method statement for cable installation works
DESCRIPTION
method statementTRANSCRIPT
SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM
0 FOR APPROVAL RNM KS PB 06.10.2011
REV. ISSUED FOR BY CHECKED APPROVED DATE
OWNER
TRANSCO Contract No.:
N-6311.1
ENGINEER
ILF CONSULTING ENGINEERS
CONTRACTOR
ABB AG
ABB Contract No.:
0240295384
Format: A4
METHOD STATEMENT FOR THE INSTALLATION OF
132kV POWER CABLES & FIBER OPTIC CABLES,LOT-1
DOCUMENT NO : Sheet Rev.
1F-13-E06-010 1 of 24 0
Supplier ABB 1KGC032180
TRANSCO Sheet: 2 of 24
SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
1.0 INTRODUCTION
2.0 PURPOSE
3.0 SCOPE
3.1 PROJECT SPECIFICATIONS AND PROCEDURES
3.2 ADWEA SPECIFICATIONS
3.3 CODES AND STANDARDS
3.4 OTHER REFERENCES
4.0 DEFINITIONS
5.0 RESPONSIBILITY
6.0 EXCAVATION & BACKFILLING
7.0 DEWATERING
8.0 SITE GRADING AND LEVELLING
9.0 INSTALLATION OF 132 kV CABLES AND FIBER OPTIC CABLES
10.0 SAFETY AND RISK MANAGEMENT
11.0 ATTACHMENTS
TRANSCO Sheet: 3 of 24
SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
1.0 INTRODUCTION
The ABB is the CONTRACTOR for Transco’s project N-6311.1, being the Shuweihat Phase 2 Water Transmission System. The objective of the PROJECT is to extend and upgrade the existing facilities includes: extension of the existing Shuweihat Pumping Station by installation of additional four pump units, extension of the existing Mirfa Pumping Station by installation of additional pump units, up gradation of existing and integration of the new Tap-off stations, up gradation of the existing receiving and inlet facilities at the end points in Mirfa, Mussafah and in the Unit IV.
2.0 PURPOSE
The purpose of this document is to specify the procedure for the various activities included in the installation of 132 kV cables and Fibre Optic Cables. The Instructions of O & M User-manual must be observed.
3.0 SCOPE
The method statement describes the activities and process involved in ;
a. Civil works including the excavation ,back filling, dewatering, grading and levelling
b. Transportation, Storage , Drum handling ,Installation and Termination of 132 kV power cables and Fibre Optic Cables(FOC) in Shuweihat pumping station, Lot-1
3.1 PROJECT SPECIFICATIONS AND PROCEDURES
Particular reference is made to the following specification project
N-6311-SP-0503 : Specification for Earth Works
N-6311-SP-0505 : Specification for General Civil Construction
N-6311-SP-0512 : Specification for General Civil Construction
SP-0310 : Standard Specification for Electrical Installations
W-E-SS-013 : Standard Specification for Electrical Installations
S-CAB-132-PEST7-I(REV.0-2007).DOC : Standard Specification for 132 kV XLPE-
Insulated Single-Core Underground Cables with PEST7 Outer Sheath
S-CAB-INST-132 (Rev.0-2009): Installation Requirements for 132kV Underground Power
Cables
S-TR-CIVIL-CAB (Rev.6-2009) Cab Crossing : Civil Works for Underground Cables
D-TR-CAB-FOC(REV.0) : Standard specification for Fibre Optic Underground cables
TRANSCO Sheet: 4 of 24
SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
3.2 ADWEA SPECIFICATIONS
W-C-SS-003 –ADWEA – GENERAL REQUIREMENTS FOR WATER WORKS W-C-SS-004- ADWEA – SPECIFICATION FOR EARTH WORKS
3.3 CODES AND STANDARDS
For the applicable codes and standards for this project reference is made to:
00-05-G00-003 : List of Codes and Standards BS 6031 Code of Practice for Earthworks BS 6187 Code of Practice for Demolition BS 8004 Code of Practice for Foundations
3.4 OTHER REFERENCES
00-21-C08-001: Overall Project Quality Plan
00-21-C08-002: Overall Project HSE Plan
00-19-G01-001: Health & Safety Management Plan.
1F-13-E02-103: 132 kV HV Cables, Material Submittal, Lot-1.
1F-13-E02-104: 132 kV Fibre Optic Cables, Material Submittal, Lot-1.
1F-13-E10-110: 132 kV HV Cable route drawing, Lot-1.
1F-13-E10-108: 132 kV HV Cable sealing end drawing, Lot-1.
4.0 DEFINITIONS
CONTRACTOR : ABB AG Subcontractor for 132 kV & FO cable laying works = ETA
DAY : A consecutive calendar day unless otherwise stated
ENGINEER : ILF Consulting Engineers (ILF)
MAY : Is used where a provision is discretionary
OWNER : Abu Dhabi Water Transmission & Despatch Company (TRANSCO)
and it’s successors-in-interest and assigns.
PLANT : Machinery, computer hardware and software, apparatus, materials,
articles and things of all kind to be provided under the contract other
than Contractor’s Equipment.
PROJECT : The owners Project N-6311.1, being the Shuweihat Phase 2 Water
Transmission System
TRANSCO Sheet: 5 of 24
SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
1. Project Manager : Lead all construction activities and enforce strict adherence to all project specifications.
2. Site Manager : Lead the construction activities at site and report to the Project Manager.
3. Field Engineer : Ensure that all related works are carried out in accordance with the approved drawing and project specification. Report to the site manager.
4. QA/QC Engineer : Responsible for the necessary quality control implementation by following the customer specification.
5. Supervisor : Supervise field installations and report to the field engineer.
6. HSE Officer : Ensure that all the site activities are carried out in accordance with the project health and safety plan.
7. Other Personnel requirement:
• Technicians
• Helpers
• Banks men
• Fork lift operator
• Crane Operator
SHALL : Is used where a provision is mandatory
SHOULD : Is a strong recommendation
SITE : The actual place or places provided or made available by the
Owner, to which plant is to be delivered or where work is to be done
by Contractor.
VENDOR : Any person, firm, partnership, corporation or combination thereof,
employed by one or other or both of the members of the ABB for the
supply of materials, equipment, and/or services related to the
PROJECT.
WORKS : Works to be done by the Contractor under the contract
5.0 RESPONSIBILITY
TRANSCO Sheet: 6 of 24
SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
6.0 EXCAVATION & BACKFILLING
6.1 Preparations and Preconditions
1. Permit to Work (PTW) shall be raised for the excavation clearly mentioning the
location of work, size of excavation and levels.
2. Excavations area shall be surveyed and marked to the lines and levels as shown on
the drawings.
3. The area of excavation will be cordoned off using safety barricading to stop
trespassers.
4. Assign sufficient banks men, helpers and supervisors at the site prior to start of
excavation.
5. Required sign boards such as “DEEP EXCAVATION” “MEN WORKING”
“DANGER” and warning boards will be placed to indicate the excavation work.
6. Ensure the working area at any confined space is free from any Hazardous Gas by
proper Gas testing using the Gas testing instrument.
7. Proper temporary supports shall be provided to the adjacent structure prior to start
excavation.
8. Fences and minor structures of any character or upon within the limits of the works
and not necessary for the construction shall be removed carefully and stored neatly
for reinstating after the construction works.
9. If any Survey points, bench marks, boundary stones and markings falling on the
area shall be removed only with the OWNER / ENGINEER's written consent and
shall be stored and reinstated according to OWNER / ENGINEER's instructions.
10. Extra temporary bench mark shall be provided according to ADWEA
Specification: W-C-SS-004 if required.
11. Check the area of excavation to find out any underground facilities other than listed
in topographical survey by:
• Using appropriate detective equipment, such as cable detector, metal detector etc.
• Check existing exposed excavation nearby area to find out existing underground facilities.
TRANSCO Sheet: 7 of 24
SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
• Refer available As-built drawings from the Company, other agencies , other contractors doing projects nearby areas and mark in the area.
