UNIT 4

The International Code for the Safe Carriage of Grain in BulK(International Grain Code)

SOLAS Chapter VI:

Carriage of grain

Regulation 8

Definitions

· For the purposes of this part, unless expressly provided otherwise:

· 1International Grain Code means the International Code for the Safe Carriage of Grain in Bulk adopted by the Maritime Safety Committee of the Organization by resolution MSC.23(59) as maybe amended by the Organization, provided that such amendments are adopted, brought into force and take effect in accordance with the provisions of article VIII of the present Convention concerning the amendment procedures applicable to the annex other than chapter I.

· 2The term Grain includes wheat, maize (corn), oats, rye. barley, rice, pulses, seeds and processed forms thereof whose behaviour is similar to that of grain in its natural state.

Regulation 9

· Requirements for cargo ships carrying grain

· 1In addition to any other applicable requirements of the present regulations, a cargo ship carrying grain shall comply with the requirements of the International Grain Code, and hold a document of authorization as required by that Code. For the purpose of this regulation, the requirements of the Code shall be treated as mandatory.

· 2A ship without such a document shall not load grain until the master satisfies the Administration, or the Contracting Government of the port of loading on behalf of the Administration, that the ship will comply with the requirements of the International Grain Code in its proposed loaded condition.

International Code for the Safe Carriage of Grain in Bulk (Grain Code)

DEFINITIONS

· 1. The term “grain” covers wheat, maize (corn), oats, rye, barley, rice, pulses, seeds and processed forms thereof, whose behaviour is similar to that of grain in its natural state.

· 2. The term “filled compartment, trimmed”, refers to any cargo space in which, after loading and trimming as required by the code, the bulk grain is at its highest possible level.

· 3. The term “filled compartment, untrimmed”, refers to a cargo space which is filled to the maximum extent possible in way of the hatch opening but which has not been trimmed outside the periphery of the hatch opening either by the provisions for all ships or for specially suitable compartments.

· 4. The term “partly filled compartment” refers to any cargo space wherein the bulk grain is not loaded in the manner prescribed in Grain Code.

· The term "specially suitable compartment" refers to a cargo space which is constructed with at least two vertical or sloping, longitudinal, grain-tight divisions which are coincident with the hatch side girders or are so positioned as to limit the effect of any transverse shift of grain. If sloping, the divisions shall have an inclination of not less than 30° to the horizontal.

· To avoid shifting of cargo, the grain surfaces must be reasonably trimmed:

a) Filled compartment, trimmed: the cargo should be trimmed so that all spaces under deck and hatch covers are filled to the fullest extent possible.

b) Filled compartment, untrimmed: the cargo should be trimmed within the hatchway but may be left at its natural angle of repose on the surrounding area of the hatchway. The same can be applied for a filled compartment, trimmed if:

· dispensation is granted from trimming by the authority issuing the Document of Authorisation on the basis that the cargo can flow freely to underdeck empty areas through feeder ducts, perforated decks, etc, or

· The compartment is designated a `Specially Suitable Compartment', in which case exemption may be granted from trimming the compartment ends.

PREPARATION OF CARGO HOLDS FOR GRAIN CARGO

When nominated to load grain cargo ship staff shall remember the following issues :

1. Even after discharging other grain cargo prior to nomination, the holds will require as thorough cleaning and preparation as required for any other previous cargo.

2. There shall be no trace of any previous cargo residue anywhere in the holds and its structures.

3. There shall be no Loose Rust or flaking paint patches allowed at any part of the cargo holds.

4. The hatch covers underneath and hatch coamings with their channels & drainage shall be free of loose rust, paint flakes and cargo residue.

5. Cargo holds bulkheads and sides and hopper plates shall have no previous cargo dirty stains (coal or dark ore cargo stains)

6. Rust on the Tank top is common on bulk carriers. Loose rust is not accepted. Hard adhering rust need not be removed.

7. Cargo holds and weather decks shall be inspected after cleaning and washing to ensure that there is no trace of any live or dead insect/weevils

8. The cargo hold bilges shall be clean, free of any trace of previous cargo residue or rust particles and odour-free. The bilge suction effectiveness shall be verified

9. Weather deck including cross decks and around the coaming stays and underneath pipelines shall have no trace of previous cargo residue.

