Tech Spec 132KV Line

8/12/2019 Tech Spec 132KV Line

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HARYANA VIDYUT PRASARAN NIGAM LIMITED

BIDDING DOCUMENT NO. WB-014

(PACKAGE B )

TECHNICAL SPECIFICATION

OF

132 kV S/C LINES (NEW DESIGN)

AND

D/C LINES WITH (KRR DESIGN)

(VOLUME-II, PART-2)

Chief Engineer/ MM,Haryana Vidyut Prasaran Nigam Limited

Shakti Bhawan, Sector-6Panchkula-134109Tel/Fax: 0172-2591742

April-2012


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SECTION VI (PART-II)


CONTENTS

CHAPTER-I - TECHNICAL SPECIFICATION FOR TOWERS

CHAPTER-II GENERAL TECHNICAL REQUIREMENTS

CHAPTER-III (A)-TECHNICAL SPECIFICATION OF CONDUCTORAND EARTHWIRE.

CHAPTER-III (B)-TECHNICAL SPECIFICATION OF DISCINSULATORS.

CHAPTER-III (C)-TECHNICAL SPECIFICATION OF SILICONERUBBER POLYMER INSULATORS.

CHAPTER-III (D)-TECHNICAL SPECIFICATION OF BUS POSTINSULATORS.

CHAPTER-III (E)-TECHNICAL SPECIFICATION OF HARDWAREFITTING AND ACCESSORIES.

CHAPTER-IV - TECHNICAL DATA/INFORMATION (GTP) TO BESUBMTTED WITH THE BID


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SECTION-VI

(PART-II)

CHAPTER-I


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SECTION-VI (CHAPTER-I )


CONTENTS

Clause No. Description Page No.

1.1 GENERAL INFORMATION AND SCOPE 1

1.2 DETAIL OF TRANSMISSION LINE ROUTES AND 3TERRAIN

1.3 RESULTS OF SURVEYS 31.4 ACCESS TO THE LINE AND RIGHT OF WAY 31.5 DETAILED SURVEY, OPTIMISATION OF TOWER 3

LOCATION1.6 ENVIRONMENTAL CONDITIONS 81.7 TECHNICAL DATA 91.8 STATUTORY REGULATIONS AN STANDARDS 91.9 QUALITY ASSURANCE, INSPECION AN TESTING 101.10 TECHNICAL PARAMETERS OF 132 KV LINE 112.0 DETAIL OF LINE MATERIAL FOR 132 KV LINE 112.1 PARTICULAR OF CONDUCTOR AND EARTHWIRE 122.2 PARTICULAR OF INSULATOR STRING WITH 12

STANDARD DISC INSULATIORS2.3 INSULATOR STRING HARDWARE 132.4 ACCESSORIES FOR CONDUCTOR AND 14

EARTHWIRE3.0 TRANSMISSION TOWERS 143.1 GENERAL DESCRIPTION OF THE TOWER 143.2 TYPE OF TOWER 143.3 SPANS AND CLEARANCES 173.4 MAXIMUM TENSION 193.5 MATERIALS 243.6 TOWER ACCESSORIES 253.7 TOWR FABRICALTION 263.8 GALVANISING 283.9 EARTHING 28

3.10 INSPECTION AND TESTS 283.11 TESTING SOF TOWERS 323.12 STANDARDS 364.0 TOWER FOUNDATION 404.3 TYPEOF SOIL 404.4 FOUNDATION TYPES 434.6 PROPERTIES OF CONCRETE & REINFORCEMENT444.7 UNIT RATES AND MEASUREMENT 464.8 CONSTRUCTION OF TOWER FOUNDATIONS 464.9 SETTING OF STUBS 474.10 STUB SETTING TEMPLATES 47

4.11 MIXING, PLACING AND COMPACTING OF 47CONCRETE


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4.12 BACK-FILLING AND REMOVAL OF STUB 48TEMPLATE

4.14 PROTECTION OF TOWER FOOTING 494.14 FIELD QUALITY CONTROL PLAN 495.0 TOWER ERECTION, STRINGING AND 50

INSTALLATION OF LINE MATERIAL5.1 GENERAL 505.2 TREATMENT OF MINOR GALVANISING DAMAGE 50

5.3 ASSEMBLY 505.4 TIGHTENING ANDPUNCHING OF BOLTS & NUTS 515.5 INSULATOR HOISTING 515.6 HANDLING OF CONDUCTOR AND EARTHWIRE 515.7 STRINGING OF CONDUCTOR & EARTHWIRE 535.8 JOINTING 535.9 SAGGING-IN-OPERATION 535.10 TENSIONING AND SAGGING OF CONDUCTOR 54

AND EARTHWIRE5.11 CLIPPING IN 545.12 FIXING OF CONDUCTOR ANDEARTHWIRE 54

ACCESSORIES5.13 REPLACEMENT 545.14 PERMITTED EXTRA CONSUPTION OF LINE 55

MATERIALS5.15 FINAL CHECKING, TESTING AND COMMISSIONING 556.1 GENERAL TECHCIAL CONDITIONS 566.2 ENGINEERING DATA 566.3 DRAWINGS 566.4 DESIGN IMPROVEMENTS 586.5 DESIGN COORDINATION 586.6 DESIGN REVIEW MEETING 58

6.7 PACKING 587.1 ERECTION CONDITIONS 597.2 REGULATION OF LOCAL AUTHORITIES AND 59

STATUTES7.3 BIDDERSS FIELD OPERATION 597.4 PROGRESS REPORT 597.5 MAN-POWER DEPLOYMENT REPORT 597.6 FIRE PROTECTION 607.7 SECURITY 607.8 MATERIALS HANDLING AND STORAGE 60

7.9 CONSTRUCTION MANAGEMENT 617.10 FIELD OFFICE RECORDS 617.11 PROTECTION OF PROPERTY AND 61

BIDDERS LIABILITY7.12 PROTECTIONS OF MOUNMENTS AND 62

REFERENCE POINTS7.13 WORK AND SAFETY REGULATIONS 627.14 FOREIGN PERSONNEL 647.15 CODE REQUIREMENTS 65


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SECTION-VI(CHAPTER-I)

TECHNICAL SPECIFICATIONS1.0 General Information and scope1.1 Scope:1.1.1 This specification covers detailed survey, profiling & Check survey, tower

spotting/optimization of tower location, soil resistivity measurements andGeotechnical investigation, New tower Design, Proto-testing, fabrication and

supply of all 132 kV S/C line towers of 0.4sq ACSR ZEBRA as per BiddersDesign including bolts, nuts and washers, hanger, D-shackle and all type of toweraccessories like phase plate, circuit plate, number plate, danger plate, anti-climbing device etc. Design, selecting type of foundation for different towerheights and casting of foundation for tower footing, erection of towers, tackwelding of bolts and nuts including supply and application of zinc rich paint, towerearthing, fixing of insulator string, stringing of conductors and earthwires alongwithall necessary line accessories and testing and commissioning of the erected132kV S/C lines with 0.4sq ACSR Zebra.

1.1.2 This specification also covers the Design, fabrication and supply of Gantry

structure for 132kV S/C line of 0.4sq ACSR Zebra under crossing the variousexisting 220kV and 400kV transmission lines including bolts, nuts and washers,hanger, D-shackle and all type of accessories like phase plate, circuit plate,number plate, danger plate, anti-climbing device etc. Design, selecting type offoundation, casting of foundation for gantry footing, erection of gantries, tackwelding of bolts and nuts including supply and application of zinc rich paint, gantryearthing, fixing of insulator string, stringing of conductors and earthwires alongwithall necessary line accessories. All the clauses in the specification will be relevantfor the gantry structures also unless stated otherwise.

1.1.3 This specification also covers detailed survey, profiling & Check survey, tower

spotting/optimization of tower location, soil resistivity, measurements andGeotechnical investigation, fabrication and supply of all 132 kV D/Ctransmission line towers as per KRR Design of HVPNL including bolts, nutsand washers, hanger, D-shackle and all type of tower accessories like phase plate,circuit plate, number plate, danger plate, anti-climbing device etc., selecting type offoundation for different tower heights and casting of foundation for tower footing ,erection of towers, tack welding of bolts and nuts including supply and applicationof zinc rich paint, tower earthing, fixing of insulator string, stringing of conductorsand earthwires alongwith all necessary line accessories and testing andcommissioning of the erected 132kV D/C transmission lines .

1.1.4 This specification also covers the fabrication and supply of Gantry structurefor 132kV D/C lines as per KRR Design of HVPNL under crossing the variousexisting 220kV and 400kV transmission lines including bolts, nuts and washers,hanger, D-shackle and all type of accessories like phase plate, circuit plate,number plate, danger plate, anti-climbing device etc., selecting type of foundation,casting of foundation for gantry footing, erection of gantries, tack welding of boltsand nuts including supply and application of zinc rich paint, gantry earthing, fixingof insulator string, stringing of conductors and earthwires alongwith all necessaryline accessories. All the clauses in the specification will be relevant for the gantrystructures also unless stated otherwise.

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1.1.5 This specification includes the supply of Anti-fog type insulator or Polymer SiliconeRubber insulator and their hardwares, conductor and earthwire, earthwiresuspension and tension clamps and all other line accessories for conductor &earthwire i.e. mid-span compression joints for conductor and earthwire, repairsleeve for conductor, vibration damper for conductor and earthwire, flexible copperbond which shall be supplied by the bidder during execution of the project. The

bidder shall clearly indicate in the offer the sources from where he proposes toprocure the raw materials and the components. The type of insulator (whetherAnti -Fog disc type or Sil icone Rubber Polymer type) to be used shall beclearly indicated in the bid by the bidder.