• Take trial/ test pits to find out existing underground pipes, structures.
• Check the indication marks, signs, manholes nearby area and find out the path of services.
6.2 EXCAVATION
6.2.1 Trial Pit and Excavation Procedures
1. Prior to star of any excavation, the area shall be checked for the existing services/utilities by obtaining the approvals with reference to the relevant drawings.
2. The necessary excavation activities shall start only after getting the notice intent from the client / customer.
3. Excavation of the trial pits shall be done manually as per the size indicated in the approved drawings up to the required length and level.
4. In open areas the excavation shall be carried out by using the machineries, the exact location of each trench and pit being subjected to the prior approvals.
5. Manual excavation will be carried out to expose the existing utilities, if any, which has to be identified.
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SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
6. The trenches shall be kept dry during cable installation operation. The contractor shall deal with the dispose of water so as to prevent any risk to the cables and other materials.
7. The contractor shall provide suitable dewatering methods as explained in section 6.0 while performing the works according to the scope of work.
8. The required control measures shall be developed and implemented while performing the works and more importance will be given for public safety and environmental issues.
9. While performing the work the trenches shall be straight, free from any sharp objects/edges likely to injure the cable or accessories and filled with soft sand and sieved sand to form smooth bedding before the cables are laid.
10. The contractor shall take the necessary precautions to prevent damage to the road or ground surface due to a slip or breaking away from the side walls of the trench including the pedestrian safety as well.
11. The vehicle entry shall be restricted on the specified work area by prior approval from the concerned agencies.
12. Where ever there is a crossover of the existing services/utilities, these shall be protected with utmost care with the prior permission of concerned authorities and approved methods. The contractor shall obtain the necessary approval from the client / consultant or the concerned authorities to according to the scope of the work.
13. Excavate the area by using only hand tools as per the markings and levels with proper protection of sides. If excavation depth exceeds 1.2 m proper shoring and shuttering should be provided as per the safety norms or the excavation shall be stepped, wide enough to get stable slope on sides of wall from soil sliding.
14. Excavations in sand shall be to a slope of 1:3, one vertical to three horizontal. If any permanent slope is to be kept in the sand it shall be stabilized by one of the following means,
� Mass concrete blinding
� Cement/sand mixture
� Bituminous/cement mixture
15. Trim and form the edges of soil to profiles and levels as indicated in drawings.
16. If the excavation level is below the local water table level suitable dewatering system (well point method and/or pump and sump method, refer section 6.0) shall be designed and installed in such a way that alterations and extensions to the system during operations are possible.
17. For Rock excavation hard excavation shall be carried out by ripping, excavation, wedging, chiselling using jack hammers, or by other recognised methods approved by OWNER/ENGINEER. Blasting will not to be adopted under any circumstances for rock excavation.
18. In trench excavation the bottom width of at least in 800 mm plus the dimension of pipes, conduits, ducts, etc to be installed.
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SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
19. The bottom of the excavation shall be levelled and trimmed to receive the permanent works. The bottom of the excavation shall be moisture conditioned to + 2% of optimum and mechanically compacted to a density of not less than 95% of the maximum dry density.
20. Precautions shall be taken to protect the bottom of the excavation and, if the bottom of the excavation becomes unsuitable either by exposure to weather conditions, water, or due to any other reasonably foreseeable event, it shall be removed and replaced with suitable materials.
21. Provide proper rigid barriers around excavations include provision of ladders, emergency escape way, adequate side slopes or shoring and shuttering, detours.
22. If fossil content is noticed during excavation shall be brought in notice of the OWNER.
23. The top width of excavation shall be increased or depend upon the depth of excavation , It is required to provide suitable slope to side of excavation to avoid soil sliding, then the top trench width shall be increased accordingly by step cutting method. If the top width of excavation is restricted due to existing facilities then protect the side of excavation with proper shoring.
24. If the bottom of excavation is loose strata then excavate 300 mm more to select fill materials to form a hard and compacted grade strata for construction.
25. If the bottom of excavation is below the water table level, provide proper shoring prior to excavate below the water table level then excavate 300 mm more to fill Aggregates or Gravel to form a hard grade strata.
6.3 EXCAVATION ADJACENT TO UNDERGROUND SERVICES
1. Excavation near the existing electrical cables, instrumentation and control cables, sewer line, gas lines and any other service line shall take all necessary precautions to protect the services with proper supports & covers.
2. All existing structures, foundations, pipes and cables, if any, which are to be incorporated into the final work, shall be adequately protected from damage.
3. All underground services located during excavation shall be mapped for consideration during construction of the works.
4. If any underground service is noticed other than specified in the area during excavation shall be brought in notice of the OWNER.
5. Excavation shall not be carried out adjacent to or near existing building foundations, without suitable shoring/sheet piling.
6.4 OVER EXCAVATION
1. In case excavations executed beyond the established levels, backfill the over excavation with lean concrete or other approved material,
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SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
2. The volume corresponding to the over excavation shall not be carried out adjacent to or near existing building foundations, until suitable shoring/sheet piling has been installed.
6.5 STOCKPILES AND DISPOSAL
1. Excavation material shall be removed, stockpiled or deposited away from the excavation area for reuse, or disposed in the approved dumping area as directed by OWNER/Engineer’s.
2. Debris, rocks and unusable materials shall be removed on daily basis from the site to approved dumping area or final destination whether in the work or in the waste areas, including any necessary temporary stockpiling and the additional loading and transporting.
3. Only permitted materials or selected materials from excavation shall be stored or stockpiled for re-use.
4. Stock piles and disposal shall be as per ADWEA Specification:W-C-SS-004 item no:7.5
6.6 REFILLING OF EXCAVATION
1. The refilling of excavations shall be started as soon as practicable after the permanent works have been tested and approved by the ENGINEER.
2. Refilling of trenches over pipes shall be done by hand to a depth of 300 mm above the crown of the pipe with dune sand or lightly compacted selected excavated material free from large stones, rock, clay lumps or other substances which may cause damage to the permanent works.
3. Refill the leftover portions with suitable backfilling material in 300 mm per layer which shall be fully compacted by mechanical tamper/plate compactor/roller and tested in accordance to project requirements.
6.7 BACKFILLING
6.7.1 General
• Backfilling area shall be backfilled with approved material compacted in layers by suitable equipment like plate compactors, vibratory roller compactors, etc., until the specified density has been obtained to the satisfaction of the OWNER/ENGINEER.
• Compacting shall be carried out with special care by means of mechanical tampers of a type approved by OWNER/ENGINEER to avoid damage to structures.
• Areas to be backfilled shall be prepared so as to obtain a soil density at least equal to 95 percent of Standard Proctor test (ASTM D 698).
TRANSCO Sheet: 11 of 24
SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
6.7.2 BACKFILLING MATERIALS
• Backfilling materials shall be free from stones or rocks larger than 50 mm, or
other material which might prevent proper compaction or cause the
compacted fill or embankment to perform inadequately.
• Backfilling materials shall be free from fossil content, clay, vegetations and
its roots, waste materials, Material containing gypsum or other soluble salts
greater than the allowable limits.
• Following classified materials shall not be used for backfilling.
� Organic material, logs stumps and perishable materials.
� Material susceptible to spontaneous combustion.
� Materials with undefined properties.
� Materials having moisture content greater than the maximum
specified.
� Building rubble and domestic and industrial wastes.
� Soils and rock susceptible to deterioration/change of their properties.
� Clay, silt and other loose or soft soils not in accordance with
compaction criteria.
� Dredged material.
� Rock materials
6.8 FILLING OF MATERIALS
1. Fill material shall be spread and compacted in 300 mm layers, with a compacted layer thickness not exceeding 300 mm where mechanical compactors like vibratory plate/drum compactors are used.
2. The thickness of fill material shall not exceed 150 mm where manual compaction methods are adopted.
3. If the thickness of loose fill layers required to exceed 300 mm written approval including methods of compaction shall be required from the OWNER/ENGINEER.
