BJKBK

NATIONAL TRANSMISSION AND
DESPATCH COMPANY LIMITED (NTDCL)
ADB LOAN NO.2846-PAK: MFF 0007 POWER TRANSMISSION

ENHANCEMENT INVESTMENT PROGRAM, TRANCHE-3
BIDDING DOCUMENTS NO. ADB-65-2012 (PACKAGE-1)

FOR PROCUREMENT OF PLANT: DESIGN, SUPPLY,
INSTALLATION, TESTING & COMMISSIONING OF 500kV
TRANSMISSION LINE 3rd CIRCUIT JAMSHOROMORO
DADU TO RAHIM YAR KHAN
(Single-Stage One-Envelope Bidding Procedure)
VOLUME - II
TECHNICAL SPECIFICATIONS
March 2013
NATIONAL ENGINEERING SERVICES PAKISTAN (PVT.) LIMITED
NESPAK HOUSE, 1-C, BLOCK N, MODEL TOWN EXTENSION LAHORE PAKISTAN
Phone: +92-42-99090000 Fax: +92-42-99231936, E-mail: nespakpm@gmail.com
http://www.nespak.com.pk
3206/169/TD/09/10
Technical Specifications
Table of Contents
VOLUME-II
Clause
Description
Page No.
1.
MATERIAL AND WORKMANSHIP
1.1
Scope
1.2
Materials
1.3
Workmanship
1.4
Standards
1.4.1
Tower Steel
1.4.2
Conductor and Shield wire
1.4.3
OPGW and Associated Hardware
1.4.4
Insulators and Hardware
1.4.5
Accessories and Dampers
1.4.6
Transmission Line Construction
1.4.7
Standards Other than those Specified
1.5
Cleaning and Galvanizing
1.5.1
Galvanizing of Nut, Bolts and Washers.
1.6
Inspection
10
2.
STEELTOWERS
12
2.1
Scope
12
2.1.1
TypeofTowers
12
2.1.2
Drawings
13
2.1.3
DetailedRequirements
14
2.1.3.1
ConnectionDetails
14
2.1.3.2
StructuralSteel
14
2.1.3.3
Nut,BoltsandWashers
14
2.1.3.4
Workmanship
16
2.1.3.5
Bending
16
2.1.3.6
Punching&Drilling
16
2.1.3.7
Welding
16
2.1.3.8
GeneralRequirementsforFabrication
17
2.1.3.9
AllowanceforGalvanizing
17
2.1.3.10
Blocking
17
2.1.3.11
AngleLaps
17
2.1.4
Marking
17
ADB-65-2012 (Package-1)
Procurement of Plant: Design, Supply, Installation, Testing & Commissioning of 500 kV

Transmission Line 3rd Circuit Jamshoro-Moro-Dadu to Rahim Yar Khan
2.1.5
Tolerances
17
2.1.6
Drawings
17
2.1.7
SignPlates
18
2.1.8
BarbedWire
18
2.2
Tests for Tower Steel, Associated Hardware and Accessories
19
2.2.1
Manufacturer'sTests
19
2.2.2
PrototypeTesting
19
2.2.2.1
PrototypeTowerAssembly
19
2.2.2.2
PrototypeLoadTesting
20
2.2.3
AcceptanceTests
23
2.2.3.1
AcceptanceTestsforSectionsandPlates
23
2.2.3.2
AcceptanceTestsforPlain&SpringLockWashersandRingFillers
26
2.2.3.3
AcceptanceTestsforSign&NumberPlatesandAerialMarkers
27
2.2.3.4
AcceptanceTestsforBarbedWire
28
CONDUCTOR
28
3.1
Scope
28
3.2
Detailed Requirements
29
3.2.1
ConductorsCharacteristics
29
3.2.2
ConductorWires
29
3.2.3
Joints
29
3.2.4
Stranding
30
3.2.5
Fabrication
30
3.3
Testing
30
3.3.1
TestsonIndividualWires
30
3.3.2
DuctilityTest
31
3.3.3
TypeTestsonCompleteConductor
31
3.3.4
SampleTestsonCompleteConductorduringFabrication
32
3.4
Markings&Packing
33
4.
SHIELD WIRE AND OPTICAL FIBER EQUIPMENT
33
4.1
EHS Shield Wire
33
4.1.1
Scope
33
4.1.2
DetailedRequirements
34
4.1.2.1
ShieldWireCharacteristics
34
4.1.2.2
Joints
34
4.1.2.3
Stranding
34

4.1.2.4
TensileStrengthandElongationofWireandOtherTests
34
4.1.2.5
Galvanizing
34
4.1.2.6
SupplyofStressStrainCurves
35
4.1.2.7
MarkingsandPacking
35
4.2
Optical Fiber Equipment
35
4.2.1
General
36
4.2.2
Standards
36
4.2.3
OpticalFiberGroundWire(OPGW)
36
4.2.3.1
MaterialandWorkmanship
36
4.2.3.2
CableConstruction
36
4.2.3.3
CableCharacteristics
37
4.2.3.4
FiberCharacteristics
38
4.2.3.5
OPGWTests
38
4.2.3.6
Markings&Packing
40
4.2.4
JointBoxes
41
4.2.5
FiberOpticCable
42
4.2.5.1
General
42
4.2.5.2
CableType
42
4.2.5.3
FiberOpticCableRequirements
42
4.2.5.4
FiberCharacteristics
42
4.2.5.5
CableConstruction
42
4.2.5.6
EndingRules
42
4.2.5.7
CableInstallation
43
4.2.5.8
Labeling
43
4.2.6
Splices
44
4.2.7
TestEquipment,InstallationandMaintenanceTools
44
4.2.8
SiteTests
45
INSULATORS
45
5.1
Scope
45
5.2
45
5.2.1
PhysicalCharacteristics
45
5.2.2
MinimumElectrical&MechanicalCharacteristics
46
5.2.3
Manufacture
46
5.3
Insulator Assemblies
48
5.4
Main Design
49

5.5
Testing and Inspection
49
HARDWARE
53
6.1
Scope
53
6.2
Conductor and Shield Wire Data
53
6.3
Conductor Suspension Assemblies
53
6.3.1
General
53
6.3.2
ConductorSuspensionClamps
54
6.3.3
YokePlate
55
6.3.4
ConnectionFittings
55
6.4
Conductor Dead End Assemblies
55
6.4.1
General
55
6.4.2
Strength
56
6.4.3
TowerAttachmentFittings
56
6.4.4
HotLineMaintenance
56
6.4.5
Articulation
57
6.4.6
Power Arc Rating
57
6.5
Overhead EHS Shield Wire Suspension Assembly
57
6.6
Overhead EHS Shield Wire Tension Assembly
57
6.7
Hardware and Fittings for OPGW
58
6.7.1
OverheadOPGWSuspensionAssembly
58
6.7.2
OverheadOPGWTensionAssembly
58
6.7.3
OPGWAttachmentClamps
58
6.8
Parallel Groove Connectors
58
6.9
Tests
59
6.9.1
TypeTests
59
6.9.2
SampleTests
59
6.10
Ground Rods
61
6.10.1
SampleTests
61
6.11
Grounding Connectors for Ground Rods
62
6.12
Bare Copper-Clad Steel Grounding Conductor
62
7.
CONDUCTOR AND SHIELD WIRE ACCESSORIES
62
7.1
Scope
62
7.2
63
7.3
Conductor Compression Splice
63
7.4
Conductor Repair Sleeve
63
7.5
Conductor Compression Dead End Splice
64
7.6
Overhead Shield Wire Compression Splice
64
7.7
Tests
64

7.7.1
TypeTests
64
7.7.2
SampleTests
66
7.8
100 Ton Hydraulic Compressors (Engine Driven)
67
7.9
67
7.10
Compression Dies for ACSR & AAAC Conductor and Shield wire
67
7.11
Filler Compound
67
7.12
Electrical Joint Compound
67
8.
SPACER DAMPERS FOR CONDUCTOR AND STOCKBRIDGE DAMPERS FOR

OVERHEAD EHS SHIELD WIRE AND OPGW
68
8.1
Scope
68
8.2
68
8.2.1
General
68
8.2.2
ManufacturersDrawings
69
8.2.3
ConductorSpacerDampers
69
8.2.3.1
PhysicalRequirements
69
8.2.3.2
EnergyAbsorbingAssembly
69
8.2.3.3
ClampsandBolts
70
8.2.3.4
PerformanceRequirements
70
8.2.3.5
VerificationofVibrationBehaviorbyComputerProgram
71
8.2.3.6
ElectroMechanicalCharacteristics
71
8.2.3.7
PerformanceGuaranteeforDampingSystems
71
8.2.4
QualificationTestsRequirements
71
8.2.4.1
General
71
8.2.4.2
ClampSlippageTestsatAmbientTemperature
72
8.2.4.3
EnergyAbsorbingandFatigueTests
72
8.2.4.4
SimulatedOscillationTest
73
8.2.4.5
ConicalFatigueTest
73
8.2.4.6
BoltTorqueTest
73
8.2.4.7
SimulatedShortCircuitCurrentTest
74
8.2.4.8
CoronaandRIVTest
74
8.2.4.9
Electrical Resistance Test
74
8.2.4.10
ElastomerTests
74
8.2.5
SampleTests
75
8.2.6
VibrationDampersforOverheadEHSShieldWireandOPGW
76
8.2.6.1
General
76
8.2.6.2
PhysicalRequirements
76

8.2.6.3
PerformanceRequirementsforVibrationDampers
77
8.2.6.4
Type Tests
77
8.2.6.4.1
General
77
8.2.6.4.2
Clamp Slippage Test at Ambient Temperature
77
8.2.6.4.3
Bolt Torque Test
77
8.2.6.4.4
Attachment of Weights to Messenger Cable Test
77
8.2.6.4.5
Attachment of Clamp to Messenger Cable Test
77
8.2.6.4.6
Damper Performance Tests
78
8.2.6.4.7
Vertical Fatigue Test
78
8.2.6.5
SampleTests
78
8.2.6.6
TestRequirements
79
8.2.7
TechnicalAssistanceandResearch
80
8.3.
Basic Line Data and Environment
80
8.3.1
BasicLineData
80
9.
TECHNICAL PROVISIONS FOR CONSTRUCTION
81
9.1
General
81
9.2
Sub Soil Investigation
83
9.3
Foundation Requirements
86
9.4.
Pile Foundations
97
9.5.
Tower Erection
101
9.6.
Installation of Insulators and Hardware
105
9.7
Stringing Conductors, Overhead EHS Shield Wire and OPGW
105
9.8
Installation of Dampers
113
10
Pre Commissioning and Commissioning Tests
114
10.1
Pre Commissioning Tests
114
10.2
Commissioning Tests
115
Appendix-A
Sheet 1: Insulator Performance Data for 16,300 kg E&M Strength
Sheet 2: Insulator Performance Data for 8,200 kg E&M Strength

1.
MATERIAL AND WORKMANSHIP
1.1
Scope
500kV Transmission Line 3rd Circuit Jamshoro-Moro-Dadu to Rahim Yar Khan (600km) Package-1 to
be constructed under these Specifications is quad bundle single circuit as per following sections.
Lot-I: Jamshoro-Moro Section
Lot-II: Dadu-Moro-Goth Qazi Mahar Section
Lot-III: Goth Qazi Mahar-Rahim Yar Khan Section
(202 km)
(232 km)
(166 km)
The Line shall be of quad bundle AAAC GREELEY and ACSR DRAKE conductor per phase as per
following sketch for the above sections having two overhead shield wires, i.e. one is EHS and the other
is OPGW. Moro-Goth Qazi Mahar Section Transmission line shall pass within 300-500 m distance of
New Rohri 220kV substation and the OPGW on Moro-Goth Qazi Mahar Section shall be
tapped/extended to New Rohri 220kV substation.
The facilities to be provided under these specifications on the rates given in the Price Schedules include
but not limited to the following:

(i)
Preparation of design/fabrication drawings, generate bill of material sheets for each type of
Tower/, detailing of tower fabrication drawings (meant for fabrication of towers) supplied by
Employer, approval of drawings, data, documentation for all Facilities from the Project
Manager, and construct, complete and commission above said transmission line in
accordance with the requirements of the Contract Documents.
(ii)
Design Manufacturing, Supplying, testing, furnishing, insuring, transportation, (complete or

partial items to be transported from port or NTDCs stores at Sehwan and Rahim Yar Khan),
delivering to site (or to Employer designated warehouses in case of dismantled material and
spare parts) and storing thereof of steel towers including stubs angles for foundations,
conductor, EHS shield wire and OPGW along with associated equipment, conductor, EHS
shield wire & OPGW accessories and dampers, fog type porcelain disc insulators along with
associated hardware, grounding materials and all other Facilities
(iii)
Provision of all guarantees, insurances, field offices/camps, storage camps, labour, services,
Plant and Contractor's tools and equipment (including construction and tension stringing
equipment) to construct, complete, test and commission the said transmission line in
accordance with the requirements of the Contract Documents.
(iv)
Prepare and furnish all drawings and documents.
(v)
Provision of access roads where necessary.
(vi)
Making all necessary arrangements to access to tower locations on dry patches/land

engulfed in river Indus creeks.
(vii)
Clearing right-of-way including disposal of cleared materials.
(viii)
Establishing route alignment and detailed survey not limited to chainage & leveling,
preparation of plan & profile drawings, spotting of towers and preparation of construction
structure list. Validation, updating & preparation of as-built of the already prepared plan &
profile drawings and construction lists (to be provided after award of Contract).
(ix)
Surveying of tower sites, tower staking and establishing correct locations of footings.
(x)
Excavation, drilling, formation of ramps, grading, leveling, cutting and backfilling including
disposal of surplus/excavated material.
(xi)
Furnishing materials for constructing reinforced concrete tower foundations including

installation of steel stub angles and tower grounding.
(xii)
Ground assembly of tower sections and erection of steel towers.
(xiii)
Installing insulator assemblies for conductors.
(xiv)
Stringing conductors, overhead EHS shield wire and OPGW complete with hardware,
accessories and dampers up to substation gantry towers at both ends of the line.
(xv)
Furnishing and installing tower signs (Aerial Markers, Danger Signs, Number and Phase
Plates etc.), anti-climbing devices and welding of bolts & nuts.
(xvi)
Sub-soil investigation along the route including laboratory tests and preparation & submission
of sub-soil investigation report along with foundation recommendation.
(xvii)
Provide latitude and longitude by hand held GPS of each tower location.

(xviii)
Checking the structural integrity, dimensions (back to back & diagonal, stub level and if
required with the help of Schmidt hammer test) of already concreted conventional
foundations & pile caps. Assessment of the damage (if found damaged) and preparation of
the Damage Assessment and Remedial Measures Report for review and approval of
Project Manager and rectification of the damaged tower foundations.
(xix)
Demolishing of existing pile up to 2.4 m from the existing pile head, removal of spiral from the
existing vertical rebars, providing new vertical rebar, placement of formwork, application of
bonding agent, concreting, removal of formwork and curing etc., complete in all respect as
per drawing No. 3206/169/TD/01G124.
(xx)
Verification/checking of compatibility of insulator hardware material with hardware

components to be supplied by the Employer.
(xxi)
Testing and commissioning of the aforesaid Transmission Lines.
(xxii)
Dismantling of 500 kV towers of existing 2ndJamshoro-Dadu Circuit (maximum up to two

towers) including removal of shield wire, conductor, insulators, hardware etc, preparation of
material inventory and shifting of dismantled material to NTDC store at Sehwan.
(xxiii)
Checking and confirmation of the stress analysis of tower type M & D for various loading
conditions and full scale load testing of one tower type M and D of maximum height
including erection, rigging, testing, assuming five load tests to ultimate load without failure
followed by one test to destruction. Load cases shall be provided by the Project Manager.
(xxiv)
Provide security to his own staff and to the supervisory staff of the Employer and the Project
Manager.
(xxv)
Preparation & submission of monthly progress reports including site photographs, as-built
data and drawings including copies on reproducible transparencies and computer compact
diskettes (CD/DVD) using AutoCAD, manuals (including Operation & Maintenance Manual)
and Project Completion Report.
(xxvi)
Any other item which is not included here but is necessary for integrated operation of the
Transmission Line as advised by the Project Manager.
(xxvii)
The following vehicles to be delivered in accordance with Schedule No.4 Item (IV) Vehicles of
the Price Schedules shall be supplied to the office of the Chief Engineer EHV-II Hyderabad
and Head Office of the Project Manager Lahore by the Contractor within the forty five (45)
days from the date of signing of the Contract, failing which the Contractor shall arrange, free
of cost, vehicles of the same type/size and of acceptable condition for the Employer and the
Project Manager till such time the vehicles specified below are delivered. The balance
vehicles shall be provided according to the schedule intimated by the Project Manager.
Lot No.
Vehicle Description
Qty. for
Project Manager
Qty. for Employer
Lot-I
Locally Assembled Double Cabin PickUp Turbo 4x4
Lot-II
Lot-III
Locally Assembled
(1300CC) AC
Car
Sedan

NOTE:Employer (NTDC) shall not be liable to give any equipment/T&P for survey, foundation, erection and
stringing to the Contractors for this project. It is also mentioned that the stringing equipment/T&P and
other construction equipment/T&P is not available in Pakistan and the same shall have to be
arranged/imported by the Contractors at their own risk & cost.
The Contractor is responsible to mobilize sufficient numbers of crews for foundations, piling, tower
erection and stringing etc. equipped T&P complete in all respects for smooth execution of each activity.
For timely completion of the Project, Contractor is responsible to adhere to project schedule and ensure
that the sufficient resources are available with the crews before commencement of each activity.
Detailed methodology and list of T&P shall be got approved from the Engineer well before the
commencement of each activity. The detail of construction equipment/T&P to be arranged/imported
from abroad by the Contractor must be furnished in his Bid.
In case Contractor fails to arrange the required numbers of crews along with requisite T&P in good
working condition for inspection at site prior to commencement of respective activity, Employer has the
right, in addition to withhold current payments, terminate the Contract at any stage and to get
executed the balance work through other Contractors at the Contractors risk and cost.
1.2
Materials
All materials shall be of the highest grade, free from defects and imperfections, of recent manufacture
and unused, shall have suitable corrosion resistant characteristics and of the classification and grades
designated, conforming to the requirements of the latest issue of the appropriate specifications cited
herein.
1.3
Workmanship
Workmanship and general finish shall be of the highest grade, in accordance with the requirements
specified herein, and the best modern standard practice.
All components of the same design and designation shall be identical and like components shall be
interchangeable.
All necessary tests shall be performed to ensure that technical requirements are fulfilled.
1.4
Standards
Unless otherwise specified in these Specifications or in the drawings, the Contractor shall conform to
the applicable requirements of the latest revisions of the following standards or equivalent as approved
by the Project Manager. The latest applicable standards shall be those which are enforced thirty (30)
days prior to the date of Bid opening and the same shall be provided on request of the Engineer.
1.4.1
Tower Steel
(a)
ASTM A6: General Requirements for Rolled Steel Plates, Shapes, Sheet Piling and Bars for
Structural use.
(b)
ASTM A36: Standard Specification for Structural Steel.
(c)
ASTM A572: Grade 60 Standard Specification for High Strength Low-Alloy Columbium-Vanadium
Steels of Structural Quality.
(d)
EN 10025: EURONORM Standard Specification for Structural Steel; Rolled Steel, Steel Sheets
and Plates etc.

(e)
ASTM A123: Zinc (Hot Galvanized) coatings on products fabricated from rolled, pressed, and
forged steel shapes, plates, bars and strip.
(f)
ASTM A143: Safe-guarding against embrittlement of hot-dip galvanized structural steel products
and procedure for detecting embrittlement.
(g)
ASTM A563M:
Standard Specification for Carbon and Alloy Steel Nuts.
(h)
ASTM A153:
Standard Specification for Zinc Coating (Hot Dip) on Iron and Steel Hardware.
(i)
ASTM A239:
Standard Method of Test for Locating the Thinnest Spot in Zinc (Galvanized)
Coating on Iron or Steel Articles by the Preece Test (Copper Sulphate Dip).
(j)
ASTM A325:
High-strength bolts for structural steel joints including suitable nuts and plain
hardened washers.
(k)
ASTM A370:
(l)
ASTM A384:
Standard practice for safe-guarding against warpage and distortion during Hotdip Galvanizing of Steel Assemblies.
Standard test methods and definitions for mechanical testing of steel products.
(m) ASTM A394:

Bare.
Standard specification for Steel Transmission Tower Bolts, Zinc-coated and
(n)
ASTM F436:
Standard specification for hardware steel washers.
(o)
ASTM B201:
Chromatic treatment test.
(p)
ASTM E 94:
Radiographic Testing.
(q)
ASTM E109:
Dry powder magnetic particle inspection.
(r)
ISO 898-1: Mechanical Properties of Fasteners made of carbon steel and alloy steel.
(s)
DIN 267: Fasteners technical delivery conditions steel spring washers for bolt/nut assemblies.
(t)
DIN 7990: Hexagon head bolts for structural steel bolting for supply with nut.
(u)
DIN 555: M5 to M100 x 6 hexagon nuts.
(v)
DIN 127: Spring lock washers with square ends or tang ends.
(w) DIN 128: Spring lock washers, curved and wave.
1.4.2
(x)
ASCE Manual No. 74: Guidelines for Transmission Line Structural Loading prepared and
published by the American Society of Civil Engineers in 2010 (3rd Edition).
(y)
ASCE Standard 10-97:
Design of Latticed Steel Transmission Structures.
Conductor and Shield wire

(a)
ASTM A90: Standard Method of Test for Weight of Coating on Zinc Coated (galvanized) Iron or
Steel Articles.
(b)
ASTM A153: Standard Specification for Zinc Coating (Hot Dip) on Iron and Steel Hardware.

1.4.3
(c)
ASTM B230: Standard Specification for Aluminum Wire, EC-H19 for Electrical Purposes.
(d)
ASTM B232: Standard Specification for Aluminum Conductor Concentric-Lay-Stranded Coated

Steel Reinforced (ACSR).
(e)
ASTM A239: Standard Method of Test for Locating the Thinnest Spot in Zinc (Galvanized)
(f)
ASTM A363: Standard Specification for Zinc Coated (Galvanized) Steel Overhead Ground Wire
Strand.
(g)
ASTM B398: Standard Specification for Aluminum Alloy 6201-T81 Wire for Electrical purpose.
(h)
ASTM B399: Standard Specification for concentrically stranded Aluminum Alloy 6201-T81
conductors.
(i)
ASTM B498: Standard Specification for Zinc Coated Galvanized Steel Core Wire for Aluminum
Conductors Steel Reinforced (ACSR).
(j)
IEC-61089: Round wire concentric lay overhead electrical stranded conductors.
(k)
IEC-61395: Overhead electrical conductors creep test procedures for stranded conductors
(l)
Standard Method of Stress-Strain Testing of Aluminum Conductor and ACSR prepared by the
Aluminum Association.
OPGW and Associated Hardware

(a)
ITU-T G.652:
Characteristics of a single-mode optical fiber cable
(b)
ITU-T G.654:
Characteristics of a cut-off shifted single-mode optical fiber cable
(c)
IEC 60793:
Optical fibers
(d)
IEC 60794:
Optical fiber cables
(e)
EIA 598A: Color coding of optical fibers
(f)
ASTM B415: Standard specification for hard-drawn Aluminum-clad steel wires
(g)
ASTM B416: Standard specification for hard-drawn aluminum-clad steel wires
(h)
ASTM B398: Standard Specification for Aluminum-Alloy 201Aluminum-alloy 6201-T81 Wire for
Electrical Purposes
(i)
IEEE Std 1138: Construction of Composite Fiber Optic Overhead Ground Wire (OPGW) for use
on Electric Utility Power Lines
(j)
IEC 61300-2-36: Fiber Optic Interconnection Devices & Passive component-Basic Test and
Measurement Procedures Part 2-36: Tests-Flammability (Fire hazards)
(k)
IEC 60068-2-14: Joint boxes/hardware fittings
(l)
EN 60529: Protection class of cabinets/cubicles

1.4.4
Insulators and Hardware

(a)
ASTM A47: Specifications for Ferritic Malleable Iron Castings.
(b)
ASTM A143: Standard Recommended practice for safeguard against embrittlement of Hot-dip
Galvanized Structural Steel Products and Procedure for Detecting Embrittlement.
(c)
ASTM A153: Standard Specification for Zinc coating (Hot dip) on Iron & Steel Hardware.
(d)
ASTM A220: Specifications for Pearlitic Malleable Iron Castings.
(e)
ASTM A384: Standard practice for safeguarding against warpage and distortion during Hot-dip
Galvanizing of Steel Assemblies.
(f)
(g)
ASTM A536: Specifications for Ductile Iron Casting.
(h)
ASTM A668: Specifications for Steel Forgings, Carbon and Alloy, for general industrial use.
(i)
ASTM C151: Test Method for Autoclave Expansion of Portland Cement.
(j)
ANSI C29.1: American National Standard Test Methods for Electrical Power Insulators.
(k)
ANSI C29.2: American National Standard for Wet Process Porcelain and toughened Glass
Insulators.
(l)
IEC 575: Thermal mechanical performance test and mechanical performance test on string
insulator units.
(m) IEC 61284: Overhead Lines Requirements and Tests for fittings.
1.4.5
(n)
BS 3288: Insulators and Conductor fittings for overhead power lines Part I. Performance and
General Requirements.
(o)
IEC 61467: Insulators for overhead lines Insulator strings and sets for lines with a normal
voltage greater than 1000V-AC power arc tests.
(p)
IEC 60437: Radio Interference Test on High Voltage Insulators
(q)
Other relevant ANSI, ASTM and IEC standards.
Accessories and Dampers

(a)
ASTM A153: Standard Specification for Zinc coating (Hot Dip) on Iron and Steel Hardware.
(b)
ASTM A164: Standard Specification for Electrodeposited Coatings of Zinc on Steel.
(c)
(d)
ASTM D1149: Standard Test Method for Rubber Deterioration - Surface Ozone Cracking in a
Chamber.
(e)
ANSI B.1.1: "Unified Screw Threads" class 2A.

(f)
U.S Military Specifications MIL A-8025 C.
(g)
IEEE Paper No. 31 TP 65-156: Recommended Method of IEEE Task Force on Conductor
Vibration.
(h)
IEEE Paper T74 061.8: Decay Test Evaluation
(i)
IEEE Paper 31 TP 65-707: An Investigation of the Forces of Bundle Conductor Spacers under
Fault Conditions.
(j)
CISPR 18-1 (Part 1): Radio interference characteristics of overhead power lines and high voltage
equipment.
(k)
CISPR 18-2 (Part 2): Methods of measurement and procedure for determining limits.
(l)
CISPR 18-3 (Part 3): Code of practice for minimizing the generation of radio noise.
(m) IEC 61284: Overhead Lines Requirements and Tests for fittings.
1.4.6
(n)
BS3288: Insulators and Conductor fittings for overhead power lines Part I. Performance and
General Requirements.
(o)
IEC 61897: Overhead Lines Requirements and Tests for stockbridge type Aeolian vibration
dampers.
(p)
IEC 61854: Overhead Lines Requirements and Tests for spacers.
(q)
IEC 60437: Radio Interference Test on High Voltage Insulators.
(r)
IEEE 1368-2006: IEEE Guide for Aeolian Vibration Field Measurement of Overhead Conductors
(s)
Other relevant IEEE, IEC and ASTM Standards.
Transmission Line Construction

(a)
(b)
ASTM A615: Standard Specification for Deformed and Plain Billet-Steel Bars for Concrete
Reinforcement.
ASTM C33: Standard Specification for Concrete Aggregates
(c)
ASTM C39: Test Method for Compressive Strength of Cylindrical Concrete Specimens.
(d)
ASTM C150: Standard Specification for Portland Cement.
(e)
ASTM D1556:
(f)
ASTM D1557: Test Method for Laboratory Compaction Characteristics of soil Using Modified
Effort.
(g)
ASTM D1586: Standard Penetration Test
(h)
ASTM C989: Ground Granulated Blast Furnace Slag for use in concrete and mortars.
(i)
ASTM C494: Chemical Admixtures for Concrete.
(j)
ACI Building Code: Building Code Requirements for Reinforced Concrete (ACI-318M, latest
edition) and Commentary (ACI 318RM, latest edition).
Test Method for Density and Unit Weight of Soil in-place by Sand Cone Method.

1.4.7
Standards Other than those Specified

Where requirements for material or equivalent are specified by reference to a standard which has its
origin in one country, it is not the intention to restrict the requirements solely to that standard and that
country. Other standards, including standard of other countries, will be accepted provided the
requirements thereof, in the opinion of the Project Manager, are at least equal to the requirements of
the standard specified. The manufacturer may propose to the Project Manager an equivalent standard
other than that specified, in which case he shall submit the proposed standard and all other information
required in this respect and shall submit written proof that proposed standard is equivalent in all
significant respects to the standard specified. All submission must be made in the English language.
1.5
Cleaning and Galvanizing

All fabricated structural steel material and ferrous components shall be cleaned of rust, loose scale, dirt,
oil, grease and other foreign substances, after the shop work has been completed. Unless otherwise
specified or directed, all material, including bolts, nuts and washers shall be hot-dip galvanized, in
accordance with the relevant ASTM Specifications, after all shop work is completed except that nuts
shall be re-tapped after galvanizing, and threads of nuts left bare.
All structural steel shapes shall be galvanized in accordance with ASTM A123.
The coating shall be clean, smooth and free from defects. Bare spots, loosely attached spelter,
unevenness of coating, and globules which may be broken in handling, will be cause for rejection by the
Inspector.
If more than 5% of the galvanized material is rejected, galvanizing shall be stopped and the process
altered so that satisfactory work will be produced.
During galvanizing, the Inspector will carry out such tests on the coating and analysis of the spelter as
he may consider necessary.
The Preece Test will also be included in these tests which will be carried out in accordance with ASTM
Specification A239 latest edition but the required number of dips will be six (6).
All tower material shall, prior to shipping, be dipped in a suitable solution such as Sodium Bi Chromate
to protect the galvanizing from "white rust" corrosion during transit. Full details of the treatment
proposed shall be submitted to the Project Manager for Approval. The effectiveness of the treatment
shall be verified in accordance with ASTMB201.
All fabricated structural steel and plates that have been warped by the galvanizing process shall be
straightened by being re-rolled or pressed. The material shall not be hammered or otherwise
straightened in a manner that will injure the protective coating. If in the opinion of the Project Manager,
the material has been harmfully warped or bent in the process of fabrication or galvanizing, such
defects will be cause for rejection.
Material on which galvanizing has been damaged shall be redipped. Any member on which the
galvanized coating becomes damaged after having been dipped twice shall be rejected.
1.5.1
Galvanizing of Nut, Bolts and Washers.

The galvanizing of nuts, bolts and washers shall be in accordance with ASTM A153. Bolts shall be
galvanized in such a manner that the Zinc in the threads will not interfere with the application of the nut.
Re-threading of bolt threads after galvanizing will not be permitted.

1.6
10
Inspection
All work covered by this specification, and the inspection thereof by the Contractor, shall be subject to
surveillance and/or further inspection by the Project Manager. The Contractor's inspector shall include,
but not necessarily limit his duties to the following:
A.
Material
The Contractor shall:

(i)
Work only to those specifications provided herein and/or as specified by the Project Manager.
(ii)
Inspect the following materials for both quality and dimensions.

(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i)
Structural steel
Sheet steel
Nut and bolts
Washers and fillers
Conductor
Overhead EHS shield wire and OPGW along with associated equipment and hardware
Insulators, Hardware & Grounding Material
Conductor & Shield wire Accessories
Dampers for Conductor, EHS Shield wire and OPGW
(iii) Check and remit to the Project Manager certified copies of the mill sheets covering the total
quantity of the above applicable material.
B.
Fabrication & Manufacturing Process
The Contractor shall:

(i)
Work only to drawings and specifications approved by the Project Manager.
(ii)
Be responsible for ascertaining that all fabrication is carried out in compliance with the following:
(a)
(b)
(c)
(d)
(e)
(f)
Exact shop drawing dimensions and notes

The appropriate specifications
Good shop practice
Bending according to Clause 2.1.3.2 for tower steel herein
Member markings, corresponding to those shown on the detail drawings, are clearly
stamped on each individual member.
Galvanizing in accordance with the ASTM standards.
(iii) Inspect the fabrication for all the foregoing items, (a) to (e) of A(ii) before galvanizing, and check
that no further fabrication is carried out after galvanizing where dissimilar metals are used,
suitable precautions shall be taken at the metal interface to prevent electrolytic corrosion.
(iv) Casting of ferrous materials is not permitted, except for components not subject to stress.
(v)
All ferrous components which have been cold formed & forged shall be normalized or otherwise
heat treated to relieve stresses before galvanizing, if applicable.
(vi) Threads may be either cut or rolled except that the threads of ferrous bolts which are to be
installed with a given torque value shall be rolled after galvanizing.

