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DREDGING WORKS AT LNG TERMINAL

OFF DABHOL

Document No. 6724-12-42-TS-001

Rev. No.0 of 28

0 13.08.2010 ISSUED FOR TENDER YNK CCB BVK

Rev. No Date Purpose Prepared by Reviewed by

Approved by

Format No. EIL-1641-1924 Rev.1 Copyright EIL – All rights reserved

M/S RATNAGIRI GAS POWER PLANT LTD. (RGPPL)

DREDGING WORKS AT LNG TERMINAL OFF DABHOL

SCOPE OF WORK & TECHNICAL SPECIFICATION


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TABLE OF CONTENT 1.0 GENERAL .................................................................................................................... 4

1.1 Project Site Information .................................................................................................................... 4 1.2 Scope of Works ................................................................................................................................... 5 1.3 Standards ............................................................................................................................................ 6 1.4 Safety Regulations .............................................................................................................................. 6 1.5 Environmental Management Plan .................................................................................................... 6 1.6 Quality Assurance .............................................................................................................................. 7 2.0 TEMPORARY WORKS ................................................................................................ 8

2.1 General ................................................................................................................................................ 8 2.2 Offices & Workshops ......................................................................................................................... 8 2.3 Water Level Gauge ............................................................................................................................. 8 2.4 Telecommunications ........................................................................................................................... 8 3.0 ASSISTANCE TO THE EIC ............................................................................................................. 9 3.1 General ................................................................................................................................................ 9 3.2 Survey Boat ......................................................................................................................................... 9 3.3 Surveying Equipment ......................................................................................................................... 9 3.4 Protective Items .................................................................................................................................. 9 3.5 Photographs and Video Recordings .................................................................................................. 9 3.6 Approval Of Temporary Works ..................................................................................................... 10 4.0 SURVEYING .............................................................................................................. 11

4.1 General .............................................................................................................................................. 11 4.2 EIC’s Attendance ............................................................................................................................. 11 4.3 Setting Out Prior To Commencement Of The Work .................................................................... 11 4.4 Hydrographic Surveys ..................................................................................................................... 12 4.5 In-Surveys ......................................................................................................................................... 13 4.6 Determination of Original Rock Level. .......................................................................................... 14 4.7 Progress Monitoring Surveys (Interim surveys) ........................................................................... 14 4.8 Post Dredging-Sweeping .................................................................................................................. 14 4.9 Out-Survey ........................................................................................................................................ 14 4.10 Final Examination And Acceptance ............................................................................................... 15 4.11 Disposal of the Dredged Material ................................................................................................... 15 4.12 Traffic ................................................................................................................................................ 15 4.13 Measurement .................................................................................................................................... 16 4.14 Payment ............................................................................................................................................. 16 4.15 Cost Of Survey .................................................................................................................................. 16 4.16 Additional Surveys ........................................................................................................................... 16 4.17 Notice Of Any Irregularities ............................................................................................................ 16 4.18 Specification Of Survey Vessel ........................................................................................................ 17 5.0 DREDGING WORKS ...................................................................................................................... 18 5.1 General .............................................................................................................................................. 18 5.2 Design Dredge Level and Slopes ..................................................................................................... 18 5.3 Materials to Be Dredged .................................................................................................................. 18 5.4 Marking of the Dredging Areas ...................................................................................................... 18 5.5 Dredging Requirements ................................................................................................................... 19 5.6 Dredging Plant .................................................................................................................................. 19 5.7 Dredging Tolerances ........................................................................................................................ 19


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5.8 Use of Explosives for Pre-Treatment of Rock ................................................................................ 20 5.9 Monitoring the Blasting Operations ............................................................................................... 20 5.10 Transportation of Dredge Spoil ...................................................................................................... 21 5.11 Safeguards during Dredging Operations ....................................................................................... 21 5.12 Quality Control ................................................................................................................................. 22 5.13 Method Statement ............................................................................................................................ 22 6.0 REPORTING .............................................................................................................. 23

7.0 SUPPLEMENTARY INFORMATION ......................................................................... 23 6.1Schedule 1 : Method Statement on Execution of Dredging .................................................... 24 6.2Schedule 2 : Details of Dredging Schedule .............................................................................. 25 6.3Schedule 3 : Details of Dredging Spreads & Blasting Equipment ......................................... 26 6.4Schedule 4 : Details of Survey Spreads ..................................................................................... 27


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1.0 GENERAL 1.1 Project Site Information 1.1.1 Introduction

M/s RGPPL intends to revive the LNG terminal off Dabhol. The LNG terminal is characterised by an approach channel of 8 km , a turning basin, LNG Jetty and the partially completed Breakwater. Capital dredging of the approach channel and turning basin was completed during 2001. With the basic assumption that the channel would have got filled up through siltation by the bed load & riverine sediments, maintenance dredging was performed during Nov 2006 – Feb 2007. Thereafter, a marine survey was undertaken in May 2008. As per the information obtained during the maintenance dredging and data collected during the subsequent survey campaign, it is established that dredging is required to be undertaken for achieving a depth of 14.5m below CD. Therefore, as part of the revival scheme, dredging is required to be carried out at the turning basin and along the approach channel and near existing Jetty, which would include removal of all materials, such as, silts, embedded rock boulders, sheet rocks etc. so as to achieve the required depth. Based on the data available the estimated dredging quantity is furnished below: Item No. Description of Material Estimated Quantities 1 Rock Out crop/ sub crop and Boulders 65,000 cu m 2 Soft Sediments ( Clay / Silt) 35,00,000 cu m

The Project site, Dabhol on the West coast near Chiplun, is well connected by road and Mumbai is around 350kms from the site through motorable road & railways. (Indicative Location is given in Figure 1). For further details survey report may be referred.

