be taken to withdraw men in close proximity to, and those on the return side of the seat of the fire/ sp. heating and to send all unwanted men of the pit as soon as possible.

c) Notification of the incident must be telephoned to the surface (i.e. direct the Manager’s office, if possible) without delay, stating what action the official has taken or intends to take and if possible what kind of assistance is required.

d) A reliable man should be stationed at the telephone to maintain communication with the pit bottom and surface.

Taking into consideration the above facts, as an official of mine, I shall take the following action immediately:-

a) Sending information in-bye so that all persons assembled at one particular place.b) When the persons have assembled, situations should be explained to them and thereafter steps should be taken depending upon the circumstance prevailing –i) if the IA not affected, leave the persons out bye the lA. It must however be ensured that the team is controlled by cool headed person.ii) If there is difficulty in traveling by IA in the district concerned, try to get into another unaffected district and travel safety along the intake airway of that district.The main principle in case (a) as well as (b) above is to avoid places affected by the fire. The persons should use self rescuers and while traveling outbye, test for presence of O2 deficiency should frequently be made. Ans:- ii)- Statutory obligations to be fulfilled in case of detection of spontaneous heating/fire- The following statutory obligations / precautions are required to be fulfilled / taken while dealing with fire- 1) (a) Reg. 119 of CMR’1957 stipulates that on appearance of smoke or indication of spontaneous heating, all persons shall be withdrawn from a mine except those required for dealing with the fire. Normal work shall not be resumed till fire or heating has been extinguished or sealed off effectively and on examination made by the managerial staff, the place has been declared safe.

b) When there occurs in or about a mine, spontaneous heating or out break of fire or appearance of smoke or other indication of heating, the mine management shall forthwith inform RIM and send a notice in form IVA within 24 hours to prescribed authority.c) While dealing with a fire-i) a competent person shall be present on the spot throughoutii) adequate precautions shall be taken to prevent danger to persons from any noxious or inflammable gas, flame, steam and ejected or rolling down hot materials, explosion of water gas and falling into crevices or potholes they may occur in the area on fire.iii) there shall be kept available at or near all places belowground:

Adequate number of self rescuers and at-least two smoke helmets or other suitable apparatus.

A cage containing suitable birds or approved CO detector A flame safety lamp or other approved means of detecting CO2 gas and

O2 deficiency.d) The manager shall prepare and establish a detailed scheme for the provision and maintenance of suitable fire fighting arrangements for prevention, detection, dealing and control of fire, for examination and maintenance of protective measures taken to control and isolate the fire and for ensuring the safety of persons engaged in said operations i.e. emergency organization for fire fighting. The scheme shall be suitably modified and kept updated as the situation warrants.

2) Rule 24 of Mines Rescue Rule 1985 requires that :- a) On receiving information of spontaneous heating, the manager shall

immediately. Inform the rescue room or Rescue Station Serving the mine for

necessary assistance. Summon rescue trained persons employed in the mine. Inform the management of nearby mines to make available the services

of rescue trained persons employed therein. Summon medical assistance and Send information of the occurrence to RIM.

b) All rescue & recovery work shall be conducted under the control, supervision & direction of the manager or principal official.



SECOND CLASS




Q.No.1.What is typical composition of “Mine Air”? What are the physiological effects on human body of breathing air containing more than normal percentage of CO2? What is “oxidation of coal”?

Ans:- Typical composition of “Mine Air”:- Mine air varies from atmospheric air in its composition because atmospheric air entering the mine undergoes changes and gets contaminated with noxious gases given off by the strata and from other sources i.e. blasting, fire, burning of lights, bacterial action etc.The chief harmful gasses met within the mines are, carbon dioxide, methane, carbon monoxide and sulphuretted hydrogen.

Typical composition of mine air (return air) is given below:-

Sl.No. Gas Chemical Notation % by volume1 Oxygen O2 20.282 Nitrogen N2 78.903 Argon Ar4 Carbon

dioxideCO2 0.36

5 Methane CH4 0.46Total- 100.00

Physiological effects on human body of breathing air containing more than normal percentage of CO2:-

CO2 causes irritation of the mucous membranes of the eyes, mouth and nose and produces a sensation of burning (more than 5 -10%). It increases the rate and depth of breathing resulting in the labouring of the lung.

At higher concentration of CO2 with corresponding reduction of the 02% causes the following physiological effects on human organism:

1% Noticeably deep breathing.2% 50% increased amount of air breathed at rest.3% Breathing doubled even at rest, fatigue( flame

safety lamp extinguishes)5% Breathing tripled, extremely heavy breathing.6% Suffocation and desire to sit down.

Violent panting and exhaustion.10% Loss of sense, can not be endured for more than

a few minutes, headache, dizziness, sweating 20-25% Fatal, cause death after some hours.

Oxidation of coal: - When coal is exposed to air, oxygen is absorbed on its exposed surfaces and certain fractions of the coal substance oxidize with production of some gases (mainly C0 & C02) and water vapor, with evolution of heat. This is known as oxidation of coal.

3 C + 2 02 → 2 C0 + CO2 + Q

This is an exothermic reaction in which heat is liberated.This oxidation takes place even at normal temperature and humidity but it is a slow process and the heat evolved is carried away by the air, unless, of course if the air is stagnant. However, if the rate of dissipation of heat does not keep pace with the rate of generation of heat, the temperature of the coal rises. At this raised temperature, some other fractions of coal become susceptible to oxidation. Thus, this process accelerates until the coal reaches the stage of active combustion. This process of self heating of coal resulting eventually in its ignition without the application of heat is termed as spontaneous combustion or spontaneous heating or self heating or auto oxidation.

It is essentially a process of oxidation of coal under conditions in which this heat generated is cumulative.

Various stage of spontaneous heating of coal are :- Incubation period Indication period Open fire.

Q.No.2.There had been a number of roof and side fall accidents in the recent past while dressing the roof or sides in underground coal mines. What could be the possible reasons of such accidents? How recurrence of such accidents can be prevented?

Ans:- An analysis of roof and side fall accidents in U/G Coal Mines during the period 1997 to 2006 revealed that a good number of accidents and fatalities due to fall of roof and sides are taking place during dressing of roof and sides-- an operation being carried out to secure the roof and sides to ensure safe working.

The analysis further revealed that 10% of total roof fall accidents occurred during dressing operation in which 7% dressers were involved. Similarly 12% of total side fall accidents occurred during dressing operation in which 8% dressers were involved.Possible reasons of roof & side falls accidents while dressing the roof or sides in U/G coal mines:-

i. Non-provision of suitable tools for dressing and non-use of the dressing toolsii. Carrying out dressing operations by a coal miner’s pick at high roof.iii.Using drum for reaching high roof for dressing instead of suitable bunton or crowbar.iv. Dressing of roof or sides by dressers from unsafe position i.e. from beneath the unsafe roof or from the in-bye dip side of the roof.v. Dressing operations carried out by untrained dressers in the absence of suitable class-room and on-job-training.vi. Skilled dressing operations by unskilled mazdoors due to non-availability of regular dresser.Suitable measures / steps to avoid recurrence of roof and side fall accidents during dressing operations:- The following measures/ steps should be take to prevent recurrence of roof & side fall accidents during dressing operations:- i. Proper training of existing dressers- Available dressers in the belowground mine should be imparted class room and on-job training for adopting a sound, safe and standard dressing procedure. If, even after training, found unfit for job, they should not be engaged in dressing operations.ii. Selection of persons for dressing operation – Persons to be newly selected for dressing / recess cutting job shall have a strong physique and good health.iii. Proper training of persons selected for dressing operations-Selected dressers shall undergo initial / basic training as per VT rules and specific training

modules. be appraised of different geological disturbances likely to be encountered. be trained to note the grumbling sound to detect the bad roof with

stick/crowbar/bunton. be told about taking personal protection by way of standing at safe place and

guarding the shinbone with basket while testing and dressing the roof and sides and also about the importance of Deflector rings on crowbar/bunton.