11
(vii) Necessary precautions shall be taken to prevent embrittlement of ferrous components, as

specified in ASTM A143 & A384.
Periodically check the galvanizing against the appropriate specification requirements, which include the
testing of the galvanizing bond by the use of the Chisel-faced hammer.
C.
Note and have corrected such items as:

1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
D.
E.
Quality of materials not complying with specifications;

Incorrect quantities;
Incorrect dimensions and sizes;
Missing components and holes;
Substitution of unapproved material;
Incorrect location of bolt holes;
Burrs on punched holes;
Conically punched holes due to poor dies;
Under-sized members;
Members not bent or incorrectly bent; and
Left and Right of members not correctly bent or punched.
Electrical Requirements
1.
The corona extinction voltage shall not be less than 346 kV line to ground. All energized
hardware assemblies shall be corona free at this voltage.
2.
All energized hardware shall be designed and constructed so that the potential difference
between the conductors and any part of energized hardware will not exceed 300 V.
3.
If the Manufacturer cannot show, to the satisfaction of the Project Manager, that the
materials have been previously subjected to corona testing to the levels specified, then
the Manufacturer shall submit to the Project Manager a proposal for corona testing.
Following the Project Managers approval of the Manufacturer's proposed test program,
the Manufacturer shall carry out these tests and if required shall modify his design so
that the requirements are all met at no expense to the Employer.
Testing and Quality Control

1.
2.
It shall be the Manufacturer's responsibility to provide and perform all the inspection and
testing necessary to ensure compliance with these specifications.
Quality surveillance will be provided by the Project Manager or his authorized
representative (hereinafter called "the Inspector").
3.
The Inspector shall have free access to those parts of the Manufacturer's Works that
concern the manufacturing of this material at all times while work on this Contract is
being performed. The Manufacturer shall provide the Inspector, with all reasonable
facilities to enable him to be satisfied that the material is being furnished in accordance
with these specifications.
4.
The Inspector shall have the authority to ask any additional testing or inspection he
considers necessary in order to ensure compliance with the specifications and drawings.
5.
The Inspector's decision for acceptance or rejection of any work shall be final.

F.
Quality Control
1.
The Manufacturer shall ensure that an adequate system of marking and/or coding of
production lots for components are maintained. Once a size of production lot for a
component is established, the size of that production lot shall remain constant until the
work on the contract is completed.
2.
Standards to be checked, in the Manufacturer's Quality Control Plan shall include, but
not be limited to the following:
3.
G.
12
(a)
Dimensional tolerances;
(b)
Quality, surface finish and ease of fit;
(c)
Assembly procedures and requirements; and
(d)
Production tests.
The schedule of production tests may be amended or changed by the Project Manager
at any time prior to the completion of this Contract.
Reports
Inspector shall submit to the Project Manager four (4) copies of his inspection report, covering the
following:
1.
Progress of fabrication;
2.
Progress of fabrication and galvanizing for steel;
3.
Any change in completion dates;
4.
Substitution of material;
5.
Detailed remarks on any technical difficulties; and
6.
Detailed remarks on any material rejected before fabrication, after fabrication and after
galvanizing.
Whether the Employer and Project Manager are present or not, the Contractor shall carry out all
tests as specified in the relevant standard and he shall supply the Project Manager with three (3)
copies of all test data obtained.
2.
STEELTOWERS
2.1
Scope
This specification covers the technical requirements of manufacturing and testing of transmission line
towers.
2.1.1
Type of Towers
Following types of towers shall be used.

13
Single Circuit Suspension Tower Type SGM

Single circuit suspension tower type SGM will be utilized for straight line position or maximum line
angle of 2.The tower consists of a 25.22 m basic body, 4.5 m & 9.0 m body extension of and leg
extensions of 1.5 m, 3.0 m, 4.5 m & 6.0 m. Maximum wind and weight spans at 0 line angle will be 410
m & 500m respectively.
Single Circuit Suspension Tower Type T
Single circuit suspension tower type T will be utilized for straight line position or maximum line angle
of 2. The tower consists of a 25.11 m basic body, 6.0 m body extension and leg extensions of 2.0 m,
4.0 m, 6.0 m &8.0 m. Maximum wind and weight spans at 2 line angle will be 410 m & 500 m
respectively.
Single Circuit Transposition Tower Type TGM
Single circuit transposition tower type TGM will be utilized for straight line position. The tower consists
of a 25.22 m basic body, 4.5 m body extension and 6.0 m leg extension. Maximum wind and weight
spans will be 410 m & 500 m respectively.
Single Circuit Tower Type TR
Single circuit transposition tower type TR will be utilized for straight line position. The tower consists of
a 25.11 m basic body, 6.0 m body extension and 6.0 m leg extension. Maximum wind and weight
spans will be 410 m & 500 m respectively.
Single Circuit Light Angle Tower Type AGM
Single circuit strain tower type AGM will be utilized for line angles up to 20.The tower consists of a
21.33 m basic body,4.6 m & 9.1 m body extensions and leg extension of 1.5 m, 3.1 m, 4.6 m & 6.1 m.
Maximum wind and weight spans at 20 line angle will be 366 m &610 m respectively.
Single Circuit Light Angle Tower Type M
Single circuit strain tower type M will be utilized for line angles up to 30. The tower consists of a
23.23 m basic body, 6.0 m body extensions and leg extension of 2.0 m, 4.0 m, 6.0 m &8.0 m. Maximum
wind and weight spans at 30 line angle will be 410 m & 800 m respectively.
Single Circuit Heavy Angle/Terminal Tower Type DGM
Single circuit strain tower type DGM will be utilized for line angles up to 60 and 20 in terminal
condition. The tower consists of a 21.33 m basic body, 4.6 m & 9.1 m body extension and leg extension
of 1.5 m, 3.1 m, 4.6 m & 6.1 m. Maximum wind and weight spans will be 366 m & 610 m respectively for
line angles up to 60 and 20 in terminal condition.
Single Circuit Heavy Angle/Terminal Tower Type D
Single circuit strain tower type D will be utilized for line angles up to 60 and 20 in terminal condition.
The tower consists of a 23.23 m basic body, 6.0 m body extension and leg extension of 2.0 m, 4.0 m,
6.0 m &8.0 m. Maximum wind and weight spans will be 410 m & 800 m respectively for line angles up
to 60 and 20 in terminal condition.
2.1.2
Drawings
Detailed shop drawings to be used to fabricate the towers are attached in Volume-III of the Bidding
Documents.

14
If any changes are made to suit conditions in the country of origin for good and sufficient reasons, the
burden of proof shall be on the Contractor to show that such change or changes will result in completed
tower/towers of equal or increased capability.
No work shall be commenced prior to written approval of the Project Manager.
2.1.3
2.1.3.1
Connection Details
The connection details for insulator hardware, EHS shield wire & OPGW hardware shall be similar to
the typical details shown on the drawings. Holes for moving parts shall be drilled and chamfered unless
otherwise specified. Such holes shall have adequate bearing area and in addition to the normal edge
distance shall have an extra 6.5 mm edge distance to provide for wear.
Details of holes for danger signs, number signs, phase plates, aerial markers, grounding and anticlimbing devices shall be in accordance with Specification Drawings.
2.1.3.2
Structural Steel
All rolled steel sections, plates shall be supplied in accordance with latest edition of ASTM A572 Grade
60 High Strength Low-Alloy Columbium-Vanadium Steel of Structural quality, EN10025 S355J2 and
ASTM-A36. In addition to requirements specified herein and in the relevant standards, the offered steel
shall withstand the following bend test requirements. However, procedure of bend test requirement
shall be followed as per ASTM A370.
Type of Steel
Thickness of Material
- Mild steel
- High tensile steel
for all thickness

up to 25 mm
Over 25 mm
Ratio of bend dia. to

thickness of specimen at 180
1.5
1.5
2.0
For the fabrication of the towers, the Contractor may propose the use of any steel, provided that the
proposed steel have characteristics and properties equal to or better than those listed for steel
mentioned in the specifications.
2.1.3.3
Nut, Bolts and Washers

For all types of towers, all connections shall be secured by bolts, nuts, plain and spring washers.
Hexagonal head bolts and hexagonal nuts shall be used. Only one plain and one spring washer per bolt
shall be used.
Bolts shall be designed for only bearing and shear and the shank of all bolts except U-bolts shall extend
completely through all connected members. When in position bolts shall project through the
corresponding nuts neither less than 2 thread lengths nor greater than 10 mm. Members shall not bear
on thread. Washers shall be used under all nuts. Bolts shall be free from fins, scale or other defects and
the head shall be concentric and square with the shank. The diameter of the shank shall be full nominal
size of the bolts. The ends shall be sharp and clean and of the proper contour.
All U-bolts shall be threaded for a sufficient length to take two standard nuts plus member and washer
thicknesses.
Step bolts shall be provided as shown in the drawings.

15
Nuts shall be of sufficient height to develop the full strength of the bolt. Threads must not be torn or
ragged and shall be of proper contour. The nuts shall fit the bolts after they have been galvanized so
that they can be started and threaded by hand for the full length of the bolt thread.
The fit of the nut on to the bolt shall be such that no rocking of the nut will occur.
Nut and bolt of the same size shall be interchangeable. The bolt related dimensions for fabrication can
be referred from DIN 7990 and nut according to DIN 555. The length of bolts shall be calculated to
accommodate the thickness of one plain and one spring washer.
Material of bolts and nuts shall conform to ASTM A325 and/or ISO 898 standards.
The dimensions and material of plain washers (circular) shall be according to ASTM F436.
The dimensions and material of spring lock washers shall be according to DIN127 and 128.
At least 5% surplus of bolts, nuts and washers shall be supplied to cope with losses and future
maintenance.
The fabricated material shall not have physical properties inferior to those specified.
Bolt hole diameter shall not exceed the nominal diameter of the fastener plus 1.5 mm.
Ring fillers for the towers to be supplied in accordance with the dimensions given in the drawing No.
3206/169/TD/01F203. The material of ring filler shall conform to the properties of mild steel as per
ASTM A36.
The minimum edge distance of bolts shall be as follows:
(i)
Minimum Edge Distance: The minimum edge distances measured from the centre of the
bolt hole to the end of the member shall be as follows:
(a)
For Compression Members: One and one-half bolt diameters.
(b)
For Tension Members: In an end connection of not more than three bolts the end
distance shall not be less than that given in (a) above or the following quantity,
whichever is greater.
Minimum Bolt Diameter

16 mm
20 mm
24 mm
Minimum Edge Distance

Rolled Edge
Sheared &Mechanical
Guided
19 mm
26 mm
30 mm
(c)
For gusset plates one and one-half bolt diameter.
(d)
Minimum spacing of bolts shall be as follows:

Bolt Diameter
16 mm
20 mm
24 mm
24 mm
30 mm
38 mm
Minimum Bolt Spacing

35 mm
45 mm
55 mm
2.1.3.4
16
Workmanship
The workmanship and finish throughout shall be of a quality equal to the best that is known to the art at
the present time for this class of work. All work shall be carefully and accurately performed.
Members shall be cut to jig and holes shall be drilled or punched to jig. All holes shall be cylindrical and
perpendicular to the member. Where necessary to avoid distortion of holes close to the points of bends,
the holes shall be made after bending.
Fabricated steel work shall be in accordance with the drawings, and drilling, punching, cutting and
bending shall be carefully and accurately performed to prevent any possibility of irregularities occurring
which might introduce difficulty in the erection of towers or result in straining or distortion of the parts
thereof.
2.1.3.5
Bending
Tower members which are cold bent shall be normalized before galvanizing. Hot bending is preferred.
The heating shall be done in an oven, so that the member is uniformly heated to a distance of
approximately 150 mm either side of the bend point. Proper heat treating procedures shall be used in
order to preserve the original physical properties of the metal. Bending of thick members shall be done
in a hydraulic press with a suitable die to prevent buckling of an unrestrained leg. This process shall not
be done under quick impact but through a slow moving press.
2.1.3.6
Punching & Drilling

Punching and drilling shall be done by methods designed to ensure accuracy. The center of any hole
shall not vary more than 1.5 mm from its position neither shall the center to center distance of end holes
in a group of holes vary by more than 1.5 mm. Plugging and welding of drilled holes shall not be
permitted.
Drills, punches and dies shall be sharp and true, and holes shall be round, true to size, and free from
ragged edges and burrs.
Bolt holes shall have diameter 1.5 mm larger than the nominal diameter of the bolt.
It is preferable to have fabrication, punching and drilling carried out by means of a modern computer
program technique.
All holes in material over 19.0 mm in thickness shall either be drilled or sub-drilled and reamed.
For high tensile steel (yield point equal or greater than 35 kg/mm) holes shall be directly drilled at the
definitive diameter or punched and reamed out. The difference between the punched and reamed
diameter shall be at the minimum 4mm.
The die for all sub-punched holes, and the drill for sub-drilled holes, shall be at least 1.5 mm smaller
than the diameter of the bolt. Drifting to enlarge holes shall not be permitted.
2.1.3.7
Welding
Welding of structure members, filling or plugging of defective parts and mispunched holes shall not be
permitted in tower fabrication. When holes are mispunched so that the net section of a member is
decreased, the member shall be discarded. However, if welding cannot be avoided and is required in
certain structure components, such as for rigging/attachment plates, prior written approval shall be
obtained. In such cases welding procedures shall comply with ANSI/AWS D1.1M standards. Special
care shall be taken regarding seal welding to assure proper galvanizing and to avoid acid bleeding at
pockets in structural assemblies.

2.1.3.8
17
General Requirements for Fabrication

The towers shall be fabricated having members sizes according to the approved drawings. No angle
substitution shall be allowed for main leg and cross arm members and stubs. However member
substitution for other tower members and redundant or secondary members may be allowed with the
prior approval of the Project Manager. In such a case the total number of member substitution would
not exceed three (3).
2.1.3.9
Allowance for Galvanizing

Allowance shall be made in gauge dimensions for the thickness of galvanizing and the possible
formation of spelter fillets inside the angles so as to allow adequate erection clearance after
galvanizing.
2.1.3.10
Blocking
Blocking of outer legs of angles will not be permitted.
2.1.3.11
Angle Laps
Where angles are lap spliced, the heel of the inside angle shall be chamfered to clear the fillet of the
outside angle.
2.1.4
Marking
All structural members shall be marked with the correct designation shown on the shop drawing.
Marking shall be done by stamping the members prior to galvanizing with numerals or letters of 12mm
minimum height, and shall be clearly legible after galvanizing.
2.1.5
Tolerances
Ease of assembling the structure in the field is of utmost importance. The structure shall be so
manufactured that all members carrying the same mark shall be interchangeable when assembled. The
structure shall fit without undue pressing and no reaming or drifting of holes shall be required. When
erected, the structures shall not deviate from the vertical by more than 1/300 ratio.
The Manufacturer shall be responsible for the correct fitting of all parts and shall replace free of cost
any defective materials discovered during erection and shall pay all costs of the correction in the field of
any errors not previously discovered.
The permissible variation from dimensions for structural size steel shapes shall not exceed the
prescribed limits in ASTM A6.
2.1.6
Drawings
The Manufacturer will be supplied the drawings indicating various dimensions, angle sizes used, sizes
of bolts used, type of steel and various standards/process to be followed for fabrication and galvanizing
of the structure.
After approval of contract, the Manufacturer shall submit for approval, the following drawings.
(a)
Shop Details Drawings:

The detailed drawings shall show shop details including dimensions, shearing, punching, bevel
cutting, bending and identification mark and weight for each member.

(b)
18
Erection Drawings:
Erection drawings shall show the complete assembly of the structure indicating clearly the
positioning of the members. Each member shall be piece-marked and the number and lengths of
bolts shall be given for each connection. Shop details may be shown either by assembled
sections (in place) or piece by piece (knocked down)
(c)
Footing Installation Drawings:

Footing erection drawings showing each member with its identification mark, number and size of
connection bolts and all dimensions required for the proper setting and positioning of stub angle
footings with relation to the centre of the structure.
(d)
Bills of Material:
Bills of material for each tower shall show the quantity, type, size, length; weight and assembly
mark for each member, including bolts, washers, plates and all fittings complete for each
structure.
(e)
Outline Drawing:
The Manufacturer shall prepare single line diagram from the detailed drawings shall show the
complete information like dimensions and member, angle sizes.
2.1.7
Sign Plates
All the plates i.e. danger sign, number & phase plates and aerial markers shall be baked ceramic
surfaces on high grade steel base plates of minimum thickness of 1.5 mm except aerial marker plate
which shall be of 3.0 mm thickness. The fabrication details and dimensions of the plates are shown on
the drawing Nos.3206/169/TD/01E206 & 207.
The plates shall be painted with ceramic paint on both sides and they shall be thoroughly cleaned
before painting and the ceramic paint shall completely cover the front and back of the plates and also
the edges of plates and the interior edges of the attachment holes. The ceramic paint shall be of even
thickness, reasonably free from cracks, patches, pin holes, blisters and shall have a uniform gloss. The
ceramic paint around the holes shall be protected by means of fiber washers.
Three coats of ceramic paint shall be applied on the danger sign and number plates. The first coating
of black ceramic paint shall be applied on both sides of the plates. The other two coats of white ceramic
paint shall be applied on the front side of the danger & number plates and yellow on aerial marker
plates.
In case of phase plates, three coats of ceramic paint shall be applied. The first coat of black ceramic
paint shall be applied on both sides. The other two coats of red, yellow and blue colour shall be applied
as specified on both side of the plate.
Nos. of bolts, nuts, washers and fixtures where required shall be supplied with each plate as shown in
the drawings. Bolts, nuts and washers to be supplied with the fixture shall be galvanized in accordance
with ASTM A153.
2.1.8
Barbed Wire
Material, dimensions and testing of the barbed wire shall be in accordance with ASTM A121.
The size and characteristics of the zinc coated barbed wire shall be as per design number 12-2-4-14R,
Type Z with Class 3 coating.

19
2.2
Tests for Tower Steel, Associated Hardware and Accessories
2.2.1
Manufacturer's Tests
The Manufacturer shall select two samples from each heat to carry out the following tests to satisfy him
that the products comply with the specifications.
(a)
For Sections and Plates

1.
2.
3.
(b)
For Nuts and Bolts

1.
2.
3.
4.
5.
6.
(c)
Chemical composition (Ladle Analysis)

Tensile Tests
Bend Tests
Proof Load test

Ultimate Tensile Strength test
Ultimate tensile strength test under eccentric load
Cold bend test
Hardness test
Galvanizing test
For Washers and Ring Fillers

1.
2.
Hardness test
Galvanizing test
The Manufacturer shall maintain a record of tests carried out by him for examination by Inspector.
2.2.2
Prototype Testing
2.2.2.1
Prototype Tower Assembly

Before starting prototype load testing of towers type M and D, one tower of each type of maximum
height combination of body and leg extensions shall be shop assembled and vertically erected on a
suitable foundation bed to assure proper fit of all parts. Following should be kept in view during
prototype tower assembly.
(a)
Check carefully each member while assembling the prototype to revise and amend the detailed
drawings according to the correct solution;
(b)
For each member, the length, position of holes and interface with other members shall be
checked accurately for proper fitness;
(c)
Quantity of each member and bolts shall be carefully checked from the bill of materials when
assembling the prototype;
(d)
On the assembled tower eventual modifications shall be examined and performed, if necessary,
without modifying the functionality of the structure; and
(e)
Drawings and bill of materials, sizes of bolts, fillers etc. shall be put up-to-date accordingly, in all
details before starting mass production.
All changes/modifications incorporated in the drawings shall be brought to the notice of Project
Manager along with corrected final copies of the drawings for approval. The Manufacturer shall also
submit details of all the changes/modifications carried out.

2.2.2.2
20
Prototype Load Testing

(i)
Scope of Tests
Full scale tower tests shall be made on towers type M & D of maximum height as shown on the
drawings. Five cases are to be tested to the ultimate design loads without failure. The towers will then
be tested to destruction. Load cases shall be provided by the Project Manager. In case any
reinforcement/modification is required in the tower during the prototype testing, the Contractor shall be
paid for the additional weight of steel used in the supply of M & D type towers in accordance with the
applicable unit rate of steel calculated as per Schedule No. 1 or 2 of Schedule of Prices. In case of
retesting of tower, all material required on account of reinforcement/modification shall remain the
responsibility of the Contractor and all costs in this respect shall be deemed to be included in the Bid
price.
(ii)
Test Foundations
The tower maximum height shall be erected on a foundation structure and tower anchorage which shall
be of adequate strength and stiffness to withstand safely the tower reactions under test loadings without
any mobility. Tower members shall be connected to the anchorage with the same member size and
spacing of bolts as used in the normal stub angle details thus simulating the conditions which will be
encountered in service.
(iii)
Check of Quality of Materials Used for Test Tower
(a)
If the materials used for the fabrication of the test tower are selected at random from the
Contractor's stocks and if they can be considered as representative of the materials used in
production structures, no limitation shall be required on their yield point and ultimate tensile
strength value, and no tolerances of their geometrical dimensions other than those specified to
the material supplier.
(b)
If this requirement is not satisfied, the material of the test tower shall be checked for mechanical
characteristics and dimension tolerances. The tower testing shall not be considered complete
without material testing.
(c)
The test shall be considered satisfactory if bending and compression members with slenderness
ratios smaller than 150 and tension members have the following average yield point:
(i)
Steel members having a minimum guaranteed yield point lower or equal to 26 kg/mm2.
Average value guaranteed minimum value x 1.25
(ii)
Steel members having a minimum guaranteed yield point lower or equal to 35 kg/mm2.
(iii)
Steel members having a minimum guaranteed yield point lower or equal to 42kg/mm2.
(iv)
Steel members having a minimum guaranteed yield point lower or equal to 46 kg/mm.
The averages are obtained from eight test specimens taken from eight different most heavily loaded
members of the structure for each grade of material.
However, for members with slenderness ratio higher than those indicated in clause 2.2.2.2(iii) above
and for redundant members, the above limit may be exceeded since their yield point has little influence
on their collapse.

21
For the average value of the ultimate strength the following limit shall be accepted.
Average value less than guaranteed minimum value x 1.2.
(iv)
(d)
The average is obtained from the eight test specimens used for the determination of the average
value of the yield point of the material.
(e)
If all these conditions are not satisfied, the test is not valid and the test tower shall be rejected.
Project Manager Approval
Prior to testing, the Contractor shall submit for approval of the Project Manager a line diagram showing
a layout of the test site, rigging, location of load measuring instruments to be used and a series of line
diagrams showing the loads to be applied, taking into account the weight of rigging and angle of load
application. The Contractor shall submit for approval a tabulated form on which the applied load and
corresponding deflection readings will be entered for each load case.
The Project Manager may require from the Contractor to install strain gauges on leg and other
members carrying high compression loads to monitor closely their behavior during failure under critical
load cases. All costs related to this installation shall be deemed to be included in the bid price.
(v)
Test Facilities
Test frame at the test site shall be capable of handling ultimate loads with safety. Test frame shall be
capable of handling increased loads during destruction testing with adequate safety of personnel
working on the test facility.
Load lines shall be attached to the load points on steel structure in a manner that simulates the inservice load application as much as possible. The attachment hardware for the test shall have the same
degree of movement as in the in-service hardware. If the applied loads are not measured at the point of
application and sheaves (only roller bearing type permitted) are to be located between point of load
application and the load measuring device, then an additional 5% load may be added to all applied
loads to offset friction drag in the rigging. This requirement can be adjusted where the Testing Station
Staff can verify the actual fraction drag.
Where the Vee-strings or other multi-leg insulator assemblies are part of the structure design, test loads
shall be applied at the conductor attachment points. The Vee-strings shall be simulated using a series
of straps to ensure complete transverse and vertical articulation (i.e. the linkage shall not be capable of
withstanding compressive forces).
Wind loads on structure body shall be applied at panel points.
(vi)
Load Monitoring Equipment
The load monitoring equipment shall be electronic transducers complete with appropriate digital readout meters and recorders with an overall accuracy 1%. All load monitoring equipment shall be
calibrated before and after testing of the towers in the presence of inspectors.
The Project Manager may require from the Contractor to install strain gauges on leg and other
members carrying high compression loads to monitor closely their behaviour during failure under critical
load cases. All costs related to this installation shall be deemed to be included in the bid price.
(vii)
Deflection Measurement
Longitudinal deflections of the tower under incremental loading for each test case shall be measured at
the top of each shield wire peak and at the ends of cross arms. Transverse deflections shall be
measured at the centre of tower waist level. Deflection readings shall be recorded for the before-load,

22
load-on, and load-off condition as well as during intermediate holds during loading. All deflections
shall be referenced to common base readings, such as the initial positions taken before any test loads
are applied. Measurements shall be recorded photographically.
(viii)
Tower Assembly
The test tower shall be sub-assembled on the ground and erected on the test bed using a crane or a
gin pole. The tower shall be erected so that the vertical axis through the centre of gravity shall not be
out of plumb by more than 25 mm for every 12 m height.
(ix)
Witnessing
The tower test shall be carried out in the presence of personnel of the Project Manager and the
Employer.
(x)
Test Procedure
The ultimate loads shall be applied. The drawing showing the combination of loads for testing shall be
supplied by the Project Manager at a later stage. The loads shall be applied in increments of 50%, 75%,
90%, 95% and 100% of the ultimate loads. Each test loading shall be applied according to the drawings
and maintained for not less than 5 minutes, during which time there shall be no slacking or adjustment
of the loads. Should it become necessary to adjust the loading the 5 minutes period shall start after the
loading is stabilized and constant. All test loads shall be removed completely in a controlled manner to
avoid overstressing any members before the loads for the next test are applied. All test loads
corresponding to conductor and ground wire loading shall be applied directly to the regular attachment
details provided for these loads. Test loads equivalent to wind load on the tower shall be applied at
specified panel locations. To ensure application of full test loads to the tower, friction losses in rigging
shall be added to specified loads, if there is rigging between the tower and the load measuring device.
Application of impact loads shall be avoided.
(xi)
Failure due to Faulty Workmanship or Material
Any conspicuous yielding or any failure under any of the above test loading shall be considered a
defect. If a defect develops because of faulty workmanship or materials, the Contractor shall correct the
defect and repeat the test loading at his own expense, including any additional cost incurred by the
Employer for the witnessing of the repeat test loading by the Project Manager.
(xii) Test to Destruction
After tower has been tested in accordance with the foregoing requirements, the test tower shall be
tested to destruction as directed. Test samples shall be cut from members which fail in the destruction
tests and from those members indicated as most critical by low capacity to load ratios, and standard
tensile tests shall be performed at the Contractor's expense. Upon completion of the testing,
disassembly of the structure shall include inspection of all members for any evidence of excessive
permanent set, shear failure of the bolts, or member failure in bearing not determined during the fullscale testing program.
All design and detailing defects determined during the tests or during the disassembly shall be
considered as having incurred and shall be corrected on all structures of that type.
(xiii)
Ownership
Each member of the tower structure fabricated for testing shall be punched as TEST. After the test to
destruction of the test tower, all test tower materials shall become the property of the Contractor.
No parts of this tower shall be used in any tower to be furnished for this Project.

23
(xiv) Report on Testing
Within thirty (30) days following completion of the tower tests, the Contractor shall furnish full reports in
quadruplicate of all tower tested, shall include the following data:
(a) The type of tested tower;
(b) The name and address of the tower manufacturer and of the tower designer;
(c) The name and address of the client;
(d) The dates and location of testing;
(e) The names of persons present during the tests;
(f) A list of various assembly and detail drawings relating to the tower tested, including any
modification of the drawings referred to;
(g) A dimensioned line diagram of the tower showing the various load points and directions of loading
to be applied and a table with the specified loads;
(h) Diagram showing the rigging arrangement used to apply the test loads;
(i) Brief description of the test facility including the number, location, range and calibration charts or
tables of every loads transducer or other load measuring devices, as well as the accuracy of the
equipment used to measure the test loads;
(j) One table per test showing the loads required at the various points on the structure and for the
various loading steps;
(k) One table per test showing the various deflection values measured; and in the case of failure:
(l) a table showing the maximum loads applied to the structure just before the collapse;
(m) a brief description of the failure;
(n) the dimensional and mechanical characteristics of the failed elements.
(o) Photographs showing the whole of the structure and details of the possible failure.
(p) Environmental meteorological data during the sequences of tests.
(xv)
Colour Coding
Critical members on the tower shall be colour coded prior to the test.
2.2.3
Acceptance Tests
2.2.3.1
Acceptance Tests for Sections and Plates
2.2.3.1.1
For Sections and Plates, the following acceptance tests shall be carried out:
(i)
(ii)
(iii)
(iv)
Visual examination
Verification of dimensions
Chemical composition
Tensile tests

24
(v) Bend tests

(vi) Galvanizing tests
(vii) Prototype Tower Assembly
The Contractor shall render all necessary assistance to the Inspector in carrying out above mentioned
tests.
(i)
Visual Examination:
Samples for the tests shall be visually examined but not limited for material type, shape,
galvanizing and generally finish with respect to applicable specifications and drawings.
(ii)
Verification of dimensions:
The binding dimensions of the material shall be measured as shown on the relevant approved
drawings subject to the tolerances given in ASTM A6.
Weight of each tower type
in the offered Lot
600 tons
>600tons and 1000tons
>1000tons and 1400tons
>1400tons
Minimum nos. of samples to be taken from

each type of tower
15
20
25
30
(iii) Chemical Composition:

To indicate adequately, the chemical composition of a heat or a lot, the minimum number of
samples of each grade of steel selected to represent the heat shall be as follows:
500 tons or more
500 tons or less
No. of Samples
2
1
If a sample fails to meet the requirement, the material of the respective steel grade in the lot shall
be rejected.
(iv & v)Tensile and Bend Tests:
Sampling plan for tension and bend tests shall be made for each grade of steel as per following
Table from the offered lot.
Weight of the finished shape of angle section/plate of
each steel grade in the offered Lot
600 tons.
>600 and 1000 tons.
>1000 tons and 1400 tons.
>1400 tons
Tension Test
Bend Test
4
8
12
15
2
4
6
8
If a test sample fails to meet the specified requirements then four more samples shall be selected
for tension and bend tests from the same grade of steel. If a test sample fails in the retest then
the respective steel grade of the offered lot shall be rejected.

25
(vi) Galvanizing Tests:

To check that whether the galvanization is according to the specified standard or not, following
tests shall be carried out on all ferrous parts complying with the following requirements.
(a)
(b)
(c)
(d)
Weight of zinc coating

Uniformity of zinc coating (minimum no. of dips shall be six (6))
Adherence of zinc coating
Embrittlement test
Sampling for determination of compliance to the tests specified shall be performed in accordance
with relevant ASTM Specification and shall be taken from each lot. The lot shall consist of a
quantity as specified in the relevant specifications.
(vii) Before starting mass fabrication of towers, one tower of each type including all combinations of
body and leg extensions shall be shop assembled and vertically erected on a suitable foundation
bed to assure proper fit of all parts as finally manufactured. Following should be kept in view
during shop assembly:
(a)
Check carefully each member while assembling the prototype to revise and amend the
detailed drawings according to the correct solution;
(b)
For each member, the length, position of holes and interface with other members shall
be checked accurately for proper fitness;
(c)
Quantity of each member and bolts shall be carefully checked from the bill of materials
when assembling the prototype;
(d)
On the assembled tower eventual modifications shall be examined and performed, if

necessary, without modifying the functionality of the structure; and
(e)
Drawings and bill of materials, sizes of bolts, fillers etc. shall be put up-to-date
accordingly, in all details before starting mass production.
All changes/modifications incorporated in the drawings shall be brought to the notice of Project
Manager along with corrected final copies of the drawings for approval. The Manufacturer shall also
submit details of all the changes/ modifications carried out.
The Project Manager may witness a shop assembly of any or all types of towers before shipment.
2.2.3.1.2
For Nuts and Bolts, the following acceptance tests shall be carried out:
(i)
(ii)
(iii)
Visual inspection
Verifications of dimensions
Mechanical Tests
(a)
(b)
(c)
(iv)
(v)
Proof load test

Ultimate tensile strength test
Ultimate tensile strength test under eccentric load
Galvanizing tests
Hardness test (Alternatively to Ultimate Tensile Strength for the bolts less than M16x35).
The Contractor shall render all necessary assistance to the Inspector in carrying out above-mentioned
tests.