All the raw materials such as steel, zinc for galvanizing, reinforcement steel andcement for tower foundation, coke and salt for tower earthing etc. ,bolts, nuts,washers, D-shackles, hangers, links, danger plates, phase plate, number plate,circuit plate, anti climbing devices etc, required for tower manufacture and erectionshall be included in the bidders scope of supply. Bidder shall clearly indicate in theoffer, the sources from where he proposes to procure the raw material and the

components.

1.1.6 The entire stringing work of conductor and earthwire shall be carried out bystandard stringing practice. The bidder shall indicate in the offer, the detaildescription of the procedure to be deployed for stringing operation.

1.1.7 The following 132 kV transmission lines are included in the scope of the bidder forthis package.

S.No. Name of Line Tentative Lengthof Line (approx.)

1. 132 KV D/C Line from 400kV S/Stn. Deepalpur to 132kVS/Stn. Tajpur with 0.4sq ACSR.

9.540 Km

2. 132 KV S/C line on S/C tower from 220kV S/stn. Batta toDhanouri with ACSR 0.4sq Zebra.

20.00 Km

3. 132 KV S/C line on S/C tower from 220kV S/stn. Batta toPadla with ACSR 0.4sq Zebra.

18.090 Km

4. 132 KV S/C line on D/C towers from 220kV S/Stn. Batta to132kV S/Stn. Rajound with 0.4sq ACSR

28.060 Km

5. 132 KV S/C line on D/C towers from 132kV S/Stn.Dhudiawali to Kariwala with 0.4sq ACSR.

14.00 Km

The tentative bill of quantities for this line is indicated in the schedule of quantitiesalongwith Annexure-I B of this document. However, any item(s) though notspecifically mentioned, but which are required to make the line(s) complete in allrespect for safe, efficient, reliable and trouble free operation shall be deemed tosupplied and erected by the Bidder.

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1.1.8 LOCATION DETAILS:

The above line will be laid in the state of Haryana.

1.1.8 The contractor shall have to erect the 132 kV transmission lines completely up toterminal arrangements.

1.1.9 The entire work shall be executed by the successful bidder in compliance ofEnvironment Management Plan (EMP) and Resettlement & RehabilitationAction Plan (RRAP) reports. This shall be taken into account in the bid.

1.2 Detail of Transmission Line Routes and Terrain.

The transmission line under this package will be running almost through NCRarea, plain and irrigated farm land/cultivated area.

Tentative route alignment maps of transmission lines covered under thesepackage indicating the general topography and major crossings like river, powerlines, Railways line & Roads are enclosed with this specification for biddersreference. There are few small rivers/distributes/Nalas etc. to be crossed by the

line in the above package.

1.3 Result of surveys

The details collected through tentative surveys viz line route, general soilcharacteristics, crossings, accessibility and infra-structure details are attached atAnnexure-IB for the bidders reference.

1.4 ACCESS TO THE LINE AND RIGHT TO WAY

Right of way and way leave clearance shall be arranged by the HVPN inaccordance with work schedule. HVPN will secure way leave and right of way inthe forest area, if any.

1.5 DETAILED SURVEY, OPTIMISATION OF TOWER LOCATION

1.5.1 The HVPNL has carried out the tentative route survey of the transmission linesunder this package. However, detailed survey including profiling, Check survey,tower optimization and spotting shall be carried out by the successful bidder.

The Bidder shall finalize complete detailed surveys including any changes and willsubmit the route plans within 2 months (60 days) of issue of LoI. The soilinvestigation for the obligatory points shall be carried out by the successful bidder.

The bidder is strongly advised to visit and examine the site of works and itssurroundings and obtain for himself at this own responsibility and expense, allinformation regarding terrain of the proposed line, line route, general sitecharacteristics, crossing, accessibility, infrastructure details etc. The cost of visitingthe site shall be at bidders own expense. The HVPN will assist the interestedbidder to see & inspect the site of works. For this purpose bidders are requested tocontract.

Chief Engineer/TS Chief Engineer/TS,HVPNL, Panchkula. HVPNL, Hisar.TEL. No. 0172-2560748 TEL. No. 01662-220794

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1.5.2 The bidder should note that HVPN will not furnish the topographical mapsprepared by survey of India but will make available any assistance that may berequired in obtaining the topographical maps.

1.5.3 Soil resistivity along the route alignment, shall be measured in dry weather by four-electrode method keeping inter electrode spacing of 50 metres. For calculating soilresistivity, formula 2PI ar (where a =50 metres and r=megger reading in ohms,PI=3.14) shall be adopted. Measurement shall be made at every 2 to 3 km along

the route of transmission lines. In case soil characteristic changes within 2 to 3 km,the value shall also have to be measured at an intermediate locations. The meggerreading and soil characteristics shall also be indicated in the soil resistivity results.

1.5.4 ROUTE MARKING

At the starting point of the commencement of route survey, an angle iron spike of65x65x6 mm section and 1000 mm long shall be driven firmly into the ground toproject only 150 mm above the ground level. A punch mark on the top section ofthe angle iron shall be made to indicate location of the survey instrument. Teakwood peg 50x50x650 mm size shall be driven at prominent position at intervals of

not more than 750 meter along the transmission line to be surveyed upto the nextangle point. Nails of 100mm wire should be fixed on the top of these pegs to showthe location of instrument. The pegs shall be driven firmly into the ground to project100 mm only above ground level. At angle position stone/concrete pillar withHVPNL marked on them shall be put firmly on the ground for easy identification.

1.5.5 ROFILE PLOTTING & TOWER SPOTTING

From the field book entries, the route plan with enroute details and level profileshall be plotted and prepared to scale of 1:2000 horizontal & 1:200 vertical on 1.0,

10 mm squared paper as per approved procedure. Reference levels at every 20metres along the profile are also to be indicated on the profile besides, reducedlevels at undulations. Areas along the profile, which, in the view of the contractor,are not suitable for tower spotting, shall also be clearly marked on the profile plots.If the difference in levels be too high, the chart may be broken up according torequirement. A 10mm overlap shall be shown on each following sheet. The chartshall progress from left to right. Sheet shall be 594 mm wide in accordance withthe IS. For as built profile these shall be in A1 size.

1.5.6 TOWER LOCATION

1.5.6.1 SAG TEMPLATE

Necessary data in respect of conductor, earthwire and insulator have been given inthe specification. On the basis of these, the Bidder shall prepare the sag templatedrawing, tower spotting data, sag tension calculations of New towers design of132kV S/C of 0.4sq. For 132kV D/C lines with KRR Design, necessary Sag-Tension calculations with tower spotting data shall be provided by HVPNL. On thebasis of these, the Bidder shall prepare the sag template drawing. Sag templateprepared based on the approved sag-template curve drawing shall only be usedfor tower spotting on the profiles. Two numbers of the approved template,prepared on rigid transparent plastic sheet, shall be provided by the Bidder

to the HVPNL for the purpose of checking the tower spotting of both 132kVS/C & D/C lines. The templates shall be on the same scale as that of the profile.

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1.5.6.2 TOWER SPOTTING

With the help of approved sag template and tower spotting data, tower locationsshall be marked on the profiles. While locating the towers on the profile sheet,the following shall be borne in mind.

a) SPAN

The number of consecutive spans between the section points shall not exceed

15. A section point shall comprise of tension point as under as applicable: -

For D/C line DB type or DC type or DD type tower as applicable

For S/C line B type or C type or D type tower as applicable

b) EXTENSION

An individual span shall be as near to the normal design span as possible. Incase an individual span becomes too short with normal supports on account ofundulations in ground profile, one or both the supports of the span may be

extended by inserting standard body extension designed for the purposeaccording to technical specification.

c) Loading

There shall not be any upward force on Suspension towers under normal workingconditions and the Suspension towers shall support at least the minimum weightspan as provided in the designs. In case uplift is unavoidable, it shall beexamined if the same can be overcome by adding standard body extensions tothe towers failing which tension towers designed for the purpose shall beemployed at such positions.

e) ROAD CROSSING

At all important road crossings, the towers shall be fitted with normal suspensionor tension insulator strings depending on type of tower, but the ground clearanceat the highest point of the roads under maximum temperature and still air shall besuch that even with the conductor broken in adjacent span, ground clearance ofthe conductor from the road surfaces will not be less than 6.100 meters . At allNational Highways, tension towers with double insulator strings on crossing sideshall be used.

d) RAILWAY CROSSINGS

All the Railway crossings coming enroute the transmission line have alreadybeen identified by the HVPN. At the time of detailed survey, the Railwaycrossings shall be finalized as per the regulation laid down by the RailwayAuthorities. The following are the important features of the prevailing regulations(revised in 1987):

i) The crossing shall be supported on DD/D type tension towers only (as the casemay be) on either side and Double tension insulator string shall be used on

both the towers on the side of the crossing.