4. If the surfaces receiving fill layers is smooth, then scarified to obtain a good friction/key between the new fill layer and the sub grade.
5. Rock fill or aggregate fill materials shall be deposited under water with the OWNER/ENGINEER's permission. Fill materials like cohesive soil (i.e. soils that possess low shear strength, are plastic and compressible, deforms plastically under constant load, changes volume in the presence of water) shall not be permitted deposit under water.
TRANSCO Sheet: 12 of 24
SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
6. Where swamps, bogs or other similar wet areas must be traversed by the works, they shall be drained as directed by the OWNER/ENGINEER’S according to the material and conditions encountered. Prior to the formation of embankments, fill, etc...., any unsuitable material occurring on the site shall be removed to such depths and widths as may be directed by the OWNER/ENGINEER’S and approved excavations shall be properly backfilled with suitable and approved excavated materials and shall be deposited and compacted to the satisfaction of the OWNER/ENGINEER’S . Similarly, soft or weak spots encountered will be removed and, as with any voids, will be backfilled as specified.
7. Final layer of backfilling shall not contain soft rock fragments exceeding 50mm upon placement to the satisfaction of the OWNER/ENGINEER’S.
8. Trench backfilling containing pipes shall be properly packed at the sides with sand which shall be well rammed with narrow wooden rammers before filling further. The filling shall then be carried up to 150 mm above any sand or concrete surround with fine selected material and well watered and rammed. The remainder of the trench shall then be refilled in layers not exceeding 300 mm thickness, watered and rammed until the ground is thoroughly consolidated. No mechanical rammer shall be used with 300 mm of the top of any pipe or surround and material shall not be drooped from a height.
9. The top surface area shall be dense and level without any protruding rock fragments in excess of 50 mm, recesses or soft spots, to the satisfaction of the OWNER/ENGINEER’S.
10. Tolerance level shall be maintained as per the specifications
11. Excavated materials may only be used for backfilling after obtaining satisfactory approved lab test results; otherwise fill materials shall be imported to the site.
6.9 Formation of Cable Trench.
1) The formation of the trench shall be in accordance with TRANSCO’s standard and specification S-CAB-INST-32 (Rev.0-2009) and DWG TR CAB 01 00 05
2) The trench shall be excavated upto the required depth of 1.3m from the existing ground level
3) Dune sand bedding shall be done for a thickness of 150mm at the bottom of the trench using TR tested and approved dune sand, prior to the installation of cables.
4) Cables and the 4” uPVC pipes for the FO Cables are laid over the dune sand bedding
Sand Filling
1. TR tested and approved sand (Max 120°C cm/W) is filled in the trench to the required level as per approved drawing.
2. Sufficient Water is poured to match the required Moisture content and to get 95% MDD
3. Cable protection tiles are laid above the dune sand filling
Final Backfilling.
1. Ensure the Concrete Cable Tiles are securely placed.
2. Selected sieved materials from the excavated soil shall be backfilled for a thickness of 250mm above the cable protection tiles. Care shall be taken to avoid stones and boulders mixing with the backfill material.
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SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
3. Install 132kV Cable Warning Tape at a height of 250mm from top of the concrete cable tiles
4. Backfill to the required level in similar way.
5. Ensure Proper Compaction of soil is done after every 150mm layer laid.
6. Reinstate the area as to its original situation.
6.10 COMPACTION
1. The required density shall not be less than 95% Modified Proctor under Roads and pavements. This shall be obtained by compaction in layers by means of rollers and/or dozers, applying as many passes as may be necessary and to the approval of the OWNER/ENGINEERS.
2. Sweet water or portable water from a source approved by the company shall be sprayed on the placed material prior to compaction where necessary to achieve the optimal moisture content.
3. Brackish or salt water is not allowed to be used in compaction.
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SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
4. The density of each placed and compacted layer shall be established by testing prior to the placement of subsequent layers. If the results of test indicates that the required density is not being achieved further tests shall be carried out.
6.11 TESTING
1. All the testing shall be carried out to the satisfaction of OWNER/ENGINEER’S. All such tests shall be carried out at a laboratory approved by OWNER/ENGINEER’S. Results of all tests shall be approved by OWNER/ENGINEER’S. Filling of subsequent layers shall not commence till approval from OWNER/ENGINEER’S is obtained.
2. Field density testing shall be in accordance with BS1377 at a minimum frequency of one per 5000 m2 per layer shall be achieved.
3. Tolerance limit for the permanent finished earth work shall be included as stated in item :10 of ADWEA Specification : W-C-SS-004
4. The top surface area of the finished surface shall be dense and level without any protruding rock fragment in excess of 50 mm, recesses or soft spots, to the satisfaction of OWNER/ENGINEER.
6.12 TOOLS & EQUIPMENTS
1. Hand tools for Excavation
• Hand Shovels
• Plastic Buckets
• Wheel Barrows
2. Equipments
• Jack hammer for removing hard strata like asphalt and Rocks
• Crane & Buckets - shall be used to remove excavated material from pit
where pit is not accessible by other methods.
• Plate compactor, Mechanical Tampers to compact the backfilling materials.
• Air compressors
• Water tankers
7.0 DEWATERING
7.1 PREPARATIONS AND PRECONDITIONS
1. Permit to Work (PTW) shall be raised for dewatering clearly mentioning the location of work and levels.
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SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
2. Mark and identify the area required dewatering suitable to the area with least interface of new construction activities.
3. Layout and mark the dewatering system (well point system , suction , discharge lines, storage tank and pumps (Running & Standby).
4. Required sign boards such as “DANGER” and warning boards will be placed to indicate the work.
5. Ensure the working area at any confined space is free from any Hazardous Gas by proper Gas testing using the Gas testing instrument.
6. Check the area prior to drill / bore hole for inserting well points to find out any underground facilities other than listed in topographical survey by
• Using appropriate detective equipment, such as cable detector, metal detector etc.
• Check existing exposed excavation nearby area to find out existing underground facilities.
• Refer available As-built drawings from the Owner, other agencies , other contractors doing projects nearby areas and marks in the area.
• Take trial/ test pits to find out existing underground pipes, structures. • Check the indication marks, signs, manholes nearby area and find out the
path of services.
7.2 DEWATERING METHOD
Dewatering is the temporary reduction of pore pressures or groundwater levels to provide
dry, stable and safe soil conditions in excavations below groundwater level. Dewatering is
used to facilitate the construction of the deep excavations that are required for
foundations, basements, trenches and other underground structures.
7.2.1 DEWATERING TYPE
As per the site condition we are proposing to install a single stage Well point system to
control the ground water within the area of the excavation required to construct the below
water table level activities.
� WELLPOINT SYSTEM
• Well points are small-diameter (about 50 mm) tubes with slots near the bottom that are inserted into the ground from which water is drawn by a vacuum generated by a dewatering pump. Well points are typically installed at close centres in a line along or around the edge of an excavation.
• Well point dewatering involves the installation of riser pipes/tubes with a filter section on the lower 1 meter portion, connected into a common header pipe from which the water can be pumped by a vacuum assisted pump to a convenient discharge point.
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SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
7.3 PREPARATION OF WORKING PLATFORM LEVEL.
Initial excavation for all structures shall include an installation platform 50cm above the
existing water table.
7.4 PRE-DRILLING (if required)
As a means of ensuring the integrity of the well point installation, boreholes shall be predrilled to the required depth at 1meter intervals. Pre-drilling shall be executed by the use of a self propelled drilling rig.
7.5 WELL-POINT INSTALLATION
Well points shall be installed into the boreholes at 1meter intervals. High pressure water
shall be injected into the ground through the 6 meter lance; forming a borehole into which
the well point shall be inserted. Once the well point is installed the lance is held in this
position until the water being ejected out through the top of the borehole runs clean. The
borehole and well point surrounds are backfilled with aggregate (size 3mm to 10mm)
which cover the filter section of the riser tubes. As the jetting lance is withdrawn from
within the borehole, the aggregate shall reduce to ground level by the displacement
created by the removal of the lance. This procedure is repeated upon installation of each
well-point.