(i)
26
Visual Inspection:
The inspection shall cover finish defects such as rough galvanizing, bare spots, fins and any other
defects not permissible under the specifications.
(ii)
Verification of Dimensions:
The dimensions of the nuts and bolts shall be checked according to the specified standard
hereinabove.
(iii) Mechanical Tests:

(a) Proof Load Test (b) Ultimate Tensile Strength Test (c) Ultimate tensile strength test under
eccentric load.
These tests shall be carried out on the selected samples as per the test procedure defined in the
relevant specifications.
(iv) Galvanizing:
The galvanizing tests shall be carried out as per relevant ASTM standard, however required
number of dips will be six for the preece test.
(v)
Hardness Test:
These tests shall be carried out on the selected samples of the bolts which shall have size less
than M16x35 and shall not be undergo for tensile tests.
Sampling, Acceptance and Rejection:

Lot offered for inspection should be according to the size of bolts i.e. M16, M20 & M24. Each lot shall
be divided into the batches of 5000 units (1 unit = 1 nut & bolt). Five units shall be selected from a
batch of 5000 units or lesser in quantity and shall be tested for the above tests in the order as defined
herein above except the galvanizing tests for which sampling shall be as per ASTM A153. If any unit
selected from a batch fails (even if only bolt or nut) to meet the requirements of specified tests then five
more units shall be selected at random from the same batch for retesting. If during retesting, the entire
unit meets the specified requirements then the batch shall be accepted and, if any unit does not meet
the specified requirement during retesting, the lot of that size shall be rejected.
2.2.3.2
Acceptance Tests for Plain & Spring Lock Washers and Ring Fillers
The following acceptance tests on spring lock washers, plain washers and ring fillers shall be carried
out:
(i)
Verifications of dimensions
(ii)
Visual inspection
Tests shall be carried out as per DIN127

& 128 on spring lock washers for ring fillers as per
drawing
(iii) Galvanizing tests
As per ASTM A153
(iv) Hardness test
Tests as per DIN 127 & 128 on

spring lock washers, ASTM F436
on plain washers and as per
ASTM A36 on ring fillers.

(v)
27
Twist test for spring lock washer
(vi) Spring force test
Tests shall be carried out as per

DIN267 on spring lock washers only
The Contractor shall render all necessary assistance to the Inspector in carrying out above mentioned
tests.
Lot offered for inspection should be according to the size of spring lock washers and ring fillers i.e. M16,
M20 & M24. Each lot shall be divided into batches of 5000 units. Three units shall be selected from a
batch of 5000 units or lesser in quantity and shall be tested for the above tests in the order as defined
herein above, except the galvanizing tests for which sampling shall be as per ASTM A153. Two
samples each shall be selected from M16, M20 & M24 sizes for twist test for spring lock washer and
spring force test from the lot having a quantity of less than 20,000 and four samples each from the lot
having a quantity of more than 20,000. If any unit selected from a batch fails to meet the requirements
of specified tests then five more samples shall be selected at random from the same batch for retesting.
If during retesting, the entire unit meets the specified requirements then the batch shall be accepted
and if any sample does not meet the specified requirements during retesting the lot of that size shall be
rejected.
Plain washers (circular) shall meet the material and testing requirements as per ASTM F436M.
2.2.3.3
Acceptance Tests for Sign & Number Plates and Aerial Markers
The following acceptance tests for Sign & Number Plates and Aerial Markers shall be carried out:
(i)
(ii)
(iii)
(iv)
Visual examination
Galvanizing test (on fixture and nuts & bolts only)
Resistance to thermal shock (vitreous enamel finish)
(i)
Visual Examination:
Examination
Defects
a. Construction
Not of the shape given in relevant Drawing. Any

crack on the nut& bolt.
b. Material
Not of proper material.
c. Finish
Galvanizing of bolts, nuts, washers and fixture

not proper, presence of black spots, blisters, flux,
dress, un-coated areas or any other defects.
Bolts and nuts, rusty. Threads marred. The
plates not properly enameled or presence of
cracks, patches, pin-holes, blisters or any other
defect. Letters and numbers broken or not
properly enameled.
d. Marking
Missing or in-complete or not as per drawing.
(ii)
Dimensions of the danger, number, aerial markers, phase plates and fixtures shall conform to
those given in drawing Nos. 3206/169/TD/01E205 with allowable tolerances as marked on the
individual drawings. Any variation from the specified dimensions shall constitute a defect.

28
(iii) Galvanizing Test:

The galvanizing of the nuts, bolts, washers and fixtures shall be tested in accordance with ASTM
Specifications.
(iv) Resistance to Thermal Shock:
This test shall be carried out by subjecting the test specimen to radiant heat so as to reach a
steady temperature of 185-195C in about ten minutes. The temperature shall be measured by
means of a surface pyrometer in contact with the top surface of the heated part of the specimen.
Remove the radiant heat and within 5 seconds quench the surface with 1000 ml of water at 1520C direct from an aspirator or other container through a 5 mm diameter tube, the end of the
tube being 150 mm above the centre of the heated portion of the test specimen. The flow rate of
water shall be adjusted to 10 ml per second. It is convenient to mark the test area to ensure that
the water is correctly applied. Dry the plate, replace in the same position under radiant heat
source and repeat this procedure until six cycles have been completed.
After subjecting the test specimen to the above test, the vitreous enamel surface shall be
considered to be resistant to thermal shock provided that the enamel shows no signs of flaking-off
or crazing.
Sampling, Acceptance and Rejection:
Danger, number, phase plates, aerial markers and fixtures offered for acceptance shall be divided into
lots containing up to 200 units in each lot. A sample of 12 units (3 each from danger, number, phase
and aerial marker) shall be drawn at random from each lot. For thermal shock test two samples each
shall be randomly selected from the offered lot.
The selected samples shall be subjected to the visual examination, verification of dimensions and
galvanizing. If the number of defective units is two, the lot shall be accepted. If the number of defective
units is more than two the lot shall be rejected. If the number of defective units is three, another sample
of 12 units shall be selected at random and subjected to tests. If the number of defective units is again
three or more then the lot shall be rejected and if the number of defective units is less than three then
the lot shall be accepted.
2.2.3.4
Acceptance Tests for Barbed Wire

The following acceptance tests for barbed wire shall be carried out:
(i) Visual examination
(ii) Verification of dimensions
(iii) Galvanizing
(iv) Physical
These tests shall be carried out on the selected samples as per the test procedure defined in the
relevant ASTM specification.
CONDUCTOR
3.1
Scope
This specification covers the technical requirements for design, manufacture and testing of transmission
line conductors.

3.2
3.2.1
Conductors Characteristics
29
The conductors shall be Aluminum Conductor Steel Reinforced (ACSR) and "DRAKE" and All
Aluminum Alloy (AAAC) GREELEY. ACSR DRAKE shall conform to the requirements of ASTM B498
and B232 and AAAC GREELEY shall confirm to the requirements of ASTM B398 and B399 plus the
following requirements:
Description of Characteristics
-
Conductor size, KCM

Stranding
Aluminum/Aluminum Alloy
Steel
795
927.2
26
7
37
-
Diameter of wires
Aluminum, mm
Steel mm
4.44
3.45
4.02
-
Conductor Diameter (Nominal), mm
28.14
28.14
Cross Section Area (Nominal)

Aluminum, mm
Steel, mm
Total, mm
402.6
65.4
468
469.6
469.6
Nominal Weight
Aluminum, kg/km
Steel, kg/km
Total, kg/km
1116.2
511.95
1628
1295
1295
Rated Ultimate Tensile Strength, kg
14174
13835
Minimum DC Resistance
at 20C, ohm/km
0.07195
0.0713
Normal Reel Length, m
3200
3200
3.2.2
Requirements for
ACSR "DRAKE"
AAAC GREELEY
Conductor Wires
Each individual Aluminum wire entering into the construction of the complete conductor shall conform to
ASTM B230 for ACSR DRAKE and ASTM B398 for AAAC GREELEY.
The steel core strands must be able to withstand 4 dips of the preece test in accordance with the ASTM
A239. The other requirements of steel core shall conform to ASTM B498; Standard Specification for
Zinc Coated (galvanized) Steel Core Wire for Aluminum Conductor Steel Reinforced (ACSR). The Zinc
coating for steel core wire for conductor shall conform to class A zinc coated steel wire.
3.2.3
Joints
Joints in finished individual Aluminum and Aluminum Alloy wires composing the conductors may be
made in accordance with ASTM B232 and B398 respectively, but there shall be no joints of any kind
made in the finished individual zinc coated steel wire used for the core for ACSR conductor. Joints in

30
the hot-rolled rods or semi-finished wires before cold drawing may be made in accordance with ASTM
B498.
3.2.4
Stranding
The lay factors used shall be within the limits specified in relevant ASTM Standard. Once stranding has
been started, the same lay factor shall be maintained for all conductor shipments.
The conductor shall be stranded in one pass if this is practical. If this cannot be done, the conductor
shall be stranded in a maximum of two passes.
When stranding the steel core or the partially stranded conductor and the wires to be added shall be
inside the stranding premises for a long enough time period to ensure that the steel core or partially
stranded cable and the wires to be added are at the same temperature that will be maintained
throughout the stranding process.
Once the stranding and storing procedure has been started, the same procedure shall be followed for
the balance of the wire for a given destination in order to give all wire as near the same stranding
history as possible.
For ACSR DRAKE conductor, steel wire from various manufacturers may be used. However, all
conductors for a given destination shall be manufactured from the steel core wire from one
manufacturer. If steel core wire from more than one source is being used, this shall be indicated on the
reels.
The same stranding machine or combination of stranding machines if more than one pass is required,
shall be used for all conductor for a given destination unless otherwise approved in writing by the
Project Manager. Marking on the reels shall indicate when a different machine or combination of
machines is being used.
3.2.5
Fabrication
The nominal conductor weight is based on ASTM standard, stranding increments. The actual weight
will be dependent on production of lengths.
The wires shall be so stranded that when the conductor is cut, it shall be essentially free from a
tendency to untwist or spring apart.
The finished conductor shall be uniformly cylindrical and shall be capable of withstanding the normal
handling in manufacturing, shipment and installation without being deformed in such a way as to
increase corona losses and radio interference.
The conductor shall be free from excessive amounts of die grease, metal particles and dust, and all
imperfections not consistent with best commercial practice. The finished product shall be free from
projections to limit corona and radio interference.
3.3
Testing
3.3.1
Tests on Individual Wires

Before stranding, wire shall be tested in accordance with ASTM B230 and ASTM B398 respectively for
ACSR and AAAC conductors.
Tensile properties, electrical resistivity and diameter shall be checked using sampling described in
ASTM B230 for ACSR and ASTM B398 for AAAC conductors. For bending properties, ten percent
(10%) of reels shall be checked.

3.3.2
31
Ductility Test
This test shall be made on Zinc-coated Steel wires only.
One specimen cut from each of the sample shall be gripped at its ends in two vices, one of which shall
be free to move longitudinally during the test. A small tensile load, not exceeding 2% of the breaking
strength of the wire, shall be applied to the sample during testing. The specimen shall be twisted by
causing one of the vices to revolve until fracture occurs and the number of twists shall be indicated by a
counter or other suitable device. The rate of twisting shall not exceed 60 rev/min.
When tested before stranding, the number of complete twists before fracture occurs shall be equivalent
to not less than 18 on a length equal to 100 times the diameter of the wire. The fracture shall show a
smooth surface at right angles to the axis of the wire.
When tested after stranding, the number of complete twists before fracture occurs shall be equivalent to
not less than 16 on a length equal to 100 times the diameter of the wire. The fracture shall show a
smooth surface at right angles to the axis of the wire.
As an alternative to the torsion test, an elongation test may be made on zinc-coated steel wires. The
elongation of one specimen cut from each of the sample shall be determined. The specimen shall be
straightened by hand and an original gauge length of 200 mm shall be marked on the wire. A tensile
load shall be applied gradually. The rate of separation of jaws of the testing machine shall not be less
than 25 mm/min and not greater than 100 mm/min and the elongation shall be measured after the
fractured ends have been fitted together. If the fracture occurs outside the gauge marks, or within 25
mm of either mark and the required elongation is not obtained, the test shall be disregarded and
another test made. When tested before stranding, the elongation shall be not less than 4%. When
tested after stranding, the elongation shall be not less than 3.5%.
Note: The choice between a torsion test and an elongation test is to be at the discretion of the
manufacturer and the choice of one test or the other in no way prejudices the quality of the steel used.
3.3.3
Type Tests on Complete Conductor

Following tests shall be performed to qualify the design before regular production:
(a)
Stress Strain Test:

The stress-strain test shall be performed on the conductor in accordance with the method given in
Annex B of IEC-61089.
(b)
Stress Strain Curves:

The Contractor shall provide the data with initial and final stress-strain curves for the conductor.
These stress-strain curves shall be obtained using the "Standard Method of Stress-Strain Testing
of Aluminum Conductor and ACSR" prepared by "The Aluminum Association", 420 Lexington
Avenue, New York N.Y.10017, USA.
The creep curves shall be shown for the conductor held at a constant tension of 15%, 20%, 25%
and 30% of the rated ultimate tensile strength of the conductor. These shall be presented on loglog paper, with a minimum of 5 cycles on the time scale. These data shall be based on tests
carried out for a minimum of 1000 hours to obtain the degree of accuracy required.
(c)
Creep Test:
In addition to above, creep test for conductor shall be performed in accordance with IEC-61395 to
qualify the design and creep curves be provided accordingly.

(d)
32
Longitudinal Smoothness Test:

When the dies are ready for the conductor but before regular fabrication commences, a sample of
conductor having a minimum length of 12 meters shall be prepared and tested in the presence of
the representatives of Employer and Project Manager to ensure compliance with outside
diameter, cross-sectional area, lay, weight, ultimate strength, tightness of stranding, and
longitudinal smoothness requirements. The conductor shall comply with the requirements of
ASTM B232/B399 and Clause 3.3.1 and 3.3.2 of this Specifications.
The ultimate strength and longitudinal smoothness shall be carried out on a minimum length of 12
meter of conductor. The Contractor shall supply and install the compression fittings required at the
ends of the sample for testing.
During the test, the conductor shall be checked for longitudinal smoothness as follows:
When the conductor is subjected to a tension of 50% of the rated ultimate strength of the
conductor, a straight edge not less in length than twice the lay of the surface layer shall be placed
parallel to the length of the conductor. The maximum variation from the straight edge shall not
exceed 10% of the nominal aluminum strand diameter.
At the end of the test, the nominal ultimate strength of the conductor shall be determined without
the fracture of any wire at 95% of rated tensile strength when pulled steadily and continuously in a
tensile machine whose moving head has a no-load speed of approximately, but no greater than
75 mm/minute.
The sample shall develop the ultimate tensile strength as calculated from the sum of minimum
average ultimate strength of the aluminum wires and the procedure specified in ASTM
B232/B399.
3.3.4
Sample Tests on Complete Conductor during Fabrication

The manufacturer shall carry out during fabrication in addition to the tests specified in ASTM Standards,
any other tests specified elsewhere in this specification. A minimum 1.25 meter length sample of
finished conductor shall be cut from the finishing end of the first length in production between the
capstan and the take-up reel. To preserve the proper condition of the sample, both ends shall be taped
before cutting. This sample shall be checked for the following characteristics:
a.
b.
c.
d.
e.
Finished diameter
Length and direction of lay
Finished weight
D.C. resistance of each aluminum strand
Cracks, scores, undue cross-over marks, indentations etc. of each of the 54 layers of the
conductor.
When the conductor sample is found to be satisfactory, 1.25 meter minimum length samples shall be
taken from every 10th reel subsequently produced and the above characteristics shall be checked. If on
testing the sample from any drum fails to conform to the requirements of the specifications, two
additional samples shall be taken from the same drum for another testing. If both of these samples shall
not conform to the specified requirements the drum shall be rejected. Samples then shall be taken from
all the drums offered for acceptance and shall be tested. If sample from a drum does not meet the
requirements, that drum shall be rejected. If number of rejected drums exceeds 20% of the offered lot,
the complete lot shall be rejected.
In addition to the tests specified above, a minimum length of 12 meters of conductor shall be cut off
from reels arbitrarily selected by the Project Manager, but no more than one reel out of every 100 will
be chosen unless a production run comprises less than 100 reels of conductor. In that case, the

33
Project Manager reserves the right to test one sample from each production run of less than 100 reels.
These samples shall be checked for the ultimate strength and longitudinal smoothness following the
procedure described in Clause 3.3.3(d) of this specification.
If a conductor test piece does not meet the strength and elongation requirements, further samples shall
be tested from reels number x, x+10 and x-10, where x is the reel number from which the rejected
sample was taken.
If these three conductor samples meet the specification, the lot shall be accepted. If one of the last
three samples does not meet the specification, samples shall be tested from reels x+5 and x-5 where x
is the reel number from which the sample that did not meet the specification was taken. This process
shall be repeated until all reels containing faulty material have been located and rejected.
3.4
Markings & Packing

Flange of the reel shall bear a non-corroding tag, written in English language, identifying the following:
a.
b.
c.
d.
Type of conductor and code word

Weight of conductor
Length of conductor
Stranding
Each reel shall be stenciled to show all information as follows:

a.
b.
c.
d.
e.
f.
g.
h.
i.
Manufacturers name and country of origin

Year of manufacture
Reel number
Size of reel
Gross weight
Net weight
Consignee address
Direction of rolling with instruction ROLL THIS WAY
Instructions DO NOT LAY FLAT
The overhead line conductor shall be furnished on non-returnable wooden reels, protected by wood
lagging or other suitable method against damage during shipment and to facilitate safe and easy field
handling and long-term outdoor storage. The Contractor is required to follow the sample drawing No
3206/169/TD/01E210 for wooden reel attached in Volume-III for minimum compliance; however it is the
responsibility of the Contractor to ensure that the method of packing shall be strong enough to
withstand wear and tear during sea/inland transportation and handling at site.
However, the manufacturer may at his own option furnish the conductor on non-returnable steel reels at
no additional cost to the Employer.
Methods of packing, marking and shipping shall be submitted to the Project Manager for review and
acceptance.
4.
SHIELD WIRE AND OPTICAL FIBER EQUIPMENT
4.1
EHS Shield Wire
4.1.1
Scope
This specification covers technical requirements for the design, manufacture and testing of galvanized
overhead shield wire.

4.1.2
4.1.2.1
Shield Wire Characteristics
34
The overhead shield wire shall conform to high strength grade, class B steel in accordance with ASTM
A363, plus the following requirements.
Diameter of galvanized steel wire
Number of strands of wire
Diameter of each strand
Nominal weight of the wire
Rated ultimate tensile strength
Cross-Sectional area
4.1.2.2
9.15 mm
7 (seven)
3.05 mm
407 kg/km
6985 kg
51.14 mm2
Joints
There shall be no joints of any kind made in the finished strand entering into construction of galvanized
steel overhead shield wire. Welding before cold drawing of the strand may be made in accordance with
ASTM A363 latest edition.
4.1.2.3
Stranding
The lay factors used shall be within the limits specified in the ASTM Standards. Once stranding has
been started, the same lay factor shall be maintained for all wire shipments. The wire shall be stranded
in one pass.
4.1.2.4
Tensile Strength and Elongation of Wire and Other Tests

The Contractor shall test complete sections of the wire and follow the procedure as laid down in the
relevant ASTM Standard. The pieces of wire to be tested shall be cut off from reels arbitrarily selected
by the Project Manager but no more than 2 reels out of every 15 will be chosen unless a production run
produces less than 15 reels of wire. In that case, the Project Manager reserves the right to test 2
samples from each production run of less than 15 reels, and if the wire or strand fails in the first test to
meet any requirement of this Specification, further samples shall be tested from reels numbered, x,
x+10 & x-10 where x is the reel number from which the rejected sample was taken. If these three
samples meet the Specification, the lot shall be accepted. If one of the last three samples does not
meet the Specification, samples shall be tested from reels x+5 & x-5 where x is the reel number from
which the sample that did not meet the Specification was taken. This process shall be repeated until all
reels containing faulty material have been located and rejected.
The wire shall also withstand ductility test by wrapping 8 turns on and off round a bar of its own
diameter without fracture.
The number of samples to be tested shall be as given in the relevant ASTM Standards and test
samples shall be subjected to all tests specified in the standard from which the steel wire strand is
manufactured.
The strength and elongation test shall be done by obtaining stress-strain curves of the sample to
determine that the requirements of ASTM Standards are met. This test shall be done to destruction.
4.1.2.5
Galvanizing
(a)
Weight of Coating. The weight of Zinc coating of uncoated wire surface shall not be less than
519 grams/m2.
The weight of Zinc coating shall be determined in accordance with ASTM standard method A-90.

4.1.2.6
35
(b)
Adherence of Coating. The zinc-coated wire shall be capable of being wrapped at a rate not
exceeding 15 times per minute in a close helix of at least two turns on a cylindrical mandrel equal
to three times the nominal diameter of the wire under test, without cracking or flaking the Zinc
coating to such an extent that any Zinc can be removed by rubbing with the bare fingers.
(c)
Preece Test. The galvanized steel wire must be able to withstand 4 dips of the preece test in
accordance with ASTM A-239 standard.
Supply of Stress-Strain Curves

The Contractor shall supply the initial and final stress-strain curves, for the overhead shield wire.
4.1.2.7
Markings and Packing

Each end of the overhead shield wire (SW) in the reel shall bear a non-corrosive tag identifying the
following:
a.
b.
c.
d.
e.
f.
Grade/Type of SW;
Diameter/Size of SW;
Minimum breaking Strength;
Length of SW;
Stranding; and
Type and Class of Coating.
Each reel shall be stenciled or provided with metal plates to show all information under the above
paragraph plus additional information as follows:
a.
b.
c.
d.
e.
f.
g.
h.
Manufacturers Name and Country of Origin;

Year of Manufacture;
Reel Number;
Size of Reel;
Gross Weight;
Net Weight
Consignee Address; and
Direction of Rolling.
All markings shall appear on both sides of the reel.

The overhead shield wire shall be furnished on non-returnable wooden reels, protected by wood
lagging or other suitable method against damage during shipment and to facilitate field handling and
long-term outdoor storage. However it is the responsibility of the Contractor that the method of packing
shall be strong enough to withstand wear and tear during sea/inland transportation and handling at site.
However, the manufacturer may at his own option furnish the shield wire on returnable steel reels at no
additional cost to the Employer.
Methods of packaging, marking and shipping shall be submitted to the Employer's Representative for
review and acceptance.
4.2
Optical Fiber Equipment

These Technical Specifications pertain to the following:
-
Optical Fiber Ground Wire (OPGW)

Joint Boxes
Test Equipment, Installation and Maintenance Tools

36
Fiber Optic Cable
In the following sections, technical specifications for each of the above items are given.
4.2.1
General
The OPGW, installed on the transmission line towers, shall be designed to withstand the prevailing
environmental conditions including the effects of high electric and magnetic fields produced in the
proximity of live power conductors. The design of OPGW shall be mechanically and electrically
compatible with the design of the transmission line. The OPGW shall be able to withstand the system
fault current and lightning current without irreversible degradation of the optical properties of the fibers.
The stringing of OPGW shall be similar to conventional earth wires (bending radius, tension forces) and
shall be executed under guidance and supervision of the Manufacturers site supervisor, the cost of
which is deemed to be included in the Contract price. The bidder shall provide full details of the method
of support and installation procedures, including the jointing and splicing techniques.
The service life of OPGW shall be similar to that of conventional earthwires (i.e. 25 to 30 years) and test
evidence to support Supplier's claim in this respect shall be submitted with the Bid.
4.2.2
Standards
Unless otherwise specified herein, the Contractor shall conform to the applicable requirements of the
latest revisions of the standards stated in clause 1.4.3 or equivalent as approved by the Project
Manager.
4.2.3
Optical Fiber Ground Wire (OPGW)
4.2.3.1
Material and Workmanship

The material(s) used for the manufacture of the OPGW shall be of highest grade free from defects and
imperfections conforming to the requirements of the latest issue of the relevant standards.
The materials used shall be:
Aluminum Clad Steel (ACS) and/or Aluminum Alloy (AA) wires for outer conducting layer
(armor);
Aluminum Clad Steel (ACS) for inner conducting layer (if additional layer is used);
Glass fibers;
Metallic buffer tube;
Aluminum tube; and
Moisture proof and hydrogen absorbent gel.
Proper arrangements shall be made for the provision of corrosion prevention material and suitable filling
compounds as hydrogen absorbing gel in the offered OPGW. The bidder shall provide details in this
regard.
4.2.3.2
Cable Construction
The OPGW shall comprise:

37
a central fiber optic unit designed to house and protect the optical fibers from damage to forces
such as crushing, bending, twisting, tensile stress and moisture;
an aluminum tube over the central fiber optic unit; and
an outer metallic part (armor) designed to function as the conventional shield wire and to protect
additionally the central fiber optic unit.
The fiber optic unit, Aluminum tube and the outer stranded metallic conductors shall serve together as
an integral unit to protect the optical fibers from degradation due to vibration and galloping, wind and ice
loadings, wide temperature variations, lightning and fault currents as well as environmental effects that
may produce hydrogen.
Central fiber optic unit

The optical fibers shall be protected by metallic buffer tube made of appropriate material to
withstand temperatures of 200C under short circuit current without continuous degradation. The
buffer tubes shall not be on the outer layer in order to be protected from external mechanical
forces and electrical disturbances. Inside the buffer tube the fibers shall be loosely housed in a
waterproof gel to prevent water penetration and protection against friction.
The metallic buffer tubes shall have aluminum covering which shall be applied to prevent
corrosion. The housing of the buffer tube shall ensure protection against tensile and crushing
forces on the buffer tubes and optical fibers. The maximum number of fibers in one tube shall not
be more than eight (8). Each fiber in a tube shall be distinguishable from other fiber in the same
tube by means of colour coding in accordance with EIA-598A.
Stranded metallic wires (armor)

The OPGW shall be stranded with Aluminum Clad Steel wires (ACS). However, if more than one
stranding layer is used, Aluminum Alloy (AA) may be used in the outer layer.
The basic construction shall have bare concentric lay stranded metallic wires. The stranded wires
may be of multiple layers with a combination of various metallic wires within each layer. The
direction of lay shall be reversed in successive layers.
The wires shall be stranded such that when the OPGW cable is cut the individual wires can be
regrouped and held in place.
Sag and Tension Limits

Physical design of the proposed OPGW for installation on new overhead transmission lines shall
have sag and tension characteristics similar to the 9.15 mm diameter, extra high strength, 7
strands, galvanized steel overhead shield wire for the spans.
4.2.3.3
Cable Characteristics
From the environmental point of view, it is reminded that the OPGW will be exposed to a harsh
environment viz:
maximum summer temperature : +80C;
maximum summer relative humidity: approaching 100%; and
sand and wind storms.

38
The Contractor shall take these atmospheric constraints into account to select a suitable OPGW for
which 25-30 years service life is guaranteed.
The main features of the cable shall be:
4.2.3.4
Number of fibers
Outer diameter
Breaking load
DC resistance at 20C
Nominal weight
Minimum bending radius
(without fiber damage)
Short circuit current for 1 sec.
24
< 12 mm
> 7000 kg
< 0.75 ohm/km
< 460 kg/km
< 200 mm
> 5kA for temperature
rise from 20 - 200o C
Fiber Characteristics
The main features of the optical fiber shall be as follows:
- transmission mode
- wave length
- attenuation
- maximum splicing loss

- maximum end-connector loss
- core diameter
- cladding diameter
- maximum concentricity error
- maximum cladding non-circularity
- chromatic dispersion
- cut-off wavelength
- mode field diameter
- operational temperature range
- optical channel capacity for WDM
single mode complaint with ITU-T

Rec G.652
1310nm and 1550nm,
< 0.35dB/km at 1310nm,
< 0.22dB/km at 1550nm on Jamshoro-Moro
and Dadu-Moro links
< 0.2dB/km at 1550nm on Moro-Goth Qazi
Mahar and Rahim Yar Khan-Goth Qazi
Mahar links
0.05dB,
0.5dB,
9-10m 0.5m,
125m 2m,
1m,
2%,
< 3.5ps/nm.km at 1310nm,
< 18ps/nm.km at 1550nm,
< 1270nm,
8.1-9.7m,
-10 to 80C.
>6.
Inside the buffer tube the reserve length of fibers shall be at least 0.45% against the linear length of the
complete OPGW to prevent the fibers from coming under stress. To prove this a sample of at least
80 m shall be pulled up to endurance tensile strength while a continuous optical measurement of fiber
length and attenuation is done simultaneously.
4.2.3.5
OPGW Tests
(a)
Factory Tests
The following tests shall at least be performed. The Contractor shall indicate the standards
according to which the tests shall be performed and shall be internationally acceptable (i.e. DIN,

39
BS, ASTM, IEC...). In case OPGW is of special design, the Contractor shall attach tests of similar
design. The tests are:
(i)
Tensile Test: with indicated over length of fiber and simultaneously measured
attenuation at 1310nm and 1550nm;
(ii)
Bending Test: Similar to DIN VDE 0472 Teil 232; the bending radius shall be 25 x outer
diameter of OPGW and the test shall be carried out successfully if the attenuation of the
straightened fiber is within the fiber standards limits;
(iii)
Attenuation test using OTDR;
(iv)
Chromatic Dispersion test; and
(v)
Geometry tests of optical fibers, central optical unit, aluminum tube and outer strands.
In addition, the Contractor shall carry out tests of the single wires according to one of the above
mentioned standards. If parts of the OPGW are greased, the Contractor shall attach data sheets
of the grease.
(b) Type Tests
OPGW cable shall be subjected to the following type tests as described in IEEE 1138. Failure
criteria for each test as per IEEE 1138 are given under each type test.
(i)
Short circuit test:

A permanent increase in optical attenuation greater than 0.05 dB/fiber at1550 nm shall
constitute a failure. Permanent bird caging of any of the strands after five (5) hits shall
also constitute a failure. Cracking or breaking of any component of optical sample shall
also constitute a failure. There shall also be no excessive wear, discoloration of fibers,
deformation or other signs of breakdown. The maximum temperature of optical core
attained during short circuit testing shall not exceed 180C.
(ii)
Aeolion vibration test:

Permanent or temporary increase in optical attenuation greater than 0.2 dB/test fiber km
at 1550 nm shall constitute failure. Cracking or breaking of any component of the cable
or supporting hardware shall also constitute failure.
(iii)
Galloping test:
(iv)
Permanent or temporary increase in optical attenuation greater than 0.2 dB/test fiber km
at 1550 nm shall constitute failure. Cracking or breaking of any component of the cable
or supporting hardware shall also constitute failure.
Sheave wheel test:
Permanent increase in optical attenuation greater than 0.1 dB/test fiber km at 1550 nm
shall constitute failure. Cracking or breaking of any component of the cable shall also
constitute failure. Ovality of cable or optical units > 10% shall also constitute failure.
(v)
Crush test:
The cable shall be subjected to a crush load to be provided by the manufacturer.
Permanent increase in optical attenuation greater than 0.05 dB/test fiber km at 1550 nm

40
shall constitute failure. Cracking or breaking of any component of the cable shall also
constitute failure. Ovality of cable or optical units > 10% shall also constitute failure.
(vi)
Impact test:
An increase in attenuation greater than 0.10 dB/km at 1550 nm shall constitute failure.
(vii)
Creep test:
There is no criteria stated for this test in the standard.
(viii)
Strain margin test:

A strain margin test shall be conducted on the cable to determine the amount of strain
that the cable can withstand without placing strain on the optical fiber. Permanent
increase in optical attenuation > 0.2 dB/test fiber km from preload up to maximum rated
design tension (MRDT) = 42% of RTS at 1550 nm shall constitute failure.
(ix)
Temperature cycling test:

A change in optical attenuation greater than 0.20 dB/km at 1550 nm shall constitute
failure.
(x)
Lightning arc test:

The test shall be performed according to class 1. Permanent increase in optical
attenuation greater than 0.05dB dB/fiber at 1550 nm shall constitute failure. Minimum
remaining strength <75% of the cable RTS of any tested cable section shall also
constitute a failure.
(xi)
Water ingress test:

Any leakage of water through open end of 1 m sample after 1 hour shall constitute
failure.
(xii)
Seepage of flooding compound test:

Any flow (drip or leak) of the filling and flooding compound at 65C shall constitute
failure.
The above type tests, as a minimum, shall be performed at an NTDC approved laboratory in the
presence of an independent laboratory representative who shall sign the certificates on successful
tests and the certified Type Test Certificate/Test Report shall be submitted on completion of the
tests for review. In case any test fails to comply with the requirement, the same shall be repeated
at no additional cost to the Employer. Costs for the type tests shall be deemed to be included in
the Bid Price.
4.2.3.6
Markings & Packing

Flange of the reel shall bear a non-corroding tag, written in English language, identifying the following:
a.
b.
c.
d.
Type of OPGW and code word;

Weight of OPGW;
Length of OPGW; and
Stranding.