be trained for the use of proper tools w.r.t. situation of workings i.e. Pick for low height, crowbar for big and strong overhangs and buntons for high roofs.

be explained about cleats and how they can take advantage of weak planes so as to get more result exerting less and also about importance of geological disturbance including slip planes.

be apprised about the seals with particular attention to the dimensions of the recess for isolation/sectionalisation/ ventilation stoppings.

be made aware of the manhole size. he told about the hazard mechanisms of roof & side falls.

iv. Panel of substitutes- Panel of sufficient number of persons shall be made & they shall be trained properly to take care of the absenteeism on account of leave/sick/other reason of the regular dresser.

v. Procedure of Testing and dressing of roof & sides:- Dresser shall test the roof and sides of every face at the beginning of the shift

in the place of mining Sirdar. After blasting, all places within the zone of influence of blasting shall be tested

by dresser. He shall also test other places of the mine as instructed by supervising staff. During dressing operation, he shall stand at a place where the roof and sides

are safe and secure and then dress the roof & sides with proper tools. Dressing should proceed from out-bye to in-bye side.

He shall leave the face only when the Mining Sirdar declares that the face has been dressed properly.

vi. Supply of equipment/ tools:- Dressers shall be provided with coal miners pick, crowbar and buntons. They shall also be given personal protective equipment such as helmet,

mining shoes and shin guard. Sufficient stock of equipment & tools shall be maintained in stores.

vii. Responsibilities:- Presser shall be made responsible for dressing the roof and sides of

working places assigned to him in such a way that there is no loose coal/ stone in the roof, no overhangs and the sides are not loose.

He shall make recesses of the prescribed dimensions when engaged in recess or manhole cutting job.

He shall be responsible for his own safety while dressing the roof and sides or engaged in recess cutting job.

viii. Additional measures- He should made compulsory member of safety committee. He should also be involved in risk assessment and risk management

exercise.

Q.No,3.What are the provisions contained in the Mines Act, 1952 in respect to the following?

a) Managersb) Functions of the Committee.

Ans:-a) Managers- Section 17 of Mines Act, 1952 stipulates statutory provisions for managers as mentioned below:-

i) Every mine shall be under a sole manager having prescribed qualificationsii) Owner or Agent of every mine shall appoint a person having prescribed

qualifications to be the manager. iii) Owner or Agent having prescribed qualifications may appoint himself as manager.iv) Subject to any instructions given to him by or on behalf of the owner or agent of the mine, the manager shall be responsible for the overall management, control, supervision and direction of the mine and all such instructions when given by the owner and agent shall be confirmed in writing forthwith.v) Except in case of an emergency, the owner or agent of a mine or anyone on his behalf shall not give, otherwise than through the manager, instructions affecting the fulfillment of his statutory duties, to a person employed in a mine, who is responsible to the manager. vi) It shall be the responsibility of the manager to see that the officials and competent persons so appointed are competent to perform the duties assigned to them. No person shall be so appointed unless he is paid by the owner or agent and is answerable to the manager.vii) Every manager on taking over charge of a mine shall satisfy himself that all officials & competent persons already appointed are competent to perform the duties assigned to them and if he finds them competent, he shall either, countersign their authorizations or issue fresh ones.

Ans. b) Functions of Committee under Section 12 of the Mines Act- Functions of Committee:i) To consider proposals for making rules and regulations (not bye laws) and to make appropriate recommendations to the central Govt. ii) To enquire into such accidents or other matter as may be referred to it by the Central Govt.from time to time and make reports thereon andiii) To hear and decide such appeals or objections against notices or orders issued under the statute.

Q.No.4.What is “Safe Work Procedure? Why it is necessary? Write a “Safe Work Procedure” for manual loading of trucks in an opencast mine.

Ans:- In recent past, the rate of accidents has increased in Indian Mines, particularly in outsourcing patches in which mining operations are carried out by engaging contractors men & machines. Thus management of safety issues becomes an essentiality for mine operators. Improvement in contractor worker’s safety performance will play a significant role in the industries overall performance. Mine Operators must ensure that work is carried out in compliance with the existing statute. Any system of work established by the contractor must be consistent with the mine operators, and it is the responsibility of mine operator to determine the safety standards. For this purpose, safe work procedure or safe operating procedure as recommended by 10th National Conference on Safety in Mines is required to be prepared by the mine operator and also by contractors for strict enforcement in the mines.Safe Work Procedure- It is a working document which outlines all the actions to be carried out to ensure safety and health at the work place in order to comply with all requirements of statute and the system related to safety. It is a document that would be available to all workers on site and should enable them to be

aware of not only this framework within which they have to do their work but also what is expected from them to ensure a safe and healthy work environment. Basic ingredients of Safe Work Procedure-An effective safe of procedure should contain the following: Relevant Acts, Regulations and Circulars Emergency procedures Standing orders Individual job procedures Process for introducing new methods, equipment or materials etc. Training requirements Hazard identification and Risk Management process Safety management forms ( accident investigation, hazard analysis,

reporting etc) Medical examinations Entitlements for employees injured or suffering health impacts at the mine.It needs to be made to suit the site specific conditions of the mine. It should be simple and clear whilst meeting the requirements of legislation, regulation, standing orders etc.Thrust Areas for safe work procedure: Typically, safe work procedures would be required for the following areas:- Work associated with each step of the mine production and maintenance. Roof support methods & rules. Explosives transport, storage, handling and usage. Mineral handling, storage and transport. Traffic rules and safety in haul roads Rules for operating equipment Usage of personal protective equipment and critical spots in the mine for

dust, noise, heat, vibration, illumination etc. Inspections, Supervisions and daily reporting requirements. Emergencies House keeping rules.

Necessity of safe work procedure :- To ensure safety To reduce overall costs of operation To reduce occupational health hazards To ensure optimum utilization of available resources thereby cutting costs and

reducing wastages. To enforce strict compliance of safety legislation in mines. To ensure use of fit-for-purpose men/machine Suitable works To avoid unsafe conditions & unsafe acts. To ensure improvements in levels of safety, health and welfare of persons

employed in mine.Safe work procedure for manual loading of trucks:-

1. General Safety :-i. Loading of trucks by mannual means should be done during day light hours or the area of operations shall be properly illuminated.ii. A loading platform / stage or scaffold of adequate width with proper fencing shall be provided.

iii. A danger board indicating “MEN ENGAGED IN LOADING OF TRUCKS” shall be suitably placed.iv. Cane basket and safety shoes should be provided for loading of coal into trucks.

2. Design & construction of trucks :-Trucks shall be provided with: Canopy of an approved design. Efficient Head light Audio-visual alarms to transmit signals during reversal. Service brake, parking brake & emergency brake to be maintained in safe working order.

3. Selection & training of manual loaders :- Persons engaged in loading jobs shall be trained in safety matters

as per provisions of statute before hand. Before commencement of work, Manager shall arrange training of

loaders including briefing of traffic rules.4. Issue of identity cards - All workers shall be issued identity cards.5. Entry in Form B Register - Manager shall ensure maintenance of record of

workers in Form “B” register as per provisions contained in Mines Rule, 1955.

6. Attendance – Attendance shall be marked in statutory attendance register. Working hours shall be limited to 8 and spread over to 12 hrs (max.) Weekly days of rest shall be ensured.

7. Provision of rest shelter - Rest shelter with drinking water facility near the place of work shall be provided and maintained.

8. Fitness certificate & road worthiness of trucks :- Fitness certificate including functioning of AVA and other safety devices

should be checked by colliery engineer and records of the same should be maintained.