The holes drilled by drilling machine and holes shall be cleared or cleaned by jetting
of water through jetting pipe connected with jetting pump. During jetting, the well
point pipe shall be inserted up to the bottom of the hole until the jetting water comes
through the well point pipe top side to ensure that the installed pipe is free from
blockage and pour aggregate (filtering material) around the pipe to filter the water
during dewatering.
7.6 HEADER PIPE NETWORK
Upon completion of the installation of the pre-determined number of well-points, the well-points shall be connected to the header pipe network by means of swing pipes, which in-turn is connected to the dewatering pump.
7.7 DISCHARGE
The collected water produced by the well point dewatering system shall be discharged into
a settlement tank prior to discharging into the approved water disposal area as defined by
the OWNER/ENGINEER.
During discharging the ground water the filter screen with 3/10 mm aggregates minimises
the movement of fines in the water during the ground water discharge, the soil fines
movement is monitored via visual inspection in the settlement tank on a periodic basis.
Required drainage channels, troughs, pipes shall be provided to control the
discharge of water from dewatering from the site with suitable discharge pump and
equipments as per ADWEA specification W-C-SS-004, item No: 06.
7.8 COMMISSIONING
TRANSCO Sheet: 17 of 24
SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
Once complete, the dewatering system shall be started with the approval of the OWNER’s
representative. After the first 12 hours of running, all well-point locations shall be observed
and adjusted, so that the correct vacuum is created to achieve full efficiency of the system.
The installed system can be modified to a limited degree, header pipes can be
disconnected in sections, pumps & discharge hose can be moved. However, any alteration
& extension to the system after installation involves stoppage of pumps.
Monitor the dewatering system in a 24 hours basis with experienced technicians and
additional dewatering pumps.
7.9 MATERIAL USED
1. Aggregate - 3/10” crushed and pre-washed aggregate.
2. Well points - 6m long x 2” UPVC well points.
3. Header Pipes - 6m x 6” Galvanised steel header pipe.
4. All other pipe network accessories.
7.10 RESOURCES (MANPOWER AND EQUIPMENT)
7.10.1 MANPOWER
1. Civil Supervisors 2. Safety Officer 3. Surveyors 4. Dewatering Foreman 5. Dewatering technician 6. Helpers. 7. Drill Operator
7.10.2 EQUIPMENTS
1. Hand tools.
2. Auger Drilling Machine (Self propelled) – if necessary
3. High pressure Jetting Pump (12 to 15 bars)
4. 6” Dewatering pump
5. 6” Booster pump
6. Jetting lance (6.0m long) complete with tank and accessories.
7. Stand by pump-Dewatering Pumps
8. Stand by pump -Booster Pumps
TRANSCO Sheet: 18 of 24
SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
Note: Item: 7 and 8 shall be same number of running pumps, keeping as
reserve pumps in case of failure or repair of running pump. In case of
failure or repair on running pump immediately replace with stand by pump
(24 hours monitoring staff is available during dewatering)
8.0 SITE GRADING AND LEVELLING
8.1 PREPARATIONS,CLEARING, GRADING & LEVELLING
1. Permit to Work (PTW) shall be raised for clearing, grading and levelling, clearly mentioning the location of work, size of area and levels.
2. Area shall be surveyed and marked to the lines and levels shown on the drawings.
3. The area of work shall be cordoned off using safety barricading to stop trespassers.
4. Assign sufficient banks man, helpers, and supervisors at the site prior to start of work.
5. Required sign boards such as “MEN WORKING” “DANGER” and warning boards will be placed to indicate the work.
6. Ensure the working area at any confined space is free from any Hazardous Gas by proper Gas testing using the Gas testing instrument.
7. Proper protection shall be provided to the adjacent structure prior to start work.
8. Fences and minor structures of any character or upon within the limits of the works and not necessary for the construction shall be removed carefully and stored neatly for reinstating after the construction works
9. If any Survey points, bench marks, boundary stones and markings fouling on the area shall be removed only with the OWNER / ENGINEER's written consent and shall be stored and reinstated according to OWNER / ENGINEER's instructions.
10. Check the area of work to find out any underground facilities other than listed in topographical survey by:
• Using appropriate detective equipment, such as cable detector, metal detector etc.
• Check existing exposed work nearby area to find out existing underground facilities.
• Refer available As-built drawings from the Company, other agencies , other contractors doing projects nearby areas and marks in the area.
• Take trial/ test pits to find out existing underground pipes, structures.
• Check the indication marks, signs, manholes nearby area and find out the path of services.
11. Remove the top layer of soil approximately 300 mm depth which include vegetations, grass, rocks, and roots of vegetations. All rubbish, and any other unacceptable material.
12. Levelling the area with approved filling materials as per the requirement of projects and approved drawings.
TRANSCO Sheet: 19 of 24
SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
13. During the progress of the WORK, the WORK Site shall be kept clean. All rubbish, surplus materials, and unneeded construction equipment shall be removed, and all damage repaired so that inconvenience is reduced to a minimum. The WORK Site shall be kept in a sanitary condition.
14. Decontaminate the premises and grounds as necessary to prevent the breeding of insects or vermin.
15. Where material or debris has washed, flowed into, or been placed in drains, pipes, or structures, whether existing or installed under this Contract, such material or debris shall be entirely removed and satisfactorily disposed off. The drains, pipes, structures, etc., shall be left in a clean and neat condition.
16. Removal and disposal of construction debris, all useless materials, rubbish, rocks, stones, excess/waste asphalt and concrete, excess/waste materials, shipping materials, rebar, and other metallic debris generated by the project or placed inside and outside the WORK Site.
17. With the exception of areas to be excavated, all depressions made below and ground surface by the removal of rubbish or existing works shall be refilled with suitable material and compacted to the satisfaction of the ENGINEER.
18. Levels shall be maintains as required by the project.
8.2 DISPOSAL AND HAULING
1. Haul, load, transport the removed materials from the site and dispose in approved or designated dumping area.
2. Waste material shall not be allowed to blow or spill into any public or private property during transportation.
8.3 TOOLS & EQUIPMENTS
8.3.1 Hand tools for Work
• Hand Shovels
• Plastic Buckets
• Wheel Barrows
8.3.2 Equipments :
• Earth Moving Equipments : GRADER, EXCAVATOR, SHOVEL
• Tippers , Dump trucks
• Roller Compactor, Plate compactor
• Water tankers
TRANSCO Sheet: 20 of 24
SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
9.0 Construction of Non-Disruptive Road crossing by HDD method (Optional method)
Pre-requisites
• NDRC Profile drawing with all the existing services and facilities shall be
submitted and approved.
• Permits, licenses or approval letters issued by government or statutory bodies
have been issued and are available at site.
• Approval for Road crossing by HDD method shall be obtained from authorities
concerned and shall be available at site.
• Approved drawings shall be available on site
• Mark the location of the road crossing, entry and exit pit as per the drawing.
• Excavate the entry and exit pit of 4 mts length, 4 mtr wide and depth should be
as per drawing depending upon the existing services.
• Locate all the existing services in the work area by trial pits. The foot path and
centre median of the road can also be exposed, if required.
• If excavation is more than 1.5 m deep, step excavation should be done or
shoring shall be provided.
• If the drilling tool comes across a boulder during drilling operation, break it by
using Hard Rock breaking tool and if not possible then divert the route to avoid
such obstructions, upon approval from the Engineers.
• The contractor shall monitor road levels before and after drilling work, monthly for
a period of six months. The result of levels is to be informed to authorities
concerned. If settlement occurred due to drilling under asphalted road is found to
be more than the Calculated Value, contractor shall report the findings
immediately to Owner/Engineer.
• Ensure all the safety measures have been taken.
Reference Drawings/Documents:
• DWG-TR-CIV-CAB-14-13 & DWG-TR-CIV-CAB-14-14
• S-TR-CIVIL-CAB (Rev.6-2009) Cab Crossing
Control measures and specific control measures for the work location.