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ii) The crossing shall normally be at right angle to the Railway track.

iii) The minimum distance of the crossing tower shall be at least equal to theheight of the tower plus 6 metres away measured from the center of thenearest Railway track.

iv) No crossing shall be located over a booster transformer, traction switching

station, traction sub-station or a track cabin location in an electrified area.

v) Minimum ground clearance above Rail level of the lowest portion of anyconductor under condition of maximum sag shall be maintained as per latestRailway regulations amended from time to time.

vi) The approval for crossing Railway track shall be obtained by the HVPN fromthe Railway Authorities, however six copies of profile and plan, tower andfoundation design and drawings, required for the approval from the RailwayAuthorities shall be supplied by the contractor to the HVPN.

f) River Crossing:

In case of major river crossing, towers shall be of suspension type and theanchor towers on either side of the main river crossing shall be DD/D typetower. For navigable river, clearance required by navigation authority shall beprovided. For non-navigable river, clearance shall be reckoned with respect tohighest flood level (HFL).

g) POWER LINE CROSSINGS

Where the line is to cross over another line of the same voltage or lowervoltage, towers with suitable extensions shall be used. Where the line is tocross under the power lines, gantries shall be used. Provisions to prevent thepossibility of its coming into the contact with other overhead lines shall be madein accordance with Indian Electricity Rules,1956. In order to reduce the heightof the crossing towers, it may be advantageous to remove the ground wire ofthe line to be crossed (if this is possible and permitted by the owner of the lineto be crossed). All the works related to the above proposal shall be deemed tobe included in the scope of the contractor except if modifications are required toline below, in which case, the conditions to be agreed upon. Suitable Extensionfor towers over 11kV line crossing shall be used, where requisite electrical as

per I.E. rules is not available.

h) TELECOMMUNICATION LINE CROSSING

The angle of crossing shall be as near to 90oas possible. However, deviation to

the extent of 30omay be permitted under exceptionally difficult situations.

When the angle of crossing has to be below 60o, the matter will be referred to

the authority incharge of the telecommunication system. On a request from thecontractor, the permission of the telecommunication authority may be obtainedby the HVPN. Also, in the crossing span, power line support will be as near the

telecommunication line as possible, to obtain increased vertical clearancebetween the wires.

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i) DETAILS ENROUTE

All topographical details, permanent features, such as trees, building etc. 13.5 mon either side of the alignment for 132kV line shall be detailed on the profile plan.

1.5.7 CLEARANCE FROM GROUND, BUILDING, TREES ETC.

Clearance from ground, buildings, trees and telephone lines shall be provided inconformity with the Indian electricity rules, 1956 as amended up to date.

1.5.8 The tree cutting shall be the responsibility of the HVPN except for that requiredduring survey. However, the contractor shall count, mark and put proper numberswith suitable quality of paint at his own cost on all the trees that are to be cut bythe HVPN at the time of actual execution of the work. Contractor may please notethat HVPN shall not pay any compensation for any loss or damage to theproperties or for tree cutting due to contractors work.

1.5.9 Any way leave, which may be required by the contractor, shall be arranged by the

HVPN as required by work programme.

1.5.10 To evaluate and tabulate the trees and bushes coming within 13.5 m on either sideof the central line alignment, the trees will be numbered and marked with qualitypaint serially from angle point 1 onwards and the corresponding number will bepainted on the stem of trees at a height of 1 meter from ground level. The tree listshould contain the following: -

a) Girth (circumference) measured at a height of 1 meter from ground level.

b) Approximate height of the tree with an accuracy of 2 metres.

c) Name of the type of the species/tree.

d) The bushy and under growth encountered within the 27 m belt should also beevaluated with its type, height, girth and area in square metres, clearlyindicating the growth in the tree/bush statement.

1.5.11 Payment of compensation toward the clearances etc. will be the responsibility ofthe HVPN.

1.5.12 PRELIMINARY SCHEDULE

The profile sheets, duly spotted, alongwith preliminary schedule indicating type oftowers, type of foundations, wind span, weight span, angle of deviation, river orroad crossing and other details shall be submitted for the approval of the HVPN.After approval, the contractor shall submit six more sets of the approved reportsalong with one set of reproducible of final profile drawings to the HVPN for recordpurpose.

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1.5.13 DETAILED SURVEY OF TOWER LOATION

1.5.13.1. The detailed survey shall be conducted to locate and peg mark the towerpositions on ground conforming to the approved profile and tower schedule. In theprocess, it is necessary to have the pit centers marked according to theexcavation marking charts. The levels, up or down of each pit center with respectto the center of the tower location shall be noted and recorded for determining theamount of earthwork required to meet the approved design parametres.

1.5.13.2 Changes, if required, after detailed survey in the preliminary tower schedule shallbe carried out by the contractor and he shall thereafter submit a final towerschedule for the approval of HVPN. The tower schedule shall show position of alltowers, type of towers, span length, type of foundation for each towers and thedeviation at all angles as set out with other details.

1.5.14 CHECK SURVEY OF TOWER LOATION

1.5.14.1 The check survey shall be conducted to locate and peg mark the tower positionson ground conforming to the approved profile and tower schedule. In the

process, it is necessary to have the pit centers marked according to theexcavation marking charts. The levels, up or down of each pit center with respectto the center of the tower location shall be noted and recorded for determiningthe amount of earthwork required to meet the approved design parametres.

1.5.14.2 Changes, if required, after check survey in the preliminary tower schedule shallbe carried out by the Bidder and he shall thereafter submit a final tower schedulefor the approval of HVPNL. The tower schedule shall show position of all towers,type of towers, span length, type of foundation for each towers and the deviationat all angles as set out with other details.

1.6 ENVIRONMENTAL CONDITIONS

1.6.1 GENERAL CLIMATIC CONDITIONS

The area is in the extreme climate belt. Monsoons are generally active from themonths of July to September. The working season shall be approximately ninemonths per year.

The maximum temperature during summer shall be of the order of 50oC and theminimum temperature shall be of the order of -2

oC. Normal everyday temperature

is 32

0

C.

1.6.2 Design and Workmanship ( for New Tower Design)

The Contractor shall design the towers and foundations of 132kV S/C towers of0.4sq ACSR Zebra in accordance with clause 3, 4 of this technical specification.

1.6.3 Foundation Data ( for New Tower Design)

For the purpose of designing various type of foundations, properties of Earth arefurnished in clause 4 of specifications of tower foundations.

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1.6.4 Load on Tower ( for New Tower Design)

The 132 kV transmission lines under the scope of this specification are passingthrough Wind Zone 4 as per IS-875-1987 with basic wind speed of 47m/sec. Basicwind speed is based on peak gust velocity averaged over a short time interval ofabout 3 seconds corresponding to a mean height of 10 meters above mean ground

level.

For the purpose of computation of wind load, electrical clearance etc., bidders arerequested to refer relevant sub-clauses under Clause -3 and -5 and Table underClause -3 of this technical specifications.

1.7 TECHNICAL DATA

Bidders shall furnish all technical data as per relevant schedules in five (5) copies.

1.8 STATUTORY REGAULATION AND STANDARDS

1.8.1 STATUTROY REGULATIONS

The contactor is required to follow local statutory regulations stipulated inelectricity (supply) Act. 2003, Indian Electricity rules 1956 as amended and otherlocal rules and regulations referred to in this specifications.

1.8.2 REFERECNE STANDARDS

1.8.2.1 The codes and/or standards referred to in specification shall govern. In all cases

wherever such references are made. In case of a conflict between such codesand/or standards, and the specifications, latter shall govern. Such codes and/orstandards, referred to shall mean the latest revisions, amendments/changesadopted and published by the relevant agencies.

1.8.2.2 Other internationally acceptable standards, which ensure equivalent or betterperformance than those specified shall also, be accepted.

1.9 QUALITY ASSURANCE, INSPECTION AND TESTING

1.9.1 QUALITY ASSURANCE

1.9.1.1 To ensure that the supply and services under the scope of this contractwhether manufactured or performed within the contractors works or at his sub-contactors premises or at site or at any other place of work are in accordancewith the specifications, the contractor shall adopt suitable quality assuranceprogramme to control such activities at all points necessary. Suchprogrammme shall be outlined by the contractor and shall be finally acceptedby the HVPN after discussions before the award of the contract. A qualityassurance programme of the contractor shall generally cover but not limited tothe following:

a) His organization structure for the management and implementation of theproposed quality assurance programme.

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b) Documentation control system.

c) Qualification data for bidders key personnel.

d) The procedure for purchases of materials parts/components and selectionof sub-contractors services including vendor analysis, source inspection,incoming raw material inspection, verification of material purchase etc.

e) System for shop manufacturing including process controls and fabricationand assembly controls.

f) Control of non-conforming items and system for corrective action.

g) Control of calibration and testing of measuring and testing equipments.

h) Inspection and test procedure for manufacture.

i) System for indication and appraisal of inspection status.

j) System for quality audits.

k) System for authorising release of manufactured product to the HVPN.

l) System for maintenance of records.

m) System for handing storage and delivery.

n) A quality plan detailing out the specific quality control procedure adopted forcontrolling the quality characteristics relevant to each item of supply.

The quality plan shall be mutually discussed and approved by the HVPN afterincorporating necessary corrections by the contractor as may be required.

1.9.1.2 QUALITY ASSURANCE DOCUMENTS

The contractor shall be required to submit all the quality assurance documentsas stipulated in the quality plan at the time of HVPNs inspection of material.

1.9.1.3 The HVPN, through his duly authorized representatives, reserves the right to

carry out quality audit and quality surveillance of the systems and procedures ofthe contractors/ his sub-contractors quality management and control activities.

1.9.2 INSPECTION,TESTING AND INSPECTION CERTIFICATE

The provision of the clause regarding inspection, testing and inspectioncertificate as described in conditions of contract shall be applicable to the supplyand erection portion of the works. The HVPN shall have the right to re-inspect athis expenses any material though previously inspected and approved by him atthe contractors works, before and after the same are erected at site. If followingthe latter, material is found defective, then the contractor shall bear the cost of

this inspection and reinstatement according to specification.