41
Each reel shall be stenciled to show all information as follows:

a.
b.
c.
d.
e.
f.
g.
h.
Manufacturers name and country of origin;

Year of manufacture;
Reel number;
Size of reel;
Gross weight;
Consignee address;
Direction of rolling with instruction ROLL THIS WAY; and
Instructions DO NOT LAY FLAT.
The OPGW shall be furnished on non-returnable wooden reels, protected by wood lagging or other
suitable method against damage during shipment and to facilitate field handling and long-term outdoor
storage. However, it is the responsibility of the Contractor that the method of packing shall be strong
enough to withstand wear and tear during sea/inland transportation and handling at site.
However, the manufacturer may at his own option furnish the OPGW on returnable steel reels at no
Methods of packaging, marking and shipping shall be submitted to the Project Manager for review and
acceptance.
4.2.4
Joint Boxes
Joint boxes shall be provided to protect splices from all construction and working stresses likely to
deteriorate their characteristics. Attachment of OPGW or Fiber Optic approach Cable (FOC) ends to
joint box shall also be ensured. Operating temperature range shall be -10C to +80C.
Weather-proof units of protection Class IP65 made of non-corrosive aluminum alloy or stainless steel
shall be provided. The joint boxes shall include all necessary hardware to terminate, protect and fix the
spliced fibers. A name plate giving important information shall be attached to the joint box. This name
shall have embossed characters and shall be made of weather proof material.
Two types of joint boxes shall be provided:
Type A: Joint boxes on OHL used to connect two sections of OPGW fibers anchored on a tower. These
will be installed in about middle portion of towers or portal structure along their body. A spare fiber
length (approximately 1.5 m) shall be left inside so as to be able to remake a faulty splice.
Type B: Terminal joint boxes on OHL used to connect the optical fibers of OPGW to Fiber optic
approach cable (FOC) within the substation. These shall be similar to above type except for the
connection arrangement.
The Contractor shall also design and supply the supporting devices made of galvanized steel to install
joint boxes on the galvanized steel towers/terminal structures. Fasteners for installation of the
supporting devices on the towers/terminal structures and the joint boxes on the supporting devices shall
also be supplied by the Contractor. Design and materials of the supporting devices are subject to
approval of the Project Manager. Galvanizing on the structural steel shapes of supporting device shall
conform to ASTM A123 latest edition with average weight of zinc coating as 705 gm/m2 and on the
fasteners shall conform to ASTM A153 (latest edition) with average weight of zinc coating as
381gm/m2. One supporting device for each joint box will be supplied.

4.2.5
Fiber Optic Cable
4.2.5.1
General
42
The fiber optic cable (FOC) shall be designed to withstand all prevalent environmental conditions
including the effects of high electric and magnetic fields produced in proximity of live power cables.
A service life of at least 25 years is required, and test evidence to support Suppliers claim in this
respect shall be submitted with the bid.
4.2.5.2
Cable Type
The fiber optic cable shall be of the single mode type equipped with at least 24 fibers complying with
ITU-T recommendation G.652 and shall be suitable for underground installation and laying in
trenches/cable trays.
4.2.5.3
Fiber Optic Cable Requirements

(i)
Water-tightness
The cable shall be fully moisture-resistant and meet the longitudinal water-tightness test requirements.
(ii)
Electrical withstand
Considering there is a potential danger through fault or leakage currents, the cable must be nonmetallic.
(iii) Mechanical withstand
The cable shall suitably withstand the mechanical radial stresses and shall be protected against rodents
and termites. The crush resistance shall be at least 2kN/10cm.
(iv) Temperature withstand
The operating temperature range shall be 0 to +70C and the cable shall be suitable for operation in
tropical climate with humidity approaching 100%.
4.2.5.4
Fiber Characteristics
Identical to those given in Section 4.2.3.4.
4.2.5.5
Cable Construction
A loose tube, minimum strain configuration, which provides protection from external forces and
possesses high tensile strength/resistance to crushing, shall be supplied. The fibers shall lie loosely
inside plastic tubes filled with a gel to protect the fibers from the ingress and propagation of moisture.
The maximum number of fibers inside any one tube shall be 8. Each tube and fiber shall be colour
coded to be distinguishable from the other.
The cable construction shall comprise a dielectric central strength member surrounded by loose buffer
tubes and fillers covered by moisture-resistant wrapping. The interstices among the loose tubes shall
be filled with water blocking jelly compound. The wrapping shall be covered with thermoplastic sheath
surrounded by aramid or glass yarn reinforcement. Anti-rodent protection shall be applied around the
reinforcement layer by means of glass tape. The outer jacket of the cable shall be made of rugged nonmetallic material of thickness not less than 1.5mm and covered with anti-termite coating.
Full constructional details of the cable offered shall be submitted with the bid.
4.2.5.6
Ending Rules
After factory acceptance, the inner end of the cable shall be fitted with an end cap to ensure watertightness; the outer end shall be fitted with a water-tight head compatible with cable pulling. Caps
(material and implementation) shall comply with applicable standards. They shall not be removed until
immediately prior to optical jointing.

4.2.5.7
43
Cable Installation
The fiber optic cable shall be laid in a buried 100mm PVC duct from/to the terminal joint boxes.
However within building premises it shall be laid in a flexible duct on cable trays. Drawings showing the
installation details shall be submitted to the Project Manager/ Employer for approval.
Any damage to the cable which is laid and exposed but not protected and during installation shall be
made good by the Contractor at his expense and to the satisfaction of the Engineer/Employer.
For buried PVC duct, a trench 0.5 m wide x 1m deep shall be excavated with provision of manholes at
every 1km distance for cable pulling and future maintenance.
PVC duct shall be laid on a sand bed of at least 100mm thickness and shall be covered by sand layer
of 300mm thick
A cable warning tape shall be placed on the top of sand layer. It shall be bright yellow in colour and of
plastic material 300 mm wide by 0.1mm thick shall be supplied. The tape shall be continuously and
indelibly marked in English and Urdu with the words:
CAUTION
CAUTION
CAUTION
FIBER OPTIC CABLE 700 mm BELOW
The lettering shall be black on yellow.
The excavated material shall be used for the remaining back filling of the trench.
The openings to the ducts shall be closed with a suitable compound after the cable has been laid. A
10m loop shall be kept in manholes.
4.2.5.8
Labeling
All cables and cable ends should be labelled clearly in accordance with the specification. The meter run
should be marked on the outer sheath. This speeds up localisation of faults which are detected during
calibration of cable.
Drums shall be fitted with securely attached, unalterable identification plate bearing the following
information:
Employers name,
suppliers name,
contract number,
content (including drum no.),
manufacturing date,
length of cable on drum,
direction of rotation of the drum,
position of the cable nose,
weight of drum.
The cable shall be furnished on non-returnable wooden reels, protected by wood lagging or other
suitable method against damage during shipment and to facilitate field handling and long-term outdoor
storage. However, it is the responsibility of the Contractor that the method of packing shall be strong
enough to withstand wear and tear during sea/inland transportation and handling at site.
However, the manufacturer may at his own option furnish the cable on returnable steel reels at no
Methods of packaging, marking and shipping shall be submitted to the Employer's Representative for
review and acceptance.

4.2.6
44
Splices
Fusion splicing shall be employed to join the fibers, and shall be carried out by trained personnel of the
Contractor, using the tools and instruments recommended by the Manufacturer. Prior to splicing, the
fiber ends shall be cleaned and prepared, using tools and methods recommended by the Manufacturer
of OPGW/FOC. A splice shall be suitably supported within the joint box. It shall be possible to remove
and replace the splice in the support device without risk of damage to the splice or fiber.
4.2.7
Test Equipment, Installation and Maintenance Tools

The bidder shall provide technical details, manufacturers catalogues and drawings of all the mandatory
test equipment, installation and maintenance tools being supplied, which shall include, as a minimum,
the following:
(a) 1 No. Optical Time Domain Reflectometer (OTDR), Yokogawa make, type AQ7260 or equivalent
with a range 400km and including:
(i)
(ii)
Software and PC notebook for operation of above

Accessories consisting of, as a minimum:
(b)
1 No. Fiber Optic Splicing Unit, Fujikura make, type FSM60S or equivalent/better including:
(i)
(ii)
(iii)
(iv)
(c)
Optical adapters
Cleaning tape for optical parts
Battery backup including charger
AC Adapter
Connection cable to PC, printer, remote etc.
Hand carrying case
Carrying case
Mini tools and spares kit
AC & DC leads
Re-chargeable battery and battery charger
2 No. Fiber Optic Toolkit including at least the following:

(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)
(ix)
(x)
(xi)
(xii)
(xiii)
(xiv)
Stripper for 0.9 mm tight secondary coated and

for 250 m primary coated fibers.
Stripper for buffer tubes and cord-type fiber
optic cables
Cutting tool for the core of OPGW
Fiber holder for stripping optical fibers
High-precision cleaving tool
Cleaning tissues, 200 pcs/pack
Cotton sticks for cleaning the V-grooves of a fusion
splicer, 100 pcs/pack
Cleaning solution, 300 ml/bottle
Air blast, dust-off
Tweezers for handling optical fibers
Microscope 30X with universal connector adapter
Cleaning cassette for fiber optic connectors
Self-adhesive warning label FIBER OPTIC CABLE
Size 185 mm x 15 mm, 120 pcs/pack
Number tape set with replacement rolls of
Numbers 0-9
1 pc
1 pc
1 pc
1 pc
1 pc
1 pack
1 pack
1 pc
1 pc
1 pc
1 pc
1 pc
1 pack
1 set

(xv)
(d)
45
Rugged carrying case
Instruction Manuals of tools and test

equipment (in English).
1 pc
1 set
Additional recommended tools shall be listed and described separately.

4.2.8
Site Tests
Testing of the OPGW on site will be carried out as mentioned below. Any micro bend, irregularity or any
other defect found during testing shall constitute failure.
The Contractor shall depute a competent person(s) for carrying out the site tests mentioned below. The
experience and CVs of the person(s) to carry out the tests shall be submitted to the Engineer/Employer
before any site test is carried out. All costs including traveling, boarding, lodging etc. in respect thereof
shall be deemed to be included in the Bid Price.
A.
Testing of OPGW on receipt at Site

The following test shall be carried out on each individual fiber on each drum. Any defect found in
the fiber shall constitute failure of the whole OPGW cable drum.
(i) OTDR test
(ii) Attenuation test
B.
Testing of OPGW during/after installation

a)
OTDR test of each fiber for each of the individual section of OPGW laid and prior to splicing
of fibers.
b) Measurement of Splice loss of all fibers at the jointing locations.
c) End to end testing of all fibers (to be done from both ends) consisting of:
i. OTDR test
ii. Attenuation loss measurement for all fibers
iii. Measurement of length of OPGW/Continuity test
INSULATORS
5.1
Scope
These specifications cover the technical requirements for design, manufacture, and testing of porcelain
fog type disc insulators.
5.2
5.2.1
Physical Characteristics
1.
2.
3.
4.
5.
6.
The insulators shall be of high impact strength, glazed, wet-process porcelain.

The entire exposed surface shall be glazed and free from imperfections.
The insulators shall have clevis and tongue fittings, securely connected to insulators.
Care shall be taken when providing the required leakage distance to avoid designs in which skirts
are mechanically fragile.
The design of the insulators shall be such that breakage of the porcelain cannot materially affect
the mechanical strength of the insulators.
The strength of the insulators shall comply with the requirements of applicable ANSI standards.
The criteria for acceptance shall be the same as for Clause 5.5(2)(e).

5.2.2
46
Minimum Electrical & Mechanical Characteristics

16,300kg
E&M
Strength
1.
ANSI Class
52-10
52-6
2.
Dimensions
(a)
Disc diameter (maximum), mm
(b)
Spacing (maximum), mm
320
170
254
146
Withstand Values
(a)
Low Frequency:
1.
Dry, kV
2.
Wet, kV
90
50
90
50
135
145
135
145
3.
(b)
4.
5.2.3
8,200kg
E&M
Strength
Critical Impulse 1.2 x 50 Microsecond wave:

1.
Positive, kV
2.
Negative, kV
Radio Influence Voltage

(a)
Test Voltage, kV
to ground
(b)
Max. RIV at 1000 kHz, Micro V
10
10
50
50
5.
Leakage distance (minimum), mm
545
432
6.
Dry arcing distance (minimum), mm
225
203
7.
Low frequency puncture voltage, kV
140
130
8.
Combined, Electrical and Mechanical

strength (minimum), kg
16300
8200
9.
Impact Strength, kg-cm
115
115
10.
Glaze Colour
Light Grey
Brown
Manufacture
(a)
Porcelain Components
The porcelain shell shall be wet process, homogeneous, free of laminations, cavities or other
flaws affecting the mechanical and electrical strength and shall be well vitrified, tough and
impervious to moisture. Porcelain head shall be straight head type so that it shall have uniform
electrical and mechanical strength in long service of life.
The entire surface that will be exposed after assembly shall be glazed and free from imperfections
such as blisters and burrs.
The shell shall be subject to porosity test in accordance with ANSI C29.1 Standard, "Test Method
for Electrical Power Insulators".
The maximum tolerance on length of individual units shall be as specified in ANSI Standard.

(b)
47
Metal Components
(i)
General
The metal parts shall be designed to transmit the mechanical stresses to the porcelain
by compression and to develop maximum and uniform mechanical strength of insulators.
In general, the contours of the metal and porcelain parts shall be such as to eliminate
area of high electrical stress concentrations. All surfaces of metal parts shall be smooth
with no projecting points or irregularities which may cause corona.
(ii)
Caps
The metal cap shall be made of one of the following ferrous materials conforming to the
applicable ASTM Standard:
1)
Malleable cast iron - ASTM standard A47 or A220
2)
Ductile (spheroidal) cast iron - ASTM standard A536, Grade 60-40-18 or 65-4512.
These shall be free from cracks, shrinks, air holes, burrs or rough edges. The cap shall
be circular with the inner and outer surfaces concentric and of such design that they will
not yield or distort under the specified mechanical loading in such a manner as to add
undue stresses to the shell.
(iii)
Pins
The pin shall be made of forged steel and shall be free from laps, folds, burrs or rough
edges. All bearing surfaces shall be smooth and uniform so as to distribute the stresses
evenly. The pins shall be of such a design that they will not yield or distort under the
specified mechanical loading in such a manner as to add undue stresses to the shells.
The steel forging shall meet the mechanical properties of ASTM A668.
(iv)
Locking Device
Standard split pin locking device shall have the shapes and dimensions in accordance
with ANSI Standard/IEC Publication 372-1.
The split pins shall show no cracks by visual inspection when the prongs of the key are
opened to 180 and then returned to the original position.
The material for split pin shall be standard quality stainless steel or bronze as per ANSI
304, having quality for resistance to internal corrosion.
Steel parts shall exhibit a minimum elongation at room temperature of 16% when tested
in accordance with ASTM A370 (standard 50 mm gauge length).
(v)
Galvanizing
All ferrous material shall be hot dip galvanized in accordance with ASTM A153
"Specifications for Zinc coating (Hot-dip) on Iron and Steel hardware", however, the
thickness of Zinc coating shall not be less than 850 &770 gm/m for insulator cap & pin
respectively for fog type insulators.

(vi)
48
Metal Corrosion
The insulator unit shall be designed to inhibit the accelerated corrosion of metal fittings
due to leakage currents. Enlarged pin with greater surface area for decreasing the
current density and thus counteracting corrosion action or corrosion intercepting zinc
sleeve fused to the pin shall be provided at the point where the steel pin emerges from
the cement. The sleeve shall be formed from zinc having a purity of not less than 99.8%.
The total fused area of the interface shall be more than 80% of the total area of interface
between zinc sleeve and pin shank. The exposed part of the sleeve should have a mass
of at least 5g and 50% of the total length of the sleeve shall be exposed.
(vii)
Assembly
The cap, porcelain shell and pin shall be concentric and coaxial within production limits.
Portland cement or Alumina cement shall be used as the bonding agent between the
porcelain and the metal parts.
(c)
Marking
Each wet-process porcelain insulator shall bear a durable marking in accordance with ANSI
Standards, identifying the following:
a.
b.
c.
d.
e.
5.3
Manufacturers Name/Insignia
Year of Manufacture
Combined Mechanical and Electrical Strength, M&E
Tension Proof Test Load, TEST
Country of Origin
Insulator Assemblies
Insulator class and number of insulators for the various assemblies to be used shall be as follows:
(a)Type VS(4)
Suspension Assembly, using 23 or 29 nos. of 16,300kg E&M Strength

Insulators.
Drawing No. 3206/169/TD/01E151
(b)Type IT (4)
Suspension Assembly for Transposition, using 26 or 32 nos. of 16,300kg E&M

Strength Insulators.
Drawing No.3206/169/TD/01E152
(c)Type VJ(4)
Jumper Assembly using 29 or 36 nos. of 8,200kg E&M strength Insulators for

tower type AGM, M, D, DGM(for middle phase only) & DD1.
(d)Type IJ(4)
Jumper Assembly, using 32 or 36 nos. of 8,200kg

E&M Strength Insulators for tower types AGM, M, D& DGM (for outer
phases only).
Drawing No. 3206/169/TD/01E154.
(e)Type DE (4)
Tension Assembly, using 23 or 29 nos. of 16,300kg E&M Strength Insulators.

(f)Type DSD1
Tension Assembly (tower side in gantry span), using 23 or 29 nos. of 16,300 kg

E&M strength insulators.

(g)Type DSD2
5.4
5.5
49
Tension Assembly (gantry side in gantry span), using 23 or 29 nos. of 16,300 kg

E&M strength insulators.
Main Design
(1)
The performance characteristics under various ESDD values shall be supplied with the Bid by
filling the Table of Insulator Performance Data attached as Appendix "A tests shall be carried out
in accordance with clean fog test method recommended by EPRI. The insulators are required to
perform satisfactory in a I string configuration under maximum ESDD condition of 0.12, 0.50 &
1.0 mg/cm. Testing required as above shall be from an independent laboratory of international
repute.
(2)
The insulators shall be suitable for dust contamination conditions and of modern fog type design
embodying outer deeper skirts and shallow inner grooves. The manufacturer shall prove to the
satisfaction of the Project Manager that the contamination collection properties of the insulator
units are 60-70 percent of the standard disc insulators of the same diameter and spacing.
(3)
The FOV 5% (withstand voltage) for 200-Multiple string shall be applicable for its performance.
(4)
The arrangements of insulators in suspension, tension and jumper assemblies are shown in
drawings attached in Volume III of the Bidding Documents.
Testing and Inspection

Acceptance tests shall include all of the applicable tests, specified in ANSI C29.1 "Test Methods for
Electrical Power Insulators" and ANSI C29.2 "Wet Process Porcelain Insulators". Each insulator shall
also be subjected to Tension Proof Test at the minimum load of half the Electrical and Mechanical
strength of insulators.
The Project Manager may require the Contractor to perform all the type tests in accordance with the
applicable standards to verify the main electrical and mechanical characteristics of an insulator unit, if
the type test reports/results provided are not for the identical insulator to be supplied under the
Contract. The contractor will carry out Type Tests to be witnessed by the representatives from
Employer and Project Manager from an independent internationally reputed laboratory
(accepted/approved by the Employer/Project Manager).
These tests are generally required to be done once to qualify the design. Type tests shall also be done
if dimensions or materials described on manufacturers drawings are modified or if manufacturing
processes or manufacturing place have been changed.
Design Tests
Following design tests are to be carried out in accordance with the requirement and methods laid down
in the standard mentioned therewith.
1.
Visual and Dimensional Test
2.
3.
4.
5.
6.
Low-frequency dry flashover test

Low-frequency wet flashover test
Critical Impulse flashover test-positive and negative
Radio-Influence Voltage Test
Thermal-Mechanical Load Cycle Test
7.
Thermal Shock Test
(as per approved

drawings and ANSI C29.2)
(ANSI C29.2)
(ANSI C29.2)
(ANSI C29.2)
(ANSI C29.2)
(as per clause 5.5(2)
specified herein below)
(ANSI C29.2)

50
8.
9.
10.
11.
Residual-Strength Test
Impact Test
Cotter Key Test
Cement Expansion
12.
Steep Wave Front
13.
Power Arc Test
(ANSI C29.2)
(ANSI C29.2)
(ANSI C29.2)
Quality Conformance Tests

1.
Visual and Dimensional Test
2.
3.
Porosity Test
Galvanizing Test
4.
Combined Mechanical and Electrical Strength Tests
(as per approved

drawings & ANSI C29.2)
(ANSI C29.2)
(ASTM A-153 and coating
Thickness as per clause
5.2.3(b)(v) and ASTM A239)
Test method
The test shall be performed in accordance with clause 8.3.4 of ANSI C29.2. The applied load shall be
increased up to the ultimate fracture of insulators. The individual measured failing load shall not be
lower than the rated value and electrical puncture shall not occur before the ultimate fracture.
Furthermore, the fracture pattern shall be also recorded, for hardware breakage or broken insulating
part.
(i)
Criteria for judgment

X R + 3S:
Where,
X = average value of measured failing loads.
R = rated value
S = standard deviation
(ii)
The individual measured failing load shall not be lower than the rated value.
Electrical puncture shall not occur before the ultimate fracture.
5. Puncture Tests
(ANSI C29.2)
6. Thermal-Mechanical Load CycleTest
7. Steep Wave Front
8. Thermal Shock Test
(ANSI C29.2)
Routine Tests
1.
2.
3.
4.
Cold-to-Hot Thermal Shock Test

Hot-to-Cold Thermal Shock Test
Tension Proof Test
Flashover Test
(ANSI C29.2)
(ANSI C29.2)
(ANSI C29.2)
(ANSI C29.2)

51
For quality conformance tests, insulators shall be offered in lots of 15,000 insulators or fraction thereof.
The insulators intended for the quality conformance tests as per ANSI C29.2 shall be taken at random from
each lot by the Project Manager after performing routine tests as per requirement of ANSI C29.1 and
elimination of any defective insulator.
All quality conformance tests required under the above standards shall be made at the Manufacturer's
factory and the Manufacturer shall furnish all test apparatus and instruments required for the tests. The
Project Manager reserves the right to witness all tests and to approve the manner in which tests are
conducted.
Two (2) certified copies of the results of routine factory tests shall be submitted for each lot of 15,000
insulators or fraction thereof whether or not inspection is conducted by the Project Manager.
If required by the Project Manager, the Manufacturer shall make each mechanical test on caps, pins and
split pins as necessary to demonstrate their conformance to the Technical Specifications.
In addition to the above ANSI test requirements, the following tests shall be carried out:
(1)
Steep Wave Front Impulse Test

Ten (10) insulator units shall be selected at random from the first lot brought for acceptance.
(2)
(a)
Insulators shall be subjected to five successive positive and negative impulse flashover
voltages with wave having an effective rate of rise of 2500 kV per micro second. Each of
the ten (10) insulators shall be individually tested.
(b)
Each unit shall then be subjected to five flashovers of low frequency dry flashover test as
per ANSI C29.1 latest revision and shall pass a flashover test of not less than 95 percent
of the rated value. No electrical puncture shall occur, and the flashovers arc must be
external.
(c)
Failure of any one unit of either of steep wave front or flashover tests shall be cause for
testing additional twenty (20) units. Failure of any one unit from this group of twenty, to
the tests in (a) and (b) above, shall be cause for rejection of the lot brought for
acceptance.
(d)
In case of non acceptance of one lot, subsequent lots shall be tested till a successful test
indicates the design of the insulators has been corrected.
Thermal-Mechanical Performance Test.

Ten (10) insulator units of each type shall be selected at random from the first lot and tested in
accordance with IEC Publication 575; latest revision except that the temperature variations shall
be from -5 deg to 70 deg C and the criteria for acceptance of the lot is as below:
(a)
The results of the Performance tests shall match the results of ordinary electromechanical
or mechanical failing load test. Thus, the specified electro-mechanical or mechanical
failing load that applies to the ordinary electro-mechanical or mechanical failing load test
should be reached also in the performance tests.
(b)
The test equipment shall be such as to generate graph automatically as exhibited in Fig.1
of IEC 575. Graphs generated shall be Load-Time graph and Air Temperature-Time graph
for a time period of 96 hours.
(c)
Fracture pattern shall not change.

52
(d)
Electrical puncture or shattering should not occur before reaching the maximum load and
the ultimate fracture.
(e)
The quality index Qs should be equal to or greater than the acceptance constant K to
meet the requirements of the test. The acceptance constant K shall be equal to or greater
than 3 for a sample size of ten insulators. The quality index is defined by:
Qs
R - Rs
R1 + R2 + + Rn1
n1
R1, R2, R3, , Rn1 are the measured values of electro-mechanical failing load.
Average Value R =
Rs.
value)
1n1(R - R)
n1 - 1
S=
S
(3)
Specified electromechanical or mechanical failing load (rated load
Standard deviation
Autoclave Expansion Test for Portland Cement

The soundness of Portland cement to be used as the bonding agent for insulators shall be tested
in accordance with the ASTM C151, "Standard Test Method for Autoclave Expansion of Portland
Cement". Six (6) samples of cement for the test specimens shall be selected at random from the
batch to be used for insulators.
The bars prepared from neat cement when subjected to high pressure steam at 295 psi for three
hours at 216C shall not show an expansion of more than 0.12 percent. The expansion of cement
more than 0.12 percent in the test shall be the cause for the rejection of the whole batch of
cement brought for acceptance.
Alternatively the soundness of Portland cement may be tested on the full assembled insulators as
described below:
Ten (10) insulator units of each type shall be selected at random from the first lot and tested in
accordance with ASTM C151. After this test, each unit shall be subjected to combined
mechanical and electrical strength test of ANSI C29.2. The acceptance criteria shall be the same
as for Clause 5.5(2)(e).
(4)
Power Arc Test

The power arc test shall be performed in accordance with IEC 61467 for short string insulators.
The results thus obtained should comply with the acceptance criteria of IEC 61467.

HARDWARE
6.1
Scope
53
These specifications cover the design, manufacture and testing of clevis & pin type disc insulator
hardware for conductor and hardware for EHS shield wire and OPGW of characteristics specified
below. Specifications for design, manufacture and testing of grounding material are also included in this
section. Each hardware item shall be marked with manufacturer trade mark, strength and year of
manufacture.
6.2
Conductor and Shield Wire Data

Characteristics
Type
Conductors
EHS Shield wire
ACSR
code word
AAAC
code word
"DRAKE"
GREELEY
Size
795 KCM
927.2 KCM
51.076 mm
Stranding
26x4.44mmAl.
7x3.45 mm St.
37x4.02mmAl. Alloy
7x3.048 mm
Outside Diameter
28.14 mm
28.14 mm
9.15 mm
12mm
Ultimate Tensile
Strength
14,152 kg
13,835 kg
6,985 kg
7000 kg
Nominal Weight
1,628 kg/km
1295 kg/km
406 kg/km
460 kg/km
6.3
Conductor Suspension Assemblies
6.3.1
General
EHS Galvanized
Steel Wire
OPGW
Alumoweld
OPGW
The suspension assemblies shall be in a 'V' configuration, except for jumper assembly for outer phases
of single circuit towers, which shall be a single string 'I' type. For transposition, I-suspension assembly
shall be used. The general arrangement of assemblies and attachment details are shown on drawings
No. 3206/169/TD/01E151 ~154.
All hardware between the point of attachment and the conductors shall be supplied under this Section
of Specification except insulator discs covered under Section 5 of Technical Specifications.
V-String and I-String assemblies required under this Section of the Specifications shall be as follows:
(1)
'V' single string suspension assembly type 'VS(4)' for 16,300 kg E&M strength insulators for tower
type SGM and T.

54
(2)
'V' single string jumper assembly type 'VJ(4)' for 8,200 kg E&M strength insulators which shall be
used on center phase of single circuit and double circuit angle towers types AGM, M, DGM,
D & DD1.
(3)
'I' single string suspension assembly for transposition type 'IT(4)' for 16,300 kg E&M strength
insulators to tower TGM and TR.
(4)
'I' single string jumper suspension assembly type 'IJ(4)' for 8,200 kg E&M strength insulators
which shall be used on outer phases of single circuit angle towers AGM, M, DGM & D.
Each phase conductor assembly shall be in a quad bundle with the sub-conductors at each corner of a
square. The spacing between any two sub-conductors on each corner of the square shall be 457 mm
(18 inches) centre to centre.
The shielding of the bottom insulator units shall be done keeping the conductors distance between the
bottom insulators and conductors to the minimum without violating other requirements of these
Technical Specifications.
All suspension assemblies are designed for short circuit current of 40kA for duration of 1 sec.
Contours, edges and corners of line hardware shall be rounded to eliminate areas of high corona stress
concentration.
All hardware shall be designed for hot line maintenance operation with minimum hole size of 25mm.
The assembly shall be corona free at a voltage of 346kV line to ground.
6.3.2
Conductor Suspension Clamps

(1)
The suspension clamp shall be of aluminum alloy, non-magnetic type required to support KCM
ACSR DRAKE and 927.2 KCM AAAC GREELEY conductors.
(2)
Conductor take-off angle shall be in a range of 15 degrees and the minimum radius of curvature
of the clamp shall be 360 mm approximately in the centre part of the clamp and 250mm at bell
ends with the conductor to be always on a rounded smooth surface.
(3)
The clamp seat shall be rounded and curved into bell mouth at each end with a rounded lip edge.
The clamp shall be shaped in such a way that the clamping pressure on the conductor will
increase gradually from the point at which the conductor enters the clamps to a maximum at the
centre of the clamp. The conductor shall be supported by the suspension clamp for a minimum of
165 mm for the minimum angle of entry of the conductor.
(4)
The radius of the curvature of the keeper portion of the clamp shall not be less than the radius of
curvature of the seat of the clamp.
(5)
The suspension clamp shall be free to operate in a vertical plane parallel to the conductor up to
an angle of at least 30 to the horizontal. The suspension clamp shall be free to swing
transversely to the yoke plate up to an angle of at least 55 from the vertical.
(6)
The conductor suspension clamp shall withstand an unbalanced conductor tension of upto 1400
kg without any slippage and must slip at a maximum tension of 1900 kg.
(7)
The suspension clamp shall permit the conductor to slip before failure of the conductor occurs.

55
(8)
The conductor suspension clamp shall be designed to withstand a vertical load of 12000 kg
without any permanent deformation in any of the components.
(9)
The suspension clamp shall be corona free at a voltage of 346 kV line to ground.
(10) The clamps shall have sufficient contact surface to minimize damage due to fault current.
(11) The bodies and keepers shall be of cast or forged high strength corrosion resistant aluminum
alloy with silicon and copper contents of less than 2% and 1% respectively. Connecting pieces,
bolts, nuts and locks washers shall be made of hot dip galvanized steel. Cotter pins shall be made
of stainless steel. The wire groove shall be within the limits of 0.9 and 1.15 times the diameter of
the conductor.
6.3.3
6.3.4
Yoke Plate
(1)
When the yoke plate is swung about one of the 'V' assembly insulator-string so that the other
string becomes slack as in a maximum wind condition, the bottom insulator unit of the slack string
shall be able to freely swing downwards relative to the yoke plate up to an angle of at least 75
from its normal position, measured with the top edge of the yoke plate held horizontal.
(2)
The clevis connecting the yoke plate to the tongue of the bottom insulator shall be designed in
such a way that the bottom insulator unit shall not rotate to such an extent as to contact the yoke
plate when the bottom insulator on a slack string is swung to its extreme downward position
relative to yoke plate.
(3)
The yoke plate shall be free to swing longitudinally to the conductor up to an angle of 20 from the
vertical.
(4)
The yoke plate shall be made from high grade, hot dipped galvanized steel and subject to
normalizing process. The yoke plate shall have round smooth edges and be free of burrs.
Connection Fittings
(1)
(2)
(3)
Hot dip galvanized steel fittings suitable for hot line maintenance work shall be provided to
perform the following functions:
(a)
Connect insulators to tower
(b)
Connect insulators to yoke plate
(c)
Connect suspension clamp to yoke plate
Bolts and nuts with cotter pins shall be used where the cotter pin can be subjected to abnormal
wear or strain. The edges of bolts and nuts shall be rounded smoothly.
Cotter pins shall be made from bronze or stainless steel.
6.4
Conductor Dead End Assemblies
6.4.1
General
The tension assemblies shall be in a horizontal configuration. The general arrangement of assemblies
and attachment details are shown on drawing Nos. 3206/169/TD/01E155~157.
All hardware between the point of attachment and the compression deadend shall be supplied as per
the specified requirement mentioned in this Section of the Technical Specifications except insulators
discs, which are specified in Section 5 of these Technical Specifications.