While drilling, reaming and pulling preventive measures are made to minimize down Hole pressures or erosions.
The drilling fluid flow is analysed to adjust hole dimensions, geological properties, flow rates, viscosity, gel strength, filtrate and solids content to the annular flow. Geological properties in the annulus are measured in the field and adjusted as required to conform to the analysed circuit and ground conditions.
Issue personal protective equipment to all site personnel appropriate to their nature of works.
Comply with safety local standards. Comply with local police guidelines in the Temporary Signing requirements.
TRANSCO Sheet: 21 of 24
SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
Safety precautions to be maintained for the personnel, Pedestrians and environment within the occupied area, all as per approved HSE manual. Attention shall be paid to regular site cleaning and keeping the working area as confined as possible. List of Equipment, Machinery & Materials HDPE pipes, Drilling machine, Jet Assembly (Drilling head , water tanker & Bentonite mix ) , Transmitter , Receiver , Wire line , Reamer tool , Welding Machine , Towing head , Swivel and Polymers Extenders Responsible Persons to carry out the Job.
Site Manager, Project engineer, QA/QC Engineer, HSE Engineer, Drilling In-charge, Civil foreman and Subcontractor’s Team as per the organization chart. a) Site Manager: To arrange all the pre-requisites, to arrange for Inspections with prior information to the Client / Consultant, supervising all construction activities. b) Project Engineer: To ensure compliance of related procedures, to keep all the related documents and drawings at the work place, supervising all construction activities as per the approved procedures, to carry out the Inspections. c) QA/QC Engineer: To ensure all work activities are carried in accordance with the Project Quality Plan and method statements, Control of non-conformity. d) HSE Engineer: To Implement the safety aspects, to Issue PPE’s to all the personnel, Inform Site manager about unsafe conditions and ensure those are rectified, to conduct safety meetings, arrange safety signs and display boards, Investigate all the accidents and circulate the learning points, and report to head office.. e) Drilling In-charge: To ensure all activities to be carried out as per approved procedures in the required time limit. f) Civil Foreman: To carry out all the civil related works.
Method :
I) The guided pilot hole:
To drill soft sediments like clay, sand and medium gravel the rotating drilling head has to cut a micro tunnel into the soil supported by a high-pressure jet of water and bentonite mix. This equipment is called a jet assembly. The drilled soiled material flows back into the start pit, transported by the drilling mud. The size of the pilot hole is approx.70 mm and the mudflow is approx.40 ltr/min and the pressure is about 60 bars. To follow the designed drill run, the drilling tool is equipped with a transmitter, which is given permanent information about the depth, the distance, the inclination and the direction of the drilling tool. This information in reported on a drilling report to provide the as-built documents. The transmitter gives a signal to the surface above, which is received by a receiver and recorded as down hole data, for future reference.
TRANSCO Sheet: 22 of 24
SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
To follow the drilling tool one person will walk and stay over the tool and hold the receiver. On road crossings one lane has to be blocked for few minutes while the drilling tool is moving under it. While closing the road, traffic-engineering rule has to be followed. The receiver sends the information to a remote control panel on the drilling rig. The driller can correct the position of the drilling tool and can keep it in the desired level & direction. All the information of the depth, distance and inclination are sent from down hole through a wire line in the drill rod into the computer. The steering engineer and the driller can keep the drilling tool on the designed curve. During drilling the position of pilot hole is recorded every 3 mtr along its route and this data will form a part of the as-built records of the HDD crossing. J) Reaming of pilot hole: When the pilot hole reaches the exit pit the drill equipment will be re-placed and connected to the pullback assembly called a reamer tool. There are different shapes of reamers that enable you to cut soft and hard formations. The number of reaming steps depends on the diameter of the pipe and the hardness of the geological formations. These operations always start with a small-scale reamer and end with a diameter that is around 1.2 times bigger than the overall bundle diameter. Behind the reamer, drill rods are pulled into the hole, so as to keep a too & fro motion on the drilling operation, also to maintain an opportunity to with draw & re-position the reaming tool should the geological structure change. K) Installation of the product pipe: While reaming the bore hole the pipe is Fusion or Butt welded (Fusion or Butt welding method on PE-HD pipes) to the full length of the drill run and is formed into a tied bundle of individual pipes. It is placed in line of the drill run behind the exit pit. After the last reaming step is finished, the pipe is connected to the reamer with a towing head and the swivel. The swivel is used to prevent the pipe bundle from rotating, because the reamer will rotate continuously during the operation of pulling back the pipe bundle so as to ensure a clean bore hole is maintained during this pulling in of the bundle operation. Drilling mud: a) The directional crossing process requires the use of Bentonite slurry that provides the following functions:
1. Hydraulic cutting jet. 2. Lubrication to the drilling tool and drilling rods. 3. Transport drill-cut material (sand etc) to the start or exit pit. 4. Stabilize the hole against collapse while drilling and reaming. 5. Make a filter-cake to guard against loss of slurry into surrounding
formations. b) Slurry composition The slurries most commonly used are bentonite based. Often polymers extenders are also added to enhance certain characteristics. c) Pump volume and pressure
TRANSCO Sheet: 23 of 24
SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
For each project, a drilling fluid calculation is made according to the ground conditions, the hole size, hole length, pump volume and pump pressure. To drill a pilot hole in sand with a 12-ton machine, a pump volume from 40-50 ltr/min and a pressure from 30-40 bar is required. The jets are facing forward and they are making tunnel with approximately 20-80 mm diameter. To ream the hole to 360 mm diameter a pump volume from 50-70 ltr/min. and a pressure from 20-30 bar is used. To pull the pipe, a volume from 40-60 ltr/min. and a pressure from 20-30 bar is used.
A mandrill test will be performed on the installed pipes after completion of grouting procedure hence confirming the suitability of the HDD crossing at its completion.
10.0 Construction of Open-cut Road Crossings
Pre-requisites - Permits, licenses or approval letters issued by government or statutory bodies have been
issued and are available at site. - Proper permits or safety documents to be obtained from service department.(TRANSCO) - Work Area is Demarked and Barricaded as per permit requirement and Limit of Work.
Reference drawings/Documents: - TRANSCO/ADWEA Specifications: S-CAB-INST-132(Rev-0-2009) and TR-CIVIL-CAB(Rev.6-2009) - TRANSCO standard drawing for road crossings DWG TR CIV CAB 14 01 - 1F-13-E10-110A – 132kV Cable Route
TRANSCO Sheet: 24 of 24
SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
Procedure
1. The Asphalt/concrete to be removed shall be demarcated exactly and it shall be cut with Road Cutting Machine (Saw cutter) along the length and width of the excavation.
2. Then the asphalt/concrete shall be removed by suitable means using excavator or JCB. 3. Excavation shall be carried out to the required depth 4. A concrete duct as per the above section thickness conforming to the TRANSCO standard
drawing and specifications shall be constructed. 5. The concrete duct shall be wrapped with PE sheet of 150 micron thick.
TRANSCO Sheet: 25 of 24
SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
6. Concrete (C40) shall be poured above the concrete duct upto the level of the existing road so that the whole of the trench below the road is filled with concrete.
7. Bitumen paint shall be painted over the exposed surface of the concrete.
8. The Road shall be open to traffic after 24 hours of completion of reinstatement. Safety Measures and Traffic Arrangements to be taken for all the activities.
Issue personal protective equipment to all site personnel appropriate to their nature of works.
Comply with local safety standards. Comply with Police guidelines in the Temporary Signing. Ensure other services are completely Protected. HSE engineer, Route in-charge and Project Engineer (Competent Person) to take all required safety measures.
11.0 INSTALLATION OF 132 kV CABLES AND FIBER OPTIC CABLES
• PREPARATION AND PRECONDITIONS
1. All the works in the pumping station area are subjected to the approval and permit to work (PTW) of TRANSCO.
2. Before the start of the installation activities, all the approved installation drawings with IFC status shall be available at site for the verification of actual routes and dimensions. The entire work done shall comply with the approved installation drawings.