1.1.2 Climate

Climate of the region is tropical and is characterised by heavy monsoon. The region is influenced by annually recurring seasons of southwest monsoon, post monsoon winter and summer.

1.1.3 Rainfall

This region of the western coast of India experiences a very heavy rainfall during the Southwest monsoon season. The rainy season falls between June and September, with August being the wettest month. Annual mean rainfall is about 180 cms.

1.1.4 Temperature

April and May are the hottest months of the year with a mean maximum temperature of about 360C recorded. January is the coldest month with mean minimum temperature of about 140C. The extreme temperatures are 100C and 420C minimum and maximum respectively.

1.1.5 Relative Humidity

The area experiences high relative humidity. The annual average relative humidity in the region during morning and evening are 80% and 65% respectively. During the monsoon period, the relative humidity exceeds 80%.


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1.1.6 Winds

Throughout the year, the winds are generally light to moderate in this region except during the late summer and the southwest monsoon seasons, when some stronger winds (20-30 kmph) are observed. However, wind speeds upto 90 kmph have been recorded during the cyclonic storms.

During the period from April to September, the winds blow mostly from northwest-southwest sector. During the rest of the year, winds are from direction between southwest and northwest and occasionally from the northeast and southeast.

1.1.7 Tides

The tides in the area are mixed semi-diurnal type. Mean tidal variations for Dabhol are as follows:

Mean High High Water (MHHW) : 2.6m Mean Low High Water (MLHW) : 2.4m Mean Sea Level (MSL) : 1.7m Mean High Low Water (MHLW) : 1.2m Mean Low Low Water (MLLW) : 0.6m

1.1.8 Waves

The sea may be calm throughout the year except during the pre-monsoon and monsoon season (May to August).

1.1.9 Currents

The currents in the area are predominantly tidal with maximum ebb (southward) current of 1.6knots and maximum flood (northwards) current of 1.2 knots.

1.1.10 Use of the Site Information

The climatic and oceanographic conditions described above (sections) are for general information only. Bidders are advised to get familiarise themselves with the prevalent environmental conditions.

1.2 Scope of Works

The brief scope of work includes the following: 1. Mobilisation of a suitable dredging spread with valid certificates (Trailer Suction Hopper

Dredger/ Cutter Suction Dredger/ Clamshell Grab Dredger/ Backhoe Dredger or a suitable combination) to dredge all materials including rock out crops, sub crops, boulders, sand and soft sediments with compatible equipments, either by explosives/drilling/blasting spreads or any other method of rock removal along with spares and experienced personnel for achieving the required dredged depth of 14.5m below CD, along with split open dump barges for offshore disposal, so as to meet the time schedule.

2. To submit the production rates and capacity of dredging spreads to establish that the works shall be completed within the specified time and requirements of the Owner


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along with the Procedure document prior to commencement of works at site for review and approval of Owner/Consultant.

3. Mobilisation of a survey vessel as per specification along with the necessary survey equipments.

4. To carryout necessary Pre-dredging surveys deploying echosounder, subbottom profiler and side scan sonar in a close grid for accurately establishing baseline data and estimate the quantities of dredging.

5. To carry out pre-dredging works such as, finalising drilling/blasting pattern, pre treatment of rock and under water blasting by deploying suitable equipment or other works related to rock removal.

6. To carryout dredging in the approach channel, the turning basin and the jetty without causing any damage to the neighbouring existing structures viz. LNG Terminal, Break water etc..

7. To mobilise suitable monitoring equipment and measure the vibrations due to blasting, as per specifications, if blasting methodology of rock removal is planned by the Contractor.

8. To dump the dredged material at the specified dumping site about 15 kms offshore from the dredging site.

9. To mark the dredging channel, the turning circle and the dumping site with suitable marking arrangement

10. To carryout interim, progress and post dredging surveys for the purpose of monitoring, interim and final payments, as per specifications.

11. To carryout sweeping surveys as specified and handover the area dredged to a level of 14.5m CD.

12. To prepare Survey Reports, Final Dredging Report and Photographic & Videographic Coverage of the entire Dredging Campaign.

13. To submit a final report, as specified, on the dredging works carried out. 1.3 Standards

Dredging activities shall conform to the British Standard BS 6949, Part-5 “Code of Practice for Dredging and Land Reclamation “.

1.4 Safety Regulations

In respect of all labour, directly or indirectly employed in the work for the performance of contractor’s part of this agreement, the contractor shall at his own expense arrange for all the safety provisions as per safety regulations of the port trust, Indian Standard Institution, The Mines act and such other acts as applicable along with the necessary Insurance cover.

1.5 Environmental Management Plan

The Contractor shall prepare an execution plan of the Environmental Management Plan (EMP) and submit it for approval by the Owner within two weeks of award of the contract.

No damage to the neighbouring structures is permissible, directly or indirectly, while carrying out the dredging activity. Any such damage shall be to the Contractor’s account.

Spillage of any mineral oil products shall be prevented and immediately mitigated in the exceptional occurrence of spillage.

The contractor shall take adequate anti-pollution measures while dredging and transportation of the material so that the environmental quality parameters are maintained well within the prescribed norms.


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As the execution plan of the EMP is a management tool for the Contractor’s use, it shall present details of how these measures are being operated, the resources required, etc.

The Contractor shall respect all restrictions and safety rules as applicable and as imposed by the authorities concerned.

1.6 Quality Assurance

The contractor shall document and operate a Quality Assurance System complying with ISO 9000 Part I or an equivalent standard approved by the ENGINEER-IN-CHARGE (EIC).

In addition, the Contractor shall prepare a Quality Assurance Plan for the execution of the works. The plan shall be submitted within fifteen days of receipt of the Letter of Acceptance. The Quality Assurance Plan shall be reviewed, updated and resubmitted for approval as necessary throughout the Construction period. The Quality Plan shall specifically address, the procedures for maintaining the project quality requirements with respect to the structure of all correspondence between the Contractor and EIC; the software that will be used for dredging volume calculations and preparation of Daily/Monthly Progress Reports.