Colliery Engineer and safety officer shall make random checks of fitness certificates, brakes, lights, horns, AVA’s etc. Defective truck shall not be permitted for loading purposes.

Time in and out shall be recorded in a register at the check post.9. Unauthorised driving / riding :-

Drivers license shall be verified by the colliery engineer. No helper or unauthorized persons shall drive/ ride/ travel trucks. Trained trip men and helpers be provided at loading points during the

loading operation. No negligent / careless driving.

10. Supervision :- Mine management shall deploy competent persons for statutory supervisions.

11. Traffic :- As far as practical one way traffic shall be adopted. Sufficient space shall be provided to avoid over crowding. Manual loading and dumping shall not be allowed at the same place. Standard traffic rules shall be adopted and followed during movement of

trucks. 12. Parking :-

During loading of trucks, vehicles shall be parked on level ground. Adequate width shall be ensured for parking of trucks. Maintenance of minimum safe distance between two tracks.

13. Roads- Roads should be well maintained and kept free from spillage and slipping matters. Proper arrangements should be made for dust suppression for good visibility.

14. Operation- Loaded trucks shall not be reversed on gradient. While trucks being loaded on gradient, the same shall be secured

stationery by parking brake & other means. Driver shall keep the cab window clean so as to ensure clear vision at all

times. He shall handle the trucks carefully and keep it under control at all times. He shall see that the truck is not overloaded and material is not loaded in

a truck so as to project horizontally beyond the sides of its body. Q.No.5.What dangers may be anticipated while sealing off a fire in the goaf of a

degree lll gassy mine? What procedure would you follow to seal off such a fire? What precautions should be taken against the anticipated dangers?

Ans:- An underground fire is sealed off, by creating stoppings when all other direct methods of combating proves unsuccessful or are considered not possible.

It is a sure method of cutting of oxygen feed to the fire though it requires a long time for extinguishing the fire.An area under fire in a mine may have to be sealed off in the following cases:-i. When the fire has attained so large proportions that it cannot be extinguished by methods of direct attack.ii. When the fire is inaccessible, as in the case of a spontaneous heating or fire in a goaf or in a crushed zone or near fault plane - where methods of direct attack fail.iii. When there is a possibility of occurrence of an explosion. Sealing off consists of building stoppings in all the galleries to prevent access of air to the fire. The fire soon dies out through lack of oxygen, provided the stoppings are not leaking.

Dangers while sealing off fire area:Dangers anticipated while sealing off a fire in the goaf of a degree III gassy mine are enumerated below:-

i) Risk of dust or gas explosion (from air borne coal dust or methane or other combustible gasses) threatening heavy casualty of men & material.

ii) Risk of toxic and asphyxiating fumes, particularly from CO – moving through the workings downwind the fire and endangering workmen, even in remote areas from the location of fires.

iii) Chances of flash over of fireiv) Chances of back lush of smoke.v) Affecting the U/G ventilation – due to constriction effect and buoyancy effect. vi)Chances of roof falls.Sealing off fire in the goaf of a degree III gassy mine:-Once it is decided to seal off a fire area, no time should be lost. The materials of construction of stoppings should be speedily transported to the site and arrangements should be made for adequate labour force to form relays of builders.The main problems posed in sealing off a fire are the leakages of air within (even after sealing) and the threat from explosion during the sealing off operation,

immediately after it and during recovery operation of the fire area. The different phases of sealing off operation are carried out keeping the above problems in view. These operational phases for underground sealing are:-i. Site selection for erecting stoppings- While selecting the site, distance from fire, minimum number of stoppings, good ground conditions, space for reinforcement, transport facilities, ease of ventilation, accessibility for inspection, facility of balancing air pressures etc. should be taken into consideration.ii Sequence of seal making.iii.Modus oparandi of building up the stoppingsiv.Inspection and subsequent control of the fire.v.Recovery of the fire area.Essential requirements for sealing off fire area- The first requirement of stoppings constructed to seal off a fire area in a

degree lll degree mine is the construction of explosion proof stoppings to withstand the force of possible explosion.

The second requirement is that the ventilation is to be maintained as near to normal as possible and stoppings at the intake and return end are to be sealed simultaneously.

Sudden reduction of ventilation is to be avoided to prevent the fire gases on downwind side of fire being blown back to the fire causing an explosion.

Procedure to be followed for sealing of a fire in the goaf of a Degree lll gassy mine1. Organisation of the work of sealing off:

a. The work of sealing should be done by workers trained in the use of rescue apparatus and a rescue team with SCBA should be kept in reserve.

b. A control room should be set up at the surface of the mine. Duty roster of officers and supervisory staff should be drawn up. The requirement of workman shiftwise should be assessed and arrangement should be made accordingly. An officer should be incharge of manpower and allotment of duties.

c. For supply and issue of essential stores such as building materials, appliances, tools and safety devices and for their speedy transport to the selected site, a separate officers should be made responsible.

d. Haulage track and telephones should be extended as near to the site of stoppings as possible.

e. At the operation control room, a mine plan and large scale tracings of the affected area should be kept available. Progress of all operations should be recorded in the operation register kept in the control room.

2. Operating procedure:- During the construction, the affected area is heavily stone dusted. Sufficiently large area near the fire is enclosed by the stoppings so that a large volume of air is trapped behind them to ensure that there is enough air near the fire to prevent formation of explosive gas – air mixture and the normal quantity of ventilating air should be allowed to reach the district by keeping the fan at the usual speed. First of all, sand bag stoppings about 1.5m thick followed by 0.5m thick brick in cement stoppings on their out bye sides are built. One stopping in the intake airway and other in the return airway are provided with a tapered passage, about 1m square at the in bye end and about 0.75m square at the out bye end for maintaining the ventilation in the area to be sealed off. The

floor & sides of this passage are made of sand bags while the roof is of corrugated sheets to take up the load of sandbags above. An observer is stationed at the return stopping to check the % of CH4 in the return air at short intervals and to take samples of air periodically. If the % of CH4 rises, the air passage must be enlarged. The air passages in the two stoppings are then quickly closed simultaneously by sand bags. Every stopping is provided with a sampling pipe. After initial closure in this airway, men are withdrawn to surface and after waiting for 48 hrs. , the stoppings are inspected by a rescue team for any signs of disruption or leakage. The team also collects samples of air. When these stoppings show that the atmosphere inside the sealed off area is non-explosive and there is no CO or CH4 in the mine roadways upto the stoppings, ordinary workmen are employed to repair the stoppings. The stoppings are then strengthened by adding a brick work 0.5 m thick and 1 m brick work so formed is plastered outbye. The seals are then made permanent and explosion proof by building a 1 m thick brick stopping 4.5 m out bye of it and filling the intervening space with sand or other inert packing material.Precautions against anticipated dangers during sealing off operations:-i. Stoppings should be sited as far as possible from seat of fire.ii. Under no circumstances the ventilation be interrupted when building stopping.iii. In order to prevent propagation of explosion of fire damp or fire gases and coal dust during sealing operation, the roadways between seat of fire and stoppings shall be thoroughly stone dusted. iv. During sealing operation with ordinary men, rescue teams should be kept stand-bye. v. Detection of inflammable gas from return of fire area shall be made at shorter intervals and persons shall be withdrawn from mine if the methane content approaches explosive limit.vi. Ventilation shall be maintained to the fire area to prevent building up of inflammable gases to a dangerous level. The last intake and return seals shall be closed simultaneously preferably by closing small steel doors provided in the stoppings.vii. The affected area should be isolated quickly by erecting temporary stoppings which will require minimum time for construction with reasonable air tightness such as sand bags, stone dust bags, sheet & brattice, and brick stoppings etc.viii. Permanent stopping out bye of temporary stopping shall be built later to withstand rock pressure and to have complete air tightness of the sealed off area.ix. Permanent stopping should be built after a lapse of at-least 48 hours being the critical period during which methane content may reach explosive limit before O2 is reduced to 12% or less.(iii) Before construction of a stopping is begun, an adequate SDB should, if practicable, be erected in the part of the roadways between the seat of the fire and that of the stopping proposed to be sealed.