56
Tension string assemblies required under this Section of the Specifications shall be as follows:
(1)
Quad string deadend assembly type DE(4) for 16,300 kg E&M strength insulators which shall be
used on single circuit and double circuit towers.
(2)
Double string dead end assembly type DSD1 for 16,300 kg E&M strength insulators shall be
used on tower side of gantry span.
(3)
Double string dead end assembly type DSD2 for 16,300 kg E&M strength insulators shall be
used on gantry side of gantry span.
(4)
Three attachment points will be provided on each face of the cross arm of the single circuit tower
types AGM & DGM and DE(4) assembly will be attached on the outermost attachment hole
when faces towards the cross arm whereas on single circuit tower type M, D and double circuit
tower type DD1, only one attachment hole will be provided for DE(4) assembly.
(5)
All hardware from the hole on a horizontal attachment plate of tower up to, but not including the
compression deadend shall be supplied as per the specified requirement mentioned in Section-6
of Technical Provisions.
(6)
Hot dip galvanized steel fittings suitable for hot line maintenance work shall be provided to
perform the following functions:
(a)
(b)
(c)
(7)
6.4.2
Connect insulators to tower

Connect insulators to yoke plate
Connect tension clamp to yoke plate
The yoke plates shall be made from high grade, hot dipped galvanized steel and subject to
normalizing process. The yoke plates shall have round smooth edges and be free of burrs. Yoke
plate on the line end of the "DE(4)" assembly shall be as shown in drawing No.
3206/169/TD/01E159.
Strength
The dead end assembly type DE(4) shall withstand without breakage of any of the components, at
conductor tension equal to the full rated ultimate strength of the conductor applied simultaneously on all
of the four conductors in a bundle.
6.4.3
6.4.4
Tower Attachment Fittings

(1)
The fittings between the tower/gantry attachment point and the insulator string shall be as shown
on the specification drawings.
(2)
Sufficient articulation shall be provided such that the complete assembly including the insulator
units can be attached in the vertical position and then moved to the horizontal position.
Hot Line Maintenance

(1)
Provisions shall be made on both sides of insulator strings for the attachment of a strain carrier to
facilitate the replacement of insulator strings for all types of assemblies during hot line
maintenance.
(2)
These provisions shall be in the form of hot line socket eye below each insulator string as shown
on drawing No. 3206/169/TD/01E159 on the strain yoke set or with two maintenance holes on
each suspension yoke plate or equivalent.

6.4.5
6.4.6
57
(3)
Contours, edges and corners of line hardware shall be rounded to eliminate areas of high corona
stress concentration.
(4)
The assembly shall be corona free at a voltage of 346 kV line to ground.
Articulation
(1)
The assembly shall be designed in such a way that the load will be evenly distributed among the
four insulator strings at all time. The assembly shall be designed to withstand a broken conductor
without permanent deformation on any of the component when the tension on each of the
remaining three conductors is 5500 kg.
(2)
The assembly shall be designed to withstand a broken insulator string without permanent
deformation of any of the components when the tension on each of the four conductors is 5500
kg. The spacing among the conductors shall be maintained under this condition.
Power Arc Rating

All deadend/tension assemblies shall be designed for short circuit current of 40kA for duration of 1 sec.
6.5
Overhead EHS Shield Wire Suspension Assembly

The general arrangement shall be as shown on the specification drawing No. 3206/169/TD/01E158.All
hardware shown on the specification drawing shall be supplied under this clause of the Specifications.
The suspension clamps shall be suitable for 9.15 mm diameter 7-strand EHS galvanized shield wire.
The suspension assembly shall withstand a vertical load of 5000 kg without permanent deformation on
any of the components. The assembly shall withstand an unbalanced shield wire tension of upto 700 kg
without any slippage and must slip at a maximum tension of 900 kg.
The radius of curvature of the keeper portion of the clamp shall not be less than the radius of curvature
of the seat of the clamp.
The assembly of the suspension clamp and its hanger shall be able to swing freely in both the
longitudinal and transverse directions up to an angle of 70 deg with the vertical.
The clamps shall be shaped in such a way that when the ground wire enters and leaves the clamp at
the maximum angle of 15 deg with the horizontal, the shield wire shall always be on a rounded smooth
surface. The clamp seat shall be rounded and curved into bell mouth at each end with a rounded lip
edge.
6.6
Overhead EHS Shield Wire Tension Assembly

The general arrangement shall be as shown on the specification drawing No. 3206/169/TD/01E158. All
the materials between a take-off hole on a horizontal flat strain plate on the tower and the overhead
shield wire shall be supplied as per the requirements mentioned in this clause.
The assembly shall develop 95 percent of the full rated strength of the overhead shield wire. Under this
condition the overhead shield wire shall not slip through the clamp after final makeup of the assembly,
and there shall be no permanent deformation on any of the components of the assembly when
subjected to slippage test.
The assembly shall be free to swing so that the clamp will stay in line with the overhead shield wire
when the overhead shield wire approaches the tower at any horizontal angle within 30 from the

58
longitudinal direction of the transmission line and at any vertical angle between the horizontal and 20
below the horizontal.
The distance from the centre of the take-off hole to the edge of the plate will be 32mm. The maximum
thickness of the strain plate will be 16mm.
The clamp shall be a bent-leg bolted type malleable iron strain clamp with provisions for attachment of
pulling fittings for erection and maintenance.
6.7
Hardware and Fittings for OPGW

All hardware & fittings shall be designed in such a way that no degradation of the optical transmission in
the fibers of the wire will occur under all service conditions. The optical fibers shall be freely moveable
in the wire under service load.
6.7.1
Overhead OPGW Suspension Assembly

At suspension points, armour grip suspension clamps must exclusively be used. The clamp body shall
be of Aluminum alloy, which shall preferably be forged. The rod material shall be drawn from aluminum
alloy.
The assembly of the suspension clamp and its hanger shall be able to swing freely in both the
longitudinal and transverse directions up to an angle of 70 with the vertical.
The general arrangement for suspension set for OPGW is given in drawing No. 3206/169/TD/01E160.
6.7.2
Overhead OPGW Tension Assembly

The tension assembly shall consist of a line guard and a preformed dead end, which is placed on the
line guard. The line guard shall be laid in the opposite direction of the outer layer of the OPGW and the
dead end must be laid in the opposite direction of the line guard. The length of line guard shall be
sufficient to install vibration dampers, if necessary. It shall protect the OPGW against concentrated
radial forces in the region of contact between the dead end and the OPGW. All helical rods shall be
made of aluminum clad steel.
The distance from the centre of the takeoff hole to the edge of the plate will be 32mm. The thickness of
the strain plate will be 16mm.
The assembly shall have provisions for attachment of pulling fittings for erection and maintenance.
The assembly shall be free to swing so that the clevis will stay in line with the OPGW when the OPGW
approaches the tower at any horizontal angle within +30 from the longitudinal direction of the
transmission line and at any vertical angle between the horizontal and 20 below the horizontal.
The general arrangement of tension assemblies for single and double tension set for OPGW are given
in drawing Nos. 3206/169/TD/01E161 ~ 163.
6.7.3
OPGW Attachment Clamps

Attachment clamps to hold the OPGW to the tower for splicing shall be made of Alumoweld and shall
be provided as shown in the drawing No. 3206/169/TD/01E165 and166.
6.8
Parallel Groove Connectors

The material of parallel-groove connectors shall be hot dip galvanized for EHS shield wire and
Aluminum Alloy for OPGW.

6.9
Tests
6.9.1
Type Tests
59
applicable standards to verify the main electrical and mechanical characteristics of the hardware
assemblies, if the type test reports/results provided are not for the identical hardware assemblies to be
supplied under the Contract.
processes or manufacturing place have been changed. The number of samples shall be as per BS
3288: Part 1. The type tests to be performed are as follows:
(i)
Mechanical Test:
On each individual item of hardware
(ii)
Resistance to Conductor, EHS Shield wire and OPGW Slippage Test:

On conductor, EHS shield wire and OPGW suspension clamps and EHS shield wire & OPGW
tension clamps.
(iii) Magnetic Losses Test:

The test shall be performed on conductor suspension clamp in accordance with IEC 61284 to
ascertain the magnetic losses.
(iv) Corona (Visible Discharge) and RIV Test:
The corona test shall be performed on complete insulator assemblies of each type i.e. VS (4), DE
(4) & IJ (4).
The test shall be performed on complete insulator suspension as well as tension strings
completely assembled with all fittings in a manner as nearly as possible to the arrangement to be
used. A test voltage of 346 kV shall be applied between the conductor and earth for five minutes
during which time no corona formation shall be visible or audible with the room in complete
darkness.
The RIV test shall be performed in accordance with IEC 60437 with 60dB V as the limiting value
of radio interference characteristic.
(v)
Power Arc Test:

The power arc test shall be performed in accordance with IEC 61467 for test series X on
hardware assembly type VS (4) & DE (4).
6.9.2
Sample Tests
Sample tests on each item of hardware shall be made to verify the quality and workmanship. The
number of samples shall be as per BS3288-1. The sample tests to be performed are as follows:
(i)
Visual examination (on each item of hardware):

The objects shall be examined visually for the following defects:

60
Examination
Defects
Material
Not as specified in the relevant clauses/drawings.
Construction
Not of the shape given in relevant Drawing. Any part missing.
Finish
Galvanizing not proper. Presence of burrs, black and bare spots,

dross and projections, which will interfere with proper use of the
articles.
(ii)
Verification of dimensions (on each item of hardware):

The binding dimensions of the hardware shall be measured and shall be as shown on the relevant
approved drawings subject to the tolerances given in BS 3288-1.
(iii) Mechanical test (on each item of hardware)

(iv) Resistance to conductor, EHS shield wire and OPGW slippage test:
The test shall be performed on conductor suspension clamp and EHS shield wire and OPGW
suspension and tension clamps in the following manner:
Test piece shall be assembled in accordance with the Manufacturer's recommendation on
conductor and shield wires of size and type which is to be used. The assembly shall be mounted
in a manner approximating as nearly as possible to the arrangement to be used in service.
Precautions shall be taken to avoid bird caging of the conductor. The length of the conductor and
shield wires in the test assembly should preferably be not less than 100 times the overall diameter
of the conductor and shield wires respectively.
A tensile load of about 50% of the relevant minimum failing loads as specified for conductor
suspension clamp and shield wires suspension and tension clamps shall be applied and the
conductor or shield wires be marked in such a way that the movement relative to the fitting can
easily be detected, without any subsequent adjustment of the fitting, the load shall be steadily
increased to 95% of the minimum failing load and then reduced to 90% of the minimum failing
load and maintained for one minute. There shall be no movement of conductor or shield wires
relative to the fitting due to slip during this one minute period and no failure of the fitting.
The conductor and shield wire suspension clamps shall also be subjected to loads which will
cause the slippage of clamps. The maximum specified loads in this case shall be of 1900 kg and
900 kg for conductor suspension clamp and shield wires suspension clamp respectively. The
procedure for application of loads shall be similar as mentioned in the above paragraph.
(v)
Galvanizing test:
Following tests shall be carried out on all ferrous parts complying with the relevant ASTM
standards.
-

Uniformity of zinc coating

6.10
61
Ground Rods
The ground rods shall be copper-weld/copper covered high strength carbon steel of circular crosssection 16 mm in diameter and 3.0 meters long. Each ground rod shall have a conical machined point
at one end and shall be chamfered at the other end for ease in driving in the soil. The copper
weld/copper cover shall be of uniform thickness not less than 0.38 mm for copper weld and 0.45 mm for
copper cover. The copper covering shall be applied by either the molten-welded or copper bonded
process (electro-deposited), giving a moisture proof seal between copper and core. The Contractor
shall clearly state the process of manufacture. The length, diameter and copper thickness shall be
marked on the rod. The applicable ANSI standard for material, fabrication and testing shall be
ANSI/UL467.The steel used in the manufacturing of earth rods shall have the following characteristics:
Tensile Strength
Yield Point (min)
Elongation (min)
6.10.1
:
:
:
41-56 kg/mm2
25 kg/mm2
20% in 200 mm gauge length
Sample Tests
Sample tests shall be made to verify the quality and workmanship of ground rods as per following
procedure:
Individual rods shall be visually examined for the defects given below:
Examination
Defects
Construction
Not of shape shown in drawing.

Not of correct material.
Any crack on the material
Finish
Copper thickness not proper, presence of burrs, black or

base spots, and projections which will interfere with the
proper use of the article.
Corner edges not rounded.
Marking
Missing, not legible, incomplete or not permanent.
(i)
(ii)
The dimensions shall conform to the approved drawing.

Bending Test:
The earth rod shall be subjected to a cold bending test at ambient temperature. The rod shall be
held in a suitable rigid clamp or vice and the free end bent by applying a force perpendicular to
the rod at a distance of 40 times rod diameter from the clamping device. The normal force shall
be applied until a permanent angular bent of 30 degree is achieved by the rod. The rod shall be
capable of withstanding the cold-bent test without any evidence of pits, cracking, or separation of
copper from steel on the surface of the bent portion.
(iii) Tensile Test:

The steel shall be tested for mechanical strength and elongation mentioned in Clause 6.10.

62
(iv) Adherence Test:

The earth rod shall be subjected to adherence test to determine the bondage between copper and
steel surfaces. A half meter length of rod with one end cut to a 45 degree point. This end shall be
driven between two steel clamping jaws of a vice set at one millimeter less than the diameter of a
vice set at one millimeter less than the diameter of the rod so as to shear off sufficient metal to
expose the bond between the jacket and steel core. There shall be no evidence of any
separation.
(v)
Sample, Acceptance and Rejection:

The earth rod shall be divided into lots containing up to 500 units each. A sample of 20 rods shall
be drawn at random from each lot.
The selected samples shall be subjected to visual examination and verification of dimensions. If
the number of defective units is two the lot shall be accepted, if the number of defective units is
more than three the lot shall be rejected. If the number of defective units is three, another sample
of 25 units shall be selected at random and subjected to tests. If the number of defective units is
again three or more, the lot shall be rejected. If the number of defective units is three or less the
lot shall be accepted.
Three random samples shall be selected from a lot of 500, each rod shall be subjected to tensile,
bending and adherence tests.
If one rod from any group of three units selected fails to meet the requirement, another group of
three rods shall be selected at random. If any unit in the second group fails the test, the lot shall
be rejected.
6.11
Grounding Connectors for Ground Rods

The connector for attaching ground wire to ground rods shall be bronze or high strength copper alloy.
The clamps shall be as shown on the specification drawings.
The connector for attaching ground wire to tower stub angle shall be hot dipped galvanized steel. The
clamps shall be secured by one 16 mm diameter steel bolt.
The connectors shall be tested for mechanical strength test specified in ANSI/UL467.
6.12
Bare Copper-Clad Steel Grounding Conductor

The material, fabrication, sampling and testing of copper-clad steel grounding conductor connecting the
ground rods to the tower stub angles shall be made from bare round 7 No. 10 annealed copper-clad
steel wires of 40% conductivity of IACS, conforming to ASTM B227 and B228.
7.
CONDUCTOR AND SHIELD WIRE ACCESSORIES
7.1
Scope
These specifications cover the technical requirements for the design, testing, fabrication and furnishing
the accessories for ACSR DRAKE and AAAC GREELEY Conductors as specified in Clause 3
hereinbefore and for 9.15 mm diameter, 7 strands galvanized steel EHS Overhead Shield Wire as
specified in Clause 4 hereinbefore. The accessories to be furnished are as follows:
1.
2.
3.
Conductor compression splices

Conductor repair sleeves
Conductor compression dead end splices

4.
5.
6.
7.2
63
Overhead shield wire compression splices

Hydraulic compressors
Compression dies
The compression splices shall not permit slipping of or cause damage to or failure of the complete line
conductor or any part thereof at a load less than ninety-five percent (95%) of the ultimate strength of the
conductor.
Contours and edges of line accessories shall be rounded to eliminate areas of high corona stress
concentration.
The line accessories shall be corona free at a voltage of 346 kV line to ground.
The conductance per unit length of the splices shall not be less than that of the conductor itself. The
temperature rise shall not be greater than the temperature rise in the conductor.
All splices shall be pre-filled with appropriate filler compound. Besides, the filler compound shall also be
supplied separately. The open mouths of the splices shall be capped properly to provide protection
against moisture and dust etc.
All current carrying parts shall be coated with plastic to inhibit corrosion on such surfaces during
transportation.
The ends of compression accessories (mid span joint, deadend joint and jumper terminals) shall be
tapered in such a manner that the applied pressure shall be gradually reduced to zero on that part of
the conductor leaving the accessory and that the conductor stresses caused from bending and vibration
reduced to a minimum.
The compression fittings shall meet the specification requirements of Duty of Heat Cycling as per
Clause 7.7.1(ii) herein when subjected to a Heat Cycle Test. This requirement shall be met for the
compression dead end assembly when bolted jumper terminals are included in the test.
On each compression accessory, manufacturers name/trade mark, country of origin, catalog number,
year of manufacturing, die size, start knurl, stop knurl and knurl locations (if applicable) and name/code
of conductor shall be stamped legible.
7.3
Conductor Compression Splice

The conductor splice shall be of two piece compression type consisting of inner galvanized steel sleeve
for jointing steel core and an outer aluminum sleeve alloy for connecting aluminum strands for ACSR
conductor whereas one piece of aluminum alloy sleeve for AAAC type conductor. The splice shall be
suitable for two step compression requiring separate compression for steel sleeve for ACSR conductor
and one step compression for AAAC conductor. The splice shall develop at least ninety-five percent
(95%) of the ultimate strength of the conductor.
7.4
Conductor Repair Sleeve

Repair sleeve shall be of aluminum alloy open type, consisting of body and keeper, which interlock
when compressed. The sleeve should restore 95% of the conductor rated strength with a condition
where no more than 1/3 of the aluminum strands are damaged.

7.5
64
Conductor Compression Dead End Splice

Dead End compression splice for ACSR DRAKE and AAAC GREELEY conductors shall be of two
piece compression type consisting of single aluminum alloy body, steel body of the eye and provided
with a four-hole terminal pad and jumper compression sleeve. The steel eye shall be vertical as shown
in the specification drawing No.3206/169/TD/01E169 and 192 respectively.
The compression dead end shall be supplied with one steel compression dead-end body separately for
ACSR and AAAC conductor and shall be suitable for two step compressions requiring separate
compression for aluminum alloy body on steel eye.
The required nuts, bolts and spring washers/belleville washers to connect the jumper terminal pad to
the dead end terminal pad shall be supplied and made of aluminum alloy/stainless steel. The bolts,
nuts and washers shall be M16 aluminum alloy or M12 stainless steel.
The jumper and terminal connector and its pad shall be constructed with a 15 degree angle, which
permits the terminal connector to be bolted in either the straight or the 30 degree position. The jumper
sleeve shall be one piece compression type. Both sides of the pad shall have even surfaces for better
electrical contact.
Pads of the jumper terminal connector and dead end compression joint shall be factory protected by
removable plastic.
7.6
Overhead Shield Wire Compression Splice

The splice for overhead shield wire shall be a one part steel sleeve with open mouth and when
compressed will grip the shield wire and develop 95% of the full rated strength of the shield wire.
The conductivity of the splice shall equal the conductivity of the shield wire. The shield wire splice shall
withstand the high currents caused by lightning.
On each compression splice, the catalog number, die size and diameter of shield wire shall be
stamped.
7.7
Tests
7.7.1
Type Tests
applicable standards to verify the main electrical and mechanical characteristics of the accessories, if
the type test reports/results provided are not for the identical accessories to be supplied under the
Contract.
processes or manufacturing place have been changed. The number of samples shall be selected as
per BS 3288: Part 1. The type tests to be performed are as follows:
i)
ii)
iii)
iv)
Mechanical Test
Heat Cycle Test
Resistance Test
Corona Test
On conductor compression splice and

conductor compression dead end only

i)
65
Mechanical Test:
Test piece shall be assembled in accordance with manufacturers recommendations on conductor
of the size and type with which it is to be used. The fittings when tested in accordance with BS
3288-1 or ANSI C119.4 shall withstand a load of minimum ninety five percent (95%) of the rated
strength of the conductor. There shall be no movement of the conductor relative to the connector
and no failure of the connector due to slip during one-minute hold period at ninety percent (90%)
of the conductor rated strength.
ii)
Heat Cycle Test:

The test current shall be the power frequency current and should raise the surface temperature of
the conductor to 140 degrees centigrade. The ambient temperature must be kept between +15C
and +30C. The minimum length of conductor used for determining this current shall be 2 meters
and the conductor temperature shall be measured near the centre of the test length.
The compression fittings (compression splices, repair sleeve and compression dead-end) shall be
assembled in accordance with the Manufacturers recommendations on conductor of the size and
type with which it is to be used. The assembly, to which a tensile load not exceeding 20% of the
UTS of the conductor may be applied, shall be erected indoors so that the conductor is roughly
horizontal. Air shall be able to circulate freely around the assembly which shall not however, be
exposed to draughts. The minimum length of conductor on each side of the fitting shall be 2
meters.
The test current shall be passed continuously through the assembly for a period of 30 minutes.
The current shall then be interrupted, and the assembly shall be allowed to cool to within 5C
above the ambient temperature. The sequence of operation shall be repeated so that 500 cycles
of heating and cooling are applied. Temperatures of joint, jointed conductor and of room shall be
recorded in a continuous way.
During the last 5 cycles, the maximum temperature measured when the test current is flowing at
any points on the surface of the fittings, shall not exceed that of the conductor.
The strength of the fittings and that of the reference conductor shall be measured before and after
completion of heat cycle test. All measurements shall be made at ambient temperature.
At the end of the test the resistance shall be measured between points on the conductor on either
side and just clear of the fittings and shall not exceed 75% of the measured resistance of the
equivalent length of conductor. There shall be no sign of local heating, burning or fusing of any
part of the joint or of the conductor.
iii)
Resistance Test:
The electrical resistance of the assembly when tested in accordance with BS 3288-1 or ANSI
C119.4 shall not exceed seventy five percent (75%) of the measured resistance of the equivalent
length of the conductor. The test shall be made with a direct current and test shall be repeated
with the polarity and the average of the two results taken as the measured value.
iv)
Corona (Visible Discharge) and RIV Test:

The connectors shall be attached to a length of conductor of the size and type with which these
are to be used. The connectors when tested in accordance with NEMA 107 shall not exhibit any
sign of visible corona at a power frequency voltage of 346 kV line to ground. The test shall be
performed on a quad bundle conductors arrangement with inter spacing of 457 mm.
The RIV test shall be performed in accordance with IEC 60437 with 60dB V as the limiting value
of radio interference characteristic.

7.7.2
66
Sample Tests
Sample tests shall be made to verify the quality and workmanship. The number of samples shall be
selected as per BS 3288-1.
The following sample tests shall be performed on all conductor fittings.
i)
ii)
iii)
iv)
v)
Visual examination
Mechanical tests
Resistance tests
Galvanizing tests on ferrous parts
Note: The compression of the accessories for testing shall be carried out with the dies to be supplied
by the Contractor under this Contract.
i)
Visual Examination:
The tests objects shall be examined visually for the following defects:
ii)
Examination
Defects
Material
Not as specified in relevant clauses.
Construction
Finish

articles.
The binding dimensions of the hardware shall be measured and shall be as shown on the relevant
approved drawings subject to the tolerance given in BS 3288-1.
iii)
Mechanical and Resistance Tests:

These tests shall be carried out as per procedure defined herein above.
iv)
Galvanizing Tests:
These tests shall be carried out on all ferrous parts complying with the following requirements:
a)
b)
c)
Weight of Zinc coating

Uniformity of Zinc coating
Adherence of Zinc coating
These tests shall be performed in accordance with relevant ASTM Standards.

7.8
67

The hydraulic compressor shall be supplied with hydraulic power pump (with gasoline engine drive).
The compressor shall be of latest model capable of being operated remotely and shall permit fast field
installations. The compressor shall be supplied with ground stand and shipping steel case. The design
of compressor shall be coordinated with the design of accessories. The compressor shall develop a
thrust of 100 tons at a nominal pressure of 700 kg/cm. The above would include 5 m long, low and very
high pressure hoses along with necessary adaptors, fittings compatible with the actual site temperature
and pressure gauge (range 0 - 1500 kg/cm).The working temperature range shall be -10C ~ 55C.
7.9

The hydraulic compressor shall be of portable type supplied with hydraulic power pump (with gasoline
engine drive). The compressor shall be of latest model equipped with an integral hinged head with eyes
suitable for hot line maintenance work. The compressor shall be supplied with ground stand and steel
carrying case. The design of compressor shall be coordinated with the design of accessories. The
compressor shall develop a thrust of 60 tons at a nominal pressure of 700 kg/cm. The above would
include 5 m long low and very high pressure hoses along with necessary adaptors, fittings compatible
with the actual site temperature and pressure gauge (range 0 - 1500 kg/cm). The working temperature
range shall be 10C ~ 55C.
7.10
Compression Dies for ACSR & AAAC Conductor and Shield wire
Conductor compression dies for aluminum and steel parts shall be suitable for use on accessories of
795 KCM ACSR "DRAKE" and 927.2 KCM AAAC GREELEY Conductors. The dies shall be of steel
having hexagonal configuration. The design of all compression fittings shall be such that only one pair
of dies is necessary. The die for the steel core of ACSR conductor should be marked/ painted to
distinguish it from the EHS shield wire die.
Shield wire compression dies shall be suitable for use on accessories of 9.15 mm dia, 7 strands
galvanized steel overhead shield wire of extra high strength. The dies shall be of steel having
hexagonal configuration.
The dies (conductor & shield wire) should be compatible with type of compressors and accessories
being supplied.
In addition each die cavity will be imprinted with die section/identification number so that the same is
embossed on the compression fitting each time a crimp is made.
The Contractor shall provide the detailed drawings along with the dies material properties for approval.
7.11
Filler Compound
The filler compound shall be of suitable material to be used as filler for compression accessories. The
filler should effectively seal out the compression fitting against air and moisture. The filler compound
shall be supplied in a package/carton of hundred (100) tubes each having 0.5 kg filler weight.
7.12
Electrical Joint Compound

The electrical joint compound shall be of suitable material to be used for making aluminum-to-aluminum
& flat-to-flat surface contacts such as jumper terminal to deadend joint. The compound shall be an
active chemical in a grease type sealer and shall act to dissolve the oxide film and seal the joint against
moisture especially formulated to ensure high conductivity. The drop point of the compound shall not be
less than 100C. The flash point should not be less than 190C and alkalinity/basicity < 0.1%. The
compound shall be supplied in a package/carton of 10 tubes each having 0.25 kg compound weight.

68
8.
SPACER DAMPERS FOR CONDUCTOR AND STOCKBRIDGE DAMPERS FOR

OVERHEAD EHS SHIELD WIRE AND OPGW
8.1
Scope
These specifications cover the specific requirements for design, manufacture, performance,
qualification tests and furnishing of Spacer-Damper for quad-bundle conductor and Stockbridge
Vibration Dampers for overhead EHS shield wire and OPGW.
The spacer dampers shall be designed for use on quad-bundle 795 KCM 26/7 ACSR "DRAKE" and
927.2 KCM 37/0 AAAC GREELEY conductors. The vibration dampers for the overhead shield wires
shall be Stockbridge type to be used with 9.15 mm diameter 7 strands EHS grade galvanized steel
shield wire and on the OPGW to be supplied.
The supplier shall guarantee that the proposed vibration damping systems will be adequate for the
purpose and capable to perform within the established safe limits.
8.2
8.2.1
General
All items furnished shall be standard manufactured products, as supplied to the major portion of utility
industry.
The spacer dampers shall be designed to prevent physical contact between sub conductors in sub
spans between spacers, except during the passage of short circuit currents when the possibility of
contact is accepted provided that the specified spacing is restored immediately following fault
clearance.
During installation, maintenance and service (including short circuit conditions), it should withstand
mechanical loads without any component failure or any unacceptable permanent deformation.
The spacer dampers shall be designed so as to ensure that individual components will not become
loose in service and permit relative vertical, horizontal, torsional and axial movement between sub
conductors.
All materials shall be of recent manufacture, unused and free of defects or irregularities and shall be
resistant to corrosion formed by electrolytic action due to application of dissimilar materials.
Workmanship shall follow the best practices of the industry. All components of the same design and
designation shall be identical and like components shall be interchangeable.
Where different materials are used in the spacer dampers, then the design shall ensure that neither
electrochemical action nor any other adverse effects associated with dissimilar materials can occur.
All ferrous components shall be protected by zinc coating, nuts and screws by hot dip galvanizing and
washers by zinc plating.
The clamp bore shall be smooth and free of projections and shall not be sand blasted or refilled to
increase artificially the coefficient of friction between the clamp and the conductor as these can cause
damage to the conductor.
Screw and bolt threads shall be in accordance with ANSI B.1.1. "Unified Screw Threads" class 2A. All
internal threads shall be machined after manufacture to allow for galvanizing and conforming to
appropriate class tolerances.

69
All ferrous metal shall be galvanized to conform to ASTM A153 and A239 specifications. Electrolytic
zinc plating shall be in accordance with ASTM A164 and heat treated to overcome hydrogen
embrittlement.
Anodic coating for Aluminum and Aluminum Alloy shall be in accordance with U.S. Military Specification
MIL- A-8025 C.
8.2.2
Manufacturers Drawings
The Contractor shall submit detailed drawings of the assemblies and component parts, which show all
dimensions and necessary tolerances.
Catalog and part numbers including material and specified finishes and coatings shall be included.
Assembly drawings shall include:
-
Installation instructions.
Rated mechanical strength in tension and compression.
Design installation torque for break-away head bolts or cap screws showing minimum and
maximum values.
Weight of the assembly.
8.2.3
Conductor Spacer Dampers
8.2.3.1
Physical Requirements
The spacer dampers shall be designed for use on quad-bundle 795 KCM 26/7 ACSR "DRAKE" and
927.2 KCM 37/0 AAAC GREELEY conductors.
All break-away bolts or break-away cap heads must be oriented for ground-level viewing.
The spacer-dampers shall be capable of being installed and removed from energized lines by means of
hot-line tools. The Contractor shall furnish detailed information on tools needed and procedure required
to perform the hot-line removal and installation of spacer-dampers.
8.2.3.2
Energy Absorbing Assembly

The energy absorbing assembly shall have the ability to:
a.
b.
c.
d.
Withstand any heat generated

Avoid any displacement in the housings
Resist bond failure
Avoid any other damage which would appreciably decrease the damping efficiency
Where elastomers or other non-metallic materials are used, they shall be capable of withstanding
temperatures of -10C to +100C without permanent loss of essential properties. Assembly shall be
designed to provide effective damping for the line technical and environmental conditions prevailing in
the area.
The elastomer materials or other energy absorbing assembly shall have adequate resistance to the
effects of ozone, ultra violet radiation, dust particles and other atmospheric contaminants over the entire
temperature range, including fatigue and work softening.
The energy absorbing assembly shall be electrically conductive. The conductivity of individual
components shall be stated by the Contractor.