Presence of Insect/ Weevil/Larvae in cargo holds.

· If vessel had carried grain cargo in the recent past it is possible to have such live or dead insect/weevil/larvae in holds

· They are usually found at the welding seams of tank top & hopper or bulkheads, in the hold bilges upper corners, corners of frames and brackets.

· Crew shall look for these insect specifically and carefully after all cleaning is done.

· Brooms, Mops and burlaps used for preparation may also bring them in.

Pre loading inspections/surveys

· In most contracts of carriage, the ship owners’ responsibilities begin at the time of loading and it is therefore important to inspect the cargo at this stage.

· Before loading, the holds must be examined for potential defects such as rust scale, insect infestation, oil sludge, and water. The ship must be substantially clean, dry, and ready to receive grain before the loading can begin.

· The vessel shall pass the inspections of the relevant Port, State or National Authority at the first or sole port or place of loading, certifying the Vessel's readiness in all compartments to be loaded with the cargo covered by this Charter Party.

· Pre-shipment inspection of cargo is intended to determine and document the condition of the cargo at this time. This inspection is commonly referred to as the pre-loading survey.

· This survey can be carried out by the ship's master and officers, owners’ representatives, or surveyors instructed by the owners depending on the trade and nature of the cargo.

· It is at this time that decisions have to be made, if the cargo is not as described in the shipping documentation, whether to reject the cargo or accept the cargo and adequately describe any differences on the mates’ receipts and bills of lading.

· Early notification of any deficiencies to the shippers is desirable together with owner’s intentions on rejection of the cargo or clausing the mate’s receipts and bills of lading.

· Grain which appears to be unfit for shipment, such as wet, sprouting, mouldy, discoloured or contaminated with rat droppings or insects, dead or alive, and other signs of unfitness should be a warning that the grain is in poor condition; should be rejected.

· If owners decide they require a surveyor to attend their ship to carry out a pre-loading survey then the instructions given should be comprehensive, precise and given as early as possible allowing sufficient time for the surveyor to conduct an efficient survey. This will avoid confusion and disagreement at a later date when the surveyor presents his report and invoice.

· A characteristic of grain is that it flows freely, and the IMO Code of Safe Practice for Solid Bulk Cargoes states that 'non-cohesive bulk cargoes having an angle of repose less than or equal to 30 degrees flow freely like grain, (and) should be carried according to the provisions applicable to the stowage of grain cargoes', taking account of the density of the material.

· The free-flowing characteristic of grain reduces the stability of any ship which carries it. Grain in a partly- filled cargo compartment displays a free-surface effect similar to that of a liquid in a partly-filled tank. If the ship rolls the grain is likely to flow to one side of the compartment, where it will cause the ship to list or to capsize.

Grain securing methods

· Following are recommended methods for securing grain as per international grain code

1. Shifting boards (Filled/partly filled)

2. Saucers (Filled)

3. Bundling of bulk grain (Filled)

4. Over stowing arrangements (Filled/partly filled)

5. Strapping or lashing (Filled/partly filled)

6. Securing with wire mesh

Shifting Board

· Longitudinal divisions (called shifting board), which must be grain tight may be fitted in both "filled" and "partly filled compartments".

· In "filled compartments, they must extend downwards from the underside of the deck or hatchcovers, to a distance below the deckline of at least one-eighth the breadth of the compartment, or at least 0.6m below the surface of the grain after it has been assumed to shift through an angle of 15°

· In a "partly filled compartment', the division, should extend both above and below the level of grain, to a distance of one-eighth the breadth of the compartment.

Bundling of bulk grain

· As an alternative to filling the saucer in a filled, trimmed, compartment with bagged grain or other suitable cargo a bundle of bulk grain may be used provided that:

1. The dimensions and means for securing the bundle in place are the same as specified for a saucer.

2. The saucer is lined with a material acceptable to the Administration having a tensile strength of not less than 2,687 N per 5 cm strip and which is provided with suitable means for securing at the top.