The contractor shall provide all necessary access to works and records to enable the EIC to assess the Contractor’s quality plan and associated procedures.

The Contractor shall not commence works until he has submitted to the EIC a written statement of his proposed procedure for his own inspections of the item, recording such inspection and obtaining the EIC’s written approval thereof. The record shall identify the inspector, the place, the date and time when the inspection was completed, the section of the works inspected and its state of completion. Reference shall be made to the relevant drawings and the specific aspects or properties which were checked or measured. The record of inspections and tests shall be stored in an orderly fashion on the site by the Contractor until the issue of the Take-Over Certificate for the whole of the Works, or such earlier time as the EIC may instruct, and the EIC shall have the right of access to them at all times. After the issue of the Take-over Certificate for the whole of the Works or such earlier time as the EIC may instruct, the Contractor shall, as instructed by the EIC either dispose off the records or deliver them as directed.


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2.0 TEMPORARY WORKS 2.1 General

As soon as practicable but in any case not later than two (2) week after receipt by the contractor of the notification in writing that the contract is awarded, the contractor shall submit detailed work plans, procedures, drawings, specifications and details of the equipment, permissions obtained for his equipment to be used for the project etc., for the approval of EIC before the mobilisation of the marine spread.

2.2 Offices & Workshops

It shall be the full responsibility of the contractor, within his tender to provide, erect, construct and equip a base office, workshops stores, buoys, harbouring, moorings, loading and unloading facilities and the like required by him or his principals, employees or agents complete with all machines and equipment.

2.3 Water Level Gauge

The contractor shall, at the commencement of the contract install an automatic tide gauge with telemetry to continuously measure tides with respect to the chart datum at an approved location near the shore and maintain and keep running during the contract period. The contractor shall keep daily records of the water levels throughout the contract period.

2.4 Telecommunications

The Contractor shall arrange for a suitable and adequate mobile communication systems for inter communications between base office, dredging spreads and transport barges. An adequate number of walkie-talkie/mobile communication sets shall be provided for key personnel to be contacted on VHF channel/mobile. Two mobile phones shall be provided to Owner and Owner’s representative for operations during the dredging activities.


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3.0 ASSISTANCE TO THE EIC 3.1 General

The contractor shall render such assistance with facilities, labour, boats and materials as at any time may be required by the EIC’s Representative directly or indirectly in connection with the works. The costs of such assistance shall be borne by the contractor if such assistance is intended by or provided for or specified in the contract. The assistance to the EIC’s Representative includes, but not by way of limitation, the items in the clauses described in the sub-sections.

3.2 Survey Boat

The Contractor shall mobilise a survey boat (as specified below), maintain the boat in good running condition and provide the same, for the period, as required by the EIC’s Representative in connection the supervision of the subject works. One (1) suitable seaworthy motor boat of minimum 200 HP to operate within the site and in the adjoining offshore waters, with a skilled and efficient crew and a complete outfit for use of the EIC and his principals, employees and agents and such other persons as the EIC authorizes in so far required directly or indirectly in connection with the works, including survey equipment as described below (Sec.3.3), and a marine radio. The boat shall include life saving equipment as required by the Mercantile Marine Department.

3.3 Surveying Equipment

The Contractor shall provide and keep all surveying equipment in absolute working condition, including DGPS and echo sounding system connected to an onboard computer and printer. The contractor shall moblise standard survey navigation software packages.

3.4 Protective Items

The contractor shall provide for the use of the EIC’s Representative and his principals, employees and agents and such other persons as the EIC’s Representative authorizes adequate protective items such as gumboots, waterproof top-coats, first-aid equipment, life-jackets, hard hats and other safety equipment as required by the EIC’s Representative in connection with the Contract.

3.5 Photographs and Video Recordings

The Contractor shall, before commencing and during the progress of the works, take photographs of such sites, like, erection works, machinery, plant etc. as may be directed by the EIC or the EIC’s Representative. Copies of such photographs and videos providing a record of the progress of the works shall be given by the contractor to the EIC, with no restrictions by way of copyright or any other tie on the EIC or Owner’s use of such record. There shall be no separate payment for these photographs and videos, and the contractor should allow for the costs in his own overheads.


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3.6 Approval Of Temporary Works

Before any temporary works are commenced, the contractor shall submit sufficiently in advance to the EIC’s Representative for approval, his proposals for all temporary works including drawings and calculations. Notwithstanding the approval by the EIC’s Representative of any submitted design for any of the temporary works, the contractor shall remain entirely responsible for such works in all aspects. The EIC shall be at liberty to require modifications to the temporary works in accordance with the conditions of contract. Unless otherwise specified, the contractor shall carry out such modifications without any extra payment.


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4.0 SURVEYING 4.1 General

The contractor shall perform all necessary survey works required to be executed by him as per the Technical Specifications and as directed by the EIC. For this purpose, Contractor shall furnish and employ experienced personnel, equipment and supplies needed to perform the surveys and all the incidental work required for :

• Setting out, including the marking of all points for the works to be carried out • Registration of water levels • Pre dredging surveys and charts • Interim surveys for progress monitoring and interim payments • Post dredging surveys and charts • Intermediate progress surveys and additional surveys (as required by EIC) • Provision of the DGPS • Provision of the hydrographic survey vessel with onboard processing and dredging

software and printing hardware.

In case the Bidder is not capable of carrying out the surveys as specified, they shall deploy reputed survey agencies and submit their details for Owner’s review and approval. Field measurements and collection of data shall be executed to a degree of accuracy in horizontal and vertical direction and processed to scales to the full satisfaction of the EIC. EIC’s representative shall be entitled to be present during any surveys or any connected activities. Contractor shall give ample prior information of plans to work in this respect and provide the EIC’s representative with every assistance to fulfil his duties. The surveys shall be carried out in accordance with schedules to be approved by the EIC’s representative.