Q.No.6.Write short notes on any three of the following:- a) Standards of medical examination

b) Controlled blastingc) Natural ventilationd) Abandonment Mine Plan.

Ans:- (a) Standards of medical examination- The Rule 29B of Mines Rule 1955 provides for :-a) Initial Medical Examination of every person to be employed in the Mine.b) Periodical Medical Examination of all persons already employed in the mines once in five years.c) In case of asbestos mines, PME to be done once in a every 12 months and every such examination shall include all the tests except the x-ray examination, which shall be carried out once in every three years. The medical examinations provide valuable information about the health of the individual workers and epidemiological information on prevalence of occupational diseases in mines.IME provides baseline data on the health parameters of the workers, enables identification of workers sensitive to a particular hazard, identification of workers whose handicap can be safety risk and suitable placement of worker depending on his physiological and mental capacity.PME are helpful in early detection of occupational diseases and other non-occupational diseases so that they can be treated at an early stage and the worker can be suitably rehabilitated by providing job placement if required.Rule 29F of Mines Rules’1955 requires that IME & PME of persons should be conducted in accordance with the standards laid down in Form P and Form P1 respectively as mentioned in the table given below:- Sl.

Parameter Standard of IME (Form- P1) Standard of PME( Form-P)

1 General Standard

The person should be in good mental and bodily health and free from any physical defect likely to interfere with his efficient employment in a mine.Due allowance in the standard should be made for the age of candidate.

The person should be in good mental and bodily health and free from any physical defect likely to interfere with his efficient employment in a mine.

2 Locomotor system

The limbs should be well formed and developed and the function of all the limbs should be within normal limits. Any deformity should be recorded. There should be no deformity or paralysis which may interfere with his efficient employment in a mine.

The limbs should be well formed and developed and the function of all the limbs should be within normal limits. Any deformity should be recorded. There should be no deformity or paralysis which may interfere with his efficient employment in a mine.

3 Skin There should be no evidence of extensive and chronic skin disease or ulceration.

There should be no evidence of extensive and chronic skin disease or ulceration.In case of infective type of skin disease; the candidate could be made fit after medical treatment.

4 Vision a) Distant vision of eye with or without glasses should be not less than following standard; Surface U/GBetter eye – 6/12 6/6Worse eye – 6/18 6/9b) Night blindness should be

a) Eye vision should be not less than the following standard:Better eye – 6/12Worse eye – 6/18b) There should be no night blindness for persons

tested in special cases only of underground workers where the examining authority considers it necessary.c) Unioculor person should not be employed belowground. For employment on surface, the vision of such a person in the other eye should be 6/12 with or without glasses. d) Colour blindness will be tested only in special caees. Where the job requires good colour discrimination. (e) There should not be any organic disease of the eyes which is likely to affect the distant vision within a period of five years.

employed below ground and for persons employed in open cast workings in shifts other than in morning shifts.

c) Unioculor person should not be employed belowgro und. For employment on surface, the vision of such a person in the other eye should be 6/18 with or without glasses.

5 Hearing Hearing should be good and person be able to hear voice from a distance of 3m. Any progressive disease affecting hearing should be recorded.

Hearing should be good. Any progressive disease affecting hearing / or occupational deafness should be recorded.

6 Speech Speech must be without serious impediments.

Speech must be without serious impediment. Unless this is also accompanied by generalized partial paralysis, this should not be reason for declaring unfit.

7 Respiratory system

a) It should be sound and free from any chronic bronchial or laryngeal disease. b) After chest radiograph and lung function test, there should not be any evidence of active pulmonary disease.

a) It should be sound and free from any chronic bronchial or laryngeal disease. b) After chest radiograph and lung function test, there should not be any evidence of active pulmonary disease. If, there are evidences of active pulmonary tuberculosis, he may be permitted to work if his sputum is negative on repeated examination on production of a certificate that he is taking treatment from a qualified medical practitioner/ Hospital.

8 Circulatory system

There should be no evidence of any cardiac or vascular disease which may interfere with his efficient employment in a mine

There should be no evidence of any heart or vascular disease which may interfere with his efficient employment in a mine.

9 Disease of abdominal organs.

There should not be any evidence of disease of abdominal organs which is likely to affect his efficient discharge of duty in a mine.

10 Hernia In case the candidate has hernia, In case the candidate has

he may be declared fit after he has been successfully operated for the same.

hernia, he may be declared fit after he has been successfully operated for the same.

11 Hydrocele It should not be large enough to impede the normal activities of the candidate. In such a case he may be declared fit after being successfully operated.

It should not be large enough to impede the normal activities of the candidate. In such a case he may be declared fit after being successfully operated.

12 Nervous system

It should be sound. Persons with history for epilepsy or any other type of organic or historical fit, should not be declared fit for employment.

13 General Examination

The medical examination should include examination of urine. Mere presence of albumen and sugar in the urine without any gross organic disease producing signs and symptoms should not be considered as a disability.

The medical examination should include examination of urine and other system for evidence of disease. Mere presence of albumen and sugar in the urine without any gross organic disease producing signs and symptoms should not be considered as a disability.

14 Skiagram Skiagram of the chest should also be obtained by directing the candidate to undergo special test or / and to obtain opinion of a specialist from recognized institutions / hospitals.

The Standard of medical examination should be in conformity with the ILO classification.Ans:- (b) Controlled Blasting- Controlled blasting is a method of rock blasting where the risk for damage to surrounding structures and installations are eliminated by planned drilling and charging procedures to enable vibration control and by taking all measures such as covering for protection against fly rock.Purpose of Controlled Blasting – Controlled blasting is done to :i) Reduce over-break. ii) Minimise fracturing of rock at the bottom of an excavation and iii) Control fly rocks

In controlled blasting, blast dimension is achieved by trial and error method.Techniques of controlled blasting1. Blast design- Optimum blast design should be adopted based on blast parameters such as depth and diameter of blast hole, burden, spacing, charge factor, stemming etc in order to have desired peak particle velocity (PPV), frequency and amplitude within permissible limit. Use of computerized blasting model, constant monitoring and review of blasting practice is recommended. 2.Deck charging- Dividing the explosive charge in more than one deck by incorporating inert material between different segments when strata are alternately hard and soft. This provides better energy distribution and different decks can be blasted with different delay timings to reduce the charge per delay.

3.Air decking- In this method, during deck charging, instead of inert material, gas bags or wooden spacers are used between decks. Air column lowers the initial pressure of explosion products and increases time of interaction of detonation front with surrounding strata.4.Use of Electronic detonators- Normal pyro-technique delay detonators have a scatter in the delay timings. Electronic detonators provide accurate delay (upto 1ms) and cut down chances of overlapping of different delays.5. Use of Non-electric detonators (Nonels)- These shock tube based initiating devices provide a low order shock wave for initiation of the explosives. They have an advantage over detonating cord in that they do not de-sensitize the explosives and do not disturb the stemming column thus avoiding fly-rock. Nonels also help in firing deck charges with separate delays.6.Line drilling- It involves in a single row of closely spaced uncharged holes between the blasting site and the area to be protected. It provides a plane of weakness to which the primary blast can break and effectively arrest ground vibrations. It is tedious and more suited for protection of construction sites. 7. Pre-splitting- It consists of a row of holes on 3 sides of the blasting block at a closer spacing (8- 12 diameters) charged with lesser explosive (only 10-15% per hole of the main blast). It isolates the blasted zone from remaining rock mass by creating a fracture line.8. Cushion blasting-

Drilling of row of 50- 100 mm dia bore holes along final line of extraction. Loading with light well distributed charge Burden = spacing Loading similar to pre-splitting Maximum depth – 30m