3. As an alternative to the above, a material acceptable to the Administration having a tensile strength of not less than 1,344 N per 5 cm strip may be used if the saucer is constructed as follows:

3.1. Athwartship lashings acceptable to the Administration shall be placed inside the saucer formed in the bulk grain at intervals of not more than 2.4 m. These lashings shall be of sufficient length to permit being drawn up tight and secured at the top of the saucer.

3.2. Dunnage not less than 25 mm in thickness or other suitable material of equal strength and between 150 mm and 300 mm in width shall be placed fore and aft over these lashings to prevent the cutting or chafing of the material which shall be placed thereon to line the saucer.

· 4. The saucer shall be filled with bulk grain and secured at the top except that when using approved material. Further dunnage shall be laid on top after lapping the material before the saucer is secured by setting up the lashings.

· 5. If more than one sheet of material is used to line the saucer they shall be joined at the bottom either by sewing or by a double lap.

· 6. The top of the saucer shall be coincidental with the bottom of the beams when these are in place and suitable general cargo or bulk grain may be placed between the beams on top of the saucer.

Overstowing arrangements

· 1. Where bagged grain or other suitable cargo is utilized for the purpose of securing partly filled compartments, the free grain surface shall be level and shall be covered with a separation cloth or equivalent or by a suitable platform. Such platform shall consist of bearers spaced not more than 1.2 m apart and 25 mm boards laid thereon spaced not more than 100 mm apart. Platforms may be constructed of other materials provided they are deemed by the Administration to be equivalent.

· 2. The platform or separation cloth shall be topped off with bagged grain tightly stowed and extending to a height of not less than one sixteenth of the maximum breadth of the free grain surface or 1.2 m, whichever is the greater.

· 3. The bagged grain shall be carried in sound bags which shall be well filled and securely closed.

· 4. Instead of bagged grain, other suitable cargo tightly stowed and exerting at least the same pressure as bagged grain stowed in accordance with para2 may be used.

Document of authorisation

1. SOLAS regulation Chapter VI/9.1 (Requirements for cargo ships carrying grain) provides that a cargo ship carrying grain must hold a Document of Authorization.

2. A Document of Authorisation must be issued by or on behalf of the flag State Administration for every ship loaded in accordance with the Code, and must be accepted as evidence that the ship is capable of complying with the Code.

3. The document shall accompany or be incorporated into the grain loading manual provided to enable the master to meet the Stability requirements.

4. Such a document, grain loading stability data and associated plans may be drawn up in the official language or languages of the issuing country. If the language used is neither English nor French, the text shall include a translation into one of these languages.

5. A copy of such a document, grain loading stability data and associated plans shall be placed on board in order that the master, if so required, shall produce them for the inspection of the Contracting Government of the country of the port of loading.

6. A ship without such a document of authorization shall not load grain until the master demonstrates to the satisfaction of the Administration, or of the Contracting Government of the port; of loading acting on behalf of the Administration, that, in its loaded condition for the intended voyage, the ship complies with the requirements of this Code.

Contents of Grain loading booklet

· IG Code - Regulation 6 lists the specific data and information which is to be included in the Grain Loading Manual.

This information shall include:

· 1ship’s particulars;

· 2light ship displacement and KG;

· 3table of liquid ‘free surface moments’ (or I values) for ship’s tanks to allow a free surface correction to be calculated;

· 4capacities and centres of gravities of compartments;

· 5curve or table of angle of flooding, where less than 40°, at all permissible displacements;

· 6hydrostatic data curves or tables suitable for the range of operating draughts; and

· 7cross curves of stability (KN curves) that are sufficient in number to verify stability criteria compliance and to include curves for 12° and 40° heel.