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1.10 TECHNICAL PARAMETRES OF 132KV LINE

Electrical system data

a) Nominal voltage 132 kVb) Maximum system voltage 145 kVc) BlS (Impulse) 650 KV (peak)

d) Power frequency withstand voltage (wet) 275 KV (rms)

2.0 DETAILS OF LINE MATERIAL FOR 132 KV LINE

2.1.1 Particulars of Conductor and Earthwire:-

Sr. No Particulars Conductor Earthwire

1 Type ACSR Zebra ACSR Panther G.S.S

2 Stranding andwire diameter

Aluminium

Steel

mm

mm

54/3.18

7/3.18

30/3.00

7/3.00

-

7/3.153 Total sectional

areaSq. mm 484.5 261.50 54.55

4 Approximateoverall diameter

mm 28.62 21.00 9.45

5 Approximatemass

Kg/km 1621 974 428

6 Calculated DCresistance at 20deg. Centigrade

(Max.)

ohm/km .06868 0.140 3.375

7 Approximatecalculatedbreaking load

kN 130.32 89.67 56

8 Modulus ofelasticity

Kg/mm 7034 8158 19361

9 Co-efficient oflinear expansion

Perdeg. c

19.30x10-

17.8x10-

11.5x10-

10 Mass of zinccoating

Gm/sq.m

260 260 240

11 Configuration of

conductor

D/C line

S/C line

Near vertical

on each sideof tower

Triangular

Near vertical

on each sideof tower

-

12 Location ofearthwire - -

Onecontinuousearthwire torunhorizontallyabove theconductors

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2.1.2 PARTICULARS OF INSULATOR STRINGS WITH A/F TYPE DISC INSULATORSFOR 132KV LINES WITH ZEBRA CONDUCTOR :

SrNo

Particulars Singlesuspensionstring

Doublesuspensionstring

Doubletensionstring

Singletensionstring

Single pilotsuspensionstring

1 No. of standardinsulator discs

1x9 2X9 2x10 1x10 1x10

2 Size of disc mm 255x145 255x145 280X145 280x145 255x1453 E&M strength of

each insulatordisc

70 70 120 120 70

4 Size ofdesignation ofpinball shankmm

16 16 20 20 16

5 Minimumcreepage

distance of eachdisc mm

432 432 432 432 432

2.1.3 PARTICULARS OF INSULATOR STRINGS WITH A/F TYPE DISC INSULATORSFOR 132KV LINES WITH PANTHER CONDUCTOR :

SrNo

Particulars Singlesuspensionstring

SinglesuspensionPilot

Doubletensionstring

Single tensionstring

1 No. of standard

insulator discs

1x9 1x9 2x10 1x10

2 Size of disc mm 255x145 255x145 255x145 255x145

3 E&M strength ofeach insulatordisc

70 70 90 90

4 Size ofdesignation ofpinball shankmm

16 16 16 16

5 Minimum

creepagedistance of eachdisc mm

432 432 432 432

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2.1.4 PARTICULARS OF SILICONE POLYMER INSULATOR STRINGS FOR ACSRPANTHER:-SrNo

TYPE ofString

Size ofCompositeInsulator(mm)

Min.CreepageDistance(mm)

No. ofIndividualunits perstring(Nos.)

EMstrengthofInsulatorUnit (KN)

Mechanicalstrength ofInsulatorstringalongwithHardware

fittings(kN)

1 SingleSuspension

20X1305 4495 1X1 70 70

2 Single pilotSuspension

20X1305 4495 1X1 70 70

4 SingleTension

20X1450 4495 1X1 90 90

5 DoubleTension

20X1450 4495 2X1 2X90 2X90

2.1.5 PARTICULARS OF SILICONE POLYMER INSULATOR STRINGS FOR ACSRZEBRA :-

SrNo

TYPE ofString

Size ofCompositeInsulator(mm)

Min.CreepageDistance(mm)

No. ofIndividualunits perstring

(Nos.)

EMstrengthofInsulator

Unit (KN)

Mechanicalstrength ofInsulatorstring

alongwithHardwarefittings(kN)

1 SingleSuspension

20X1305 4495 1X1 70 70

2 Single pilotSuspension

20X1305 4495 1X1 70 70

4 Single

Tension

20X1450 4495 1X1 120 120

5 DoubleTension

20X1450 4495 2X1 2X120 2X120

2.2 INSULATOR STRING HARDWARE

a) Anchor shackleb) Ball Hookc) Chain linkd) Yoke platee) Ball clevisf) Arcing horn holding plate

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g) Socket clevish) Arcing hornsi) Clevis eyej) Free center type/armour grip suspension clamp for suspension strings and

envelope type clamp for pilot suspension string for jumper support.k) Compression type dead end clamp.

2.3 ACCESSORIES FOR CONDUCTOR AND EARTHWIRE

a) Mid-span compression jointsb) Repair sleeves for conductorc) Flexible copper bondsd) Vibration dampers for conductor and earthwiree) Suspension clamps for earthwiref) Tension clamps for earthwireg) Preformed Armour rods.

3. TRANSMISSION TOWERS

3.1 General Descript ion of the Tower

3.1.1 The towers shall be of following types:-

a) Double circuit (DA, DB, DC & DD type) of HVPNs KRR Design for both 0.4sq ACSRZebra and 0.2sq ACSR Panther.

b) Single Circuit (A, B,C & D ) of 0.4sq ACSR Zebra to be designed by the Bidder.

3.1.2 The towers are of self supporting lattice steel type, designed to carry the line

conductors with necessary insulators, earthwire and all fittings under all loadingconditions.

3.1.3 The tower shall be fully galvanized structure. New Design 132kV S/C towers and132kV D/C KRR Design towers to be fabricated shall have a combination of twogrades of steel, as detailed in structural drawings/bill of material. One is MS steel andother is HT steel conforming to IS:2062.

3.2 TYPE OF TOWERS3.2.1 The towers are classified as given below for 132 KV lines.

A) FOR KRR Design D/C Towers:-Type of Tower Deviation limit Typical use

DA 0 deg.-2 deg. To be used as tangent tower.DB 2 deg.-15 deg.

0 deg.

a) Tension towers with tensioninsulators string.

b) Tension towers for upliftforces resulting from anuplift span upto 200 m.

c) Also to be designed for anti-

cascading condition.d) To be used as SectionTower

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DC 15 deg.-30 deg. a) Tension towers with tensioninsulators string.


c) Also to be designed for anti-cascading condition.

DD 30 deg.-60 deg.

55 deg

a) Tension towers with tensioninsulators string.


c) Dead end with 0 deg. to 15deg. deviation both on lineand substation side (slackspan).

d) When DD type tower used

with +12m to +25m Extension by restricting thespan to 250m.

e) For river crossing anchoringwith longer wind span with 0deg. deviation on crossingspan side and 0 to 30 deg.deviation on other side.

B) For New 132kV S/C towers of 0.4sq ( to be designed by the Bidder):-

Type of Tower Deviation limit Typical use

A 0 deg.-2 deg. To be used as tangent towerupto 2 deg. deviation

B 0 deg.-15 deg.

0 deg.

a) To be used for line Angledeviation from 0 to 15 Deg.

b) Tension towers for uplift

forces resulting from anuplift span upto 200 m.


d) Section tower.

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C 15 deg.-30 deg. a) To be used for line Angledeviation from 15 to 30 Deg.



D 30 deg.-60 deg.

0 deg.

a) To be used for line Angledeviation from 30 deg. to 60Deg.


c) Complete Dead end with 0deg. to 15 deg. deviationboth on line and gantry side(slack span).

d) For river crossing anchoringanchoring with longer windspan with 0 deg. deviationon crossing span side and 0to 30 deg. deviation onother side.

Note: The angles of line deviation specified above are for the design span. The span may,however, be increased upto an optimum limit with reduced angle of line deviation, ifadequate ground and phase clearances are available. The bidder shall indicateoptimum limit of spans for each type of above mentioned towers with reducing angle

of deviation with supporting calculations.

3.2.2 EXTENSIONS

3.2.2.1 The towers shall be designed for adding 3 m, 6 m body extensions for maintainingadequate ground clearances without reducing the specified factor of safety in anymanner.

3.2.2.2 In the New Design of 132kV S/C towers of 0.4sq, The provision for adding 9m bodyextensions for all tower type shall also be kept by the contractor. For power line

crossing or any other obstacle, tower type A and D shall be used with 12m/15mextensions depending upon the merit of the prevailing site condition.

3.2.2.3 The design & drawings of the Extensions including their foundations (i.e. +9m for alltype of towers and +12m / +15m for A & D type tower) and Gantry is in the scope ofthe bidder. The design cost of these extensions & Gantry including foundations, whichmay not be used are deemed to be included in the quoted prices of Normal towers &foundations.

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3.2.2.4 The tower shall be designed in such a manner that in case of (individual) unequallegs extension required as per site condition can be added without changing inbracing pattern of all four types of normal tower and towers with +3m and +6mbody extensions.

3.2.2.5 All above extension provision to normal towers shall be treated as part of normaltower only.

3.2.2.6 Extra cross-arms for 132kV New tower design shall also be provided by the

bidder and the span to be kept on both sides of these tower shall be shownin the Design.

3.2.2.7 The Extensions of 132kV D/C KRR Design towers shall be provided to successfulbidder as required as per site conditions.

3.3 SPANS AND CLEARNACES

3.3.1 NORMAL SPAN

The normal ruling span of the line shall be 300 meters for both New and KRRdesign towers.

3.3.2 WIND SPAN

The wind span is the sum of the two half spans adjacent to the support underconsideration. For normal horizontal spans this equal to normal ruling span. Thesame shall be intimated by the Bidder in New Designs of towers.

3.3.3 WEIGHT SPAN

The weight span is the horizontal distance between the lowest point of theconductors on the two spans adjacent to the tower. The bidder shall howeversuggest the weight spans suitable for New Design tower of span length of 300mtrs. The weight span of 132kV D/C KRR design towers shall be supplied tosuccessful bidder.