9. Muffle blasting- It aims to limit the blasted material within 10m of the hole. Generally, rejected tyres are kept over the holes and mats or meshes( 40mm x 40mm) made of locally available rope strands (5-6mm) loaded with sand bags of 40-50kg placed over it are used. Loading should be adequate otherwise, mat would be thrown away causing damage and allowing fly-rock. Mats should overlap and a portion also kept hanging over the free face.Ans :- (C) Natural Ventilation:- Flow of air through the mine workings by purely natural means is called natural ventilation. Such flow takes place when there is a natural difference in densities between the up cast and downcast shafts. Small and shallow mines are some times ventilated by natural means only though the ventilation in such cases is usually poor, fluctuated to a large extent and is even subject to reversal of direction.Causes of Natural Ventilation- i. Temperatureii. Moisture content of air iii. Barometric pressureiv. Addition of gasesv. Leakagesvi. Circulation of refrigerated air.All the above factors are responsible for the difference in densities of air between up cast and down cast shafts.Mechanism of Natural Ventilation:- The heavier air sinks down and the lighter air moves up setting an air current. The difference in densities may be due to difference in temperature, moisture, gas content etc.

Consider two shafts AB and CD whose mouths are situated at two different levels as shown in above fig. In winter the cold and consequently heavy outside air in the column EA together with AB will force out of the mine the lighter warm column of air CD. The shaft AB will be working as downcast shaft and CD the up-cast shaft. If one of these shafts is replaced by an incline, the same principle will hold good, that is, if there is difference in densities of two vertical or inclined columns of air contained between two horizontal planes, natural ventilation pressure will be created.In the above illustration, in summer season when the temperature of outside air is higher than mine air temperature, CD will act as the downcast shaft and AB as the up-cast shaft. In a season when the temperature of outside air and underground air are the same, there would be no natural ventilating pressure. Thus both the direction and the amount of n. v. p. vary with weather. Also in an emergency like fire in the mine, mechanical ventilation can be controlled which is not possible with natural ventilation. As such natural ventilation cannot be relied upon, and installation of mechanical ventilators for mine is a statutory requirement.However, even in mechanically ventilated mines, natural ventilation has a role to play. In case the two shaft collars are at the same level, in winter the fan would draw cold air into the mine. As a result the natural ventilation draught in winter is in the same direction as the fan draught but in summer it usually opposes the fan draught or its assistance reduces.

Calculation of N.V.P. from air density- Natural ventilation pressure in a mine is the difference in pressures of air columns in the downcast and up-cast shafts.

i.e. N.V.P. = P1 – P2

= D. Pd . g – D. Pu . g (pascal)= D.g (Pd – Pu)

Where D = depth of D.C. shaft (in m )g = acceleration due to gravity in ms-2

Pd = mean density of air in D.C.shaft in kg.m-3

Pu = mean density of air in U.C.shaft in kg.m-3

Density of air is affected mainly by temperature (effect of moisture is minor and neglected in usual calculations). If the mean temperature ( in K) in the downcast and up-cast shafts are Td and Tu respectively.

Density of air in D.C.shaft Pd = Bd x 10 3 kg.m-3

287 Td

And density of air in U.C. shaft Pu = Bu x 10 3 kg.m-3

287 Td

Where Bd and Bu are mean barometric pressures in Kpa in the downcast and up-cast shafts respectively.

For mine shafts in general barometric pressure Bd = Bu say B

:. N.V.P. = D. g (B/287 Td – B/287 Tu) x 103 pascal= g.D.B ( Td - Tu ) x103 Pascal 287 Tu.Td

Note:- In the above formula, barometric pressure is in kPa.

Motive Column: - It is defined as the height of air column in the down cast shaft which causes the natural ventilating pressure. In other words, motive column is the N.V.P. expressed in terms of the height of a column of air with a density equal to that of air in the down cast shaft.The hight of motive column is expressed as:

H= N.V.P Pd. g

Where H = height of motive columnNVP = natural ventilating pressurePd = density of downcast air g = acceleration due to gravity.

Ans:- d) Abandonment Mine Plan- This is the true copy of up-to-date plan and section of the u/g workings of the mine or part and seam having average inclination more than 30º from the horizontal. It shall show the bearing and distance of at least one of the shafts or openings of the mine from a tri-junction pillar or revenue pillar or from any other prominent and permanent surface feature, the position of water dams built u/g (with its dimension and other particulars of construction) and also the spot levels at the end of the workings.Statutory obligation-

i) When any mine or seam or section thereof is abandoned or the working thereof has been discontinued over a period exceeding 60 days, the owner of the mine shall submit within 30 days of abandonment or 90 days of discontinuance, to the DGMS, two copies of Abandoned Mined Plan and sections.

ii) The original or certified true copy of the AMP shall be kept in the office of the mine.

iii) DGMS may supply copies of AMP to: a) any person having a bona-fide interest in the mine, seam or section or b) the owner, agent or manager of an adjacent mine. Utility of AMP-a) When an adjacent mine is worked at a later date, the AMP is utilized to leave adequate barriers to avoid danger of inrush of water/liquid matter or gas or ingress of fire.

b) It helps in assessing danger to surface structures also.Requirement of AMP- The AMP should be submitted on tracing cloth or polyester tracing film with index number of the original plan from which it is traced. It should be certified to be a true copy of the original plan by the surveyor and countersigned by the manager. The AMP shall show the detailed information as required under statute as follows:i) Name of owner, mine, plan, true north or magnetic meridian with date of the latter, a scale at least 25cm long and suitably divided; conventions as per the second schedule.

ii) Distance and bearing of at least one shaft or opening of the mine in relation to tri-junction or revenue pillar or any other permanent surface feature.iii) Up-to-date position of workings belowground, ends of workings to be marked with dotted lines and last date of survey.iv) General direction and rate of dip of strata. Section of the seams(s).v) Position of every fault, dyke and other geological disturbances with amount of throw and direction.vi) Vertical mine sections (if inclination exceeds 30º)vii) Multi-section workings lying within 9m to be shown in different colours on a combined plan separately.viii) Every important surface feature with the boundaries such as railway, road, river, stream, water course, tank / reservoir, opencast working, village (with name) and building which is within 200m of any part of the working measured horizontally. HFL of river/stream.ix) Surface contour lines at vertical interval not exceeding 5m. Bench mark on the surface in relation to mean sea level (MSL) x) Spot levels along all important drivages and at the ends of the heading; also at the end of all workings.xi) Mine boundary.xii) Up-to-date workings of all the mines situated within 60m from the boundary any connection with adjacent mines.xiii) Position of water dams and embankments (with dimensions and particulars of construction).xiv) An abstract of all statutory restrictions in respect of the workings (with DGMS letter number)xv) If the plan has not been updated up to the time of abandonment, this fact should be recorded on the plan. If barriers with adjacent mines are not adequate, this fact should be recorded on the plan and , where necessary management of the adjacent mines should be warned. If any workings lie beneath railway, public road and building not belonging to the owner, and are inaccessible, the fact should be recorded on the plan.xvi) Position of all pumps and lodgments underground together with information concerning the quantity of water being pumped out before abandonment. Also position and extent of known water logging.xvii) A certificate of correctness of the plan (as printed in the original plan.)xviii) In case of coal mines only

degree of gassiness of the seam particular section of the seam being worked abstract of precautions taken against heating or fire or explosion, if

any.

Q.No.7.How the brakes of a dumper are tested in an opencast mine? What are the different types of brakes provided in typical dumpers? What steps can be taken to reduce accidents caused by dumpers in opencast coal mines?