In addition to the above:

· 1. curves or tables of volumes, vertical centres of volumes, and assumed volumetric heeling moments for every compartment, filled or partly filled, or combination thereof, including the effects of temporary fittings;

· 2. tables or curves of maximum permissible grain heeling moments for varying displacements and ship’s KG values to allow the master to demonstrate compliance with the minimum stability criteria (this requirement only applies to ships built on or after the entry into force of the Code;

· 3. details of the scantlings of any temporary fittings and, where applicable, the provisions necessary to meet the requirements of the Code (including the requirements for ships not issued with a document of authorisation carrying partial cargoes of bulk grain);

· 4. loading instructions in the form of notes summarising the requirements of the Code;

· 5. a worked example of the grain loading calculations for the guidance of the master; and

· 6. typical loaded service departure and arrival conditions and where necessary intermediate worst service conditions based on three representative values of grain stowage factor e.g. 1.25, 1.50 and 1.75 m3/t.

Intact Stability Criteria for Ships Carrying Grain Issued with a Document of Authorisation (Reg.7)

· The intact stability requirements that must be met throughout the voyage for any ship carrying grain issued with such a document are detailed in IG Code are given below:

· 1. the angle of heel due to the shift of grain shall not be greater than 12°, or in the case of ships constructed on or after 1st January 1994 the angle at which the deck edge is immersed, whichever is the lesser;

· 2. in the statical stability diagram, the net or residual area between the heeling arm curve and the righting arm (GZ) curve up to the angle of heel of maximum difference between the ordinates of the two curves, or 40° or the angle of flooding (ƟF), whichever is the least, shall in all conditions of loading be not less than 0.075 metre-radians; and

· 3. the initial metacentric height (GM), after correction for the free surface effects of liquids in tanks, shall be not less than 0.30 metres.

· Before loading bulk grain the master shall, if so required by the Contracting Government of the country of the port of loading, demonstrate the ability of the ship at all stages of any voyage to comply with the stability criteria required by this section.

· After loading, the master shall ensure that the ship is upright before proceeding to sea.

· Above figure details the stability requirements with respect to the curve of statical stability.

· Because the maximum permitted list after assumed grain shift is 12° (or ƟDEI) the curve of statical stability must be derived from cross-curves (KN curves that are sufficient in number to accurately define the curve for the purpose of these requirements, and, shall include cross-curves for the values of heel 12° and 40°.

OPTIONAL STABILITY REQUIREMENTS FOR SHIPS WITHOUT DOCUMENTS OF AUTHORIZATION CARRYING PARTIAL CARGOES OF BULK GRAIN (Reg.9)

A ship not having on board a document of authorization issued in accordance with this Code may be permitted to load bulk grain provided that:

· 1. the total weight of the bulk grain shall not exceed ⅓ of the deadweight of the ship;

· 2. all "filled compartments, trimmed" shall be fitted with appropriate centreline divisions , except that saucers may be accepted in lieu of a centreline division;

· 3. all hatches to "filled compartments, trimmed" shall be closed and covers secured in place;

· 4. all free grain surfaces in partly filled cargo space shall be trimmed level and secured;

· 5. throughout the voyage the metacentric height after correction for the free surface effects of liquids in tanks shall be 0.3 m or that given by the following formula whichever is the greater:

Where:

· L = total combined length of all full compartments (metres)

· B = moulded breadth of the vessel (metres)

· SF = stowage factor (cubic metres per tonne)

· Vd = calculated average void depth calculated in accordance with the code. (metres - Note: not millimetres)

· Δ = displacement (tonnes); and

The master demonstrates to the satisfaction of the Administration or the Contracting Government of the port of loading on behalf of the Administration that the ship in its proposed loaded condition will comply with the requirements of this section.

· The International Grain Code (IMO) substitutes the notation GGH for the symbol λ.

Therefore, for the horizontal component of a shift of grain:

· The loss of GZ at 0° heel = λ0 The loss of GZ at 40° heel = λ40

· where and λ40 are the values that create the heeling arm to be plotted on the curve of statical stability.

To calculate λ0:

· Since λ0 = GGH and; GGH =

· There fore λ0 =

· Since: mass (t) = volume (m3)/SF (m3/t)

· λ0 = =

· where: (volume (m3) x distance (m)) gives a value of Volumetric Heeling Moments (m4)

· The volumetric heeling moment, in quadro metres, divided by the stowage factor of the grain loaded, in cubic metres per tonne, would give the heeling moment in tonne metres. This method has been adopted because the voids, and their assumed shift, are only dependant on the ship’s geometry whereas the weight of cargo depends on the SF also.