4.2 EIC’s Attendance

The setting out of the works under contract shall be executed by the contractor, with the EIC’s representative in attendance or with his approval for the same.

4.3 Setting Out Prior To Commencement of The Work

Setting out of the works shall be done by the contractor on such date as to permit timely commencement of the work.

The Contractor will be responsible for the accuracy of the setting out of the works. He shall establish tide gauge at suitable place, as approved by the EIC, and the same area shall be adequately illuminated. The Contractor shall be responsible for marking and lighting the dumping areas.

The contractor shall furnish, install and maintain all markers, buoys, shore beacons and other items necessary to define the works and facilitate the inspection and measurement thereof. It shall be the responsibility of the contractor to obtain all licenses, permits and permissions for the use of marine radios, walkie-talkies, for the placing of onshore, offshore and under water beacons and marker buoys, and for giving the proper statutory notices for all maritime operators. The costs of such licenses, permits and notices are to be borne by the contractor, and shall be deemed to be covered by the rates and prices quoted in the Tender.


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4.4 Hydrographic Surveys

Hydrographic surveys shall be performed by using multibeam echosounder, subbottom profiler and side scan sonar along with DGPS positioning system, with an accuracy which ensures that the requirements of the contract are achieved. These surveys shall be carried out in good weather conditions, condition of equipment and methods of execution and interpretation are, in the opinion of the EIC, satisfactory for this purpose. The EIC may resolve to check echosounding by means of other methods to measure water depths, such as sounding poles or lead lines. EIC may also order calibration checks of the equipment as and when considered necessary. The contractor shall cooperate in this respect and supply any manpower, boats and equipment that may be required for this verification. The survey line pattern for carrying out surveys deploying side scan sonar shall be decided during kick-off-meeting while approving the Procedure Document., so that the entire area is covered and data required for estimation of the survey quantities by the contractor is achieved. The survey shall be carried out to ascertain the disposition of boulders and rock exposures and quantity of silt. i) Calibration of multibeam echosounding equipment Multibeam echosounding equipment shall be checked and calibrated as per standard practice and shall not be disturbed after calibration. Checking shall be performed at the actual location of the survey and the EIC’s representative may require additional checks during surveying. Adjustments to the recording/readings taken will be made accordingly. Records of calibration checks shall be retained

ii) Digital recording and plotting Interpretation of echo rolls, reduction of sounded depths for tidal heights obtained from tide gauges, corrections for squat and wave motions (to be made using appropriate observed data and/or compensating devices ) and definition of bottom levels on the echograms are to be done to the satisfaction of the EIC’s Representative. Each fix on the echo roll shall be annotated on the track plot chart of the survey vessel, and there should be at least one fix for every 10 m of cross section and the interpreted data shall be plotted.

iii) Tide gauge The contractor shall install tide gauge for observing the tides throughout the dredging period. The tide gauge shall be connected to a bench mark provided by Owner or as directed by Owner iv) Reduction of sounded depths The contractor shall place special stress on the accurate reduction of sounded depth in relation to the prevailing tidal levels. v) Provision of differential global positioning system (DGPS) The Contractor shall provide, install, operate and maintain an approved differential global positioning system (DGPS) which shall fully cover the site of the works and be constantly in operation during the course of the dredging works. The system shall consist of ship borne master or receivers (one for each dredger in case of multiple deployment and one for each survey launch), distance measuring units, the


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requisite number of shore stations, interfaces, track plotters, data storage facilities and sufficient spares to enable uninterrupted operation of the system, to the accuracy specified and on board computer and printer and suitable navigational software.

vi) Installation and testing The positioning system shall be installed, tested and set to work for continuous operation during all dredging and survey operations. The system shall be fully operational, a minimum of 7 days before surveying operations commence including field calibration and base line check. Once operational, the system shall remain in continuous operation until the last Post-dredging survey is completed and the last post dredging survey drawings have been signed and have been accepted by the EIC’s representative.

The positioning system should have one hundred percent back up standby equipment to cater for the failure of any individual components. The positioning system shall along with all accessories, maintain a repeatable accuracy, for any point within the work site of plus or minus 1.0 m. vii) Survey Charts The Contractor shall maintain strict confidentiality regarding the survey data and no data shall be sent out without prior notice to/ approval of the Owner. Only after finalisation of the dredging quantities by the Bidder and approval of the Owner, the quantities can be officially declared. All survey charts to be produced by the Contractor shall be reduced to Chart Datum (CD) and the depths shall be plotted in meters and centimetres. The charts shall be presented to the EIC in an approved number of soft & hard copies. Data generated by the surveys shall be elaborated in accordance with sound topographic and hydrographic practices and be presented at a scale of 1:500 on survey charts of the sites or as desired by the EIC. All survey lines shall be shown on the charts with plot-intervals in the lines not exceeding 20 meters with intermediate plots, if necessary. Furthermore, the charts shall incorporate all reference points, buoys, beacons, markers, gauges and benchmarks, together with the location and nature of obstructions, structures and facilities. Items of interest shall also be indicated on the charts. Only after the submission of the In-survey report the first payment shall be released.

4.5 In-Surveys

Contractor shall carry out pre-dredging surveys (In-surveys) before commencement of dredging operation. While, available survey reports are provided as information only, it shall be responsibility of the Contractor to ascertain the data provided so as to satisfy himself and accept responsibility of the intended dredging works in entirety, without any additional cost implication to the Owner. The level of the seabed shall be recorded by means of multibeam echosounding equipment. Simultaneously, Subbottom profiler shall also be used for ascertaining the level of bed rock. Surveys shall be taken on lines 20m apart or as directed by the EIC. The equipment shall be calibrated in the presence of the EIC before and after carrying out Soundings. All the levels shall be reduced to Chart Datum.