3. The contractor shall inspect the site location prior to start of the work.
4. The contractor shall obey all relevant rules as applied by the Traffic department with reference to the traffic sign, diversions, etc during the performance of the work.
5. Special care shall be taken to avoid disturbances in the operational areas.
6. Free access to site.
7. All required tools and Equipment must be available.
8. Manufacturer’s instructions for safety, transportation and installation must be followed. The temporary warning placard shall be displayed at the entrances to ward off unauthorized personnel from entering the work area to avoid any untoward incident.
9. Tool box talk
• MATERIALS USED
1. PVC pipes – 100mm internal diameter and 4.5mm wall thickness for the underground Fiber Optic Cables.
2. Warning Tapes
3. Cable markers
4. Dune sand
TRANSCO Sheet: 26 of 24
SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
• SEQUENCE OF INSTALLATON ACTIVITIES
All the installation activities will be carried out in compliance with the rules and regulations of the project as specified by TRANSCO.
The activities include:
Manufacturer’s installation instructions have to be followed up for transportation, drum handling and installation of the 132 kV power cables and Fibre Optic Cables at site
(See Attachments-1-6)
•••• Cable Laying
1. Manufacturer’s instructions for installation have to be followed up.
2. Loading of cable drum has to be done by using suitable crane. There after it is transported by means of cable trailer/jack. The access up to the trench should be checked before transportation.
3. Location of cable drum should be planned before transportation of cable drum. (Practically could differ at one or two places for easy installation of cable).
4. The cable drums shall be inspected for mechanical or physical damages and check the cables to be used at site prior to the start of the installation process. Any sort of damage shall be noted in the damage report.
5. The whole trench /pit/ cable trough shall be inspected before the cable pulling work begins. CBS / FBS or sand bedding of special thermal backfill for the cables shall be filled in smoothly and any objects as stones /gravels which have fallen from the ground to the surface of the bedding layers shall be removed.
6. The ducts for the roads crossing shall be checked before the cable pulling works starts to make sure that they are thoroughly cleaned and shall ensure it is free from debris and foreign bodies.
7. Soil thermal resistivity test shall be conducted and report will be forwarded to the client /consultant for their review.
8. Trough shall be filled with dual sand before and after cable laying. Concrete block shall be placed over the trough before backfilling the trench.
9. The pulling winch machine shall be set firmly and its variable pulling speed is set in the range of zero (0) to ten (10) meters per minute. Pulling winch machine should be equipped with a tension gauge so it is possible to control the cable pulling tension.
10. The winch machine shall be fitted with over load cut – out chart recorders. Chart records will be used to record the pulling tension and the drum of cable pulling wire should be appropriately positioned in order to roll up the rope easily.
11. Cable rollers shall be positioned properly in to the cable trench. The intervals for the rollers are to be kept approximately two meters.
12. The rollers shall be maintaining its smooth rotation. If the cable will run through the curves and edges the, curve rollers should be used at the proper position in order to keeps a safe
TRANSCO Sheet: 27 of 24
SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
cable bending. Usage of bell mouths will guide rollers and shall be installed at duct in the road crossing or other service crossings. Key rollers shall be secured and tightened by using braces supported to the trench walls.
13. Communication tools / equipments shall be arranged after the facilities and the equipments were properly set. The major communication tools will be the wireless radio and shall be located on the drum side, leading end of the cable and the winch side. They are utilized to control the cable pulling speed and other required communication.
14. Approved drawing or a sketch of the each pulling section which is showing clearly the position of winch, cable drum, calculated pulling forces and side wall pressure at each stage.
15. The required cable pulling speed and tension requirement shall be maintained according to the manufacturer’s specification. If any problem arises during the pulling, the proceedings shall be stopped immediately and restarted only after the problem has been cleared.
16. The pulling speed shall be controlled during the cable pulling and it will be assured by observing the indication of the tension meter.
17. Surplus materials are to be organized by suitable methods and transposition of the phases shall be arranged as\s per the specifications. Coloured tapes (red, yellow and blue) shall be wrapped around the cables for the phase identification at both ends of the cables.
18. Cables shall be arranged in the joint bay and protect it by covering with sand bags/ plywood. If required, cables will be cut and the ends will be protected using heat shrinkable caps to prevent ingress of moisture. Keep the cable ends pointing upwards as an additional safety precaution against the ingress of moisture in case of heavy rain or flooding.
19. After the cable laying the trench shall be filled by stabilized materials with self compaction by watering. While passing the cables through the ducts or pipes or NDRC, bentinite filling shall be adopted.
20. The necessary sheath testing shall be conducted by the approved / competent testing engineers.
21. The high voltage indication or necessary warning tapes shall be fixed along the cable route and required compaction procedures shall be followed as per the manufacturer’s recommendations (see attachment-1). The route markers shall be fixed on regular intervals or as required.
22. The final survey shall be conducted for the additional details and informations needed to prepare the as built drawings.
23. Cable pulling shall be done under strict supervision during the entire period of operation. Safety norms shall be observed and shall stick to the standard requirements of TRANSCO.
•••• Laying of Fibre Optic cables:
1. Manufacturer’s instructions for installation have to be followed up.
2. Loading of cable drum has to be done by using suitable crane. There after it is transported by means of cable trailer/jack. The access up to the trench should be checked before transportation.
TRANSCO Sheet: 28 of 24
SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
3. Location of cable drum should be planned before transportation of cable drum. (Practically could differ at one or two places for easy installation of cable).
4. The cable drums shall be inspected for mechanical or physical damages and check the cables to be used at site prior to the start of the installation process. Any sort of damage shall be noted in the damage report.
5. The whole trench /pit/ shall be inspected before the laying of 4” uPVC pipes.
6. Nylon ropes shall be pulled inside the uPVC pipes using duct cycle.
7. The pipes shall be checked for straightness before filling the dune sand.
8. Fibre Optic cable drum shall be kept at the middle of the span (i.e. equidistant from both the terminals) and cables shall be pulled towards one end manually inside the uPVC pipes using the Nylon ropes.
9. The backfilled trenches are excavated at intervals of every 300m and also at each bend to act as Fibre Optic cable pulling draw pits.
10. Once the cable reaches the terminal end, the remaining cable in the drum shall be looped and coiled in the form of “8”
11. After looping the remaining cables in the drum, pulling of the Fibre optic cable inside the uPVC ducts, as before shall be carried out towards the other terminal end.
12. After pulling of all the Fibre Optic cables, the draw pits are backfilled according to the backfilling procedure
13. The final survey shall be conducted for the additional details and information needed to prepare the as built drawings.
14. Cable pulling shall be done under strict supervision during the entire period of operation. Safety norms shall be observed and shall stick to the standard requirements of TRANSCO.
•••• Cable Terminations
1. Al the necessary materials like the joint kits, long barrel ferrule etc for the jointing shall be used as per the approved TRANSCO specification.
2. The cable termination shall be undertaken only by competent cable jointer from the factory of the manufacturer, approved by the client.
3. Cable termination will be carried out as per the recommendation by the manufacturer (See Attachments- 2, 3 & 4)
4. Unless and other wise permitted the cable terminations shall be carried out only in the presence of the Client/ Consultant representative and a fire warden with extinguisher from the contractor side shall be available throughout the cable termination works.
5. Auxiliary erection structures like tarpaulin tents, free standing structure and LPG cylinder shall be provided. Precautionary measures shall be taken in wet conditions to prevent moisture from getting into the cables during the work.
6. Each cable termination work shall be started and finished on the same day. Phase identification shall be ensured before the commencement of the termination work.
TRANSCO Sheet: 29 of 24
SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
7. The cables shall be tested for moisture, phasing and insulation resistance measurements before the commencement of the cable termination.
8. Deployment of manpower will be as per site requirements practically it can vary. Work will be accomplished keeping in view all the safety requirements.