The Effect on the Curve of Statical Stability of a Shift of Solid Bulk Cargo

· Consider the vessel in the figure where a shift of cargo has taken place within a hold.

Effectively, a wedge of grain has moved from g to g1. This movement has two components:

1. A small vertical component which causes the ship’s centre of gravity to rise (GGv), causing an increase in KG/decrease in GM;

2. a larger horizontal component which causes the ship’s centre of gravity to move off the centre line (GGh), causing list.

The original GZ values will be reduced as a result of both components of the shift of the ship’s centre of gravity to give the final condition after the shift of cargo has taken place.

Loss of GZ due to vertical component upwards = GGV x Sin Ɵ;

Loss of GZ due to horizontal component = GGH x Cosine Ɵ.

· Values of Volumetric Heeling Moments (VHM’s) are calculated for each hold or compartment designated for the carriage of grain by the naval architect and are based on the movement of a volume of grain in cubic metres through a horizontal distance in metres across the hold. The volume of grain shifted is based on the assumed 15° and 25° shift of grain surface (depending on whether a compartment is full or part full).

· VHM values will be given in the ship’s Grain Loading Manual, either in tabular format, or, in the form of curves.

· Thus: λ0 =

· To calculate λ40 = λ0 x Cosine 40°

· where Cosine 40° = 0.766044

· The International Grain Code allows an approximation of Cosine 40° of 0.8; therefore the other end of the heeling arm to be plotted at 40° is found by:

· λ40 =λ0 x 0.8

· A straight line is used to join the two points of the heeling arm (the Code ignores the fact that it should really be a cosine curve).

Methods to reduce Grain heeling moments in order to meet Grain stability criteria

1. Potential heeling moments are reduced to a minimum value by carrying as few slack holds as possible;

2. Keep the slack surfaces trimmed;

3. Use Grain securing methods recommended for securing grain as per international grain code;

4. Ensuring the metacentric height (GM) of the vessel throughout the voyage after correction for liquid free surface, is in excess of the required metacentric height (GM); and

5. Follow weather routing to avoid adverse weather conditions that may cause heavy rolling on the voyage.

Separation of different grain cargoes loaded in same compartment

· A number of products such as cereals, oil seeds and their derivatives may be shipped simultaneously onboard bulk carriers. It is not uncommon for three or more consignments to be stowed in the same hold using separation material in order to avoid mixing of cargo.

· Where it is intended to over-stow one bulk parcel with another, the lower parcel should be trimmed as flat as possible. If the surface is left uneven there is a risk that the separation material may be damaged either as the result of uneven stresses during the sea passage or as a result of contact with the grab or elevator legs and bulldozers which may be used during the discharge of these commodities.

· When following procedure is carried out, a single layer of separation material of good quality is considered adequate. Recommended materials include woven polypropylene, polythene sheets or burlap.

· During loading operations, it is essential that the distance between the separation material and either the top of the weather-deck hatch coamings or the deck head of the hold is measured and recorded. In this way it is possible to effectively locate the separations between the parcels during discharge and thus avoid any tearing or damage to the separation material.

· The loading of second and third parcels may entail pouring cargo from a considerable height. As a result the surface of the lower stow inevitably becomes depressed.

Separation of different grain cargoes loaded in same compartment

· Because of the need to ensure a relatively even surface between any two parcels it may be wise to plan the stowage so that commodities with a high angle of repose, such as cereals and oil seed derivatives, are loaded below those with a low angle of repose such as canary seed or linseed.

· Ideally, the level of the separation between any two parcels should not be located in the vicinity of the upper ballast tank hoppers. This will ensure that when the inevitable settling of the cargo occurs, during the course of the voyage, the surface area of the separation material will remain adequate, and prevent mixing of cargo. This problem does not arise in the vicinity of the lower hopper tanks.

· Note: Siting the separation material at a level between the slant plating of the upper and lower hopper tanks will eliminate any difficulties on account of settling of the cargo.

Properties and characteristics of COAL

· 1.Coals may emit methane, a flammable gas. A methane/air mixture containing between 5% and 16% methane, constitutes an explosive atmosphere which can be ignited by sparks or naked flame. Methane explosions can be extremely violent and may cause considerable damage.