8.2.3.3
70
Clamps and Bolts

Clamps, which are fastened with bolts, shall be provided with breakaway heads or caps and suitable
washers. The bolts shall be lubricated with an appropriate lubricant.
The clamps shall be designed so that they will seat firmly and smoothly on the conductor with sufficient
pressure to compensate for creep, cold flow, and/or nesting.
The arm clamp shall be of aluminum alloy commensurate with the design requirements. The clamp cap
shall also be of aluminum alloy.
The arm clamp and clamp cap shall each have an effective length in bearing on the conductor of not
less than 65 mm for metal surfaced clamps. Exit radii shall be excluded in meeting this requirement.
Bolted type spacer assembly clamps shall be capable of withstanding a torque equal to 150 percent of
nominal design installation torque, without failure of component parts when installed on the conductor.
This value shall be obtained by applying the torque to the lower head of the breakaway bolt or cap
screw.
Clamping bolts or cap screws shall be M16 aluminum alloy or M12 stainless steel with a break-away
type head or cap. The break-away bolt or cap screw shall be furnished with a wrench stop to prevent
the socket from engaging the lower head during installation.
The torque required to break away the upper head from the lower head shall be within a tolerance of
plus or minus ten percent of the Contractor's design value.
The break-away head bolts or cap screws shall be fabricated from 6101-T8 or AA7075 high strength
aluminum alloy or stainless steel (austenitic stainless steel ANSI 300 series). Any other material must
be approved by the Project Manager.
The anodization for aluminum alloy shall be according to US Military Specifications MIL A-8025C.
Clamping bolts or cap screws are to be equipped with steel belleville type spring washers designed to
compensate for a potential relaxation in bolt tension, the washer(s) shall be displaced at least 50% of
the total as-flat deflection at nominal installation torque, the washer(s) shall have a recoverable
deflection of at least 0.9 mm as determined by the difference between the loaded and subsequent
unloaded height.
8.2.3.4
Performance Requirements
The Contractor will submit with the bid, the spacer-damper's proven ability to effectively suppress subconductor oscillation and to control Aeolian vibration. The Contractor will also submit with the bid, the
number of similar units in service at the time of bidding. This will also include their location, approximate
date of installation, the conductor size and configuration.
The dynamic strain caused by vibration in the vertical direction shall not exceed 150 micro-meter/meter
peak-to-peak for AAAC GREELEY Conductor and 200 micro-meter/meter peak-to-peak for ACSR
DRAKE Conductor, at the suspension point as measured according to the method recommended in
IEEE 1368-2006.
The positioning of spacer dampers shall be optimized in such a manner that the sub span ratio is 0.850.90 between lengths of adjacent sub spans and 0.55-0.65 between the length of an end sub span and
adjacent sub span.
Proposed material shall meet the performance requirements without failure in service or damage to
conductors. For the purposes of these specifications, the word "failure" as applied to design tests and
service conditions shall mean the following:

8.2.3.5
71
a.
Failure of any component, part, or damage to conductor other than the normal deformation which
results from conductor clamping action.
b.
The torque in clamp bolt or bolts is reduced to such an extent that the conductor has rotated or
slipped in the clamp or if the torque is reduced to 60 percent of the Contractor's recommended
installing torque, regardless of whether the conductor rotates or slips in the clamp. All torque
measurements will be taken in the tightening direction.
c.
Any wear of any conductor strand which exceeds 70 percent in width or 10 percent in depth of the
conductor strand diameter shall constitute a failure.
Verification of Vibration Behavior by Computer Program

Vibration study of the spacer dampers for the transmission line shall be carried out using computer
simulation. The vibration behavior shall be observed by simulating the load due to various kinds of
conductor motions as per the environment parameters such as temperature, wind speed and EDS etc.
The final staggering scheme of the spacer dampers shall be mentioned according to the bending strain
curve.
8.2.3.6
Electro-Mechanical Characteristics
The spacer damper shall be designed to be free from visible corona when viewed in a darkened
laboratory at a system voltage of 346 kV (line to ground).
The spacer damper shall be designed to withstand the electromagnetic forces resulting from shortcircuit currents of 40,000 Amps. r.m.s. symmetrical for 4 cycles (50 Hz.).
The load arising from such a fault condition is estimated to be towards the geometric centre of the units
on the basis of the relationship given in the IEEE Paper 31TP 65.707 by C. Manuzio, "An investigation
of the Forces of Bundle Conductor Spacers Under Fault Conditions".
8.2.3.7
Performance Guarantee for Damping Systems

By way of further definition, all the guarantee provisions set out in the Contract Documents shall extend
to cover not only the individual pieces of material supplied but also the capability of the spacer damper
system to control Aeolian vibration to within accepted safe limits with no other damping device fitted to
the line, when installed in accordance with the Contractor's installation instructions and recommended
sub-span locations.
The spacer damper system will be considered defective if unacceptable Aeolian vibration above the
limits as defined in Clause 8.2.3.4 herein occur in more than 1% of the total number of spans fitted with
the Contractor's units; this quantity of 1% should be considered as being distributed over the entire
length and not concentrated in any one location. Should this 1% limit be exceeded, additional damping
devices shall be provided, free of charge, by the Contractor to reduce Aeolian vibration amplitude on
affected spans to acceptable safe limits.
The spacer damper system shall also control sub- conductor oscillation.
This guarantee in respect of system performance is applicable under the basic line data and
environmental conditions prevailing in the area.
8.2.4
Qualification Tests Requirements
8.2.4.1
General

72
The following tests shall be performed by the Contractor to establish the characteristics of the spacer
dampers when installed on the conductor and to assure compliance with all requirements specified.
Three certified copies of test data which show that the spacer damper assemblies meet all the
requirements of these specifications shall be submitted. The performance of tests must have been
completed and test data approved before any of the spacer assemblies are shipped. All tests shall be
performed on each of at least three assemblies selected at random from the first offered lot and
performed in the order prescribed below. The failure of any one sample shall constitute failure to meet
the requirements of this specification.
8.2.4.2
Clamp Slippage Tests at Ambient Temperature

Each clamp of the spacer damper assembly shall be separately tested. The Spacer Damper shall be
installed in accordance with manufacturers installation instructions on a minimum length of 4.0 m
conductor tensioned to approximately 20% of its rated strength. A load shall be applied to each clamp
parallel to the axis of the conductor. For each of the following tests, the loads at which initial slip and
continual slip of each spacer occurs shall be recorded.
For metal surfaced clamps, the initial slip load is defined as the load at which the spacer clamp moves
0.5 mm or more on the conductor.
For rubber surfaced clamps, the initial slip is defined as the load at which the permanent displacement
between the conductor and the metal body of the clamp exceeds 1.5 mm, measured after removal of
the load. Deflection may be measured between the third or fourth loading to compensate for temporary
rubber set.
The continual slip load is defined as the maximum obtainable load.
The clamps of the spacer assembly that have successfully passed the longitudinal and vertical slippage
tests shall withstand a load of 450 kilograms for metal-surfaced clamps and 200 kilograms for rubbersurfaced clamps for a minimum period of 60 sec without slipping on the conductor. Clamps shall not be
re-installed and bolts or cap screws shall not be re-torqued after the longitudinal and vertical slippage
tests.
8.2.4.3
Energy Absorbing and Fatigue Tests

a.
General
The spacer damper assembly shall be clamped to ACSR "DRAKE" and/or AAAC GREELEY
conductors. During the tests, the axis of each spacer clamp shall be parallel to its initial static
position by applying of at least 25% of the U.T.S of the conductor tension on each conductor or by
two or more fixed clamps on each conductor. Where fixed clamps are used, there shall be no
more than 200 mm of conductor between the spacer and the clamp for the vertical test and as
recommended by manufacturer for longitudinal test.
The spacer damper assembly shall withstand the tests without slipping on the conductors or
failure of component parts. These tests shall be performed on the same spacer-damper. The
clamps shall not be removed from the conductors, nor shall any bolts or cap screws be re-torqued
until completion of the clamp slip tests.
b.
Vertical Vibration
The spacer damper assembly shall be vibrated vertically from 5 to 50 Hz to determine if the
spacer assembly has resonant frequencies within that range. If resonant frequencies are
observed, the vertical vibration fatigue test shall be run at the highest resonant frequency found. If
no resonant frequency between 5 and 50 Hz is observed, the test shall be run at a frequency from

73
20 to 30 Hz with amplitude of +3 mm for 1,000,000 cycles. A check for resonance and the fatigue
test shall be run for.
i)
ii)
c.
Two upper conductors fixed by clamps

One upper and lower conductor fixed by clamps
Longitudinal Displacement
The displacement of the unrestrained conductor shall be either plus and minus 25 mm or the
displacement from a 22.7 kg static force whichever is smaller. The longitudinal movement shall be
parallel to the conductor at a frequency not less than 2 Hz for 1,000,000 cycles.
i)
ii)
8.2.4.4
Two upper conductors fixed by clamps

One upper and lower conductor fixed by clamps
Simulated Oscillation Test

Using the same spacer damper that was tested in Clause 8.2.4.2 hereof, the spacer arm cycled in
Clause 8.2.4.3 shall be tested. With the body of the spacer damper restrained, each arm shall be cycled
in a plane at right angles to the normal conductor axis continuously for 1,000,000 cycles at not less than
4 Hz. The motion at each conductor clamp shall be in a path around the pivot point(s) of the arm which:
8.2.4.5
a.
Produces a conductor displacement of plus and minus 38 mm, or
b.
Produces a displacement resulting from the application of sinusoidal force having a peak to peak
value of 600N. The displacement shall be determined at the beginning of the test and kept
constant during the test, or
c.
Produces at least 95 percent of the total stop to stop displacement. The clamp need not be
installed on conductor. Endurance shall be assessed in accordance with the requirements of
Clause 8.2.3.2, hereof.
Conical Fatigue Test

The same spacer damper used in test under Clause 8.2.4.4 shall be tested for conical fatigue by fixing
the central frame and installing the clamp on a cylindrical bar of dia equal to the specified conductor dia.
The clamp shall be excited through rotation so that a conical movement is achieved. The angle
between the conical surface of the revolution generated by the cylindrical bar and the longitudinal axis
of the clamp shall not be less than 2 degrees. The test shall be performed for 1 million cycles at
frequency between 2 to 5 Hz. After the test, there should be no damage to any of the components or
loosening of the bolt.
8.2.4.6
Bolt Torque Test

The four clamps of the spacer damper assembly shall be attached to the ACSR "DRAKE" conductor,
AAAC GREELEY conductor or to a bar of 28.14 0.254 mm diameter. Torque shall be applied to the
upper head of each break-away bolt. The head shall not break away at a value other than the
Contractor's design installation torque plus or minus ten percent. The torque required to break away
each upper head shall be recorded.
At a torque of 150 percent of nominal design installation torque there shall be no failure of component
parts. The torque shall then be recorded.
Records shall be made of the lower head withstand torque, failure torque, and the part(s) of the clamp
assemblies that fail.

8.2.4.7
74
Simulated Short Circuit Current Test

The spacer damper shall be tested to withstand three consecutive "shots" at a current of 40,000
Amperes r.m.s. for four cycles (50 Hz) without permanent deformation or damage when installed at
spacing up to a maximum of 76meters, between spacers. The tension on all sub-conductors will be
minimum 25% of the U.T.S of the conductor. The spacer damper shall be capable of restoring the subconductors to its original spacing without deformation or damage to spacer damper or conductor.
Mechanical testing will be considered in lieu of the above short-circuit test. The mechanical tests will be
defined by mutual agreement between the Contractor and the Project Manager. After the test, there
shall be no indication of failure of any component or any permanent deformation from the original
geometric configuration.
Compression
The compressive forces shall be gradually increased until they reach 1000 kg. At this value the forces
shall be held constant for 60 sec. and then removed. The test shall be executed twice; the first one with
the spacer in its normal position and the second one with one clamp displaced longitudinally of an
agreed amount, with reference to the other clamp(s).
Tension
Following compressive forces, tensile forces shall be applied. These forces shall be gradually
increased until they reach the specified value at which they shall be maintained for 60 sec. The value
of the tensile forces shall be taken as 50% of the corresponding compressive forces.
8.2.4.8
Corona and RIV Test

The corona extinction voltage for the spacer damper shall be determined visually in a virtually dark
laboratory. The corona extinction voltage is the voltage at which the spacer damper is free of all visual
corona.
The spacer damper assembly shall be installed on section of ACSR "DRAKE" and/or AAAC
GREELEY conductors or bar not larger than 28.14 mm diameter. The conductor or bar shall be
arranged as a quad bundle.
The spacer damper assembly shall be subjected to a voltage to determine that the corona extinction
voltage level is not less than 346 kV line-to-ground. The ground plane shall be a maximum of 4 meters
from the assembly.
The exposure shall be made with an applied voltage and the laboratory virtually dark. There shall be no
evidence of corona on the spacer-damper.
Digital camera shall be used to satisfy the condition of corona.
The RIV test shall be performed in accordance with IEC 60437 with 60dB V as the limiting value of
radio interference characteristic.
8.2.4.9
Electrical Resistance Test

This test shall be performed in accordance with clause 7.7.2 of IEC 61854.
8.2.4.10
Elastomer Tests
Typical properties and values of the elastomer or other energy absorbing assembly shall be specified.
The tests shall be performed on samples taken from elastomeric components. The following tests on

75
elastomers shall be performed as per relevant ASTM Standards to ascertain the requirements specified
in Clause 8.2.3.2:
(i)
(ii)
(iii)
(iv)
(v)
(vi)
Specific Gravity and Density Test (ASTM D 792).

Temperature Test.
Shore A Hardness Test (ASTM D 2240).
Electrical Resistance Test (IEC 61854).
Ultraviolet Resistance Test.
Ozone Resistance Test:
Non-metallic spacer damper parts shall resist Ozone attack and shall show no sign of damage
after the following Ozone test as per ASTM D-1149 modified as follows:
Two finished full size specimens, mounted in their normal housing will be placed in an Ozone
chamber for 72 hours at a temperature of 60C. The concentration of Ozone shall be 50 parts per
100 million. One specimen shall be unstressed, and the second specimen will be subjected to the
maximum stress.
No cracks shall be visible under 7 Magnification.
(vii)
(viii)
(ix)
(x)
(xi)
(xii)
(xiii)
Tension and Elongation Test (ASTM 412 C).

Tear Resistance Test (ASTM D 624 B).
Compression Set at 70h, 20C-100C-0C (ASTM D 395 B).
Rebound Resilience at 20C-100C-0C.
Air-Oven Deterioration Test 72h, 70C (ASTM D 573).
Deterioration in Oils 72h, 70C (ASTM D 471).
Water Immersion Test (ASTM D 471).
The values for these tests shall fulfill the requirements specified in the Clause 8.2.3.2 and those guaranteed by the
supplier.
8.2.5
Sample Tests
Sample tests shall be made to verify the quality and workmanship of the offered lot. The number of
samples shall be selected as per BS 3288-1 for the following tests.
i)
ii)
iii)
iv)
v)
Visual examination
Clamp Slippage Test at Ambient Temperature
Bolt Torque Test
i)
Visual Examination:
The tests shall be examined visually for the following defects:
Examination
Defects
Material
Construction

76
Finish
ii)

articles.
The binding dimensions of the spacer dampers shall be measured as shown on the relevant
approved drawings.
iii)
Galvanizing Tests:
This test shall be carried out on all ferrous parts complying with the following requirements:
a)
b)
c)

This test shall be performed in accordance with ASTM A123 & A153.
iv)
Clamp Slippage Test at Ambient Temperature:

This test shall be performed in accordance with clause 8.2.4.2
v)
Bolt Torque Test:

This test shall be performed in accordance with clause 8.2.4.6
8.2.6
Vibration Dampers for Overhead EHS Shield Wire and OPGW
8.2.6.1
General
The vibration dampers for the overhead shield wires shall be suitable for use on 9.15 mm diameter 7strand EHS grade galvanized shield wire and OPGW.
Technical characteristics of EHS shield wire and OPGW are given in Clause 4 hereinbefore.
Contractor shall submit with his bid, data showing similar type units in service at that time along with the
location and approximate installation dates. All general requirements as related to materials, standards,
drawings and performance guarantee specified for conductor spacer damper hereinabove apply for
vibration dampers as well.
8.2.6.2
Physical Requirements
The vibration dampers shall be of the stockbridge type having clamp compressed or cast onto the
stainless steel messenger wire of minimum 19 strands between the weights. Dampers weights shall not
be cast on the messenger strands. All ferrous components shall be protected by zinc coating and shall
be according to ASTM A 153 and ASTM 239.The dampers clamp shall be designed in such a manner
that moisture cannot accumulate anywhere in the dampers. Each damper weight shall be provided with
drain hole.
No line-guard or armour-rods are to be used for EHS shield wire.
Dampers clamps shall have bolts having break-away type head or cap made of aluminum alloy or
stainless steel with belleville washers. The materials of the damper clamp/cap and clamping
bolt/breakaway caps shall not exhibit galvanic corrosion due to bimetallic action. Contractor shall

77
ascertain the damper spacing and the number required in accordance with the sag-tension, span
lengths limits and environmental conditions of the line.
8.2.6.3
Performance Requirements for Vibration Dampers

The dynamic strain caused by vibration in the vertical direction shall not exceed 600 m/m peak-topeak at the suspension point as measured by the recommended method of the IEEE Task Force on
Conductor Vibration (IEEE Paper No 31 TP 65-156) for galvanized steel shield wire and 200 m/m
peak to peak alumoweld OPGW. Proposed material shall meet the performance requirements without
failure or damage to overhead shield wires.
The status of the device clamping the damper to the overhead shield wires shall be capable of being
determined from the ground. Sufficient detailed information shall be provided to substantiate
Contractor's recommendations for system.
8.2.6.4
Type Tests
8.2.6.4.1 General
The following tests shall be performed by the Contractor to establish the characteristics of Stockbridge
Vibration Dampers and to assure compliance with the specified requirements.
Three certified copies of test data which shows that all the specified requirements have been met shall
be submitted. The performance of all the tests shall be completed and approved before any of the
Stockbridge vibration dampers are shipped.
8.2.6.4.2 Clamp Slippage Test at Ambient Temperature

The vibration damper shall be installed on the EHS shield wire/OPGW in accordance with manufacturer
installation instructions. The minimum free length of test shieldwire/OPGW between its terminating
fittings shall be 2m. The EHS shieldwire/OPGW shall be tensioned to approximately 20% of its rated
strength and by applying a tightening torque on the upper head of break-away bolt until breakage of the
upper head occurs. The relevant torque shall be recorded. By means of a suitable device a load parallel
to the axis of the EHS shield wire/OPGW shall be applied to the clamp. The load shall be gradually
increased (not faster than 100 N/s) until it reaches 2.5 kN and held for minimum 1 minute without initial
slip. The initial slip load is defined as the load at which the clamp moves 0.5mm or more on the EHS
shield wire/OPGW. The load shall be increased until the continual slip occurs. The relevant value shall
be recorded.
8.2.6.4.3 Bolt Torque Test

Using the same dampers that were tested in Clause 8.2.6.4.2 hereof, a torque of 150 percent of
nominal design installation torque shall be applied at lower head of the bolt in order to see that there
shall be no failure of component parts. Records shall be made of the lower head withstand torque,
failure torque and the part(s) of the clamp assemblies that fail.
8.2.6.4.4 Attachment of Weights to Messenger Cable Test

This test shall be performed in accordance with Clause 7.8 of IEC 61897 should conform compliance to
the acceptance criteria stated therein.
8.2.6.4.5 Attachment of Clamp to Messenger Cable Test

This test shall be performed in accordance with Clause 7.9 of IEC 61897 should conform compliance to
the acceptance criteria stated therein.

78
8.2.6.4.6 Damper Performance Tests

Damper Performance Tests shall be performed in accordance with Clause 7.11 of IEC 61897 according
to variant B in conjunction with the respective acceptance criteria. The Damper Perforamance Tests
include:
(i)
Damper Characteristic Test

This test shall be performed in accordance with Clause 7.11.2 of IEC 61897. The results thus
obtained should fulfill the respective acceptance criteria.
(ii)
Damper Effectiveness Evaluation

The laboratory tests evaluation method of this test should be adopted and the test shall be
performed in accordance with Clause 7.11.3 of IEC 61897. The results thus obtained should fulfill
the respective acceptance criteria.
8.2.6.4.7 Vertical Fatigue Test

Two samples of dampers each from EHS shield wire and OPGW shall be selected at random and
tested from the offered lot of 1500or lesser in quantity.
The stockbridge dampers shall be installed on a shaker at the recommended torque and vibrated at the
highest resonance frequency with an amplitude of 1 mm. The test shall be continued for 10 million
cycles. After the test, no breakage of any part shall occur and the torque on the bolt is not less than
60% of the recommended value of the torque.
8.2.6.5
Sample Tests
Sample tests shall be made to verify the quality and workmanship of the offered lot of EHS shield wire
and OPGW dampers. The number of samples shall be selected as per BS 3288-1 for the following
tests.
i)
ii)
iii)
iv)
v)
vi)
vii)
viii)
Visual examination
Clamp Slippage Test
Bolt Torque Test
Attachment of weights to messenger cable
Attachment of clamp to messenger cable
(i)
Visual Examination
The tests shall be examined visually for the following defects:
Examination
Defects
Material
Construction
Finish

articles.

(ii)
79
Verification of Dimensions
The binding dimensions of the dampers shall be measured and shall be as shown on the relevant
approved drawings.
(iii) Galvanizing Tests

a)
b)
c)

This test shall be performed in accordance with ASTM A123 & 153.
(iv) Clamp Slippage Test
This test shall be performed in accordance with Clause 8.2.6.4.2.
(v)
Bolt Torque Test

This test shall be performed in accordance with Clause 8.2.6.4.3
(vi)
Attachment of Weights to Messenger Cable

(vii)
Attachment of Weights to Messenger Cable

(viii)

8.2.6.6
Test Requirements
Three certified copies of test results showing that the dampers meet the performance requirements of
these specifications shall be furnished. Results of laboratory tests may be furnished in lieu of the tests
results on outdoor spans.
The effectiveness of dampers shall be determined on span lengths which may be encountered in the
line. Three spans, one with two dampers, one with one damper and one without shall be used. 9.15 mm
diameter EHS galvanized steel shield wire and alumoweld OPGW with tension equal to the everyday
stress shall be used. Duration of tests shall not be less than one year.
A certified curve shall be furnished for the damper proposed showing the frequency response in watts
versus frequency from 1 Hz to 60 Hz.
If available, the bidder shall supply the data regarding fatigue life of the dampers with sinuous able
force at the clamp and at a frequency of maximum power absorption.
The Contractor shall perform the bending amplitude test for shield wires dampers for frequency range
of 15-140 Hz for shield wires at an average span of 365 m.

8.2.7
80
Technical Assistance and Research

It is intended to make vibration measurements on the lines (both for conductors and shield wires (i.e.
EHS & OPGW) for the purpose of evaluating damper systems performance.
The Contractor shall provide at least four (4) vibration recorders (two for conductors and one for shield
wire/and one for OPGW) will be installed on completed sections of the line before energizing. Proposed
type, and number of vibration recorders provided by the Contractor, the rental price, cost of supervision,
cost of interpretation and any other cost incidental to the work shall be deemed to be included in the
unit price bided for dampers. Installation of the recorders in the field will be done by the Contractor
himself under the supervision of the manufacturer.
The Project Manager shall select the line(s) and span(s) where recorders are to be installed.
Each interpretation shall be of a minimum fourteen (14) days duration record or as proposed by the
Contractor and approved by the Project Manager.
Two graphs per interpretation are required and these will be as follows:
1.
2.
Number of megacycles per day at various frequencies.

Cumulative number of megacycles per day exceeding the following amplitudes:
a.
b.
From 0.05 mm to 0.50 mm in 0.05 mm increments.

From 0.50 mm to 2.0 mm in 0.1 mm increments.
The bending amplitudes shall be measured at a distance of 89 mm from the closest contact between
the conductor and the suspension clamp. The bending amplitudes measured shall not exceed the
endurance limits as per IEEE 1368-2006.
8.3.
Basic Line Data and Environment
8.3.1
Basic Line Data

The following information is to be considered for determining the spacer and stockbridge vibration
dampers application:
(a)
Total line length of transmission line is 600 km (approx.)
(b)
Estimated total number of structures is 1615

Conductors:
927.2 KCM 37/0 strands AAAC code word GREELEY

795 KCM 26/7 strands ACSR code word "DRAKE"
Shield wires:
9.15 mm diameter galvanized steel EHS overhead shield wire and

Alumoweld 24 Fibers OPGW
Limiting Conditions:
(Every day stress)
22% UTS, final bare for conductors at 25C

15% UTS, final bare for shield wires at 25C
Span Schedule:
Average span
Ruling span
Minimum span
Maximum span
Average conductor attachment height

360 meters
395 meters
154 meters
620 meters
21m

81
Average shield wire attachment height
9.
TECHNICAL PROVISIONS FOR CONSTRUCTION
9.1
General
(1)
31m
Clearing Right-of-Way
Right-of-Way clearing shall be restricted to the minimum necessary for the safe construction and
operation of the line. Clearing shall generally consist of brushing out the centre line, tower
locations and conductor pulling sites within 25 meters on each side of the centre line. Trees over
2.5 meters in height which constitute a hazard or danger to the transmission line, or whose tops
are within 6 meters at 65C final conductor sag position, shall be removed.
The clearing of desert vegetation shall be restricted to that required for placement of footings and
for the assembly and erection of towers and wire pulling Site.
No clearing will be allowed in orchards or other areas of fruit bearing trees, except as specifically
approved by the Project Manager.
The cleared materials will be the property of the Land Owner. If any disposal of cleared material is
required it will be disposed of by burning or other methods approved by the Project Manager.
(2)
Engineering and Surveying

The transmission line route marked on SOP sheets is firm and final as established by the
Employer and is shown in the specification drawings. However, the Contractor shall check this
line route prior to start the field ground survey.
The Contractor shall be responsible to carry out final route alignment detailed survey, prepare
plan and profiles, tower spotting and prepare construction structure list for transmission line
portion for which plan & profile drawings are not available with the Employer.
The work to be done by the Contractor shall include but not limited to the following:
(i)
Before starting the detailed survey, walkover survey of the line route as shown in the
specification drawings shall be carried out to mark underground utilities/services and built
up areas falling in ROW corridor on SOP sheets of 1:50,000 scale for the approval from
Project Manager.
(iii)
Carry out final route alignment and the detailed survey along the approved line route.
(iii)
If any line diversion along the proposed transmission line route is necessitated as
decided/approved by the Project Manager, the Contractor will carry out an investigation of
the route along with necessary plan tabling of the area and shall make necessary
modifications and establish the terminal points, the angles locations, road crossings and
other points of interest as advised by the Project Manager or his nominated person.
All the proposed modifications are then to be transferred on to the route map by the
Contractor and submitted to the Project Manager for approval.
(iv)
Contractor shall be responsible for obtaining approvals from various agencies following the
necessary rules and regulations. Survey of Pakistan maps will be shown to the successful
bidder in the office of the Project Manager when requested.
82
(v)
During the survey, the Contractor will ascertain whether the route indicated to him is most
desirable. If in his opinion another route would be more desirable on technical grounds or
more economical, he shall report his findings to the Project Manager who will then decide
about the adoption of new route.
(vi)
The survey shall be executed using high precision Electronic Total Station equipment.
Ground elevations are to be taken at regular intervals as directed by the Project Manager
and at locations of change of slope and for various features like roads, rail tracks, canals,
power & communication lines, water courses etc. The leveling along the route shall be
connected and confirmed from the nearest available bench marks (BM) of national
reference datum i.e. Survey of Pakistan. In the absence of such bench marks, leveling and
check leveling should be done by using high precision handheld GPS.
(vii) The line route has to be marked on the ground with permanent concrete markers. However
if markers have not been installed or found missing anywhere or if required by the Project
Manager, the Contractor will install the Concrete markers of at least 130 x 150 mm at top
and bottom with a height not less than 1m. The markers shall be buried 0.5 m below
existing ground level. The markers shall be white washed and a red point shall be made on
the top of the marker to indicate the exact centre of the line.
(viii) Total accumulated error in longitudinal and transverse measurements should not exceed
0.05% and in the vertical direction should not exceed 0.20%.
(viii) Longitudinal profiles and strip plans are to be prepared by the Contractor and shall be
submitted for Project Managers approval as per following scales;
Horizontal
Vertical
1: 2000
1: 200
The profile shall be prepared on plans of 700 mm x 2000 mm size, or other size approved
by the Project Manager. Each sheet shall repeat 1/5 km of route on either side. Also the
sheet numbers shall be indicated on a key map for reference.
(ix)
Profiles shall include all details relevant to the survey of the routes including position of
concrete markers, crossings, transversal slopes, location of forest reserves, population
limits and position of road.
The ground profile shall be along the centre line of the approved route. All obstacles, and
important features within 50 meters on either side shall be shown on the profiles.
Tower spotting shall be carried out by the Contractor using template (for DRAKE and
"GREELEY" conductors) approved by the Project Manager. The template shall be based
on the actual ruling span calculated from angle to angle, with maximum & minimum
temperatures shall be 65C and -4C. Templates of various ruling spans will be provided
free of cost to Project Manager on celluloid sheets indicating hot, cold and ground clearance
curves. The tower positions shall be verified for suitability.
Construction structure lists shall be prepared by the Contractor as approved by the Project
Manager.
(3)
Validation, updating & preparation of as-built of the already prepared plan & profile drawings and
construction structure lists (to be provided to the Contractor after award of contract) of the
proposed transmission line route with the actual field developments. Staking (centre and
reference pegs) of the tower locations which have to be concreted are included in the Contractors
scope.