•••• TOOLS AND EQUIPMENTS
• Lifting crane
• Lifting tackles
• Cable jack
• Cable Trailer
• Cable winch machine with cable socks
• Cable pusher - which can push the cable where high tension appears in the bend areas
• Cable ladder
• Flags
• Cable Rollers
• Cable roller guide
• Cable pulling grips
• Nylon rope
• Wireless sets
• Cable jack / shaft
• Fork Lift
• Knock- out Punch( for cable entry holes)
• Hydraulic cable cutter
• Heat Blower
• Cleaning agent (CRP)
• Hydraulic crimping tool
• Hand crimping tool
• Cable ties
• Nylon ropes
• Blunt shovels
• Scaffoldings
• Standard electrical tools and accessories for electricians
• Personnel Protective Equipments.
TRANSCO Sheet: 30 of 24
SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
12.0 SAFETY AND RISK MANAGEMENT
The contractor will be responsible for all necessary safety measures at all times. All related works will be executed in accordance with the project health and safety plan. The detailed Risk Assessment plans for the transportation, storage, drum handling and installation of 132 kV power cables and FOC is provided as Attachment-7 Safety induction will be conducted at site before the start of the job activities to make all the personnel associated be aware about the necessary safety precautions. Following risk management is performed in general:
• The tools used are suitable and safe to use.
• Supervisor shall be present at work site throughout the execution of the work.
• Scaffoldings are used in the trenches, transformer side and cable cellars for laying and termination of cables.
• Scaffolding when used is confirmed “Tagged for use” by authorized person.
• Safety harnesses are being used by personnel working on high-elevated platform.
• Precautionary warning signs for this type of work place are visibly kept in place.
• Supervisor or Foreman in charge shall ensure the proper equipment for lifting are available with valid test certificates.
• Equipment such as the overhead crane and forklift shall be used with a rate capacity suitable to weight of the load to be lifted.
• Supervisor or Foreman in charge shall ensure the proper equipment for lifting is available with valid test certificates.
• All personnel handling the heavy equipments and associated accessories shall be provided with proper type of gloves.
• The safety officer shall report any untoward incident and stop any unsafe activity.
• The safety officer shall inform the site engineer and the project manager of any violation against HSE and report to the HSE manager.
• Safety Working Procedures which shall be followed during the cable laying include:
� Cable pulling machines (Winch Machine) cable trailer shall be placed in the correct position which is straight to the trench and properly locked to be intact without movement.
� Check the trench which is safe to access for pulling the sling from the winch machine to the cable trailer.
� Cable socks shall be tied properly with the cable end.
� A signal man shall give signal to the winch operator and the workmen near the drum for giving signal by Red and Green colour flags .This is provided to
TRANSCO Sheet: 31 of 24
SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Document No. /Rev.
1F-13-E06-010/0
Subject: METHOD STATEMENT FOR THE INSTALLATION OF
132 kV POWER CABLES & FIBER OPTIC CABLES, LOT-1
Subcontractor
Contractor Client
ABB AG TRANSCO
indicate if any problem is found in the trench especially in the bend and duct area.
� Sand bed for 15 cm shall be done before cable laying and any stones or hard substances which can damage the cable will be removed immediately.
� All personnel shall be in proper PPE’s
� Close supervision shall be arranged during the entire activity period.
13.0 ATTACHMENTS
11.1. Attachment -1
• Standard operation and maintenance manual(19 pages)
11.2. Attachment – 2
• Cable data sheet and cross section details (6 pages)
11.3. Attachment – 3
• GIS cable termination (2 pages)
11.4. Attachment – 4
• Transformer cable termination drawing(2 pages)
11.5. Attachment – 5
• Link boxes drawings / details(3 pages)
11.6. Attachment – 6
• Data sheet for 11 kV sheath voltage limiters(4 pages)
11.7. Attachment – 7
• Transportation and storage of the cables and accessories (2 pages)
11.8. Attachment – 8
• Risk Assessment for the transportation storage and installation of 132 kV Power cables and FOC in Shuweihat pumping station, Lot 1.Rev00 (06 pages dated 06.10.2011
ATTACHMENT - 8
RISK ASSESSMENT
Project: SHUWEIHAT PHASE 2 WATER TRANSMISSION SYSTEM Rev. 00
No Activity Hazards Conditions for Hazards
Realization
ConsequencesSeverity
Likely-
hood
Risk
score
Control Measures Residual
Risk
Remarks
1.1. Transportation of cables
to site
Traffic accident over
turning
Toppling of cable drum,
Obstacles in front of site
access and people working
around while bringing the cable
drum at site
Fatality
Serious personnel injury.
Property damage.
Damage to the truck or third
party if involved in an accident
4 3 12 1.Ensure that the cable drum is
secured properly. 2.Banksman
shall be available all the time with
the trailer. Obstacles shall be
removed for the trailer reach
close to the crane.
L Minimize the risk
using control
measures
1.2. Loading/unloading of
cable drums & concrete
tray
1.Overloading the crane
2.Failure of lifting gear
3.Wrong
signals/confusing
signals/different signal,
different sources
4.Directing load by
hands
5.Moving load
overheads/working/walk
ing in loading area
6.Sling load may hit
employees or materials
7.Falling materials while
lifting 8.Slind or
boom may hit on
electrical lines/other
utilities
Failure of crane / lifting
equipment.-Unsafe act caused
by inexperienced personnel.
Fatality, Personnel injury,
property damages, cable
damage
4 3 12 1.Check crane capacity, check
groung inclination.check rating of
rigging components for intended
loads. SWL to be clearly
indicated.mobile cranes to be
securedly footed.outtriggers to be
checked ,supporting plates to be
used when the ground is loose.
2.Clear the loading aea,
barricaded well and nre the sign
boards and ensure the PPE also.
Cranes to be inspected & tested
by approved third party .All lifting
gear and operator to be certifiued
by 3rd party. safe working load
should be clearly marked on
crane and lifting gear.
3.One banks man/signal
man,training,direct eye
contact.Banks men and crane
operator to be fullt familiar with
hand signals.use standard crans
hand signals for visual lifting
commands.
L Control measures
must be used to
minimize all risk
Control Measures
Date: 06.10.2011
Risk evaluationRisk detection
Activity: INSTALLATION OF132 kV POWER CABLES & FOC in Shuweihat pumping station,LOT-1.
Page 1 of 6 1F-13-E06-010_0_ATT8_Risk_Assessment_Installation_132k_Cables_FOC.xls
ATTACHMENT - 8
No Activity Hazards Conditions for Hazards
Realization
ConsequencesSeverity
Likely-
hood
Risk
score
Control Measures Residual
Risk
Remarks
Control MeasuresRisk evaluationRisk detection
4.Use tag line to direct
load.Ensure the relevant PPEs in
oreder to avoid any injuires.
5.Clear the loading area,PPE.
6.Boom swing area to be
barricaded:unauthorized
personnel not to be allowed.
7.Loose materials shall not be
lifted other than in material
basket.clear the loading area.
8.Rigging and rigginpg plans
checked by competent person
prior to use ans ensure the lifting
area is free from those hazards.
1.3 Slipping, Tripping and
Falling
1. uneven or slippery
work surfaces
2. poor housekeeping,
e.g.. Swarf in the
vicinity of the
equipment, spillage not
cleaned up
3. lack of a proper work
platform 4.
lack of guardrails or
suitable edge protection
5. unprotected holes,
penetrations or gaps
6. poor floor or walking
surfaces, such as the
lack of a slip resistant
surface 7.steep walking
surfaces
8.collapse of the
supporting structure
1. Slippery due to cleaning of
the floor
2. Slips and Trips due the
improper cable management &
other obstacle
3.Path way not clear
4.Slips, trips and falls due to
poor housekeeping.
Personal Injury / Property
damage
2 3 6 1. Proper housekeeping
2. Proper signs at needed
location e.g. "Slippery Surface"
3. Keeping walkway clear of
waste, sharp edges etc.
4. Access ways/walk ways to be
kept clear and free of
obstructions.