3.3.4 ELECTRICAL CLEARANCES

3.3.4.1 GROUND CLEARANCE

The min. ground clearances from the bottom conductor shall not be less than 6100mm at the max. sag conditions i.e. at max. temperature (75

oC) and still air.

However, to achieve the above clearance the height of tower shall be increased inthe following manner:

a) An allowance of 150 mm shall be provided to account for errors in stringing.

b) Conductor creep shall be compensated by over tensioning the conductor attemperature of 26

oC (for ACSR Zebra) & 21

oC (for ACSR Panther) lower than

the stringing temperature.

For river crossing tower the minimum electrical clearance including ground clearancewill be same as normal towers except an allowance of 4% of maximum sag ofconductor instead of 150 mm for normal towers shall be provided to account for errorsin stringing.

3.3.5 RAIL CROSSING

In case of Rail crossing, the min. height above Rail level of the lowest portion of anyconductor under condition of max. sag, in accordance with the regulation for Electrical

crossing of Railway tracks as prevailing at the time of construction of line shall beapplicable.

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3.3.6 POWER LINE CROSSING

Minimum clearance between Power line to Power line shall be as follows:

i) 132 kV to 132 kV and below: 3050 mmii) 132 kV to 220 kV 4580 mmiii) 132 kV to 400 kV 5490 mm

3.3.7 Live Metal Clearance :

3.3.7.1 The minimum live metal clearance to be provided between the live parts and steelwork of super structure shall be as per IS:5613 (part-ii/sec-1) 1985 as given in tablebelow:

Sr. No Type of insu latorstring

Swing in deg. Min. live metal clearancein mm

1 Single suspensioninsulator string

Nil15

304560

15301530

137012201070

2 Tension insulator string(single/double)

Nil 1530

3 Jumper Nil102030

1530153010701070

4 Double suspensionstring

Nil153045

1530153010701070

3.3.7.2 Bidder shall adopt same cross arm design where jumper is projecting outside ofcross -arm for new Design D type tower to be used as Dead end angle tower.

3.3.7.3 For computing the live metal clearances the dimensions of single I-Suspension,Single Tension and double tension strings shall be taken. The design of tower

shall be such that it should satisfy all the above conditions when clearances aremeasured from any live point of the strings.

3.3.8 ANGLE OF SHIELDING

The angle of shielding is defined as the angle formed by the line joining the centerlines of the earthwire and outer power conductor, in still air, at tower supports, to thevertical line through the center line of the earthwire. Bidders shall design the tower insuch a way that the angle of shielding does not exceed 30 deg. The drop of theearthwire clamp, should be considered while calculating the minimum angle ofprotection. For estimating the minimum angle of protection, the drop of the earthwire

suspension clamp alongwith shackle shall be taken as 150mm.

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3.3.9 MID SPAN CLEARNACE

The minimum vertical mid span clearance between the earthwire and the nearestpower conductor shall not be less than 6.1 meters for 132 kV which shall mean thevertical clearance between earthwire and the nearest conductor under alltemperatures and still air condition in the normal ruiling span. Further, the tensions ofthe earthwires and power conductors shall be so co-ordinated that the sag ofearthwire shall be at least 10% less than that of power conductors under all

temperature loading conditions.

3.4 Normal Loading Condi tions ( for 132kV New Tower Design )

3.4.1 Loads at Conductor and Earthwire Points

The ultimate external loadings at conductor and earthwire points shall be calculated &submitted by the bidder.

3.4.2 Wind Loads on Tower Body

The wind load on tower body shall be calculated by the contractor as per IS:802

(1995). The following data shall be considered for calculating wind load on towerbody: -

a) Wind zone = 4 (47 m/sec)

b) Reliability level = 1

c) Terrain category/ = 2ground roughness

d) Design wind pressure = 701 N /m2

(pd)

e) The angle of incidence = 0 degree.of wind (Theta)

3.4.3 MAXIMUM TENSION

3.4.3.1Max tension shall be based on either

At 0oC with 36% full wind pressure, or

At 32oC with full wind pressure whichever is more stringent.

Sag-tension calculations for Conductor and Earthwire for a span length of 300 mtrs.shall be calculated and submitted by the bidder in accordance with the relevantprovisions of IS: 5613 (Part-3/Section-1) for both 132kV new tower designs.

The sag-tension calculation for 132kV D/C KRR Design tower shall be supplied byHVPNL to successful bidder.

3.4.4 LIMITING TENSION OF CONDUCTOR & EARTHWIRE

The ultimate tension of conductor and ground wire shall not exceed 70 percent of their

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3.4.5 Broken Wire Condit ion (for 132kV S/C New Tower Design of 0.4sq ACSR Zebra)

3.4.5.1 Suspension Tower Type A

Any one phase or Earthwire broken, whichever is more stringent for a particularmember.

3.4.5.2 Tension Tower Type B and C

Any two phases broken on the same side and the same span or any one phase andone earthwire broken on the same side and same span whichever combination ismore stringent for a particular member.

3.4.5.3 Tension Tower Type D

All three phases broken on the same side and the same span or any two phases andearthwire broken on the same side and same span whichever combination is morestringent for a particular member.

3.4.6 Design of towers

The towers shall be designed as per IS: 802(1995).

3.4.7 Design Criteria

The following design strength factor shall apply for tower design only (not forfoundation design)

3.4.7.1 If steel with minimum guaranteed yield strength is used for fabrication of tower, Loadsgiven in IS: 802, part-I, section 2 shall be increased by 1.02.

3.4.7.2 If steel with minimum guaranteed yield strength is not used for fabrication of tower.Loads given in IS: 802, part-I, section 2 shall be increased by a factor of 1.05 inaddition to that mentioned in clause -3.4.7.1.

3.4.8Design Temperatures

The following temperature range for the conductors and ground wires shall beadopted for line design:

i) Minimum temperature : 0 deg. C

ii) Every day temperature : 32deg. Cof conductor

iii) Max. temperature of

a) Conductor : 75 deg. C

b) Earthwire exposed to sun : 53deg. C

3.4.9CONDUCTOR AND EARTHWIRE CONFIGURATION

The three phases shall be in vertical formation on both sides of tower. The phase tophase spacing for tower shall not be less than 4.05 meters ( vertical) and 7.06 meters

(horizontal).

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3.4.10Redundant and Bracing Design

All redundants in the towers are to be triangulated

All bracings and Redundant members of the towers which are horizontal or inclinedupto 15o from horizontal shall be designed to withstand an ultimate vertical load of1500 N considered acting at centre independent of all other loads. The bendingmoment for designing of redundant members shall be considered as WL/4 irrespective

of end connections and continuity. The contractor has to furnish the calculations forthe same (Where W is ultimate load of 1.5 KN and L is length of redundant from boltto bolt). The redundants shall also be designed for 2.5% of maximum axial load ofconnecting members (i.e. leg members, bracing members etc.). The contractor has tofurnish the calculations for the same.Unbraced portion of the stub shall be designed for combined direct and bendingstresses. The Contractor has to furnish the calculations for the same.

3.4.11Bracing Patterns

Staggering of bracings and redundants are not allowed. Bracings and redundantspatterns in tranverse and longitudinal faces will be exactly identical.

3.4.12Steel sections

For designing of towers, preferably rationalized steel sections shall be used. Duringexecution of the project, if any particular section is not available, the same shall besubstituted by higher section at no extra cost to HVPN and the same shall be borne bythe contractor. However, design approval for such substitution shall be obtained fromthe HVPN before any substitution.

3.4.13Thickness of Members

The minimum thickness of angle sections used in the design of towers, unlessotherwise specified elsewhere in this specification, shall be kept not less than thefollowing values:

a) Main corner leg members including the : 5 mmground wire peak and main cross arm

b) For all other members : 4mm

3.5 Bolts & Nuts

3.5.1The minimum bolt spacing and rolled edge distance and sheared edge distance fromthe centers of the bolt holes to be maintained are given in Table below:-

Diameter ofbolts (mm)

Holediameter

(mm)

Min. Boltspacing

(mm)

Min. rolled orswan edge

distance (mm)

Min. shearedor flame cut

edge distance(mm)

16 17.5 40 20 23

Bolts sizes mentioned above shall only be used. The minimum width of the flangeswithout bolt holes shall be 30mm.

3.5.2 For the purpose of calculating shearing stress and bearing stress for bolts clause 14.4& 14.5 of IS: 802 Part-1/Sec-2 1992 may be referred.

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3.6 Slenderness Ratio3.6.1 Slenderness ratio for members shall be computed in accordance with clause 10 of IS:

802 (Part-1/Sec-2) 1992. Slenderness ratio for compression and tension membersshall not exceed the values specified therein.

3.6.2 The following maximum limit of the slenderness ratio (KI/r) i.e. the ratio of effectiveunsupported length of the section in any plane to the appropriate radius of gyration willbe used:

a) For main corner leg members including 120the corner members of earthwire peakand the lower corner members of thecross-arms in compression

b) For other members carrying computed stresses. 200

c) For redundant members and those carrying 250nominal stresses

d) For members having tensile stress only. 375

3.7 Erection stress

Where erection stresses combination with other permissible co-existent stresses couldproduce a working stress in any member appreciably above the specified workingstress, such other provisions are to be made as may be necessary to bring theworking stress within the specified permissible limit.

3.8 Design calculation and drawings

3.8.1 On award of contract, the following design calculations and drawings are required tobe furnished to HVPN :-

The Design calculations for all towers / extensions & Gantry of new Design shall begot checked and approved from CPRI India. The CPRI approved Design of tower,extensions, Gantries, stub template, loading/rigging arrangement and details ofcalculations shall there upon will be supplied to HVPNL for further approval. .