Methane is lighter than air and may, therefore, accumulate in the upper region of the cargo space or other enclosed spaces. If the cargo space boundaries are not tight, methane can seep through into spaces adjacent to the cargo space.

· 2.Coals may be subject to oxidation, leading to depletion of oxygen and an increase in carbon dioxide or carbon monoxide concentrations in the cargo space. Carbon monoxide is an odourless gas, slightly lighter than air, and has flammable limits in air of 12% to 75% by volume. It is toxic by inhalation with an affinity for blood haemoglobin over 200 times that of oxygen.

· 3.Some coals may heat spontaneously and the spontaneous heating may lead to spontaneous combustion in the cargo space. Flammable and toxic gases, including carbon monoxide, may be produced.

· 4.Some coals may be liable to react with water and produce acids which may cause corrosion. Flammable and toxic gases, including hydrogen, may be produced. Hydrogen is an odourless gas, much lighter than air, and has flammable limits in air of 4% to 75% by volume.

Segregation and stowage requirements

· 1. Boundaries of cargo spaces where this cargo is carried shall be resistant to fire and liquids.

· 2. This cargo shall be “separated from” goods of classes 1 (Division 1.4), 2, 3, 4 and 5 in packaged form (see IMDG Code) and “separated from” solid bulk materials of classes 4 and 5.1.

· 3. Stowage of goods of class 5.1 in packaged form or solid bulk materials of class 5.1 above or below this cargo shall be prohibited.

· 4. The master shall ensure that this cargo is not stowed adjacent to hot areas.

· 5. This cargo shall be “separated longitudinally by an intervening complete compartment or hold from” goods of class 1 other than Division 1.4.

Definitions of the segregation terms

Away from:

· Effectively segregated so that incompatible materials cannot interact dangerously in the event of an accident but may be transported in the same compartment or hold or on deck provided a minimum horizontal separation of 3 m, projected vertically, is provided.

Separated from:

· In different holds when stowed under deck. Provided an intervening deck is resistant to fire and liquid, a vertical separation, i.e. in different compartments, may be accepted as equivalent to this segregation.

Separated by a complete compartment or hold from:

· Either a vertical or a horizontal separation. If the decks are not resistant to fire and liquid, then only a longitudinal separation, i.e. by an intervening complete compartment, is acceptable.

Separated longitudinally by an intervening complete compartment or hold from:

· Vertical separation alone does not meet this requirement.

Coal cargo

Precautions for Carriage of Coal

General precautions for the carriage of coal include:

· 1. The Master should be informed about the cargo in the `Cargo Information Form' ( ie. Shipper's Declaration/Cargo Information ) and the material safety data sheet (MSDS) prior to loading.

· 2. The precautions that need to be taken depend upon the information provided, eg if the cargo is liable to emit methane, then the Master should refer to the IMDG Code to obtain the loading, stowage and carriage information.

· 3. It is, therefore, imperative that the cargo information be supplied to the Master prior to commencing loading, or they may not allow the operation.

· 4. Before loading cargo:

· i) Bilge wells should be cleaned, residual cargoes removed, suction tested and covered with taped down double wrapped burlap.

· ii) Hatch top wheels and associated equipment should be greased to ensure that no sparks are caused during opening and closing.

· iii) Electrical cables, cargo hold lights and any other electrical instruments within cargo holds should be checked for insulation damage to ensure that they are safe for use in an atmosphere containing explosive gases. On bulk carriers, as no lighting is needed, the fuses should be pulled to isolate electricity.

· iv) Ships that carry coal are required to carry instruments to measure:

· a) Methane, oxygen and carbon monoxide levels in cargo holds

· b) cargo hold temperature (between 0-100°C)

· c) the pH of bilge water.

· The installation of these instruments or the taking of measurements, should be possible without entering the cargo space. Arrangements should also be made to calibrate and test the instruments.

Precautions for Carriage of Coal

General precautions for the carriage of coal include:

· 5. Extra monitoring should be implemented when coal is loaded in holds adjacent to hot areas, such as heated fuel DB tanks and engine room bulkheads.