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All the dredging drawings shall be plotted on 1:500 scale or as specified by the EIC In charge and these shall be constructed on local port's grid.

On completion of the survey the Contractor shall prepare within 24hrs, survey charts and cross sections showing the full results of the survey. Drawings in AutoCAD shall be submitted in soft and hard copies to the Owner/EIC-in-charge(EIC).

4.6 Determination of Original Rock Level.

Before starting the dredging operations in areas where rock dredging is anticipated, a joint survey shall be carried out by the Contractor and the EIC to determine the level of rock in various areas to form the basis for payment for rock dredging. The rock levels have to be accurately assessed during In-surveys based on Subbottom profiler surveys.

4.7 Progress Monitoring Surveys (Interim surveys)

Interim surveys shall be carried out during the period of dredging works at weekly intervals along the same surveys line interval deploying only dual frequency echosounder or multibeam echosounder. Soundings shall be taken under same configuration and settings as used for the in-surveys. On completion of each survey, the Contractor will prepare record drawings showing surface levels of bed reduced to Chart Datum and submit the same to Owner/EIC for approval. These approved drawings shall be used for interim measurement and payment, subject to Sec.4.14(d). Suitable software such as HYDRO volume should be used for hydrographic data processing, editing, plotting, contouring, profiling and quantity calculation and digitising. Suitable standard software shall be used for calculation of volumes based on average end area volume equation. It may be noted that once the in-surveys are completed, a suitable grid shall be selected for conducting interim surveys and the same grid has to be followed throughout the works and data provided in XYZ fomat. The procedure for doing so shall be finalised during kick-off meeting.

4.8 Post Dredging-Sweeping

On completion of the dredging works and before final measurements, all dredged areas shall be swept by deploying a dual channel and dual frequency side scan sonar and associated analog and digital recorder, to ensure that the seabed is level and free from projections above the dredged level.

4.9 Out-Survey

The Contractor shall remove any projections and sweep the areas again, so as to ensure their removal is complete. A repeat survey has to be carried out to confirm completeness of dredging.

After completion of the dredging, the area shall be surveyed jointly by the Contractor in the presence of the EIC and Owner on the same basis as specified for survey before dredging (In-survey). That is by deploying Dual frequency Echosounder and Subbottom Profiler surveys. On completion of the survey the contractor shall prepare survey charts and cross-sections showing the full results of the survey. All the data, fair charts/ plotting sheets, survey report, positioning data, tidal data, echo-traces, computation work sheets, and analysed charts (both hard & soft copies) shall be submitted to the EIC-In-Charge. On completion and agreement on the contents of the drawings and if the EIC’s representative has satisfied


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himself that the works have been executed according to the contract, the Contractor, the EIC’s representative and Owner shall sign the drawings, which shall then acquire the status of “Post-dredging survey”.

4.10 Final Examination And Acceptance

As soon as practicable after the Completion of the dredging, if any part of the dredged area is found to be under-dredged, such sector will be thoroughly examined by the EIC and the Contractor by additional soundings. If it is observed that the design dredge level is not achieved during this examination the contractor will be required to remove same by dredging. The contractor shall notify the EIC and the EIC's representative not less than 48hrs in advance when soundings are to be made. When the site is found to be in satisfactory condition, it will be accepted finally.

4.11 Disposal of the Dredged Material

All the dredged material shall be disposed off at designated offshore dumping grounds in water depths ranging from 20m and more. The disposal ground is located at about 15kms Offshore from the dredging site. The exact coordinates of the dumping site will be provided to the contractor. The Contractor shall ensure that no spoil is dumped outside the limits of the dumping areas. Any such dumping outside the limits of the specified dumping location shall be removed by the Contractor at his own cost and time. A record shall be kept of the position, time and quantities of barge discharges and this record shall be forwarded to EIC every week. The contractor shall install and maintain standard marker buoys for identification of the dumping area and the same shall be approved by EIC. The dredged spoil shall be dumped fairly uniformly in the entire dumping area marked. Soundings shall be carried out (spaced at 100m grid) before dumping and after dumping. In no case the elevation of the spoil shall reach 2.5m above original water depth (Seabed).

4.12 Traffic

The Contractor shall, at all times, observe and comply with all laws including regulations that are related to navigation, and anchoring of his floating crafts being used throughout the works. The Contractor shall follow instruction in this regard given by the EIC or Owner. The Contractor shall carry out his work strictly in a manner which would not obstruct or endanger the normal use of water ways, anchorages, and approaches and other construction activities. Bidder to note that, owner may engage various agencies for carrying out the other marine activities viz. activities at jetty head area, construction of the breakwater, tug berth, unloading of LNG, etc. Bidder to plan and operate accordingly, so as to have smooth operation of all the activities without any interference to Owner’s envisaged activities. As the dredging site is close to the approach to the Dabhol Port, the dredging operations shall be carried out without causing any obstruction to the port's traffic. The Contractor shall, at all times, observe and comply with the laws including regulations that are related to navigation, and anchoring of his floating crafts being used throughout the works. The Contractor shall follow instruction in this regard given by the EIC or Owner. The Contractor shall carry out his work strictly in a manner which would not obstruct or endanger the normal use of water ways, anchorages, and approaches.


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4.13 Measurement

Measurement shall be based on the Surveys specified in Sec.4.5 4.6, & 4.7 and payment shall be based on the unit rates specified in SOR No.6724-00-12-42-SR-001.