3.8.2 HVPN shall then carry-out destruction testing of all new design A, B,C, D type towersat the test bed of CPRI. The prototypes for destruction testing of towers shall befabricated/ supplied by the contractor at the test site. All the arrangement / costinvolved for carrying-out the tests shall be the responsibility of the contractor.

3.8.3 After approval of design/successful testing of tower, the contractor shall furnish thefollowing in fifteen (15) copies alongwith all Original drawings on Micro-film and

their soft auto-cad copy to the HVPN for necessary distribution within fifteen (15)days: -a) Detailed design calculation and drawing for towers / their Extensions and

foundations.

b) Detailed structural drawings indicating section size, length of members, sizes ofplate along with hole to hole distance, joint details etc.

c) Bill of materials, indicating cutting and bending detail against each member.

d) Shop drawings showing all details relevant to fabrication.

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3.8.4 The contractor is required to submit four copies of the drawings as mentioned inclause 3.8.3 for HVPN approval. While submitting the designs, structural drawings, billof materials and any other drawings pertaining to the subject transmission line, thecontractor shall clearly indicate on each drawing HVPN specification No., Name of thetransmission line and project, letter reference No. and date on which the submissionare made. The same practice is also to be followed while submitting distributioncopies.

3.8.5 The CPRI approved design and drawings as covered in clause 3.8.3 above shall beapproved/commented by the HVPN as the case may be within 21 (twenty one) days ofreceipt of designs/drawings in HVPN design directorate. If the design/drawings arecommented by the HVPN , the contractor shall submit revised designs/ drawingswithin 15 (fifteen) days of date of issue of comments.

3.8.6 The contractor is required to furnish the progress of submissions and approvals ofdesigns and drawings on twenty fifth day of every month till the completion of all thedesign activities.

The details shall include description of design/drawing, schedule date of submission,actual date of submission, schedule date of approval, actual date of approval,schedule date of submission of distribution copies, actual date of submission ofdistribution copies, schedule date of tower test, actual date of tower test andRemarks column. Provision of six additional columns shall also be made in the aboveprogress report to indicate date of comments issued by the HVPN and details ofsubmission of revised designs/drawings.

3.9 Design of Gantries

3.9.1 The entire clauses relating to Towers will be relevant for Gantries in general unless

otherwise stated.

3.9.2 All Gantries shall be designed for the worst combination of dead loads, wind loads,loads due to deviation of conductor, load due to unbalanced tension in conductor,torsional load due to unbalanced vertical & horizontal forces, erection load, shortcircuit forces etc. short circuit forces shall be calculated at a fault level of 31.5-kA etc.as per IEC:865:1991.

3.9.3 The design of structure shall also be based on the condition where stringing is doneonly on one side i.e. all the three conductors broken on other side.

3.9.4 Static tension pull on gantries shall be taken as minimum 2000kgs per phase. Vertical

load of half the span of conductors and earthwires on either side of the beam shall betaken into account for the purpose of design. Earthwire tension shall be taken as800kgs.

3.9.5 The distance between gantry and adjacent tower shall be taken as minimum 175m fordesign purpose. The design of those gantries shall also be checked considering 30deg. deviation of conductor in both vertical and horizontal planes.

3.9.6 All foundations shall be designed to withstand the forces resulting due to worstpossible combination of loads on superstructure as specified in above clauses.

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3.10 Material

3.10.1 TOWER STEEL SECTIONS

3.10.1.1 The towers shall be fully galvanized structure of MS steel and HT steel as pergrades shown in Structural drawings / BOM

3.10.2 FASTENERS: BOLTS NUTS AND WASHERS

3.10.2.1 All bolts and nuts shall conform to IS:6639-1972. All bolts and nuts shall begalvanized and shall have hexagonal head and nuts, the heads being forged out ofthe solid steel rods and shall be truly concentric, and square with the shank, whichmust be perfectly straight.

3.10.2.2 The bolt shall be of 16 mm dia and of property class 5.6 as specified in IS:1367(part-III) 1979 and matching nut of property class as specified in IS:1367 (part-VI)1980.

3.10.2.3 Bolts up to M 16 and having length upto 10 times the diameter of the bolts shouldbe manufactured by cold forging and thread rolling process to obtain good andreliable mechanical Properties and effective dimensional control. The shearstrength of bolts for 5.6 grade should be 310-MPa minimum as per IS: 12427, boltsshould be provided with washer in accordance with IS: 1363 part-I to ensureproper bearing.

3.10.2.4 Nuts should be double chamfered as per the requirement of IS:1363 part-III, 1984.The manufacturer should ensure that nuts should not be over tapped beyond 0.4mm oversize on effective diameter for size upto M16.

3.10.2.5 Fully threaded bolts shall not be used. The length of bolts shall be such that thethreaded portion will not extend into the place of contact of the members.

3.10.2.6 All bolts shall be threaded to take the full depth of the nuts and threaded forenough to permit firm gripping of the members, but not further. It shall be ensuredthat the threaded portion of each bolt protrudes not less than 3 mm and not morethan 8 mm when fully tightened. All nuts shall fit and tight to the point where theshank of the bolt connects to the head.

3.10.2.7 Flat and tapered washers shall be provided wherever necessary. Spring washersshall be provided for insertion under all nuts. These washers shall be of steel

electro-galvanised steel, positive lock type and 3.5 mm in thickness for 16 mm diabolt.

3.10.2.8 The bidder shall furnish bolt schedules giving thickness of members connected,the size of bolts nut and the washer and the length of shank and the threadedportion of bolts and sizes of bolt holes and any other special details of this nature.

3.10.2.9 To obviate bending stress in bolts or to reduce it to minimum, no bolt shall connectaggregate thickness of more than three (3) times its diameter.

3.10.2.10 The bolt position in assembled towers shall be as per IS:5613 (Part-II/secton-2-1976).

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3.10.2.11 Bolts at the joints shall be so staggered that nuts may be tightened with spannerswith out fouling.

3.10.2.12 To ensure effective in-process quality control it is essential that the manufacturershould have all the testing facilities for test like weight of zinc coating, shearstrength, other testing facilities etc. in-house. The manufacture should also haveproper Quality Assurance System, which should be in line with the requirement ofthis specification and IS:14000 series quality system standard.

3.10.3 TOWER ACCESSORIES

i) STEP BOLTS & LADDERS

Each tower shall be provided with step bolts in one of the main leg confirming toIS:10238 of not less than 16mm diameter and 175 mm long, spaced not morethan 450 mm apart and extending form about 3.5 metres above the ground level tothe top of the tower. The step bolt shall be fixed on one leg of single circuit towerfrom 3.5 m above ground level to top of the towers. Each step bolt shall beprovided with two nuts on one end to fasten the bolt securely to the tower and

button head at the other end to prevent the feet from slipping away. The step boltsshall be capable of withstanding a vertical load not less than 1.5 KN. For specialstructures, where the height of the super structure exceeds 50 metres, laddersalong with protection rings as per the HVPNL approved design shall be provided incontinuation of the step bolts on one face of the tower from 30 metres aboveground level to the top of the special structure. From 3.5 m to 30 m height of superstructure step bolts shall be provided. Suitable plat form using 6 mm thickperforated chequred plates along with suitable railing for access from step bolts tothe ladder and from the ladder to each cross-arm tip and the groundwire supportshall to be provided. The platform shall be fixed on tower by using countersunkbolts.

ii ) INSULATOR STRING AND EARTHWIRE CLAMPS ATTACHMENTS

a) I shaped suspension insulator string assemblies shall be used for suspensiontowers, the drawing of which is enclosed with specification. For the attachmentof suspension insulator string, a suitable dimensioned swinging hanger on thetower shall be provided so as to obtain requisite clearance under extremeswinging condition and free from swinging of the string. The hanger shall bedesigned to withstand an UTS of 70 KN for single suspension string and 140KN for double suspension string.

b) At tension towers, strain plates of suitable dimensions on the underside of eachcross-arm tip and at the top earthwire peak should be provided for taking thehooks or D-shackle of the tension insulator strings or earthwire tension clamps,as the case may be. Full details of the attachments shall be submitted by thebidder for HVPNL approval before starting the mass fabrication.

iii) EARTHWIRE CLAMPS

SUSPENSION CLAMPEarthwire suspension clamps will be supplied by the bidder, the reference drawing

for the same is enclosed with the specification. Earthwire peaks/cross-arms are tobe suitably designed to accommodate the shackle of the suspension clamp.

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TENSION CLAMPSThe bidder shall supply earthwire tension clamps for incorporation on the tensiontowers. The reference drawing for the same is enclosed with this specification.

iv) ANTICLIMBING DEVICE

Barbed wire type anticlimbing device/ fencing as per enclosed drawing shall beprovided and installed by the Bidder for all towers/gantries. The height of the

anticlimbing device shall be provided approximately 3m above ground level. Thebarbed wire shall conform to IS:278-1978. the barbed wires shall be givenchromating dip as per procedure laid down in IS:1340-1959.

v) DANGER, NUMBER, AND PHASE PLATE

Danger, Number, Circuit and phase plates shall be provided and installed by theBidder.

a) Each tower shall be fitted with a number plate, circuit plate (in case of doublecircuit) and danger plate. Each tension tower shall be provided with a set of phaseplates also. All the double circuit towers are to be provided with circuit plate fixednear the legs. The height for fixing these accessories shall not be more than 4.5mabove the ground level.

b) The letters figures and the conventional skull and bones of danger plates shallconform to IS:2551-1963 and shall be in a signal red on the front of the plate.

c) The corners of the number, danger & circuit plate shall be rounded off to removesharp edges.

vi) BIRD GUARDS

To prevent birds perching immediately above the suspension insulator string andfouling the same with dropping, suitable bird guards shall be provided at cross armtips of all suspension towers. The bird guard arrangement shall be such that it shalleither prevent bird from perching in position where they are liable to cause thedamages or ensure that if birds do perch, dropping will fall clear of the insulatorstring.