5.Good housekeeping practices
need to be maintained
L Minimize the risk
using control
measures
Page 2 of 6 1F-13-E06-010_0_ATT8_Risk_Assessment_Installation_132k_Cables_FOC.xls
ATTACHMENT - 8
No Activity Hazards Conditions for Hazards
Realization
ConsequencesSeverity
Likely-
hood
Risk
score
Control Measures Residual
Risk
Remarks
Control MeasuresRisk evaluationRisk detection
1.4 Manual handling The risk of back injury
increases if the task:
1. is too strenuous, e.g.
it is carried out too
frequently or for too
long a time;
2. involves awkward
postures or movements,
e.g. a bent and/or
twisted trunk, raised
arms, bent wrists, over-
reaching;
3. involves repetitive
handling. slippery
materials/objects
handled.
1. Physical stress
2. Back pain due improper
lifting materials
3. Twisting
4. Object falling from height
5. Improper usage of lifting
equipment
6. Slipping materials from
hands and resulting crushing
injuries.
Sprain/Strain type of injuries,
particularly to neck and back
pain
3 2 6 1. Follow material handling
procedure
2. Use proper lifting equipment
3. Manual handling training
provided.
4. Use proper hand gloves when
required while handling materials.
L Minimize the risk
using control
measures
1.5 Portable Tools (Hand
tools)Cable cutter,
Hydraulic cable cutter,
crimpers, heat blowers
1. Electrical , hand tools
are in working condition
1. Handling wrong tools /
damaged tools
1.Fatality/ Serious personnel
injuries/ Property damage.
2.Laceration or abrasion wound
2 2 4 1.Selection of equipment to
suitable standards.
2. Ensure good insulation.
3. Qualified and trained
electricians are required.
4. Ensure circuits are designed to
be capable of carrying all
foreseeable loads.
5. Protective clothing, hand
protection, foot protection & head
protection shall be used.
L Minimize the risk
using control
measures
Page 3 of 6 1F-13-E06-010_0_ATT8_Risk_Assessment_Installation_132k_Cables_FOC.xls
ATTACHMENT - 8
No Activity Hazards Conditions for Hazards
Realization
ConsequencesSeverity
Likely-
hood
Risk
score
Control Measures Residual
Risk
Remarks
Control MeasuresRisk evaluationRisk detection
1.6 Installation of cable
supports -trays,
Ladders in the cable
cellar. Scaffolding for
working at height
Working at height ,
cable cutting, sharp
edges,
Falling from the height,
electrical shock, Material falling
.
1.Fatality
2. Serious injury to personnel
3. Material damage
5 2 10 1.Competent Electricians are to
be used for the activity.
2.Mobile Scaffolding of Approx 3
meters to be installed on the
platform and to be secured on the
permanent Hand rails and the
beam by using competent
scaffolders. To be inspected and
tagged by the supervisor before
using by the Electricians.
3.Scaffolding to be shifted to
each beams and the activities to
be continued same way.
4.Only authorized people shall be
available at job location.
5.A safe distance must be
maintained between the Bus Bar
and Operation area and covered
with non conducting materials.
6.Always the area should be neat
and tidy and do not spread
materials as it is a live area.
7.The required PPEs such as
insulated hand gloves are to be
worn and do not use loose
clothes..
L follow the all control
measures
Page 4 of 6 1F-13-E06-010_0_ATT8_Risk_Assessment_Installation_132k_Cables_FOC.xls
ATTACHMENT - 8
No Activity Hazards Conditions for Hazards
Realization
ConsequencesSeverity
Likely-
hood
Risk
score
Control Measures Residual
Risk
Remarks
Control MeasuresRisk evaluationRisk detection
1.7 Excavation 1.Collapse of trench
sides
2.Material falling onto
people working in the
excavation
3.People & vehicles
falling into excavation
4.People being struck
by plant
5.Contact with
underground services
6.Biological hazards:
Rubbish and
waste Drains/sewers
Leptospirosis
7.Flooding of
excavations
Unsafe act caused by
inexperienced personnel.
Improper housekeeping.
No barriers, sign boards.
Injury to the personnel, cable
damage
4 3 12 1.Sides of excavation, deeper
than 2m to be stepped
1m increments with 45 degree
slope or suitably shored.
Support sides in suitable way.
2.Provide guard rails, Do not
keep any material close to
excavation, Warning tape to be
placed around all
excavations less than 2mt deep,
Metal or wooden
barriers to be placed around all
excavations deeper than 2mt.
3.Stop blocks to prevent vehicles
over-running, Keep
vehicles away from excavations ,
prevent vehicles
over-running, stop signs, Metal or
wooden barriers to
be placed around all excavations
deeper than 2
meters
L Use control
measures to
minimize all risk
4.High visibility PPE, Keep
workers separate from moving
plant, Make proper awareness.
Ensure the reverse
alarm, revolving lights for
machineries
5.Use cable locators to trace in
services.Hand dig if in doubt.
Existing services to be located
and clearly marked before
beginning excavations,
Approved existing services layout
drawing to be
distributed to all concerned
parties through controlled
document distribution
6.Prevent contact, Make
awareness, Existing services
tobe located and clearly marked
before beginning
excavations
7.Prevent entering trench while
flooding.Use dewatering system
and support sides.
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ATTACHMENT - 8
No Activity Hazards Conditions for Hazards
Realization
ConsequencesSeverity
Likely-
hood
Risk
score
Control Measures Residual
Risk
Remarks
Control MeasuresRisk evaluationRisk detection
1.8 Backfilling 1.Backfilling trench
while worker inside
2.Usage of compactor
machine 3.working
near excavator machine
working
4.Working in hot
weather
Unsafe act caused by
inexperienced personnel.
Lake of supervision.
Injury to the personnel, cable
damage
2 3 6 1.Avoid backfilling while anyone
inside the trench.
Arrange closed supervision.
Make proper awareness
2.Reduce exposure time.
Shifting of personnel.
3.Increase distance and reduce
exposure to noise, use
ear muffs, awareness, PPE, Use
less noisy excavator
and do regular inspection and
maintenance.
4.Increase distance and reduce
exposure to noise, use
ear muffs, awareness, PPE, Use
less noisy excavator
and do regular inspection and
maintenance.
L
Follow all the
control measures
1.9 Cable laying Pulling 1.Pulling cable to
trench/out of trench
2.Working in vicinity to
live cable
3.Slipping during laying
cables/ removing cables
4.Flooding of trench
Unsafe act caused by
inexperienced personnel.
No awarness, lake of
supervision
Improper techniques and
wrong procedures
1. Serious injury to the
personnel.
2. Injury/ Fracture to the
personnel.
4 3 12 1.Follow manual handling
techniques. Machines the
work, proper awareness,
selection of man power.
Ensure PPE's
2.Avoid connection with live cable
/ water in trench,
PPE, Awareness, ensure and
check the up dated
drawings.
3.Avoid walking on the trench
sides, proper sign boards,closed
supervision, watch steps, PPE
4.Prevent entering the trench
while flooding, use
dewatering system and support
sides, closed
supervision
L Use control
measures to
minimize all risk
1.10 portable Tools (Hand
tools)Cable cutter,
Hydraulic cable cutter,
crimpers, heat blowers
1.Removing
insulation/jacket of
cables using sharp
blade
2.Working in vicinity to
live cable
3.Jacketing cable
junction using gas flame
Unsafe act caused by
inexperienced personnel.
No awarness, lake of
supervision
Improper techniques and
wrong procedures
Injury to personnel, cable
damage, fatality
3 3 9 1.Use of proper PPEs
2.Availability of fire fighting
equipments
3.Maintain the work area clean,
proper housekeeping 4.Avoid
contact with fire and live cables.
5.Proper training should be given
and only experienced person can
undertake the work.
L Use control
measures to
minimize all risk
Page 6 of 6 1F-13-E06-010_0_ATT8_Risk_Assessment_Installation_132k_Cables_FOC.xls