Ans:- Testing of brakes of a dumper in an open cast mine:- Brake system is vital element for controlling accidents caused by wheeled trackless transportation machinery like dumpers, trucks and tippers.Following international standards provide requirement of brake system and procedure of brake testing:-i. ISO V3450-1985(E):- Earth Moving Machinery- Wheeled machines – Performance requirement and test procedures for braking system.

ii. SAE J1152 April 1980 - Braking performance – Rubber Tyred Construction Machine.As per circular No. 3 of 1981, brakes of a dumper shall be tested as per the following details :-i) Periodicity - Brakes of dumpers are required to be checked /tested at least once in every two weeks.ii) Test Procedure- a) Service Brake Test – The brake shall be tested on a specified gradient and speed when the vehicle is fully loaded. The vehicle should stop within a specified distance when the brake is applied.As per manufacturers instructions, service brake should be checked by application of brake when a fully loaded dumper is running at a speed of 32 km/ hr. The dumper should stop dead within 21m from the application of brake. This is for dumpers having capacity more than 32 Te. b) Parking Brake Test- The parking brake should be capable to hold the vehicle when it is fully loaded and placed at the maximum gradient of roadway which is permitted for a period of a least 10 minutes.Parking brake should be capable to hold a fully loaded dumper at a roadway gradient of 15 0 and an empty dumper at a gradient of 18 0

.

c) Emergency Brake Test- Functioning of emergency brake should be checked at specified intervals.A record of above tests shall be maintained in a bound pages book and shall be signed by the persons carrying out the test. These records should be countersigned by the engineer and manager.Surprise inspection shall also be carried out by the engineer / superior official at an interval not exceeding 15 days to ensure that the examination schedule of dumpers are carried out. Different types of brakes provided in typical dumpers- As per standard, all dumpers shall be equipped with:-a) A service brake system- the primary system used for stopping and holding the dumpers.b) An emergency / secondary brake system:- the system used for stopping the vehicles in the event of any single failure in the service brake system.c) A parking brake system:- a system used to hold the stopped dumpers in a stationery position.d) A retarder brake system.e) A dump brake system. Brake system may have common components. However, in the event of failure of any single components, the brake system shall have the capability of bringing vehicle to a halt. Such arrangement will not allow rolling down of vehicles in case of busting of hose pipes etc. Parking brake system shall be so designed that it shall not depend on exhaustible energy source like air in reservoir. In most of the dumpers working in our country parking brakes are working on air. This leads to rolling down of vehicles when air pressure becomes low. Steps to be taken to reduce accidents caused by dumpers in opencast coal mines:- i) Arresting negligent and un-authorized driving – a) Dumper drivers must be selected very carefully and given a through initial training.b) Periodical refresher training and examinations should be organized to test their skills and attitude.

c) Only authorized and properly trained operators should operate the vehicle.d) Adequate number of operators should be appointed to avoid deployment on OT.e) No dumper should be driven in fog or mist unless special fog lights are provided. f) Competency of operators should be evaluated by a Board.g) To prevent un-authorized driving, a system should be evolved whereby the ignition key and / or cabin key always remains with the operator or with specifically designated competent persons.ii) Arresting un-authorized traveling on dumpers- a) Adequate transport arrangement should be made for the equipment maintenance staff, operators, cable man, dump man etc. so that they are not tempted to steal a ride on dumpers.b) Any unauthorized person including driver caught a riding on a dumper should be given exemplary punishment to deter others from doing so.iii) Planning and designing of haul roads:- a) Haul roads should be planned, designed, constructed and maintained on sound scientific principles. Particular attention should be paid to the drainage of surface water.b) All bends in haul roads should be designed with a large radius so that the driver has a clear view for a distance of not less than 30 m along the road. iv) Safe Practices:- a) Selection of dumpers:- Only well designed vehicles conforming to international safety

standards should be used. Vehicles should be provided with service, emergency and parking

brakes. All dumpers must be equipped with audio-visual alarms to facilitate

safe reversal. Where reversal is required as a routine, a “stopper” should be appointed to guide the driver.

A seat belt for the safety of operator should be provided in operators cabin.

b) Maintenance of dumpers:- A scheme of maintenance, examination and testing should be drawn up

and strictly followed. Such a scheme must specify the nature and frequency of examinations and the way in which the information is to be reported and stored.

Testing of brakes should be carried out as per laid down schedule. Lights and horn of each dumper must be checked at the start of each shift. Test run of the dumper should be done only by a mechanic holding driving

license. Starting – key of dumper should remain with the supervisor as long as

works are being done below or beneath it. Dumper should be parked on a hard and level ground and tapered

wooden blocks should be placed in front of and behind the tyres to avoid rolling of dumper on either side.

For lifting purpose, only tested and certified slings should be used.

c) Traffic rules:- Traffic rules specifying speed limits, right of way, overtaking, parking and other general precautions should be framed and strictly enforced.

d) Code of practice for safe tipping and dumping -

Code of practice should be framed for prevention of injuries to persons engaged in tipping on stock piles and dumping of OB at dump-yard.

All unloading points should be adequately manned for traffic control and safe unloading.

Dumping edge should be provided with properly designed portable wheel stops to prevent the dumpers from running into unstable ground, loosing their balance and falling down the slope.

e) Precautions against fire - Every dumper must be provided with at least one fire extinguisher in the driver’s cabin so that as soon as a fire is noticed, it can be extinguished.

Q.No.8.What do you understand by the following terms?a) Vertical coincidenceb) Safety Management Systemc) Wide stall method of working. Ans:-a) Vertical coincidence-If the distance between the consecutive seams is small, the workings of one seam may affect the workings of the other seam. If the workings of a seam are above the one being worked, the workings in the top seam will certainly be affected.

In India, seams lying within 9 m of each other, are termed as contiguous seams and their workings must confirm the certain statutory requirement as laid down in reg.104 of CMR 1957 , which are re-produced below:- No work in a higher seam or section shall be done over an area in a lower

seam a section which may collapse. Where two or more such seams or sections are worked in a mine, the

pillars in one seam or section shall, as far as possible, be vertically above or below the pillars in the other seam or section unless the strata are inclined at an angle more than 30º from the horizontal.

The parting left between the two such seam/sections shall not be less than 3 m in thickness at any place.

A thick seam may be worked in two sections, one along the floor and another along the roof and parting between any two such sections of a thick seam or between two contiguous seams should not less than 3m thick . If two sections of a thick seam or two seams of contiguous seams, have to be work at a time or one after and another, prior approval of DGMS is essential.When two seams lying within 9m of each other or when two or more sections of a thick seam are worked in such a manner that pillars and galleries of one seam or one section lies vertically above or below the pillars and galleries of another seam or section, then this is known as vertical coincidence of pillars and galleries

(i) Vertical coincidence in contiguous seams (ii) Vertical coincidence in thick seams

Possible alternatives for the extraction of contiguous seams / thick seam:i. Extraction in the upper seam / section followed by extraction in the lower seam/section.

ii. Extraction in lower seam / section followed by extraction in upper seam/ seam.iii. Simultaneous extraction in both the seams / sections.All the above alternatives have their applications in different conditions. None of them can be of universal application. But by and large; the extraction in descending order is preferred, especially if extraction is done with caving. In designing the extraction system in contiguous seams or thick seam, the prime consideration is the stability of workings.General precautions during extraction of pillars in contiguous seams / thick seams:-

Seam-ISeam-II

θ<30º

3m4m3m

θ<30ºCoal Seam

Roof

floor

1. The extraction of pillars i.e. drivage of split gallery and the extraction of slices in two sections/ seams shall be done simultaneously such that the line of extraction in both the section / seams are superimposed.2. The workings in each of the sections / seams shall be under the supervision of a separate mining Sirdar.3. The working of both the sections/ seams will be placed under the charge of same overman for better co-ordination of the workings.4. The overman shall be furnished with an offset plan showing the workings in both the sections / seams in different colours showing there on the sequence of extraction of pillars.5. For easy access from one section/seam to the other for supervision, drift or staple pits with ladders shall be provided at every alternate junction of galleries.6. If at any time, any danger is noticed in any of the sections/seams, persons shall be withdrawn from both the sections/seams.