3.11 TOWER FABRICATION

The fabrication of towers shall be in conformity with the following:

3.11.1 Except where hereinafter modified, details of fabrication shall conform to IS:802(Part-II) 1978 or the relevant international standards.

3.11.2 The tower structure shall be accurately fabricated to connect together easily at sitewithout any undue strain on the bolts.

3.11.3 The diameter of the hole shall be equal to the diameter of bolt plus 1.5 mm.

3.11.4 All similar parts shall be made strictly inter-changeable. All steel sections before anywork is done on them, shall be carefully leveled, straightened and made true todetailed drawings by methods which will not damage the materials so that when

assembled, the adjacent matching surfaces are in close contact throughout. Norough edges shall be permitted in the entire structure.

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3.11.5 DRILLING AND PUNCHING

3.11.5.1 Before any cutting work is started, all steel sections shall be carefully straightenedand trued by pressure and not by hammering. They shall again be trued afterbeing punched and drilled.

3.11.5.2 Holes for bolts shall be drilled or punched with a jig but drilled holes shall bepreferred. Punching may be adopted for thickness upto 16mm. tolerances

regarding punched holes are as follows:a) Holes must be perfectly circular and no tolerance in this respect is permissible.b) The max. allowable difference in diameter of the holes on the two sides of

plates or angle is 0.8 mm i.e. the allowable taper in a punched hole should notexceed 0.8 mm in diameter.

c) Holes must be square with the plates or angles and have their walls parallel.

3.11.5.3 All burrs left by drills or punch shall be removed completely. When the towermembers are in position the holes shall be truly opposite to each other. Drilling orreaming to enlarge holes shall not be permitted.

3.12 ERECTION MARK

3.12.1.1 Each individual member shall have an erection mark conforming to the componentnumber given to it in the fabrication drawings. This mark shall be made withmarking dies of 16 mm size before galvanizing and shall be legible aftergalvanizing.

3.12.1.2 ERECTION MARK SHALL BE A-BB-CC-DDD

A = HVPNL code assigned to the Bidder -Alphabet

BB = Bidders Mark-Numerical

CC = Tower type-Alphabet

DD = Number mark to be assigned by Bidder -Numerical.

H = HT Steel

3.12.2 QUANTITIES VARIATION

3.12.2.1 The provisional quantities required are mentioned in the respective schedule ofprices. Final quantities shall be determined after completion and approval of thedetailed route survey and check survey. The final quantities of towers, gantries,line materials and foundations shall be confirmed by the HVPNL based on therequirement of quantities of various items furnished by the Bidder after completionof detailed survey. Hence it will the responsibility of the Bidder to intimate the exactrequirements of all towers, line materials and foundations required for the lineimmediately after the survey. The Empowered officer of the HVPNL will order thefinal quantities at the unit rates quoted in the bid.

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3.12.2.2 The Empowered officer of the HVPNL reserves the right to increase or decreaseupto 15% (fifteen percent only) of contract value. The quantity of bid and servicesspecified without any change in the unit price or other terms and conditions duringthe execution of the contract. The quantities of individual items may vary upto anyextent after the final route plans and route profiles of the lines covered in thepackage are finalised.

3.12.2.3 The estimated unit weight of each type of tower, stubs and extensions shall be

furnished by the HVPNL. The weight of tower shall mean the weight of towercalculated by using the black sectional (i.e. ungalvanised) weight of steel membersof the size indicated in the approved fabrication drawings and bills of materials,without taking into consideration the reduction in weights due to holes, notchesand bevel-cuts etc. but taking into consideration the weight of fastners,anticlimbing devices etc.

For payment purpose, the round plane washers, hangers, D-shackles, U-bolts,step bolts, spring washers, bolts and nuts etc. shall be termed as fasteners.

3.13 GALVANISING

Fully galvanized towers and stub shall be used for the lines. Galvanizing of themember of the towers shall conform to IS:2629-1985 and IS:4759-1968. Allgalvanizing members shall withstand tests as per IS:2633-1986. For fasteners thegalvanizing shall conform to IS:1367 (Part-13). The galvanizing shall be done afterall fabrication work is completed, except that the nuts may be tapped or re-run aftergalvanizing. Threads of bolts and nuts shall have a neat fit and shall be such thatthey can be turned with finger throughout the length of the threads of bolts and theyshall be capable of developing full strength of the bolts. Spring washers shall beelectro-galvanised as per grade 4 of IS: 1573-1970.

3.14 EARTHING

3.14.1 The footing resistance of all towers shall be measured by the Bidder in dry weatherafter tower erection but before the stringing of earthwire. All the towers are to beearthed, however, in no case tower footing resistance shall exceed 10 ohms. Pipetype earthing and counterpoise type earthing wherever required shall be provided inaccordance with the stipulations made in IS:3043-1987 and IS:5613 (part-II/section-2)1985. The details for pipe and counterpoise type earthing are given in drawingenclosed with the specification.

3.14.2 The provisional quantities for pipe type earthings and counterpoise earthing, arefurnished in price schedule. The bidders are required to furnish unit rates also foradjustment purpose with actual quantities. The quoted price shall include fabrication,supply and installation of earthing material including supply of coke, salt etc. in case ofcounterpoise type earthing, the quotation shall be based on 100 metres of wire pertower.

3.15 INSPECTION AND TESTS

3.15.1 All standards tests, including quality control tests, in accordance with appropriateIndian/International standard, shall be carried out unless otherwise specified herein.

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3.15.2 All Goods being supplied shall conform to type tests, sample tests as per the technicalspecifications and shall be subject to routine, acceptance and site tests inaccordance with requirements stipulated under the respective Sections, unlessotherwise stated. The HVPNL reserves the right to witness any or all the type andsample tests. The Bidder shall inform the HVPNL of the detailed program of tests atleast two (2) weeks in advance in case of domestic supplies and four (4) weeks inadvance in case of foreign supplies.

3.15.3 The Bidder shall furnish to HVPNL the reports of all type tests, sample and routinetests as per technical specification along with the equipment/materials drawings. Thetype tests conducted earlier should have been conducted in accredited laboratories(based on ISO/IEC by a reputed accreditation body) or witnessed by HVPNL oranother electric power utility. The type test reports submitted shall be of the testsconducted within last five (5) years prior to the date of bid opening. In case the testreports are of a test conducted five (5) years prior to the date of bid opening, anddont correspond to the offered equipment/material, or dont comply with theTechnical Specifications, the Bidder shall repeat this / these test / tests at no extracost to the HVPNL before sample(acceptance) tests. The cost of conducting typetests and additional tests shall be included in the Bid price .

3.15.4 The HVPNL, his duly authorized representative and/or outside inspection agencyacting on behalf of the HVPNL shall have free access at all reasonable times to theBidders/sub-vendors premises or Works and shall have the power at all reasonabletimes to inspect and examine the equipment/materials and workmanship of theWorks during its manufacture or erection. If part of the Works is being manufacturedor assembled at other premises or works, the Bidder shall obtain for the HVPNL, hisduly authorized representatives and/or outside inspection agency permission toinspect as if the works were manufactured or assembled on the Bidders ownpremises or works. Inspection may be made at any stage of manufacture, dispatchor at the Site at the option of the HVPNL, and the equipment if found unsatisfactory

due to bad workmanship or quality or material is liable to be rejected.

When the factory tests have been completed at the Bidders or Sup-Bidders works,the HVPNL/Inspector shall issue a certificate to this effect within fifteen (15) daysafter the completion of the tests, but if the tests are not witnessed by theHVPNL/Inspector, the certificate shall be issued within 15 days of receipt of theBidders test certificate by the HVPNLs representative. Failure of theHVPNL/Inspector to issue such a certificate shall not prevent the Bidder fromproceeding with the Works (as defined in SCC). The completion of these tests or theissue of the certificate shall not bind the HVPNL to accept the equipment/materials

should it, on further tests after erection, be found not comply with the Contract. Theequipment/materials shall be dispatched to Site only after approval of test reportsand issuance of the inspection certificate by the HVPNL.

3.15.5 The inspection by the HVPNL and issue of the inspection certificate thereon shall inno way limit the liabilities and responsibilities of the Bidder in respect to the agreedquality assurance program forming part of the Contract.

3.15.6 The HVPNL will have the right of having at his own expenses any other test(s) ofreasonable nature carried out at the Bidders premises or at any other place inaddition of aforesaid type and routine tests to satisfy that the equipment/materialscomply with the specifications.

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3.15.7 The HVPNL deserves the right for getting any field tests not specified in the respectivesections of the technical specifications conducted on the completely assembledequipment at Site. The HVPNL will provide the testing equipment for these tests.

3.15.8 The Bidder shall ensure that his subBidders manufacturing and supplying the goods(material and equipment) shall perform the routine tests specified in the relatedstandards and in the Technical Specifications of this Contract regularly.

3.15.9 The Bidder shall notify the HVPNL in writing at the latest four (4) weeks for inspectionoutside of India and two (2) weeks for local inspection and testing or as otherwisedirected in advance of the date and place at which any Material or Work will beready for inspection and testing.