4.14 Payment

Payment shall be made on unit rate basis at the contract price against the appropriate item in the schedule of quantities for dredging and offshore disposal as per the Schedule of Rates (SOR) No.6724-00-12-42-SR-001. a) Only after the submission of the In-survey report the first payment shall be released. b) The payment for dredging is to be paid as per the actual dredging quantities certified

based on Interim and final surveys. c) No payment shall be made in respect of materials dredged beyond the specified limits of

tolerance. Final payments shall be made after the agreed design dredge level of 14.5m below CD is achieved and is ascertained from the in survey and the agreed surface levels from the out survey.

d) Standard software, such as, HYDRO volume shall be used for computing dredging volumes.

e) Monthly Interim payments for quantities dredged, as per the tender, will be based on quantities measured using the calculated difference between the levels obtained during in-surveys and the levels obtained from interim surveys. The difference in levels shall be used to compute volume dredged and estimated up-to-date agreed bed levels during interim surveys.

f) All the survey data (In Surveys, Interim Survey and out surveys) shall be provided in same XYZ format in MS Excel. The details of format shall be provided during execution. This is a mandatory requirement for certification of all measurements.

g) Final payments shall be based on completing the entire dredging works as per the technical specifications of the project and to the satisfaction of the EIC-in-Charge/Owner.

4.15 Cost Of Survey

The costs of providing differential global positioning system, survey launch, survey equipment, consumable and carrying out all surveys and setting out, etc., and preparation of all record drawings for the purpose of the execution of the Contract, are deemed to be included in the rates and prices as per the Schedule of Rates. No additional cost shall be payable to the Contractor in this regard.

4.16 Additional Surveys

Additional surveys deploying the survey boat with echosounding survey equipment and personnel, upon request of the EIC’s representative shall include regular surveying of the approach channel and turning basin, disposal areas and areas (within or in the vicinity of the site). In case of any discrepancy in data regarding rock levels, soft quantity of sediments and boulders, Contractor has to prove the same by carrying out standard investigations deploying Echosounder, subbottom profiler and side scan sonar, to substantiate their claims. Cost of such surveys shall be included in the price quoted as per the SOR.

4.17 Notice Of Any Irregularities

The Contractor shall inform the EIC’s representative forthwith of any breakdown irregularities or otherwise, affecting the positioning of his vessels or other equipment.


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Delays incurred in the dredging operation due to malfunctioning of the positioning system shall not entitle the contractor to an extension of time for completion.

4.18 Specification Of Survey Vessel

The survey vessel shall have, but not limited to, the following: • Sufficient size and stability to safely and properly carry out the survey work under the

prevailing site and sea conditions. • Good maneuverability, even at low speeds of 1 to 2 knots • Ample space for instruments, recorders, etc. • Day accommodation for two men of the EIC’s/Owner's representatives, besides the

normal crew and contractor’s own surveyors. • A helmsman experienced in survey work • Adequate radio communication between all persons concerned in the surveys • A suitable shallow draught vessel to assist in the surveys of slopes close to the surface • Clean power for the operation of the positioning system. • Certificates of Sea Worthiness of Vessels.


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5.0 DREDGING WORKS 5.1 General

The dredging works under this contract shall involve the following: 1. Mobilisation of Trailer Suction Hopper Dredger, Cutter Suction Dredger, Clamshell Grab

Dredger, Back hoe Dredger or a suitable combination thereof along with split open Hopper barges for offshore disposal, so as to meet the time schedule and to dredge rock out crops, sub crops, boulders and soft sediments with compatible equipments, such as, explosives, blasting spreads/ other methods of rock removal and spares for carrying out the dredging.

2. To carry out pre-dredging surveys and pre-dredging works such as pattern drilling, pre treatment and under water blasting or works related to rock removal by any other method.

3. To carryout dredging of all the materials upto 14.5m in the approach channel, the turning basin and near jetty without causing any damage to the neighbouring existing structures viz. LNG Terminal, Break water etc.

4. To monitor the blasting/rock removal activity as specified. 5. To dump the dredged material at the specified dumping site about 15 kms offshore from

the dredging site. 6. To mark the dredging channel, the turning circle and the dumping site with standard

marking arrangement. 7. The Owner desires to berth LNG tanker of lower parcel size and hence requires the soft

material to be dredged first and complete the same by Dec 2010. 8. To submit a final report on the entire dredging activities including submission of final

bathymetry charts and videographic recordings of the dredging activities. 5.2 Design Dredge Level and Slopes

The designed dredged level of 14.5m w.r.t. CD shall be achieved through the present dredging campaign in the areas mentioned above. The contractor shall maintain a channel width of 300m at the bottom, 700m diameter in the turning basin and with a stable side slope of 1:6 throughout the length of the approach channel, jetty and turning circle.

5.3 Materials to Be Dredged

The envisaged materials at the proposed dredging site are mostly very soft marine clay, silty clays with sand and rock out crops, sub crops and boulders. These were ascertained by carrying out seabed engineering surveys at the turning basin & approach channel by the owner. The survey report along with the charts and drawings are enclosed for reference. The quantities for the dredging has been calculated based on the above inputs and are for estimate purpose only. However, the contractor shall carry out surveys to ascertain the quantity and quality of the dredged material to complete dredging/removal of all materials near the jetty, in the turning basin and in the approach channel upto a depth of 14.5m below CD.

5.4 Marking of the Dredging Areas

The contractor shall provide and place in position and maintain adequate number of buoys to mark the dredging areas, limits and boundaries of blocks, dumping location, etc. The contractor shall at his own cost provide all assistance boats, labour etc. which the EIC or his representatives may require to enable him to carry out required checks. The contractor


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shall allow for all relaying or replacement of buoys and navigation lights arising from drifts or any other cause as is considered necessary by the EIC. Such buoys shall be removed upon completion of the dredging works.