Ans:-8(b)-Safety Management System- It is essential to offer a working condition free from hazards to the extent of highest magnitude by the application of safety management.Safety management may be defined in very simple terms as the control or elimination of the origins of the causes for the harm. This helps to realize that the hazards are not simply the agents most closely identified with the injuries. Therefore, it is necessary first to employ means of controlling the causes responsible for the presence of injuries agents.Aim of Safety Managements:-Safety managements must aim for the identification of hazards, determination of their significance, evaluation of the available correctives and selection of the optimum remedies. Unwanted events can be controlled to an irreducible minimum. Therefore the hazard that causes the unwanted harmful events is to be eliminated to have an accident free environment. Hence the focus of safety efforts should be on hazard control rather than on accidents.The basic purpose of health and safety management is to create a mechanism involving all concerned at every level by which dangerous events and accidents may be prevented.Health and safety management system include well documented modules of safety management method in the form of action procedures at all levels of management and decision making. It may be defined as an auditable documented system that forms part of the overall management that includes organizational structure, planning activities, responsibilities, practices, procedures, processes and resources for developing, implementing, achieving, reviewing and maintaining a safety and health policy of a company.Safety Management is as a structured process composed of well defined system that emphasizes continuous improvement in work quality, health, welfare and productivity of workforce engaged in mineral industry through setting up of improved safety standards and their effective implementation and administration. Because the statutory provisions can never be fully comprehensive, appropriate and site specific and the process of legislation making is often slow, these often trail behind the technological innovations. Trend, world over is, therefore, to make the statutory provisions “Flexible” by switching over from the regime of ‘Prescriptive Regulations’ to Self Regulatory or Goal Setting Legislation’.

The Safety Management System established by a mine must ensure all risks are identified and critical risks are controlled to ensure long-term health and safety.A safety Management System should set the culture, framework and actions necessary to ensure that mining operations are carried out safely.Elements of SMS:-

Health & Safety Policy of the company and the mine. Roles and Responsibilities at all levels in the organisation Specified competencies of staff Safety Committee, its formation and role Method to identify and control high risk Forward program to ensure actions to control hazards are carried out Emergency Preparedness to cope with a hazard if it should occur. Monitoring process for all identified hazards with or without residual risks. Identification of trigger points and resultant actions if these are reached. Safety clearance for new equipment, work methods and materials used. Accident statistics collection, analysis & actions. Reporting and record keeping requirements. Auditing and review processes.

Structure of Safety Management System:- Structure of safety management system may be broadly classified into following categories containing different elements:1. Strategic level-

a. Health & Safety Policy- This is a statement by the organisation of its occupational health and safety philosophy and intentions. It provides a framework for action to achieve safety objectives and targets.

b. Roles & Responsibility- Ensuring the safety of a mining operation is a complex task requiring the continued commitment of all personnel associated with the mine, as well as compliance with all safety legislation, guidelines and circulars.

c. Health & Safety Committee- The Safety committee can have a significant role in effective Mine Safety Management. It contains representatives from all aspects of the mine, with a focus on ensuring and improving health and safety in the workplace.

2. Management Level:- a. Hazard Identification & Risk Management- The management of the

mine should conduct a risk assessment process to identify any hazard that could influence the safety and health of workers of the mine. It should not be considered to be a once off occurrence but should be done at regular intervals to ensure that the plans to cope with the identified hazards are pertinent and up to date.

b. Preparation of safety management plan- The Safety Management Plan is a working document, which outlines all of the actions to be carried out to ensure the safety and health at the work place.

3. Operational level- Operational process and safe operating procedures need to be made to suit the site-specific conditions of the mine. These need to be simple and clear whilst meeting the requirements of legislation, regulations, mine standing orders and recognize hazards associated with the work.

The safety management system should at all time be such that it promotes a process of continuous improvement.

Because of their status and immediacy to the job, Managers and Supervisors have a key safety role in the mine to ensure:-

The work environment is safe for workers. Planned work methods are safe & followed. All accidents and near misses are investigated. Workers are competent & know their duties. Adequate reporting on shift change-over occur.

Benefits of safety management system:-i) Improved work culture and supervision of hazardous jobs.ii) Casts specific responsibilities on the management.iii) Gainful utilization of resources on prioritized risks. More acceptable because

of involvement of grass root level and management.iv) Selection of best possible means to achieve better work environment and

reduced risk.v) Introduction of new technology with proven safety records expedited.vi) More reliance on team work.vii) Better concentration on use of systems, standards and safe practices.viii) Consistency and control for continuous improvement.ix) Reduction of incidents, accidents and their severity.x) Making the mines more efficient along with improvement of health and

safety status.

Strategies for implementation:-i. Every mine should employ a sound risk analysis process and develop a

Safety Management Plan.ii. Management should commit itself for proper formulation and implementation

of SMP.iii. Management should allocate resources necessary for control measures.iv. All employees should be trained with the help of national and international

experts for optimal adoption of the safety management system. Ans:- (C )Wide stall method of working- Huge amount of coal in thick seams is locked up in the form of standing pillars, due to presence of important surface features, townships, rivers, rails etc. The level of coal recovery from thick seams underneath delicate structures has been 7-12% only. In general, even the final recovery from such seams by conventional method of spliting and stooking never exceeds 30-35%, after which the safety factor drops below one.To increase the recovery of locked up coal without endangering the surface feature with factor of safety more than 1 , wide stall method of mining is found suitable which is nothing but widening of galleries leaving pillars core undisturbed. In view of the pillar stability vis-à-vis strain, deformation in and around and long term stability, wide stall method of mining is preferred as compared to narrow panel mining, splitting and stooking.It is well known that strength of a pillar depends on its height. If stowing is done, the effective height of a pillar can be reduced and a pillar can, thus, be made stronger. Thus % age of coal extraction can be increased in a partial extraction scheme which first makes the pillar smaller (thus weaker) and then increases its strength by stowing to the desired level to ensure that surface features or upper seams are not distributed.If, for same F.O.S. of pillars, the choice is between widening and heightening of gallery, the later should be preferred as strength of pillars reduces more sharply with reduction in area than with increase in height.

Wide stall methods are suitable for shallow depths only as, at deeper depths, % age of extraction becomes low since wider pillars are to be kept for protection of surface features.

The wide stall method involving formation of 15m pillar core and 6m wide stall has been found to be quite safe giving 49% recovery of in-situ coal without any damage to surface feature during mining of Xl/Xll seam of selected Jharia Section as shown in the fig.(i) below:

Fig.(i) Wide stall mining – forming 6m wide stall and 15m pillar core. The success of wide stall method of mining depends upon the stability of

immediate roof and pillars under abutment loading and prevention of resultant pot holding and surface subsidence. Spliting of pillars with heightening of the galleries reduced the pillar stability and even the central portion of the stooks developed appreciable pressure and strain as shown in the fig. (ii) below:

fig-(ii)

This method has been field trialed in Xl/Xll seam at East Bhagatdih Colliery of BCCL under the following boundary conditions:-

i. Seam thickness 16.5 – 16.8m ii. Cover - 90-120m iii.Pillar & gallery size - 30m(Centre) & 3.6m wide gallery. iv.Development - in 2 sections of 3m bottom and 2.4m top v. Coal parting between the 2 Sections- 6.4m vi. Parting between x and Vll/Vlll seam – 43m vii.Surface constraint - Private dwelling & Colliery Structure. viii.RQD of immediate roof rock - 80%

Manner of extraction in wide stall method of mining- As per condition imposed by DGMS, the manner of extraction shall be as follows:-

i. (a)The pillars shall not be split. They may, however, be reduced by widening the galleries around the pillars. The width and height of such gallery shall not be more than 6.0m and 4.5m respectively and the residual pillars after widening of galleries shall not be less than 17m square in size from corner to corner.