· 6. The ideal place to monitor the temperature of the load is the centre of the stow. If the temperature is measured from the side, top or corners of the hold it must be remembered that the temperature at the centre of the cargo will be several degrees higher.

· 7. A no smoking policy should be fully implemented on the ship and hot work should not be allowed, particularly in the vicinity of cargo compartments.

· 8. Except where the shipper provides specific instructions to ventilate the cargo, compartments containing coal should only be ventilated for the first 24 hours after departure from the loading port. There should be regular monitoring of atmosphere to check the concentration of pH of bilge water. Ventilation should only be continued if the amount of methane rises above the acceptable level. Coal should also be ventilated prior to discharge owing to the danger of the build-up of gases that could be ignited by a spark from the opening of the hatches.

· 9. The gases may escape the cargo compartment to adjacent stores, mast houses, etc. These spaces should also be monitored on a regular basis.

· 10. A higher pH value reading indicates the likelihood of increased corrosion. In such cases the bilges should be kept dry by pumping out any accumulated water. However, records should be kept in the deck logbook for the quantity of bilge water discharged to justify any claims of cargo shortage.

· 11. If any suspected problem is observed during the passage the shipper should be contacted, not only to update their information but also to seek any clarification.

Special Precautions for Coals Emitting Methane

· If the shipper has declared that the cargo is liable to emit methane or the methane concentration in the cargo compartment is above 20% of the Lower Explosive Limit (LEL), the following additional precautions should be taken:

1. Surface ventilation should be maintained

2. hatch covers should not be opened until the accumulated gases have been removed. Hatch covers should then be opened carefully ensuring no sparks are initiated

3. all enclosed spaces such as store rooms, tunnels and passageways, etc, should be thoroughly monitored for methane

4. enclosed hatch covers should be ventilated.

Special Precautions for Self-Heating Coals

· If the shipper has declared that the cargo is liable to self-heat, then the following additional precautions should be taken:

1. If required, the Master should seek additional guidance from the shipper on the adequacy of the existing precautions

2. if analysis of the atmosphere of the cargo compartment indicates an increased carbon monoxide concentration, then

· i) the hatch covers should be closed after loading and additional seals applied

· ii) surface ventilation should be kept to minimum

· iii) carbon monoxide concentration should be regularly measured and recorded

· iv) if the hold temperature exceeds 55°C or the carbon monoxide concentration rises steadily, expert advice should be sought.

· v) When the carbon monoxide level in any cargo space reaches 50 ppm or exhibit a steady rise over three consecutive days, a self-heating condition may be developing and the master shall inform the shipper and the company of, at least, the following information after an accurate assessment of the situation is to be achieved:

· (a) identity of the cargo spaces involved; monitoring results covering carbon monoxide, methane and oxygen concentrations;

· (b) if available, temperature of the cargo, location and method used to obtain results;

· (c)time gas sample taken (monitoring routine);

· (d) time ventilators opened/closed;

· (e) quantity of coal in hold(s) involved;

· (f)type of coal as per cargo information, and any special precautions indicated on information;

· (g) date loaded, and ETA at intended discharge port (which shall be specified); and

· (h) comments or observations from the ship’s master.

Procedures for gas monitoring of coal cargoes

1. Observations

· 1.1 Carbon monoxide monitoring, when conducted in accordance with the following procedures, will provide a reliable early indication of self-heating within this cargo. This allows preventive action to be considered without delay.

· A steady rise in the level of carbon monoxide detected within a cargo space is a conclusive indication that self-heating is taking place.

· 1.2 All vessels engaged in the carriage of this cargo shall carry on board an instrument for measuring methane, oxygen and carbon monoxide gas concentrations, to enable the monitoring of the atmosphere within the cargo space.

· This instrument shall be regularly serviced and calibrated in accordance with the manufacturer’s instructions. Care shall be exercised in interpreting methane measurements carried out in the low oxygen concentrations often found in unventilated cargo holds. The catalytic sensors normally used for the detection of methane rely on the presence of sufficient oxygen for accurate measurement. This phenomenon does not affect the measurement of carbon monoxide, or measurement of methane by infrared sensor. Further guidance may be obtained from the instrument manufacturer.