83
Latitude and longitude by hand held GPS of each tower location should be collected and
submitted to the Project Manager.
(4)
Contractor shall be responsible for obtaining approvals from various agencies following the
necessary rules and regulations.
(5)
In case of route diversion, survey shall be conducted as per 9.1(2).
(6)
Tower Staking (for all remaining tower locations which are to be concreted)
Tower centers shall be staked in the field alongwith two-reference stakes on either side of the
tower along the line route, using wooden pegs are included in the Contractors scope. All angle
tower locations shall be bisected. Tower centers of angle locations with line angle in excess of
20 shall be fixed at off set distance 'X', which will be calculated from the following formula:
X=
A tan/2 (only for tower types M (angle more than 20o), D and DGM, DD1)
A=
Distance (width) from centre of tower bridge/cross-arm to the centre of attachment

hole for tension assembly.
Line deviation angle
Where
All surveying not mentioned in these specifications as being the responsibility of the Contractor.
The footings for terminal dead-end tower shall be so placed that the transverse axis of the tower
cross-arms shall be parallel to the transverse axis of the gantry structures of the substation up to
20 line angle. If line angle is more than 20 then terminal dead-end tower location shall be
bisected as stated herein above.
9.2
Sub Soil Investigation

The Work specified herein is to determine the type and geotechnical characteristics of the foundation
strata to the specified depth and location. This is to be accomplished through rotary drilling, field testing,
ground water observations, soil sampling and laboratory testing. The location along with depth of
investigation boreholes on the ground shall be established by the Contractor in accordance with the
Drawings and from reference points approved by the Project Manager.
(a)
Method of Drilling
Drilling shall be done by rotary including rock coring method by means of which a hole of specified
diameter is extended in depths. Use of bottom discharge drilling bit shall not be permitted. The
contractor shall be allowed to use percussion method where gravels and boulders are
encountered.
(b)
Drilling of boreholes in flowing water conditions

Drilling may be carried out under water conditions. During the investigation, the Project Manager
may change such locations to land drilling depending upon the prevailing water way conditions.
(c)
Test Pit (Not required)

The test pits shall be excavated at the locations as specified by the Project Manager.
Excavations of test pits shall be made to the depths as directed by the Project Manager by
manual labour and with the help of suitable digging tools. Test pits shall generally be excavated

84
to a depth of about 3 meters below the ground surface or bed rock whichever is encountered
earlier. Undisturbed black (30cm x 30cm x 30cm) sample shall also be extracted from each test
pit. The dimension at the bottom of pit shall not be less than 1.5 m x 1.5 m. After field testing and
sampling, the test pit should be backfilled as instructed by the Project Manager.
(d)
Drilling Fluid
The drilling fluid used for rotary drilling shall be clean water clear from suspended sediments. The
Contractor may use the natural or commercial drilling mud/bentonite slurry as drilling fluid.
(e)
Casing of Boreholes.
(i) Casing of a required size allowing entry of sampling tools shall be used in conjunction with
drilling to wall the boring to the bottom of the hole.
(ii) The casing shall be made of cylindrical steel pipes and shall have sufficient strength so as to
maintain position and shape during drilling operations.
(iii) The casing may be omitted only where it can be shown to the satisfaction of the Project
Manager that sampling operations without the casing will not entrain soils from an elevation
higher than the depth at which field testing or sampling is to be made.
(iv) It shall be the Contractor's responsibility to pull out casing from the bore holes after its
completion for which no extra payment shall be made.
(f)
Field Testing
Field testing shall include Standard Penetration Test. Standard Penetration Test shall conform to
ASTM D-1586. This designation describes as procedure to obtain a record of the resistance of
subsoils to the penetration of a standard sampler and to obtain representative disturbed samples
of the material for identification purposes and laboratory testing. The penetration resistance shall
be expressed as the number of blows of a 63.4 kg (140 lbs) hammer freely dropping 762 mm (30
inches) required to force the standard sampler 305 mm (12 inches) into the soil. Standard
Penetration Tests shall be conducted in the bore holes at one meter interval from 1 meter depth to
10/15 meter depth of bore hole and up to 40 m in case of river crossing locations, unless
otherwise directed by the Project Manager. Immediately after each penetration test a
representative portion of the soil core shall be placed in moisture proof container.
(g)
Undisturbed Sampling
The undisturbed samples shall be taken in cohesive and non-cohesive materials. Samples shall
be obtained using Denison or Pitcher sampler or equivalent double tube core barrel or shelby
tube. The sampling procedure shall conform to latest B.S./ASTM Standards. The length of
undisturbed samples obtained shall not be less than 30 cm. Immediately upon extraction from the
hole, the sample shall be properly waxed. The number and depth of undisturbed samples from
each hole shall be as directed by the Project Manager during the progress of the drilling work at
site.
(h)
Labeling and Disposition of Samples

Each sample shall have identification tags giving information regarding Sample No., Top Elevation
of Hole/Test Pit, Date of Sampling, Depth and Length of Sample, and Description of Sample.
The selected undisturbed and disturbed samples shall be carefully transported for testing by the
Contractor to the approved testing laboratory. Every precaution shall be taken to avoid damage to
samples as a result of careless handling and undue delay in transportation. The tubes containing

85
undisturbed samples and cores shall be well packed in wooden boxes to protect the samples
against vibration.
(i)
Ground Water Observations

Whenever required by the Project Manager, bore holes shall be preserved for observations of
ground water conditions. When the borings are advanced by using natural or commercial drilling
mud/bentonite to stabilize the hole, the hole shall be flushed thoroughly with clean water at the
completion of boring for the purpose of observing ground water levels.
(j)
Laboratory Tests
(i)
(ii)
General
-
The laboratories in which the samples are to be tested shall be approved by the
Project Manager.
The person representing to the Project Manager shall have access to the
laboratories to supervise and check the laboratory testing of the samples.
The testing shall be carried out in accordance with ASTM or equivalent British
Standards, or as directed by the Project Manager.
Tests
The Contractor shall arrange to carry out laboratory tests on the specified samples of the subsoil
material. The samples to be tested and the tests to be carried out for each sample shall be
specified by the Project Manager. Laboratory testing may include but not limited to the tests listed
below:
(k)
Grain Size Analysis (Sieve + Hydrometer)

Atterberg's Limits
Chloride Content (soil and water)
Natural Moisture Content
Bulk and Dry Densities
Organic Matter Content
Sulphate Content (soil and water)
PH value (soil and water)
Unconfined Compression Test
Direct Shear Test
Consolidation Test
Total Soluble Salts.
Magnesium Content
Confirmatory Sub-soil Investigation

After preliminary subsoil investigations confirmatory investigation (if required) up to maximum
depths of 25 meters will be carried out by the Contractor. The location of selected confirmatory
investigation will be conveyed to the Contractor by the Project Manager.
(l)
Record
The Contractor shall have at site, at all times only qualified, experienced, orderly and thoroughly
competent graduate Geologist who shall conduct and supervise drilling operations sampling and
logging. The Contractor shall keep accurate logs and records of all the Work accomplished under

86
this Contract. All such records shall be preserved in good condition by the Contractor until they
are delivered and accepted by the Project Manager. The Project Manager shall have the right to
examine such records at any time prior to their delivery to him. The following information shall be
included in the records for each investigation borehole:
(i)
Hole/test pit number or designation, coordinates and elevation of top of the hole/test pit;
(ii)
Type of drilling operations;
(iii)
Dates and time by depths when drilling operations were performed;
(iv)
Depths at which samples were recovered and field-testing was performed including
complete data of field-testing;
(v)
Depth of Ground water table from NSL; and
(vi)
Description of subsoil conditions.
The presence of the Project Manager Representative or keeping of separate records by him shall
not relieve the Contractor of the responsibility for the Work specified in this clause. Payment will
not be made if the Contractor has not furnished the records.
(m)
Foundation design/designation (for diverted portion only)

Contractor shall submit the foundation design/designation along with the following
data/calculations to establish that the proposed foundation type is optimized and cost effective for
the review and approval of the Project Manager:
9.3
Necessary soil design parameters to verify the bearing capacity based on geological data
(bore log) and laboratory test results i.e. from (a) standard penetration test & (b) analytical
method.
Immediate and consolidation settlements of soil.
Seasonal fluctuation of ground water.
Cement type to be used for foundation construction (based on ACI-318 Table 4.3.1).
Foundation Requirements
(1)
General
The items in the Price Schedules for constructing the various types of concrete foundations
(including pile foundations) for steel towers include the following:
(a)
Tower staking;
(b)
Performing all clearing, grading, cutting and leveling as required to construct the footings
and erect the steel towers;
(c)
Performing all required excavation, dewatering, shuttering, curing and compacting

backfill for the concrete footings;
(d)
Installing steel stub angles in the concrete footings;
(e)
Tower grounding before placement of concrete;

87
(f)
All concrete work for the concrete footings, including the cost of furnishing all reinforcing
bars, and all materials for concrete;
(g)
Installing pile foundations (pile, pile cap & tie beam) where required, including the cost of
furnishing all reinforcing bars and all materials for concrete; and
(h)
Assessment of damage and prospect of rectification of already concreted tower

foundations.
(i)
The foundation drawings included in Bidding Document are firm & final and only be
changed (if required) as directed by Project Manager.
(2)
Excavation for Tower Footings

The Contractor shall perform all excavation required for constructing various types of concrete
foundations for the steel towers. During excavation of towers sites near to amenities, the
Contractor shall ensure to perform the work in such a manner as to minimum damage to them
and if any prior approval is required that must be obtained at his own. However, in case of any
damage the Contractor shall be get repair of it at his own risk and cost under intimation to the
concerned agency.
The tower sites shall be leveled, graded/cut and cleared of trees, brush and stumps as may be
required to construct the tower footings and to erect the steel towers. Cleared materials shall be
disposed off, as directed by the Project Manager or his nominated person.
All excavations shall be sufficient to provide concrete footings with dimensions not less than
shown on the drawings.
After the Contractor has excavated the footing to the required depth, the Project Manager will
inspect the bottom of the excavation and determine if the bearing material is suitable for the type
of footing designated for that location. If it is found that the bearing material is unsatisfactory for
the type of footing designated, the Project Manager or his nominated person will either designate
another type of footing or ask for compacted crushed stone mixed with sand 50:50 ratio to be
placed underneath the footing for a depth of up to 1.2 meters. The Contractor will be paid only for
the type of footing actually installed. However, no payment will be made to the excavation &
replaced material underneath the footing.
A maximum variation of 60 mm above or below established grade will be permitted. However, if
excavations are below specified grade plus tolerance, those shall be backfilled to required grade
by the Contractor with the Contractor's furnished concrete at his own cost.
All excavated material which is suitable for backfilling shall be laid aside to be used for backfilling
at the tower site from which it was excavated, and the excess material shall be spread evenly
around the site as directed by the Project Manager or his nominated person.
Concrete shall be placed as soon as practicable after each excavation is completed and all
excavations shall be protected so as to maintain a clean sub-grade until the footing is placed,
using dewatering, timbering, shoring, or casing, as necessary. Any sand, mud, silt, or other
objectionable material which may accumulate in the excavation shall be removed at the expense
of the Contractor before placing concrete. After completion of foundations all the dewatering holes
shall be filled with dry sand.

(3)
88
Rock Excavation (Not required)

Rocks shall be excavated to the depth required to provide suitable base for the foundations as
indicated on relevant drawings. Rocks are classified as sound and mashes, layers or ledges of
mineral material 0.241 cubic meters in volume in place and of such hardness and texture that it
cannot be easily loosened or broken down.
Rock excavation includes drilling, blasting, removal, drainage and pumping as required. Drilling
and blasting techniques shall keep overbreak to a minimum and no extra compensation shall be
paid for the removal of overbroken material. The contact surface of the rock shall be cleared of all
loose rock and soil.
The cost of any damage whatsoever caused by blasting shall be payable by the Contractor. He
shall not be relieved of these costs in spite of having received approval of his methods from the
Project Manager.
(4)
Erosion/Slope Protection (Not required)

For erosion protection against water current, gravel blankets shall be placed such that they do not
flow away with water current. These gravel blankets shall be placed at or adjacent to tower sites
in the manner as directed by the Project Manager or his nominated person. Gravel for the
blankets shall be furnished by the Contractor, and it shall be pit-run, free draining, containing no
stones larger than 635 mm size obtained from the closest source approved by the Project
Manager or his nominated person. The gravel shall be reasonably clean and free from vegetation,
pieces of timber, or other foreign matter, and shall be distributed and graded evenly over the
required areas. No compaction will be required.
Slope protection will be provided for foundations, which are located/placed on uneven ground,
and/or they are partially or fully exposed in such a way that designed burden cannot be provided
on these foundations safely. Slope protection shall include but not limited to construction of
retaining walls of stone or brick masonry to a height and depth so as to provide adequate
protection and necessary burden by making a leveled platform with or without brick/stone mortar
after filling with earth as per specifications/drawings or as directed by the Project Manager. The
slope protection drawings will be prepared by the Contractor and submitted to the Project
Manager for review/approval prior to execution of Project.
(5)
Concrete Foundations
Each tower foundation will have four footings and each footing will consist of a steel stub angle
embedded in reinforced concrete. The footings for each tower in a tangent section of the line shall
be placed so that the longitudinal axis of the tower cross-arm will lie in a plane perpendicular to
the traverses of the line. Unless otherwise directed by the Project Manager, the footings for each
angle tower shall be placed so that the tower cross-arm will lie in a plane bisecting the interior
angle formed by the inter-section of the traverses of adjacent sections of the line.
The footings at the various tower sites shall be constructed in accordance with the criteria shown
on Drawings.
Pile foundations will be required where the field and laboratory tests confirm the requirements.
The pile foundations will be installed as shown on the relevant drawings and in accordance with
these Specifications.
Any type of spread footing foundation may be changed to another type of spread footing
foundation or pile foundation in accordance with field requirements during execution of the project
with the prior approval of the Project Manager.

(6)
89
Placing of Stub Angles in Footings

Stub angles shall be placed in the tower footings as shown on the drawings and shall be
supported in the proper position by means of a rigid frame or equivalent suitable device to ensure
placement of the stubs within the tolerances specified below. The stub angles shall be held rigidly
in a manner to prevent displacement during placing of concrete.
All stub angles for the tower legs shall be set accurately to the grade and alignment designated on
the drawings and as directed by the Project Manager. Work that is not within the tolerance will be
corrected as directed by the Project Manager, and at the Contractor's expense. The setting
tolerances following complete foundation installation including backfilling and compacting are as
follows:
(a)
(7)
Tower Center from theoretical location:

(i)
Transverse ................ 150 mm
(ii)
Longitudinal .............. 500 mm
(b)
Tower Orientation (angular departure from the theoretical location measured at the point
of intersection of a tower face and the longitudinal centre-line)................25 mm
(c)
Difference in Elevation between working point marks on Stub Angles including diagonally
opposite legs ......... 8 mm
(d)
Departure from theoretical Horizontal Dimensions between tower centre line and working
point marks on stub angle:
(i)
Along the tower face,

plus minus ................... 5 mm
(ii)
Along the tower diagonal,

plus minus ................... 7 mm
(e)
Batter ................................. 5 mm
per meter
(f)
Twist (about heel of stub angle) ....... 2
Tower Grounding
Each tower shall be grounded by installing one ground rod below each of two diagonal footings.
Ground rods shall be driven at least 2.5 meters into undisturbed soil at the bottom of the footing
excavation, as shown on the Drawings. The ground rod shall be connected to the stub angle by a
7 No. 10 stranded annealed copper covered ground wire. The connection of this wire to the
ground rod and to the stub angle shall be made by a bolted clamp in accordance with the
Drawings.
Where it is not possible to drive a ground rod an alternative grounding by installing 'crowfoot' shall
be adopted.
The resistance of the two rods/crowfoot in parallel shall be measured and recorded before
concrete footings are poured. If the resistance is more than 10 ohms, additional rods/crowfoot
shall be installed as directed by the Project Manager or his nominated person. No extra payment
would be allowed for laying on account of this.

90
The dead end terminal tower of the overhead lines must be connected to the earthing system of
the grid stations.
(8)
Concrete
(a)
General
All concrete and reinforcement placed for tower footings shall conform to the
requirements of this section.
At least 30 days prior to beginning concrete placement, the Contractor shall submit to the
Project Manager for approval, a design mix (along with quantity and source of each
material) along with six (6) test cylinders using the actual materials to be incorporated
into the Work. Approval of the design mix will in no way relieve the Contractor from
meeting all the requirements of these Specifications. Whenever the Contractor proposes
to use a different material source, a new design mix must be submitted and approved as
outlined above. During construction if in the Project Managers opinion the mix shall be
adjusted, the Contractor shall submit a new design mix as directed by the Project
Manager.
(b)
Materials
The Contractor shall furnish all materials for use in concrete, including but not limited to
cement, sand, coarse aggregate, water, reinforcing bars, admixture,(including ground
slag) and concrete curing compound. Air-entraining agent and curing compound shall be
accepted on manufacturer's certification of compliance with specification requirements.
However, the Project Manager reserves the right to require submission of and to perform
tests on samples of the agent and/or compound prior to shipment and use in the Work at
the cost of Contractor.
(i)
Cement
Cement shall meet the requirements of ASTM C150 and shall meet the falseset limitation specified therein. The cement shall be free from lumps and
damaged cement, when used in concrete. Adequate provisions shall be made
by the Contractor to prevent absorption of moisture when cement is stored.
Cement Type-V shall be used for all foundations (Lot-I & Lot-II). Cement Type-I
shall be used for all types of foundations other than those for which sulfate
resistant cement Type-V is required by the Project Manager (for Lot-III only). No
extra payment shall be made to the Contractor in case of use of sulfate resistant
cement.
(ii)
Sand and Coarse Aggregate

Sand and coarse aggregate shall be furnished from any approved source. The
sand particles shall be clean, hard, dense, durable, uncoated rock fragments
that will pass a screen having 6.5 mm square openings. The sand shall be well
graded from fine to coarse and shall be free from injurious amounts of dirt,
organic matter, and other deleterious substances.
The coarse aggregate shall consist of clean, hard, dense, durable, uncoated
rock fragments, shall be free from injurious amounts of flat and elongated
pieces, organic matter, or other deleterious substances. The maximum size of
crushed coarse aggregate for piles shall be 19 mm and for spread footings, pile
cap and tie beam 38 mm or as directed by the Project Manager. The grading of
these sizes shall conform to ASTM C33.

91
The Contractor shall submit, for testing and approval, representative samples of
the sand and coarse aggregate proposed for use in the concrete work. All
aggregates shall conform to the requirements of ASTM C33 including
petrographic test. During construction the Contractor shall also arrange testing
of sand and coarse aggregate if directed by the Project Manager to determine
compliance with Specifications. The cost of all laboratory testing of these
samples shall be borne by the Contractor.
(iii)
Water
Water used for mixing concrete shall be clean and free from injurious amounts
of oils, acids, alkalis, salts, organic materials, or other substances that may be
deleterious to concrete or reinforcement and shall meet the requirements shown
in Table-1 below. A complete chemical analysis of water shall be submitted
prior to the start of construction work and shall be required for each new water
source being chosen. The cost of all laboratory tests of the samples shall be
borne by the Contractor. No change in water source shall be permitted without
prior approval by the Project Manager.
TABLE-1
(iv)
Total Dissolved Solids (TDS)
700 ppm (max)
Magnesium, Chlorides and Sulfates
250 ppm (max)
pH Value
6.5 8.0
Reinforcing Bars
Reinforcing bars shall be deformed bars conforming to ASTM Designation
A615, Grade 40 & Grade 60. Representative steel bar samples shall be
collected from the site and tested in the laboratory approved by the Project
Manager. The testing shall be witnessed by the Project Manager. The cost of
all laboratory tests and traveling of Project Manager shall be arranged/borne by
the Contractor.
Negative variation in weight [mass] maximum up to 1.5% of reinforcement
bar(s) from the applicable weight [mass] per unit length prescribed in Table 1 of
ASTM A615 will be allowed for bar(s) placement. Contractor will have to make
adjustments in bar spacing/number of bars to accommodate the excessive
negative variation in weight [mass] if greater than 1.5%. Contractor will not be
allowed for bar(s) adjustment in case of overweight [excessive mass] of any
deformed bar.
(v)
Curing Compound
Curing compound shall be wax-base and white-pigmented (Type 2) and
conforming to ASTM Designation C-309 to reflect solar radiation.
(vi)
Admixtures and Ground Slag

Admixtures to be used in concrete shall be subject to prior approval of the
Project Manager and shall meet the following requirements:

92
(1)
Chemical Admixtures
a) Air-entraining admixtures shall conform to ASTM
260,"Specification for Air-Entraining Admixtures for Concrete.
b) Water reducing or water reducing and retarding admixtures

(Normal Plasticizers) shall conform to ASTM C 494, Specification
for Chemical Admixtures for Concrete, Type A or D, respectively.
c) Super plasticizers shall conform to ASTM C 494, Type F or G,
respectively
d) Only one of the Admixtures A, D, F or G, shall be added at a time.
e) Chloride-bearing admixtures shall not be permitted.
f)
(2)
Super Plasticizers shall be checked for their compatibility with

pozzolanic materials in blended cement concrete.
Ground Granulated Blast-Furnace Slag

In area where high sulphate and chloride contents are present in
soil/water, finely ground granulated blast-furnace slag can be used as
cementatious material in concrete by replacing SRC cement by
maximum up to 30%. The properties of ground granulated blastfurnace slag should meet ASTM C 989. The cost of all laboratory
testing of these samples shall be borne by the Contractor. Contractor
will not be paid extra for the purchase/procurement of ground
granulated blast-furnace slag to the construction sites.
(c)
Composition
The Contractor shall determine the proportions of the sand, coarse aggregate, and
cement needed to provide concrete, meeting the requirements of these Specifications,
and shall be approved by the Project Manager. Concrete which contains 38 mm
maximum-size aggregate shall have a cement content of not less than 380 kg per cubic
meter and concrete which contains 19 mm maximum size aggregate shall have a
cement content of not less than 440 kg per cubic meter. 38 mm maximum size
aggregate shall be used for spread footing, pile caps, tie beams and 19 mm aggregate
for piles. The net water cement ratio by weight shall not exceed 0.5. Surface water
contained in the aggregate shall be included as part of the mixing water in determining
the water content. Reinforced concrete design will be checked in accordance with the
ACI Building Code.
The Contractor will take minimum three test cylinders (152mm x 305mm) per leg, and the
average compressive strength at 28 days shall exceed 210 kg/cm (3000 psi) and no
individual test value should fall more than 35 kg/cm (500 psi) from the minimum
specified value.
The compressive strength of the concrete will be determined by the Project Manager
through the medium of test of (152 x 305 mm) cylinders made and tested in accordance
with ASTM C39. The Contractor shall furnish all necessary sampling equipment such as
slump cones, test cylinders, etc. at the site. This equipment is to be approved by the
Project Manager or nominated person by Project Manager. The cost of the material lab
tests shall be borne by the Contractor.

93
In the event that the concrete cylinder fails to meet the specified strength requirements
then in-place testing of concrete shall be conducted under the supervision of the Project
Manager. In-place as approved by Project Manager testing of concrete shall be
conducted by one or a combination of the following methods:
(i)
ASTM C42 Test Method of Obtaining and Testing Drilled Cores and Sawed
Beams of Concrete.
(ii)
ASTM C805 Test Method of Rebound Number of Hardened Concrete.
The use of calcium chloride in concrete will not be permitted.

The slump of the concrete shall not exceed 75 mm for conventional foundation, pile cap
& tie beam and 150 mm for piles.
(d)
Batching and Mixing

Unless specifically approved by the Project Manager, all concrete used on the Project
shall be machine mixed. Hand mixing shall only be used when authorized by the Project
Manager and shall be performed under his directions.
The sand and coarse aggregate shall be weighed and shall be proportioned on the basis
of integral bags of cement unless the cement is weighed. After weighing, the materials
may be proportioned on the basis of equivalent volumes. The Contractor shall provide
equipment and shall maintain and operate the equipment as required to accurately
determine and control the amount of each separate ingredient entering the concrete.
Batching shall be such that combined inaccuracies in feeding and measuring the
materials will not exceed 1.5 percent for water and weighed cement and 2 percent for
sand and each size of coarse aggregate. The concrete shall be uniform in composition
and consistency throughout the mixed batch, and from batch to batch, except where
changes in composition or consistency are directed. The mixing time shall be at least 1.5
minutes for stationary mixers. Excessive over-mixing requiring the addition of water to
preserve the required consistency will not be permitted. The temperature of the concrete
when it is being placed shall be not more than 35C and not less than 5C in moderate
weather or 10C when the mean daily temperature drops below 5C. Truck mixers will
be permitted only when the mixers and their operation are such that the concrete
throughout the mixed batch and from batch to batch is uniform with respect to
consistency and grading. Any concrete retained in truck mixers so long as to require
additional water to permit satisfactory placing shall be wasted.
(e)
Forms Preparation for Placing of Concrete

Unless otherwise provided for on the Drawings or approved by the Project Manager, all
concrete placed will be monolithic.
Forms shall be sufficiently tight to prevent loss of mortar from the concrete and shall be
maintained rigidly in position until the concrete has hardened sufficiently to prevent
damage by form removal. All surfaces of foundations upon or against which concrete is
to be placed shall be free from standing water, mud and debris. The surfaces of
absorptive foundations against which concrete are to be placed shall be moistened
thoroughly so that moisture will not be drawn from the freshly placed concrete. The
surfaces of construction joints shall be clean, rough and surface dry when covered with
fresh concrete. Cleaning shall consist of the removal of all laitance, loose or defective
concrete, coatings, sand, curing compound if used, and other foreign material. A mortar
layer shall not be used on concrete construction joints.

94
The methods and equipment used for transporting concrete, and the time that elapses
during transportation shall be such as will not cause appreciable segregation of coarse
aggregate or slump loss in excess of 25 mm in the concrete as it is delivered into the
Work. Concrete may be transported from the mixer to the forms and deposited in the
forms by any method approved by the Project Manager such as transit mixers, buckets,
chutes and pumping. Aluminum pipe or chutes shall not be used for tremie trunk line, or
chute for placing of concrete, or for the delivery of pumped concrete. Re-tempering of
concrete will not be permitted. Any concrete which has become so stiff that proper
placing cannot be assured shall be wasted. Formed concrete shall be placed in
continuous approximately horizontal layers, the depths of which generally shall not
exceed 500 mm. Concrete shall be vibrated (internal vibrators having a minimum
frequency of 8,000 vibrations per minute) until it has been consolidated to the maximum
practicable density, is free from rock pockets of coarse aggregate, and closes snugly
against all surfaces of forms and embedded materials. Standby vibrators shall be
available during concrete placement.
Exposed unformed surfaces of concrete shall be brought to uniform surfaces and worked
with suitable tools to a reasonably smooth wood float or steel-trowel finish as directed.
Concrete in the tops of foundations in which stub angles are embedded shall be sloped
to provide drainage away from the stub angles.
(f)
Reinforcement
Steel reinforcing bars shall be placed in the concrete where shown on the drawings.
Before reinforcement is placed, the surfaces shall be cleaned of heavy flaky rust, loose
mill scale, dirt, grease, or other foreign substances. Reinforcement shall be accurately
placed and secured in position so that it will not be displaced during placing of concrete.
The Project Manager shall not furnish supplemental bar-placing diagrams, bar lists, and
bar-bending diagrams. Any such additional diagrams and bar lists of this type which the
Contractor may require to facilitate the fabrication and placement of reinforcement shall
be provided by the Contractor.
Reinforcement will be inspected for compliance with requirements as to size, shape,
length, splicing, position, and amount after it has been placed.
Any bar-placing diagrams, bar lists, and bar-bending diagrams prepared by the
Contractor shall conform to the requirements shown on the reinforcement design
drawings and shall be approved by the Project Manager. Maximum two numbers of bars
(2+2) in pad and chimney can be lapped.
Lap splices shall be as under:
Bar #
10
11
Lap(mm)
305
360
460
610
840
1095
1400
1750
2160
(g)
Protection and Curing

The Contractor shall protect all concrete against injury until final acceptance. The
concrete shall be cured with two applications (coats) at right angles to each other to
ensure uniform and more complete coverage with approved membrane type curing
compound to be applied preferably by power sprayer as soon as possible after concrete
placement and in no case later than 2 hours. Curing with water shall be used only as an

95
alternative to the type curing and with Project Manager approval. The application of the
curing compound shall be in accordance with the procedures outlined by the
Manufacturer. In case of pile-cap & tie beam with form, ties are loosened and vertical
forms are still in place water should be applied to run down on the inside of the form to
keep the concrete wet. Immediately after form removal, the surfaces should be kept
continuously wet by water spray or water-saturated fabric until the membrane-forming
curing compound is applied.
In exceptional cases where extremely corrosive soil conditions are encountered, or as
directed by the Project Manager, the surfaces of the concrete, both exposed and
unexposed, shall be treated with an approved type of bituminous compound. A minimum
of two applications shall be required, and the applications shall be 100 percent effective.
Surfaces to be treated shall not be coated with curing compound. No extra payment will
be made to the Contractor for procurement/treating concrete surfaces with bituminous
compound.
(h)
Repair of Concrete
Any concrete that is damaged or defective from any cause; concrete that is honeycombed, fractured, or otherwise defective, and concrete damaged because of excessive
surface depressions, must be excavated and built up to bring the surfaces to the
prescribed lines, shall be removed and replaced and any imperfections and irregularities
on concrete surfaces shall be corrected. The removal and replacement of damaged or
defective concrete, and the correction of surface imperfections and irregularities shall be
made with concrete dry pack, or mortar (Portland cement mortar), or at the option of the
Contractor, with epoxy-bonded concrete, or epoxy-bonded epoxy mortar, where and as
applicable for the type of repair involved. All repairs should be completed within 24 hours
after removal of forms, and as directed by the Project Manager or his nominated person.
However, forms shall not be removed for a period of at least 24 hours after the concrete
work until it has acquired sufficient strength to safely carry its own weight and any
construction loads that may be imposed on it.
(i)
Tolerances for Concrete Construction

The Contractor shall be responsible for setting and maintaining concrete forms within the
tolerance limits necessary to insure that the completed Work will be within the tolerances
specified or within good construction practices. Concrete work that exceeds the
tolerance limits specified herein shall be inspected by the Project Manager and he will
determine what effect the deviations will have upon the structural action or operational
function of the structure, and what remedies may be necessary. If after such inspection
the Contractor is directed to remove or replace any defective Work, he will do so at his
own expense.
(aa)
Tolerances for footings:

-
Variation from plumb

or specified batter for
lines and surfaces of stems
In any length of 3.0

meters .........
13 mm
Maximum for entire
length .........
26 mm
Variation in crosssectional dimensions

of stems
Minus...........
Plus ............
7 mm
26 mm
Variation from specified
Minus .........
13 mm

96
elevation for top of

concrete
Plus ..........
13 mm
Variation of dimensions
in plan
Minus ..........
Plus ...........
13 mm
52 mm
Misplacement or
2 percent of the footing

Eccentricity width in the direction
of misplacement but not more than
52 mm
(bb)
(9)
Reduction in thickness
5 percent of specified thickness
Tolerance for placing reinforcing steel:

-
Variation of protective
covering:
Variation from
indicated spacing
with cover of 64 mm or
less 7 mm with cover of
more than 64 mm
......... 13 mm
.......... 26 mm
Backfill for Tower Footings

Backfill shall be placed about the tower footings to elevations indicated on the drawings or as
directed. The material used for backfilling, the amount thereof, and the manner of depositing this
material shall be approved by the Project Manager. Where the excavated materials are
insufficient in quantity or are not suitable, as determined by the Project Manager nominated
person, for use as backfill, the Contractor shall obtain suitable material from the borrow. No
borrow pits shall be made within 25 meter radius from centre of tower. Backfill shall be placed
about the tower footings as soon as practicable after removal of concrete forms, but not earlier
than 8 hours from application of sealing compound or bitumen coating to concrete surfaces.
The excavated material not suitable for backfilling or in excess of backfilling requirement shall be
spread evenly over or adjacent to the Site. The backfill adjacent to footing stems shall be
approximately 150 mm above the original ground, and shall be graded and sloped uniformly away
from the stems so that there is no pond at or around the footing.
In backfilling for concrete footings, the pad of the footing shall be covered with fine material of 300
mm thickness (after compaction) before any coarse material is deposited. Care shall be taken to
avoid damage to the concrete when backfilling. The backfill material shall be clean and free from
vegetation, pieces of timber, or other foreign matter. Suitable material for backfilling shall be a
compatible granular material having a granularity within the following limits.
Sieve
% Passing
76 mm (3 in)
100
No. 200
0-15
(10) Compacting Backfill

Backfill shall be placed in horizontal layers which after compaction shall not be more than 150 mm
thickness. Each layer shall be compacted by tamping machines or other mechanical means
approved by the Project Manager.

97
Backfill shall be moistened properly where required. When excavated material is so wet that it is
not suitable for backfilling, it shall be spread and aerated until the proper moisture content is
attained, at which time the material shall be used as backfill around tower footings. The backfill
material shall not be placed until all forms and timber used for shoring or bracing have been
removed, unless otherwise permitted by the Project Manager or his nominated person.
The Contractor shall submit, for laboratory testing and approval, representative samples of the
materials proposed to be used as backfill. On the basis of laboratory test results the Project
Manager shall specify the degree of compaction to be obtained in the field, which shall not be less
than 90% of the maximum dry density as obtained by ASTM D-1557.
Density shall be measured in the field according to ASTM D1556 or ASTM D2937 by the
Contractor in the presence of nominated person of the Project Manager to determine compliance
with the specified degree of compaction. The cost of all laboratory and field testing shall be borne
by the Contractor.
(11) Additional Foundations
In case other foundations are required to be installed, which are of different design than the
specific types listed, the Contractor shall install these foundations as directed by the Project
Manager. All work performed will be in accordance with these Specifications. Payment for
additional foundations will be made at the applicable unit prices provided in the Price Schedules
for similar works.
(12) Foundation Test (Not Required)
The Contractor may be required to perform an uplift load test on any one footing for double circuit
suspension type tower. The Project Manager will designate the location and type of footing to be
tested. All methods, procedures, equipment, jigs, apparatus etc., shall be subject to approval by
the Project Manager. No testing shall be commenced until 28 days after the final concreting nor
until all backfill is placed and compacted as specified herein.
An uplift load shall be applied until a design value is reached or the footing fails. The rate of load
application will be determined by the Project Manager.
9.4.
Pile Foundations
(1)
General
(a)
Description of Work
The Work to be performed under these Specifications shall be carried out at the
proposed site of towers after the field and laboratory test results confirmation. The Work
includes, but is not limited to the following:
(i)
Carrying out subsoil investigations at the tower locations through drilling, testing
and sampling (if required by the Project Manager).
(ii)
Construction of bored, cast-in-place reinforced concrete piles, pile cap and tie
beam as shown in the Bid Drawings or as directed by the Project Manager.
Complete borehole logs and record of all operations performed during the
investigations and the execution of the Work.
(iii)

(b)
(c)
(d)
98
Location of Investigation Borehole and Piles

(i)
The location of investigation boreholes and piles on the ground shall be

established by the Contractor in accordance with the Drawings after the approval
by the Project Manager. Establishing the investigation borehole and pile locations
accurately in the field shall be the sole responsibility of the Contractor.
(ii)
The Contractor will provide the levels, survey and ground elevations for each
investigation borehole and pile location. The elevations will be given with respect to
permanent Bench Marks in the vicinity of the Site.
Number, Diameter and Length of Investigation Borehole and Piles

(i)
One investigation borehole, not smaller than NX size, the hole diameter
approximately 75 mm shall be drilled at each location of tower where pile
foundations are proposed to a depth of 20 meters from the general ground level, or
5meters below the pile tip whichever is greater.
(ii)
Bored, cast-in-place reinforced concrete piles shall be constructed having uniform

diameter throughout the length as specified (minimum) in the relevant Bid drawings
or as directed by the Project Manager. Pile footings shall only be installed where
the field and laboratory tests confirm the requirements. The final length of the piles
shall also be determined based on field and laboratory test results confirmed after
testing.
Containers
For preserving and transporting soil and water samples collected from subsoil
investigations the Contractor shall furnish jars, tubes, boxes, bags and crates, meeting
the requirements as specified in these Specification and the cost thereof shall be
included in the Contract Price.
(e)
(f)
Care and Delivery of Samples

(i)
Contractor shall be solely responsible for preserving all samples in good condition.
He shall keep samples away from undue exposure to the weather, and shall keep
descriptive labels and designations on sample jars and boxes clean and legible
until final delivery of samples to the laboratories approved by the Project Manager.
The Contractor shall make arrangements for waxing of samples as directed by the
Project Manager.
(ii)
The Contractor shall arrange for all samples to be safely packed and careful
transportation to a laboratory as approved by the Project Manager.
Drillers and Supervisory Staff

The Contractor shall have at Site, at all times only qualified, experienced, orderly and
thoroughly competent persons including graduate civil engineers/geologists who shall
conduct and supervise drilling/concreting operations during, sampling, logging, in-situ
testing and piles construction.
(2)
Execution of Piles
(a)
General

99
This clause covers all the work necessary for the execution of the bored, cast-in-place
reinforced concrete piles namely:
(i)
Drilling and stabilizing of bore holes for the piles.
(ii)
Placing of steel reinforcement.
(iii)
Mixing and placing of concrete.
The Contractor shall perform all such work in accordance with requirements of this
clause as well as in accordance with the methods proposed or described by him at the
time of submitting his Bid and approved by the Project Manager.
(b)
Method of Drilling
The drilling of holes for piling shall be done by mud circulation or reverse rotary or
percussion method or any other method suggested by the Contractor and approved by
the Project Manager. Regardless of the method used for drilling holes, drilling operations
shall be carried out in such a way as to avoid any disturbance of the surrounding soil
especially at the bottom of the hole and successful drilling through all types of
soil/rock/boulder.
(c)
Stabilizing of Holes
There will be no permanent casing installed. Any temporary protective casing at the start
of the drilling shall be later pulled out. The stabilizing of the drilled holes shall be
achieved by using natural or commercial drilling mud/bentonite. Permanent casing shall
only be allowed with the prior approval of the Project Manager, for which no extra cost
procurement/placement shall be paid to the Contractor.
(d)
Tolerances
Tolerances for setting out and for concrete construction shall conform to Clause 9.3 of
these Technical Provisions. In case of piles, deviation from the vertical shall not exceed
one percent on any section of the length of the holes.
(e)
Concrete
All concrete and reinforcement placed in the construction of piles shall conform to the
requirements of Clause 9.3(8) of these Technical Provisions. In addition to this, following
requirements shall also be fulfilled.
(i)
Promptly after cleaning of the borehole to the entire satisfaction of the Project
Manager Representative, concrete shall be placed in a manner that will not cause
segregation of the particles or permit infiltration of water or any other occurrence
which would tend to decrease the strength of the concrete or the capacity of the
finished pile. The slump shall be limited to 150 mm maximum.
(ii)
The minimum clear distance between vertical reinforcement, including lapped

bars, shall be 100 mm (if applicable).
Either tremied or pumped-in concrete can be used in presence of water or of
drilling mud. Tremie or pump pipe shall be made of steel and have watertight
joints. Tremie pipe shall have a minimum diameter of 8 inches (200 mm) and
pump pipe shall have a minimum diameter of 4 inches (100 mm) should be used.
Embed tremie or pump pipe a minimum of 3 meters in the concrete throughout
(iii)

100
concreting. The method and equipment used shall be subject to the prior
approval of the Project Manager.
(f)
(iv)
Concrete placement shall proceed without interruption until the pile is complete.
(v)
Vibrate top 3 to 4 meters of concrete after temporary casing has been withdrawn.
(vi)
The Contractor shall make three test cylinders per pile or as directed by the
Project Manager during the concreting of piles.
(vii)
The vertical bars of pile can be coupled together as directed by the Project
Manager according to the site requirement.
(viii)
The dia of stand casing/permanent casing should be at least 25mm larger than
the pile dia, whereas bit dia should be equal to pile design dia.
Record
The Contractor shall keep accurate logs and records of all the Work accomplished under
this Contract. All such records shall be preserved in good condition by the Contractor
until they are delivered and accepted by the Project Manager. The Project Manager
shall have the right to examine such records at any time prior to their delivery to him. The
following information shall be included in the records for each pile.
(i)
(ii)
Investigation Bore-hole (if applicable)

-
Hole number of designation, coordinates and elevations of top of the hole.
Type of drilling operations.
Date and time by depths when drilling operations were performed.
Depths at which samples were recovered and field testing was performed
including complete data of field testing.
Depth of ground water table from NSL.
Description of subsoil conditions.
Piles
-
A general description of sub-soil conditions and water table position at the

location of the pile.
Pile number, ground elevation of borehole and elevation of top of pile.
Type of drilling operations.
Date and time by depths when drilling operations were performed and
piles constructed.
Total depth of each borehole.
Quantity of concrete and steel used for the construction of each pile.