(b)No heightening or widening shall be done where the pillars size from corner to corner is 17m or less.

ii. Widened galleries may be heightened upto a maximum height of 4.5m in stages in conjunction with stowing in such a manner that the height of gallery over the stowed sand shall not be more than 3.0m at any time.iii. Heightened and widened galleries shall be fully stowed with sand.iv. (a) Not more than 40m of heightened and widened gallery shall remain unstowed in the panel at any time.(b) Not more than 75 m2

of roof shall be exposed at any place at a time.v) Widening or heightening of any gallery shall not be undertaken unless all adjacent / in bye voids are fully stowed with sand. vi) Extraction shall commence from dip most side and advance towards rise maintaining a diagonal line of extraction and formation of “V “in the line of extraction shall be avoided.Sequence of extractions:- The fig(iii) below shows the sequence of extraction by wide stall method at East Bhuggatdih Colliery of BCCL under the boundary conditions mentioned above.The stall formation involves widening of 3.6m wide development gallery to 9m by operating a 5.4m wide winge face on one side of the gallery.The total workable section of 13.8m (excluding 3m parting) is worked in 2 lifts, each of 3.2m thickness in ascending order in bottom section and 2 lifts each of 3.6m in the top section also in ascending order. The pillars are attacked from dip to rise keeping diagonal line of extraction. During the widening, the pillars are not to reduced below 21m size and coincidence of verticality of pillars are maintained during workings.The stepwise operation includes widening of the existing gallery, in bottom section, upto 9m width followed by hydraulic sand stowing. Above the stowed gallery (1st list of 3.2m), further development for 2nd lift of 3.2m is done and then the galleries are widened to 9m. After stowing the 2nd lift gallery, a solid coal parting of 3m are left over the stowed bottom section and then the top section are also taken. Similarly in 2 lifts of 3.6m thickness by developing, widening and fully stowing the 9m wide galleries. Coal parting offers lateral support to the pillars and reduces slenderness ratio, which are punctured at regular intervals for sand flushing to ensure its stability.

.Fig(iii)- Plan and section showing the sequence of extraction by wide stall method at East Bhuggatdih Colliery.

In this method of mining, following study should be conducted from safety view points during actual mining operation:i. Observation within the stalls-(a) Convergence (b) Load on support ii. Observation around the stalls-(a). Bed separation (b) Stress variation (c) Strain variation (d) convergence measurement (e) Pillar dilation and (f) subsidence study.

Support System:- The widened stall is supported by 2 rows of wooden or triangular steel chocks flanked by 3 rows of wooden props as shown in fig-(iv)

Fig (iv) – Support system practiced in wide stall method of mining.

Optimization of coal recovery by spluttering & stocking of pillars causes considerable drop in strength of the natural support, which restricts % age of recovery during extraction of thick coal seam below important surface structure. The effective bearing capacity of pillar is comparatively more than a no of stooks of the equivalent area. Wide stall formation accommodates existing galleries of a developed Coal Seam as well as improves recovery and safety of the ultimate mining structure in comparison to the convectional method.

THE MINES ACT, 1952 Afternoon Session


FIRST CLASS



Answer any Six Questions(Question no. 1 carries 20 marks and all other carry 16 marks each)

………………………..

Q1. Write short notes on any four of the following:i) Site mixed slurry as compared to other explosives.ii) Flameproof apparatus.iii) Corporate social responsibility.iv) Risk management as a tool to reduce accidents.

v) Methods to make Pit Safety Committee, more effective.Ans. i) Site mixed slurry as compared to other explosives- The merits of bulk explosives are summarized below:-

Parameter Cartridge Explosives Bulk Explosives

1. Safety Explosive is handled, Stored and transported. Thus potential hazard is always there.

Explosive, handling, store & transportation totally eliminated, the ingredients become explosives on being charged into holes.

2. Explosive Maga zine size

Large size, storage magazine is needed and hence cost of magazine is more.

Small magazine needed only for cast booster and detonating fuse.

2A. Safety Zone. Large safety zone is required which would be difficult to get.

A very small safety zone is required.

3. Explosive Van. More numbers of explosive vans and more manpower is needed.

A small explosive van mounted on a jeep chasis would be sufficient.

4. Blasting crew Blasting crew comprising of large number of persons.

Blasting crew comprising of few no. of persons.

5. Charging hole Charging / stemming is time taking.

Quick charging / stemming due to fully mechanized operations.

6. Explosive energy Explosives of fixed energy A wide range of explosive energy.

7.Explosive density. Density of product cannot be varied.

Density of product can be varied to suit the requirement over a wide range.

8. Bore hole The coupling is not full. The coupling is full resulting in maximum tramper of energy from explosive to rock.

9. Cost. The cost is fixed The cost is lower as off take increase.

10. Pilferage There is hazard of explosive pilferage.

Pilferage is not possible.

The above compansion has been made for some quantity of explosives to be used either in the form of cartridge or in form of bulk, for a big O/C mine.

Q2. An explosion has been reported in a mechanized development district with five persons missing. Draw a list of action, in order of priority that you would take to deal with the emergency and rescue/recover operations.

Q3. In the present day context of heavy mechanization and outsourcing, draw up a scheme of training and retraining to ensure effective safety awareness amongst the workers at the mine.

Q4. What are the statutory provisions relating to emergency plan? Briefly describe the essential elements of an effective emergency plan and their rationale. How would you incorporate modern technology advancement into an emergency plan?

Q5. Enumerate various sources of conflict in a mining project. As manager of a mine how would you organize to deal with a conflict arising out of a complaint of neighboring villagers regarding ground vibrations being generated by the blasting being conducted at your mine.

Q6. What do you understand by pay back period of a project? Describe in details any one cost analysis and cost control methods used to operate a mine.

Q7. A 8 MT per annum opencast mine is being planned in a virgin area. Draw up a scheme for selection training and development of human resources for the project. Also state the statutory notices to be sent and the permission/relaxation to be obtained.

Q8. (a) What are the causes of Pneumoconiosis? What are its symptoms? Enumerate the precautions to be taken to prevent it.(b) State statutory provisions relating to periodical medical examinations and discuss its relevance to ILO classification of radiographs for detection of pneumoconiosis.



SECOND CLASS



Answer any SIX Questions(Question no. 1 carries 20 marks and all other carry 16 marks each)

………………………..Q1. Write statutory provisions in respect to the following:

a) Nominated ownerb) Working near mine boundaryc) Voltage limitsd) Notice of accident.

Q2. While a group of drillers was drilling holes in a rise gallery in a development districts, adjoining dip gallery which was within a distance of 3 m from the rise face was fired, resulting death of the drillers. Write an enquiry report bringing out the contraventions, responsibility and recommendations to prevent similar accident in future. Assume your own conditions.

Q3. While driving a level gallery along floor of a 8 m. thick scant, unusual seepage of water was observed from the face. What steps are required to be taken by a shift assistant manager? What information and documents are required to be submitted along with an application for permission to extend the gallery?

Q4. Enumerate the precautions required to be taken while firing shorts in vicinity of hot strata in open cast mines.

Q5. What are the objectives of Environment Management Plan (EMP)? Discuss its important features.

Q6. Write statutory provisions on any three of the following:(a) Duties of manager in emergency.(b) Rescue tracing(c) First and station (d) Initial and periodical medical examination.

Q7. What are the major causes of accidents in Indian Coal Mines?Describe in brief safety management system, which will be useful to identify and control existing and probable hazards in mine.

Q8. How workers participation in safety management can help in improving safety standards of a mine. Enumerate the existing statutory provisions in this regard.

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