3.15.10 Should any postponement become necessary, the Bidder shall provide writtennotification at least one week prior to the originally scheduled date. The HVPNL shallgive 48 hours' notice in writing to the Bidder, of his intention to attend the tests, orask for postponement, if required.

3.15.11 Should the HVPNL explicitly waive to attend the relevant test, the Bidder may

proceed with the test, which shall be deemed to have been made in his presence,and the Bidder shall forthwith forward to the HVPNL duly certified copies of the testreports for approval.

3.15.12 All sample and type tests will be performed at the presence of the authorizedpersonnel of the Bidder or inspectors authorized by the Bidder, if there is norepresentative of HVPNL.

3.15.13 HVPNL may or may not be present in any or all sample and type tests but all testreports shall be approved by HVPNL

3.15.14 This procedure shall not release the Bidder from any of his responsibilities orobligations under this Contract.

3.15.15 The Bidder shall prepare and agree with HVPNL test programs so that tests to beperformed in foreign countries (i.e., at manufacturer's factory or at internationallyrecognized test facilities) are carried out in sequence which would permit HVPNL toorganize in an optimal manner the supervision of the said tests by HVPNL staff.

3.16 Galvanizing Tests:

All fabricated materials shall be tested in accordance with the "Test and Inspection

Procedures for Galvanized Materials "as per Specification and HVPNL shall benotified at least thirty days in advance of any tests if it is performed in abroad.

3.17 Inspections and Tests: The Bidder shall make adequate tests and inspections todetermine whether the material furnished is strictly in accordance with thisSpecification. In addition, HVPNL may inspect and accept or reject the material madeunder this Specification either at the Fabricator's plant or at the point of delivery Therepresentatives of HVPNL shall have access to all parts of the Bidder's plant whichconcerns the Work while the Work is being done. The Bidder, without requesting anyfee, shall provide all the reasonable facilities to the HVPNL's representatives so as tosatisfy them that, the towers are manufactured strictly in compliance to this

Specification.

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3.18 Certif ied Tests: Regardless of whether the material is inspected by HVPNL , theBidder shall furnish certified test reports as follows:

a) Steel Mill Test Reports showing chemical, physical and mechanical propertiesof the material to be furnished under the Contract.

b) A Manufacturer's Certificate of Inspection for zinc (hot-galvanized) coatings onstructural steel with the following information:

1- Purchase order number2- Date of inspection3- Number of pieces tested for weight of zinc coating with maximum-minimum

and average weights of each.4- Number of pieces tested for adherence of coating.5- Number of rejections because of defective coating and other reasons.

Certified test reports shall be sent to HVPNL.

3.19 Shop assembly: One tower of each type and height ordered, including every combination of leg

extensions, shall be assembled in the shop to the extent necessary to assure correctfit of parts, adequate bolt lengths and proper field erection. Reaming of mismatchedholes will not be permitted. A reasonable amount of drifting will be allowed inassembling approved by HVPNL. The approved assembled parts shall be dismantledfor shipment. Shop assembly shall be controlled and approved by HVPNL.

3.20 Fabrication: Fabrication shall be in strict accordance with detail Drawings prepared by the Bidderand approved by the HVPNL. The drilling, punching, cutting and bending of allfabricated steelwork shall be such as to prevent any possibility of irregularity occurringwhich might introduce difficulties in the erection of the structure on the site.

Built pieces shall, when finished, be true and free from all kinks, twists and open jointsand the Material shall not be defective or strained in any way. Fabrication shall beginafter the approval of the shop assembly.

3.21 IDENTIFICATION AND SHIPPING

Identification: All parts designed for bolting together shall be shipped unassembledexcept as noted on the drawings. Tower members shall be bundled together in thelargest practical bundles for shipping and each bundle shall be clearly marked. Smallparts such as U-bolts and clip angles shall be boxed and each box clearly marked for

identification.

Shipping: Railroad cars, ships or trucks in which steel is shipped shall be reasonablyclean and free from foreign materials which could in any way injure the tower material.At least 8cm clearance shall be maintained between bundles and floor.

3.22 GENERAL

All standards tests, including quality control tests, in accordance with appropriateIndian/International standard, shall be carried out unless otherwise specified herein.

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3.23 INSPECTION

3.23.1 In addition to the provision of clause regarding inspection in conditions of contract,the following shall also apply:

a. The Bidder shall keep the HVPNL informed in advance about the time ofstarting and of the progress of manufacture and fabrication of various towerparts at various stages, so that arrangements can be made for inspection.

b. The acceptance of any part of items shall in no way relieve the Bidder of anypart of his responsibility for meeting all the requirements of the specification.

3.23.2 The HVPNL or his representative shall have free access at all reasonable times tothose parts of the Bidders works which are concerned with the fabrication of theHVPNL material for satisfying himself that the fabrication is being done in accordancewith the provisions of the specifications.

3.23.3 Unless specified otherwise, inspection shall be made at the place of manufacture priorto dispatch and shall be conducted so as not to interfere unnecessarily with the

operation of the work.

3.23.4 Should any member of the structure be found not to comply with the approved design,it shall be liable to rejection. No member once rejected shall be re-offered forinspection, except in cases where the HVPNL or his authorized representativeconsiders that the defects can be rectified.

3.23.5 Defect which may appear during fabrication shall be made good with the consent ofand according to the procedure proposed by the Bidder and approved by the HVPNL.

3.23.6 All gauges and templates necessary to satisfy the HVPNL shall be supplied by the

manufacture.

3.23.7 The correct grade and quality of steel shall be used by the Bidder. To ascertain thequality of steel used, the inspector may at his discretion get the material tested at anapproved laboratory.

3.24 TESTING OF TOWER ( For S/C tower to be designed by the Bidder)

Testing of Towers

3.24.1 A galvanized tower of all A,B,C,D type complete with 6 m extension shall besubjected to design and destruction tests by first applying test loads in a mannerapproved by the HVPN. The tower shall withstand these tests without showing anysign of failure or permanent distortion in any part. Thereafter the tower shall besubjected to destruction by increasing the loads further in an approved manner till itfails. The tower shall be tested for all the conditions considered for the design oftower. The contractor shall submit to HVPN for approval, the detailed programmeand proposal for testing the towers showing the methods of carrying out the testsand manner of applying the loads. After the HVPN has approved the test proceduresand programmes the contractors will intimate the HVPN about carrying out the testsat least 30 days in advance of the scheduled date of tests during which the HVPN

will arrange to depute his representative to be present at the time of carrying out thetests. Six copies of the test reports shall be submitted.

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3.24.2 The contractor shall submit one set of shop drawings alongwith the bill of materialsat the time of prototype tower testing for checking the tower material. Further at thetime submitting test report, the contractor has to submit the final tracings of shopdrawings and bill of materials for HVPNs reference and record. The type testingcharges shall be released only after approval of test report, shop drawings, bill ofmaterial and structural drawings of tower.

3.24.3 In case of any premature failure even during waiting period, the tower is to be

retested with rectified members. However, if the failures are major in nature andconsiderable portion of tower is to be re-erected, in such cases all the tests whichhas been carried out earlier are required to be re-conducted again in compliancewith specification.

3.24.4 No part of any tower subject to test shall be allowed to be used on the line. The pricewill be quoted after allowing rebate for the scrap value of the tower material whichwill be retained by the contractor.

3.24.5 The contactor shall ensure that the specification of materials and workmanship of alltowers actually supplied conform strictly to the towers which have successfully under

gone the tests. In case any deviation is detected, the contractor shall replace suchdefective towers free of cost to the HVPN. All expenditure incurred in erection, toand fro transportation and any other expenditure or losses incurred by the HVPNon this account shall be fully borne by the contractor. No extension in delivery timeshall be allowed on this account.

3.24.6 Type of towers to be tested shall be a full scale prototype galvanized tower and shallbe erected vertically on rigid foundation of the stub protruding above ground level asprovided in the design/drawing between ground level and concrete level. Thisportion of the stub shall be kept unbraced while testing. The tower erected on testbed shall not be out of plumb by the more than 1 in 360.

3.24.7 All the measuring instruments shall be calibrated in systematic/ approved manner withthe help of standard weight/device. Calibration shall be done before commencing thetest of each tower upto the maximum anticipated loads to be applied during testing.

3.24.8 The suspension tower is to be tested with an arrangement simulating the choseninsulator string. The tension tower is to be tested with strain plate as per approveddesign/drawings.

3.24.9 The sequence of testing shall be decided by the HVPN at the time of approving the

rigging chart/test data sheet.

3.24.10 The HVPN may decide to carry out the tensile test, bend test etc, as per relevantIS on few members of the test tower after completion of the test or in case of anypremature failure. The decision of the HVPN regarding choice and number ofmembers to be tested is final & binding. The contractor shall make suitablearrangement for the same without any extra cost to the HVPN.

3.24.11 Prefix T shall be marked on all members of test tower in addition to the mark no.already provided.

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3.24.12 Owners liability is limited to witnessing testing of towers only once for each type oftower. Due to premature failure, if the testing of towers is to be repeated more thanonce for any type of tower, in such circumstances the contractor has to bear all theexpenses (traveling, boarding & lodging) in respect of owners representative (twopersons).

3.24.13 HVPN, however, reserves the right to waive off the testing of the towers, providedthe successful bidder had earlier successfully tested, erected and commissioned

same towers and certificate for such tests carried out earlier are furnished dulycertified by that purchaser and are found acceptable.

3.24.14 In that case, the same designs will become the property of HVPNL for all intentand purposes. The complete drawings of towers & Extensions i.e. Structuraldrawings, shop floor drawings, assembly drawings, bill of material, foundationdrawings, design calculations and type test reports w

Tech Spec 132KV Line

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