5.5 Dredging Requirements

The Owner envisages unloading of LNG tanker. Accordingly, Owner requires the soft dredging to be completed first on priority. Keeping in view the above requirement the time schedule for the project has been finalised. Contractor shall take into account the above requirement and plan his dredging activities. Bidder to note that in case Owner unloading the LNG Tanker during the Dredging period, if the dredging equipment of the Contractor lies idle, idling charges shall be payable to the Contractor as per tender conditions, subject to the approval of Owner that the idling is due to Owner’s requirement only.

5.6 Dredging Plant Based on the above requirements of the Owner and the requirement of the project, the

minimum dredging spread envisaged is as follows,:

i) The Clamshell Dredger/Backhoe dredger shall have a minimum bucket size of 5M3 or more

ii) The Trailer Suction Hopper Dredger (TSHD) shall be of minimum 6000m3 hopper capacity

iii) The cutter suction dredger should have a total installed power of minimum 10,000KW and with a cutter power of not less than 1500KW along with suitable blasting and drilling equipment.

iv) Three hopper barges of minimum 1000m3 hopper capacity shall be mobilised to transport the blasted rock.

Bidder shall mobilize the above equipments or a combination of above equipments having the specified minimum capacities or higher capacities, based on his assessment of the material to be dredged and complete the dredging works within the time schedule. Bidder shall provide the calculations to prove that capacities of the dredging spread proposed by him are sufficient to complete the works within the time schedule. These details regarding dredging spread, capacities and production rate calculations shall be taken into account during bid evaluation and hence Bidder shall submit these documents. The dredger shall be equipped with accurate DGPS positioning system. Contractor shall provide all details of the dredgers as per the schedule of supplementary information sheets,( Refer Sec.7.0) and confirm that he is complying the bid qualifying criteria.

5.7 Dredging Tolerances

i) Vertical tolerance The design dredge level of 14.5m CD shall be achieved throughout and no ridges and pinnacles above the dredge level shall be accepted. There is no limit for lower(- negative) tolerance. Any such over dredging below the design dredge level shall not be paid.


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ii) Horizontal tolerance Horizontal tolerances for dredging shall be 5m, i.e., only 5m outside the channel boundary is permitted and paid. While carrying out the dredging works care should be taken that no damage occurs to the existing structure, directly or indirectly (over dredging in the vicinity of the structure or otherwise). Any such damage shall be made good by the Contractor at his cost and time.

5.8 Use of Explosives for Pre-Treatment of Rock

In case Bidder proposes to use blasting method of rock removal, particular care shall be taken while executing the underwater blasting in the vicinity of existing structures and structures under construction. The Contractor shall notify the EIC in writing before undertaking any rock blasting work for dredging and submit his blasting scheme, indicating the type of explosive proposed to be used, the number, depth and spacing the hole, charges proposed and the various stages for the EIC’s approval. Contractor has to follow the recommendations of MOEF for environmental safety. Underwater blasting report prepared by CWPRS and approved by MOEF shall be provided to the Contractor.

In addition to complying with the safety clauses of the Conditions of Contract, the Contractor shall permit only those workmen fully qualified/licenced and experienced in the storage, handling and use of the type of the explosives to be used for this type of works. The blasting operation shall be carried out only during day time. However, in the no traffic zone, blasting may be allowed during night also with proper safety precaution. The contractor shall take prior permission of the Owner for night blasting works. Before commencement of Blasting, the Contractor shall ascertain the methodology, type of charge, the value of charge and the spacing and submit the same for Owner’s/EIC’s approval. Controlled Blasting shall be carried out only at times to be agreed to with the Employer/EIC. The Peak Particle Velocity-PPV from the blast shall not be more than the recommended values given by CWPRS. The Contractor shall take all possible precautions to prevent accident or injury or loss to the persons and damage to the works or property. Such precautions and the safety facilities provided to the Contractor’s workmen and the method employed in storing, handling and use of the explosives shall be entirely to the approval of the EIC. Neither the provisions of this clause nor any such approval by the EIC or his staff shall relieve the Contractor from his obligations, responsibilities and sole liability under the Contract for any accident, injury or loss to persons or damage to the works or property resulting from the storage and handling or use of explosives.

The Contractor shall comply with prevalent government regulations regarding purchase, handling, transporting, storage, accounting and use of explosives and shall at all times, when engaged in blasting operations, hoist sufficient warning signals to the full satisfaction of the EIC.

5.9 Monitoring the Blasting Operations

The manufacture, possession, use, sale, transport and importation of explosives are governed under : The Indian Explosives Act, 1884


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The Explosive Substances Act, 1908 Explosive Rules, 1983 The above Act, Rules and Regulations shall apply to the work under considerations including subsequent amendments issued thereafter. Besides, following the guidelines of CWPRS/MOEF for carrying out blasting, the following sequence of blasting has to be followed: -Pre blast monitoring & Planning -In blast monitoring and -Post blast analysis A pre blast survey at all the structures in the vicinity will be carried out so as to asses the type and condition of structures in order to classify and assign threshold Peak Particle Velocities. The design of the blast shall be such as to limit the Peak Particle Velocities within the threshold values as recommended by CWPRS/MOEF. A record of all the blasts carried out shall be maintained, analysed and submitted to the EIC, accordingly the actual blasting of the rock shall be planned. A Post blast analysis of all the blasts will be prepared and submitted to the EIC. Appropriate vibration monitoring equipment shall be employed by the contractor to monitor the vibrations etc. The type and make of equipment shall be approved by the EIC before proceeding with the blasting operations. The Contractor shall plan his work such that no damage occurs to any of the structures and in the event of any damage occasioned due to blasting, the cost of reinstatement/rectification/improvement etc. shall be borne by the Contractor as directed by the EIC without any time and cost affect to the Owner..

5.10 Transportation of Dredge Spoil

The dredge spoil shall be dumped at offshore dumping sites. The proposed dumping site is around 15 kms offshore from the dredging site. However, the exact locations of the spoil dumping site will be supplied prior to dredging. The dumping activity shall neither disrupt the traffic nor cause any potential hazard.