Procedures for gas monitoring of coal cargoes

2. Sampling and measurement procedure

· 1. Equipment

· 1.1 An instrument which is capable of measuring methane, oxygen and carbon monoxide concentrations shall be provided on board a ship carrying this cargo. The instrument shall be fitted with an aspirator, flexible connection and a length of spark-proof metal tubing to enable a representative sample to be obtained from within the square of the hatch. 

· 1.2 When recommended by the manufacturer, a suitable filter shall be used to protect the instrument against the ingress of moisture. The presence of even a small amount of moisture will compromise the accuracy of the measurement.

· 2. Siting of sampling points

· 2.1 In order to obtain meaningful information about the behaviour of this cargo in a cargo space, gas measurements shall be made via one sample point per cargo space. To ensure flexibility of measurement in adverse weather two sample points shall be provided per cargo space, one on the port side and one on the starboard side of the hatch cover or hatch coaming. (Refer to the diagram of gas sampling point.) Measurement from either of these locations is satisfactory.

· 2.2 Each sample point shall comprise a hole of diameter approximately 12 mm positioned as near to the top of the hatch coaming as possible. It shall be sealed with a sealing cap to prevent ingress of water and air. It is essential that this cap is securely replaced after each measurement to maintain a tight seal.

· 2.3 The provisions of any sample point shall not compromise the seaworthiness of the vessel.

Procedures for gas monitoring of coal cargoes

3. Measurement

· The explanation on procedures for measurement is as follows:

· .1 remove the sealing cap, insert the spark-proof metal tube into the sampling point and tighten the collar to ensure an adequate seal;

· .2 connect the instrument to the sampling tube;

· .3 draw a sample of the atmosphere through the tube, using the aspirator, until steady readings are obtained;

· .4 log the results on a form which records cargo space, date and time for each measurement; and

· .5 put back the sealing cap.

4. Measurement strategy

· The identification of incipient self-heating from measurement of gas concentrations is more readily achieved under unventilated conditions. This is not always desirable because of the possibility of the accumulation of methane to dangerous concentrations. This is primarily, but not exclusively, a problem in the early stages of a voyage. Therefore it is recommended that cargo spaces are initially ventilated until measured methane concentrations are at an acceptably low level.

5. Measurement in unventilated holds

· Under normal conditions one measurement per day is sufficient as a precautionary measure. However, if carbon monoxide levels are higher than 30 ppm then the frequency shall be increased to at least twice a day at suitably spaced intervals. Any additional results shall be logged.

Procedures for gas monitoring of coal cargoes

6. Measurement in ventilated holds

· 1. If the presence of methane is such that the ventilators are required to remain open, then a different procedure shall be applied to enable the onset of any incipient self-heating to be detected.

· To obtain meaningful data the ventilators shall be closed for a period before the measurements are taken. This period may be chosen to suit the operational requirements of the vessel, but it is recommended that it is not less than four hours. It is vital in the interests of data interpretation that the shutdown time is constant whichever time period is selected. These measurements shall be taken on a daily basis.

Firefighting in coal ships

Bulk coal fires generally caused by methane gas being released from the cargo.

1. The use of CO2 or inert gas, if available, should be withheld until fire is apparent.

2. Coal fire are known to be very hot and water use with its good knockdown cooling capability would seem the obvious choice of firefighting medium. However, water should not be used as this will turn to steam on contact with the hot surface. This steam will in turn pressurise the hold and could cause the hatch tops or the ships sides to be blown out.

3. A suggested resolution is to keep the cargo hatch battened down, all ventilation to the compartment sealed and commence boundary cooling, so starving the fire of oxygen.

4. Seek expert advice and consider heading for the nearest suitable port of refuge where the hatches can be opened. Water can then be used to extinguish the fire and the steam can be escaped to the atmosphere. The fire brigade ashore could be utilised.

5. Cranes with grabs could dig out the fire within the bulk cargo.

6. Flooding the hold may also be a suitable option, provided the stability and stresses of the vessel allows this.