5.11 Safeguards during Dredging Operations

The environment of the dredging site shall not be polluted because of any oil spills during dredging operations and no damages shall be caused due to the movement of heavy machinery associated with dredging operations. Any damage to the adjoining structures (Jetty, submarine pipeline and Breakwater) due to the dredging activity, directly or indirectly (over dredging) shall be avoided. In the event of any such damage, Contractor shall repair the same at his own cost and time. Any temporary installations made for the dredging purpose in the adjacent areas during the period of dredging operations shall be removed by the contractor before demobilisation of the dredging spread.


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5.12 Quality Control

The contractor shall prepare and submit his detailed proposals of quality control system for the various dredging works for the EIC's approval, not later than seven (7) days prior to commencing dredging operations, The EIC's written approval of the system shall be obtained prior to the commencement of dredging works and shall not be altered by the Contractor without the written permission of the EIC.

5.13 Method Statement

Bidder shall be submit a detailed method statement including the details of proposed methodology, equipments, sequence of works, calculations in support of achieving production rate so as to meet the completion date ( with due allowance for all unforeseen contingencies) etc., as per the formats/ Schedules of Supplementary Information (refer Sec.7.0).


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6.0 REPORTING

After completing the dredging works as specified, the Contractor has to prepare a detailed report of the dredging activities carried out by him for the project. This shall include, scope of work, dredging spread details, survey spread details, methodology, itinerary, salient observations/events, photographs, final bathymetric charts, etc. The final report shall be submitted in two hard copies and two soft copies.

7.0 SUPPLEMENTARY INFORMATION

The Bidder shall provide supplementary information as per the attached proforma, in respect of the following along with his Technical proposal : 1. Schedule 1 - Description of proposed Methods & Procedures 2. Schedule 2 - Detailed Dredging Schedule 3. Schedule 3 - Details of the Dredging Spread 4. Schedule 4 - Details of Survey Spread


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6.1 Schedule 1 : Method Statement on Execution of Dredging

The Bidder shall submit a comprehensive Method Statement regarding the execution of dredging with drawings showing the methods which the Bidder proposes to adopt to carry out the works, both temporary and permanent works. In particular, the method statement shall include details of the work methods for mobilisation, dredging operations, production levels, dredge spoil dumping, dredging plant details including specifications of the dredgers, anchor handling tug boats, survey boats that shall be used so as to demonstrate that the work methods and plant which the Bidder proposes to use is adequate and of sufficient capacity to complete the specified works within the time period stipulated. (Signature of Bidder)


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6.2 Schedule 2 : Details of Dredging Schedule

The Bidder shall submit a bar chart showing the critical sequence of activities of his intended dredging programme including all relevant activities, dates, etc. The schedule shall define dredging sequence and shall show the allocation of resources, and shall indicate the critical dates, as applicable. The bar chart shall in particular show the dates of commencement and completion for the following types of work within the site :

• Site office and workshops. • Mobilization plant & equipment • Pre dredging survey • Pre-treatment of rock • Rock removal by blasting or any other method • Dredging and dumping • Post dredging survey & acceptance tests • Demobilisation.

The dredging schedule shall also give proposals for the working hours and for the number of staff at the site and it shall state the type of work, which, in the opinion of the contractor, it is customary to carry out by rotary or double shift. (Signature of Bidder)


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6.3 Schedule 3 : Details of Dredging Spreads & Blasting Equipment

The Bidder shall furnish details of the dredgers and blasting equipment/equipment for rock removal for use on the site in order to complete the works in the manner specified. Acceptance of these details shall not relieve the Bidder of any of his obligations under the Contract. Any additional page, if appended shall also be signed by the Bidder.

DETAILS OF PROPOSED DREDGERS The following list is presented as a typical list of required details of dredgers. The Bidder is required to develop and present with his Tender a list of similar detail and categories for each proposed dredger. 1. Name and type of dredger 2. When and where built 3. Ownership of dredger 4. Present Location 5. LOA/LBPP 6. Breadth/Depth (moulded) 7. Draught 8. Communications system 9. Positioning System 10 Details of spoil transportation system with hopper capacity 11. Dredging depth (Maximum) 12. Maximum swing speed 13. Total installed power 14. Installed power for

Dredge pump drive (s) KW Diameter of suction/discharge pipeline Cutter/Suction head power KW Output rates

15. Hopper Capacity of TSHD 16. Bucket size of the Backhoe/Clamshell dredger 17. Maximum operating conditions

i. Wind speed ii. Wave height

18. Noise Rating 19. Blasting Equipment/Dredging Spread for rock removal 20. Details of certificates

Registry/Classification/Seaworthy/loadline last survey of an Authorised marine surveyor, if applicable Survey report(s), if applicable, to be attached survey

21. Commitment letter from owner ( for all hired equipments) (Signature of Bidder)


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6.4 Schedule 4 : Details of Survey Spreads

1.0 On board & Land Reference station (DGPS)

• Model • Channels • Method of Plotting • Accuracy • Method of Permanent Record

2.0 HYDROGRAPHIC SURVEY VESSEL

• LOA • Breadth • Depth Moulded • Loaded Draft • Details of Propulsion • Details of Multibeam and singlebeam dual frequency Echosounder • Subbottom Profiler • Details of Side Scan Sonar • Valid certificates • Commitment letters from Owners (if hired).

3.0 Details of Tide gauge. 4.0 Survey Software

• For Navigation • For Analysis and Plotting • For Dredging and volume calculations

(Signature of Bidder)


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Figure No. 1: Indicative Location Map

m/s ratnagiri gas power plant ltd. (rgppl)gailtenders.in/writereaddata/tender/03 techncail...

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