9.5.
101
Quantity of constituents for each batch of mix, water cement ratio and the
results of all quality control tests.
Time of start and completion of Concrete.
Remarks concerning any unusual occurrence during drilling and

concreting of piles.
Tower Erection
(1)
General
Contractor's work includes supply of manpower, providing construction equipment, vehicles,
rigging tackles for complete assembly of towers.
Profile drawing indicating the location, height and type of each tower and the construction data
sheets showing the length of leg extension for each of the four legs of each tower will be
submitted by Contractor after final survey for approval of the Project Manager.
Erection shall be done strictly in accordance with the approved manufacturer's drawings, material
lists and approved construction data sheets.
No tower shall be erected until seven days after the last concrete was placed in the foundation,
nor until backfill has been completed where and as required.
(2)
Handling
Tower steel shall be handled so as to prevent deformation of the members and damage to the
galvanizing. Materials shall not be dumped, dragged, barred; rolled or dropped but shall be
carefully loaded, unloaded and stored. A mechanical means such as hoist or crane shall be used
when material cannot be properly handled or placed by hand.
Bare wire rope or steel chains shall not be used for handling without adequate protection of the
surface coating. Heavy members shall not be stacked on top of lighter members. Structural
members shall be stored according to size, lengths and markings. The maximum weight of steel
bundles shall not exceed a specified weight, typically 1600 kg to 1800 kg, to facilitate handling
and unloading. Members with dissimilar finishes shall not be stored over one another to minimize
discoloration of the lower members.
All members shall be placed on wood blocking or other suitable material to ensure that the
materials to be stored are not in contact with the ground. Blocking shall also be used to separate
layers of stacked materials. Members shall be supported in such a manner as to prevent bending
and distortion as well as to allow water to drain from the materials.
Failure to provide for proper drainage of stacked galvanized steel members could result in the
formation of white rust. White rust (zinc oxide) forms when two galvanized surfaces are closely
rested for an extended time without adequate ventilation. Ingress of water between the surfaces
forms an electrolytic cell, which may, in time, erode some of the zinc layer. The white rusting
action will stop after exposure to air. Spacers placed between the nested pieces ensure adequate
ventilation when extended transport storage is anticipated.
The material yard shall be kept relatively neat and clean and the growth of vegetation kept to a
minimum. Good housekeeping minimizes damage and loss of material handling; periodic physical
inventories and complies with environmental considerations.

(3)
102
Assembly Methods
All assembly and erection shall be done by methods and equipment that will not cause damage
to, or distort any part of the tower. Extreme care shall be taken to establish and maintain the true
geometric shape of the sections of tower assembled.
Preassembly techniques are generally influenced by site terrain and available equipment.
Generally, the larger section that can be pre assembled, the more efficient is the
assembly/erection operation. Preassembly techniques shall consider placement of the assembled
sections to provide for the most efficient, safe lifting for erection. Structural assemblies, which are
not sufficiently rigid to be raised in one piece, shall be stiffened by means of adequate temporary
bracings.
Towers assembled on the ground shall be placed on suitable blocking so as to be kept free of dirt,
mud or other foreign material that might adhere to the structure and damage the coating. Blocking
shall be placed in such a manner as to provide a flat surface in order to prevent over stressing or
distortion of members and to maintain the true geometric shape of the assembled members. Mud,
dirt, white rust and other foreign material shall be removed from the contact surfaces of joints prior
to assembly. Steel members shall not be dragged over the ground or otherwise handled in such a
manner as to damage the galvanizing.
The structures shall be assembled in accordance with the fabricators erection and detail
drawings. The diameter, type, and length of bolts as shown on these drawings shall be used
for each connection. Orientation of bolts can facilitate access, final tightening, installation of
locking devices and subsequent checking of the erected structure. Tower bolts shall normally be
installed so that the nuts are to the outside of the tower or, in the case of horizontal members, to
the top of the connection unless such positioning is clearly impracticable.
Installation of bolts by hammering or any method that damages the galvanized coating shall not
be allowed.
When sections of towers are being assembled prior to erection, assembly shall be on blocks that
will provide support, sufficient to prevent distortion of tower steel. If all bolts in an assembly are
not inserted, at least 50 percent of the bolts in each connection shall be inserted and those bolts
shall be finger-tightened only. All bolts in an assembly shall be inserted before any bolt in the
assembly is fully tightened.
Only wrenches which properly fit the nuts and bolt heads shall be used. The use of wrenches,
which in any way deform the nut or cut or flake the galvanizing is prohibited. All bolts shall be
entered clear to the head. All 16 mm diameter bolts shall be tightened to a torque of 10-14 kg meters and 20 mm and 24 mm diameter bolts to a torque 17-23 kg-meters. All bolts after torque
shall be centre punched adjacent to the nut in order to prevent loosening of the nut. This method
of locking the nuts will be used instead of locknuts.
(4)
Method for Erection

Towers shall be erected by any suitable method in the sequence best adapted to the equipment,
workers experience and site conditions which will not overstress structure members.
When handling assembled portions of the structure, spreader bars or other
devices with proper points of attachment shall be used to avoid distorting or
overstressing members and to maintain the true geometric shape of the section.
Adequate tag lines shall be used to ensure that no section of the tower being lifted will drag on
the ground or against any section of the tower already erected.

103
Temporary guying may be required when erecting a structure in sections. Any temporary guying
system shall be checked to ensure that the structure section is stable before workers are allowed to
work on the section.
Structures shall be completely erected, correctly oriented, with all members in place, all bolts
installed and properly tightened, and the entire structure checked in accordance with the
specifications prior to the installation of insulators, conductors and shield wires.
When erecting structure members or sections in the vicinity of energized lines, care shall be taken to
ground these members or sections before any workers come in contact with them.
The use of a crane erection is generally an efficient method of erecting latticed steel structures.
With ground pre-assembly of sections, the time spent in final erection can be greatly reduced.
Cranes with telescoping booms can be more efficient than rigid boom
cranes in rough terrain. Considerable productivity can be lost in the process of assembly and
disassembly of rigid boom cranes. In addition, continuous handling of boom sections can lead
to boom damage. Preplanning of the crane location at the structure site allows for any necessary
grading work (building of ramps, soil stabilization etc.) to be accomplished during the
foundation construction operations when suitable equipment is available at the site.
Depending on soil conditions, additional bearing support may be required under outriggers,
tracks, and tires. All soil shall be returned to a condition acceptable to the Project Manager after
erection.
Gin Pole is a boom of steel or aluminum pipe, wood pole or latticed truss secured at its base and
usually inclined at a slight angle to the vertical is also used for tower erection. Two wire-guys
about 60 to 90 apart in the plan view are attached to the top of the gin pole to resist or support
the load to be lifted. For safety, a third, and preferably a fourth guy, is installed in front to prevent
the pole from falling over backward in the event of an unexpected impact or the sudden release of
load.
(5)
Correction of Misfabricated and Damaged Steel

All shop errors and damaged steel shall be reported to the Project Manager who will decide the
manner in which corrections shall be made. All costs incurred due to punching, drilling or cutting
shall be deemed to be included in the steel erection cost.
Pieces bent in handling may be used if they can be straightened to the satisfaction of the Project
Manager, without structurally damaging the metal. If bent pieces cannot be satisfactorily repaired,
they shall be replaced.
Field punching or drilling of holes and field clipping shall be done only with the approval of
Project Manager, if the hole or clip was missed in fabrication of the member but was called for on
the fabrication detail drawings. The edges of clipped angles, new or reamed holes or any
member which has its coating scratched or damaged shall be repaired with a coating
approved by the Project Manager. Members having mis-punched holes shall not be repaired by
welding and shall be replaced with correctly fabricated members. If the field fabrication of a
member is required, the bolt spacing and edge distances shall be in accordance with the
fabrication detail drawings.
Reaming shall be done only with the approval of the Project Manager, and will be permitted, for
the correction of undersized holes, for removing excessive galvanizing, and for holes off gauge
line, to the extent that the connection cannot be made by loosening bolts in related connections.
No hole shall be reamed more than one-eighth of its original diameter.
Reaming to remove fitting difficulty due to improperly set footings, to correct improper tower
assembly and erection, that would distort holes or distort any member, or that would damage the
galvanizing, is prohibited.

(6)
104
Damage to Galvanizing
Small areas of galvanizing damaged by abrasion, in straightening bent pieces or by necessary
clipping-in the field, shall be repaired by carefully cleaning the affected area and painting. The
paint will be furnished by the Contractor.
Damaged area shall be wiped with clean rags saturated with Xylene or equivalent solvent,
followed by wire brushing then recleaned with solvent to remove residue, and painted with one
coat of "Galvanox", or approved equivalent.
Galvanizing damaged by drilling or punching shall be repaired by applying an Aluminum paste or
zinc rich coating material to completely fill all voids between the bolt and the surfaces bared, or all
exposed steel surfaces around the holes or on cuts on which such corrective work is permitted.
The coating material shall be "Galvanox" or approved equivalent.
(7) Tower Signs and Aerial Markers

Tower signs (danger sign and number signs) shall normally be installed on the tower so that they
will be readily visible when viewed in the direction of increasing tower numbers. However, if signs
installed in the normal position will not be readily visible from a permanent access road, they shall
be installed on the tower faces best exposed to view from the access roads. These signs shall be
supplied by the Contractor, and before the manufacturing, a sample shall be submitted to the
Project Manager for approval.
Aerial markers shall be installed on the upper side of bridge structure, as shown on the drawings.
Two markers shall be installed on every tenth tower of the line; one marker faced back on line and
the other ahead on line. These shall also be supplied by the Contractor.
(8)
Anti-climbing Devices
An anti-climbing device will be installed on each tower as shown on the relevant drawings. The
anti-climbing device normally will not be installed until all the tower and wire stringing work is
completed.
The tower steel will be provided with holes for mounting the anti-climbing device brackets. The
brackets shall be fabricated from mild steel and shall be galvanized in accordance with ASTM
A153. The brackets along with barbed wire shall be supplied by the Contractor. Any holes
required to be punched/drilled for installation of Anti-climbing Devices and applying of Galvanox,
shall be carried out by the Contractor without any extra cost.
Anti-climbing device will be provided with an arrangement of barbed wire around the tower to
prevent unauthorized person(s) from climbing the tower.
After erection, tower shall be cleaned of any foreign matter.
(9)
Supporting Device for Joint Boxes of OPGW

Supporting device for joint boxes of OPGW to be designed, manufactured and supplied by OPGW
manufacturer will be installed on the towers where joint boxes are required to be installed. Joint
boxes will be installed on the tower on completion or just before completion of each OPGW reels
of about 3.2 km length or wherever particularly required. The holes required to be drilled in the
tower braces for installation of these supporting devices including provision and applying of
Galvanox at the holes drilled shall be responsibility and to the cost of the Contractor.

105
(10) Welding of Nuts & Bolts

All nut & bolt connections of all types of towers shall be welded according to drawing No.
3206/169/TD/01F202, up to 8.0 m height from the top of chimney.
9.6.
Installation of Insulators and Hardware

Insulators and insulator hardware shall be assembled and installed as shown on the drawings and in
accordance with the recommendations of the manufacturers.
No insulator with chips or cracks in the porcelain or defects in the fittings shall be installed.
Uncrated or otherwise unsupported strings of insulators shall not be picked up or suspended except by
the upper units of the string. All cotter pins installed by the Manufacturer shall be checked.
All insulators shall be cleaned with a clean cloth when installed. The porcelain shall be bright and all
other parts free from dirt. Only clean rags free from any abrasive material shall be used for cleaning
insulators.
Wire brushes shall not be used for the cleaning of any parts, metal or otherwise. The use of solvents
will not be permitted.
Each completed suspension assembly shall be adjusted to hang in a vertical plane through the axis of
the tower. Where it would be possible, nuts, locknuts and cotter pins shall be placed to face the tower
body.
Workmen shall not climb on insulators during stringing operations or at any other time.
When raising conductor strain assemblies, the insulators shall be kept under tension to avoid possibility
of those being damaged due to excessive bending.
9.7
Stringing Conductors, Overhead EHS Shield Wire and OPGW

(1)
General
The conductor, overhead shield wire and OPGW shall be installed as shown on the drawings and
as specified herein.
(2)
Safety Grounding
It shall be the Contractor's responsibility to take adequate safety precautions to protect his
employees and others from the potential voltage build-up during construction. The voltage buildup may be comparatively small during normal operations, but could be lethal during switching and
ground fault conditions on the energized parallel line. The following minimum safety and
grounding procedures shall be followed by the Contractor during stringing operations in the
Sections with parallel existing high voltage lines.
Temporary electrical grounds shall be placed at both ends of the section requiring special safety
precautions and at intervals along the line which is under construction. The grounding sets
installed at both ends of the section of line shall remain in place until the completion of the work
and shall be removed as the last phase of cleanup. Hot stick shall be used for installing and
removing the grounding sets.
All temporary grounds furnished and installed for protection shall be clearly visible for inspection
and shall be flagged by use of a red cloth placed at the point of grounding. All grounds, except

106
those placed at both ends of the section, and red flags shall be removed when they are no longer
needed for protection.
All pulling and tensioning equipment shall be bonded and effectively grounded with approved-type
driven grounds securely attached to the equipment. At least two driven grounds shall be used at
both the pulling and tensioning set up. All conductive parts of the tensioning set up and equipment
shall be operated from grounded or insulated platform provided with barricades or insulated
walkways.
Running grounds shall be installed within 6 meters of the tensioning set up to constantly ground
each sub-conductor, overhead shield wire and OPGW. At the pulling set up grounding shall be
achieved by the use of block grounds connected to the adjacent tower by approved type ground
leads bonded to the tower with approved type clamps. These connections shall be removed by
the use of a hot-stick.
An approved-type driven ground shall be located at each side and within 3 meters of working
areas where conductors or overhead shield wires or OPGW are being compressed to dead-end
assemblies or spliced at ground level or jointed. The two ends to be spliced shall be effectively
bonded together prior to and during splicing operation. Splicing and compression operations at
dead-end assemblies shall be carried out on either an insulated platform or on a conductive
metallic grounding mat roped off with an insulated walkway provided for access to the mat.
Installation and removal of temporary jumpers, at any time the conductor is not continuous, shall
be performed by hot stick methods.
All conductors, overhead shield wires and OPGW shall be bonded to the tower with approvedtype tower grounds at any isolated tower where it may be necessary to complete Work. Work on
dead-end towers shall require grounding on both sides of the tower. Grounds may be removed
when the Work is completed, providing the line is not left open circuited at an isolated tower at
which work is being completed.
For all sections of the line under work, which are not in parallel with energized high voltage lines
or otherwise requiring special safety precautions, only the provision of the grounding at the pulling
and tensioning stations shall be required.
All provisions specified herein shall not prevent the Contractor from installing as many additional
grounds as deemed necessary for the protection of workmen against static and accidental
contacts with foreign circuits.
Clipping crews and all others working on the conductive pulling lines, isolated conductors,
overhead shield wires or OPGW shall be protected by individual hot stick clamp type grounds
installed at every work location.
(3)
Approved Type Grounding Material

Approved type moving grounds shall be such as to exert constant pressure on the conductor,
overhead shield wire or OPGW, and the contact rollers shall be with permanently lubricated-type
bearings.
Approved-type driven ground rods shall be minimum of 16 mm diameter copper-weld or
equivalent. Ground rods shall be driven into the ground a minimum of 2.5 meters.
Approved-type tower grounds shall be hot stick clamp grounds, bonded to the tower with a flexible
ground lead.
Approved-type ground leads shall be at least 43 mm cross-section copper or equivalent.

107
Approved-type insulated platforms shall be constructed of 65 mm nominal dimension lumber

supported on 102 mm nominal dimension sills, or of materials of equivalent insulation.
At the tensioning set up, the insulated platform and rope barriers shall extend completely around
the equipment set up in such a manner as to prevent any one standing on the ground from
contacting any conductive part of the equipment.
(4)
General Safety Precautions

Prior to initiation of the stringing in any section of the line the following shall be insured.
(5)
(a)
The installation of all towers within the section of the line is satisfactorily completed.
(b)
The stringing loads will not exceed the design loads for any of the towers.
(c)
If any tower is to be subjected to loads exceeding the design loads, the Contractor shall
provide temporary bracing for such tower, and the bracing is subject to approval by the
Project Manager.
(d)
The stringing and sagging operation is such that no sudden loads will be applied on the
towers.
Safety Precautions at Crossings

Wherever any power line, communication line, highway or railroad is to be crossed, the owners
shall be notified 30 days in advance and all temporary changes shall be pre-arranged.
The Contractor shall not erect towers near, or string conductors or overhead shield wire or OPGW
over energized power circuits until a Hot-Line Order is placed on the energized line.
Qualified personnel shall remain at the site of work while the Hot-Line Order is in effect and shall
ascertain that all personnel are in the clear and properly notified before the Hot-Line Order is
released.
All existing lines which are de-energized for crossing shall be short-circuited and grounded at
each side of the crossing.
Guard structures shall be provided at all crossings, as required for the protection of the conductor,
line, road, structure, or feature being crossed, and as required by the owner, or the Employer.
Guard structures shall be of sufficient strength and stability to withstand the stresses to which they
may be subjected.
As soon as a guard structure has served its purpose, it shall be removed and all holes shall be
backfilled.
(6)
Atmospheric Adverse Conditions

All pulling and stringing operations shall cease when either wind velocities are such as to cause
conductors to deflect more than 1.5 meters at mid-span from the normal no wind position or there
is any indication of lightning activity in the area.
(7)
Handling and Stringing of Conductors

The conductor will be furnished in matched sets of twelve reels and shall be strung by the
controlled tension method. At no time will the conductor be allowed to contact the ground or any
object which might cause damage to the conductor.

108
All reels shall be inspected in the field prior to installation. Reels showing signs of careless or
unusually rough handling, such as split frames or crashed outer protective lagging shall be
inspected carefully for conductor damage.
Preparatory to unreeling a conductor from the reel, the outer protective lagging shall be removed
carefully, and all surfaces in contact with the running conductor shall be examined for protruding
objects which might damage the conductor.
Care shall be taken to insure that no dirt is carried by the conductors from the reels. Reels shall
be properly cleaned before starting stringing operation of any line section.
A spreader bar shall be used when lifting or lowering the reels. Full or partial reels shall not be
dropped or rolled under any circumstances.
The four conductors in a bundle shall be strung simultaneously and shall hang in stringing blocks
for the same period of time not exceeding 24 hours and, in exceptional cases, up to 48 hours
before being sagged to the specified sag.
Four conductors shall start and end approximately at the same points of the line and stringing
operations shall be planned to keep waste to a minimum. Lengths of conductor less than 100
meters are scrap lengths and shall not be spliced into the line without the approval of the Project
Manager. Jumpers shall be cut only from scrap lengths unless otherwise permitted.
Stringing sheaves may be hung on the insulator strings or in straps of equal length attached to the
structure arms with suitable hooks or clamps. The sheave shall support the conductors at the
same elevation as when clipped in.
Stringing of conductors and temporary guying of conductors shall be done by methods that will
prevent damage to the conductor and structures in any way. Temporary guying/dead ending to
tower footings will not be permitted. Where temporary dead end is required, the conductors shall
be attached to suitable temporary anchors.
The general requirements for installation of the temporary anchors are as follows:
The angle formed by conductors/EHS shield wire/OPGW to the horizontal shall not exceed 15
degrees.
The anchors shall be aligned in the direction of stringing:
The anchors and their accessories shall withstand the maximum conductor tensions with a factor
of safety of three.
Four sub-conductors of one phase shall be strung simultaneously by means of running board
attached to a single pulling line with a swivel. Sub-conductors shall be connected to the running
boards with a swivel connection and a stocking-type grip. The grips shall be secured to the
conductor by means of a band installed around the tail end of the grip.
Following stringing, measures shall be taken to prevent the sub-conductors of the bundle from
contacting each other. Before adjusting the sag of the conductors, sub-conductor slapping may be
prevented by pulling each of them to a different sag which will separate them at least 153 mm
vertically from either of the other sub-conductor at mid-span. After adjusting the sag, the following
conditions will require sub-conductors tie-off: any time that sub-conductors slapping is noted, any
time that prior to spacer installation the conductors are left unattended.

109
Two reel lengths of conductor may be pulled into the sheaves using only approved swivels and
grips to make the connections between reel lengths. Double socking will be permitted, but
permanent splices shall not be pulled through a sheave or bull-wheel.
All sheaves, swivels and grips shall be inspected daily for free and easy movements and to
assure that such may be safely used. Sheaves carrying pulling lines shall not be used for
conductors.
The conductor shall be kept clean by removing grease, dust or any other contamination. Cleaning
shall be done immediately after the conductors leave the tensioning device. The method of
cleaning shall be wiping with a clean cloth saturated with proper cleaning agent. When it is
necessary to slack the conductor at any time during the stringing operation, it shall be done with
the approval of the Project Manager. Rigid plank guard or lagging, or a combination of both shall
be used to prevent damage. Lagging shall consist of nonmetallic material which will not damage
the conductor and shall be rigid so that it will not be displaced by the motion of the conductor. It
shall be free of any material, which can be transferred to the conductor.
Sections of the conductor damaged by application of gripping attachments or any other way
during stringing shall be removed before the conductor is sagged in place.
The conductor repairs shall be done as outlined in Clause 9.7(11) (b) of the Technical Provisions.
All stringing operation must be conducted so that at no time will any suspension structure be
subjected to longitudinal loads and at no time will any tension structure except dead end structure
be subjected to excessive unbalanced loads resulting from longitudinal loads on opposing faces.
At no time shall any structure be subjected to torsion. The vertical angles of pulling lines shall be
such as to minimize the vertical loading on towers. The attachment of temporary guys and
stringing equipment on towers shall be done only with approval of the Project Manager.
The conductor and shield wire reels, tensioners, and pulling machines shall be located as near to
mid-span as possible but in no case shall the slope of the OPGW or shield wire or conductor
between any machine and the stringing block or any anchor lead be steeper than three horizontal
to one vertical (15-20 to the horizontal).
The tension in the conductor during stringing shall be maintained as constant as practicable. The
sag in each conductor must be maintained at least 20 percent greater than the sagging value
specified in sag charts and the maximum pulling tension shall never exceed the sagging tensions.
If the conductor is left unattended, during stringing operations, it shall be freely suspended
between stringing sheaves so as to provide a safe clear distance over ground or obstructions.
The minimum tension shall be such as to maintain the conductors at a minimum distance of 3
meters above ground or any obstacle.
When there is possibility of conductor being damaged due to wind or other conditions they shall
immediately be fully tensioned. It is recommended that variations in stringing tensions be as small
as possible and the tension shall be near the maximum permitted. Immediately after completing
stringing of a section of the line, the tensions shall be increased to the maximum permitted
stringing values.
The spinning of the conductors and shield wires shall be prevented during stringing. Unreeling of
the conductors shall be closely watched at all times in order to detect any damage or flaw in the
conductor.

(8)
110
Handling and Stringing of Shield wire and OPGW

One 9.15 mm dia.7 strand extra high strength (EHS) galvanized steel overhead shield wire and
one 12mm OPGW shall be strung for the entire length of line.
The specifications used for handling and stringing the OPGW & overhead shield wires shall be the
same as for the conductors.
(9)
Conductor Sagging
After being pulled into the sheaves all sub-conductors in a sag section shall be sagged within 24
hours.
The conductors shall be sagged in accordance with sag charts, furnished by the Contractor. The
exact value of sag for a given span length at a given temperature can be ascertained from the
appropriate table or by linear interpolation of data.
Conductor sagging temperature shall be measured by an accurate thermometer. A length of core
shall be pulled from a 0.5 meter length of the conductor sufficient for thermometer to be inserted
into the space vacated by the core.
The length of conductor shall be placed in the full sun at least 4 meters above the ground for a
minimum period of 15 minutes. A thermometer in a container which stimulates the effect of the
conductor may also be used.
The length of conductor sagged in one operation shall be limited to the length that can be sagged
satisfactorily, usually 3,000 meters to 6,000 meters.
Temporary snubs shall be used between a section previously sagged and clipped in and the
section being sagged. Dead ending or snubbing will not be permitted on any tower except dead
end towers at the normal point of attachment.
When conductors are sagged a mark shall be placed on each conductor at the last structure in
each pull. The location of this mark shall be checked after the succeeding sag has been made to
ascertain whether or not the back spans are still sagged properly. The wire grips may be removed
only after the next section of the line has been sagged.
When sagging conductor shall have lengths of more than four spans, the sag shall be checked
near each end span and at or near the middle span of the length being sagged. The length of the
spans used for checking sag shall be as nearly equal to the ruling span as practicable.
The sag of each span more than 600 meters in length shall be checked in addition to above. Sag
at sharp vertical angles and horizontal angles of 10 or more degrees shall also be checked on
both sides of the angle.
The sags shall be determined by means of a transit or other approved methods. At least one
person shall be provided to measure the correct sag for pulls up to five spans, two persons for six
to ten spans and three persons for eleven spans or more.
The total number of spans to be checked shall be not less than two in a four-span section, three
for a section up to two kilometers and in proportion for a longer section.
In the quad conductor bundle the sag of the two upper sub-conductors shall be the same. The
lower sub-conductors shall be sagged from 30 to 60 mm more than the upper sub-conductors.

111
A tolerance of plus or minus 10 mm of sag per 30 meter of horizontal span length, but not to
exceed 150 mm in any one span, will be permitted, provided: 1) that: (1) upper sub-conductors in
the span assume the same sag; (2) the necessary ground clearance is obtained; (3) the
conductor tension between successive sagging operations is equalized so that the suspension
insulator assemblies will assume the proper position when the conductor is clipped in; (4) the sag
in the lower sub-conductor of the bundle is 30 to 60 mm more than the sag in the upper subconductors.
Log books shall be maintained to record all conductor installation data and chronological
progress.
The temperature, spans, tower, general weather, wind velocity and direction, sags, tensions, and
drawing references shall be recorded for each section of conductor as it is being installed,
tensioned and sagged. When possible, sagging operations shall be scheduled when wind velocity
is at or near zero.
Radio or telephone communication shall be used to relay information and instructions between
the conductor payout station, intermediate check points, mobile stations and the pulling stations at
all times during stringing operations. A failure of communication requires immediate cessation of
the conductor pulling operation.
(10) Conductor Clipping-in
After being sagged, the conductor shall be allowed to hang in the stringing blocks for not less than
2 hours before clipping-in is commenced, to permit the conductor tension to equalize.
Plumb marks shall be made on the conductors in the vertical plane through the centerline of the
tower prior to clipping-in. Only paint, crayon, or wax pencil shall be used for marks on conductors.
All conductors marking in the section being sagged shall be accomplished while the conductors
are in the sheaves and before clipping-in or dead ending is begun.
The total time during which the conductor is allowed to remain in the stringing blocks before being
clipped-in shall not exceed 72 hours.
Torque wrenches shall be used to tighten all nuts on clamps. The torque applied shall be in
conformance with the recommendation of the manufacturer.
Yoke plates for V-Vee string insulators shall be installed as shown on the drawings and shall hang
at 90 degrees to the conductor axis within a tolerance of plus or minus 2.5 cm.
Well-padded pull-lift hooks or other approved methods shall be used for handling conductors
during the clipping-in operation.
(11) Installation of Conductor, Shield wire and OPGW Accessories
(a)
Splices and Dead Ends

All splices shall be of the compression type.
All splices shall be made at least 15 meters away from structures and no splices shall be
made in dead end spans or spans greater than 600 meters or spans crossing over the
highways, railroads, major canals, rivers and transmission lines of voltages greater than
33 kV unless approved by the Project Manager.

112
As a rule not more than one joint or splice should be made in any one conductor in any
one span. However, in exceptional cases, as in the repair of damaged conductors, or
when necessary owing to stringing limitations two splices will be allowed.
The splices and compression dead ends shall be installed in accordance with the
recommendations of the Manufacturer of the accessories.
Conductor shall be laid out straight for a distance of 15 meters and straightened at the
end before preparation of the ends for splicing or dead-ending. The ends of the
conductor shall be thoroughly cleaned immediately prior to compressing. After the
compression has been completed, all corners, sharp projections and indentations shall
be carefully rounded and smoothed, and tape, tape residue, and filler paste shall be
removed from splice and conductor. If the completed splice requires straightening, it
shall be straightened on a wood block by use of a wooden maul.
Splicing, dead-ending and repair of damaged conductor shall be done in the presence of
nominated person of the Project Manager.
If the completed splice or dead-end is not satisfactory, in the opinion of the Project
Manager or his nominated person, it shall be removed and a new splice or dead-end
shall be properly installed.
The Contractor's inspector shall stamp his own initials on the aluminum sleeve of each
compression joint and compression dead end completed under his supervision.
(b)
Repair of Conductors and Shield wire

Damage is any deformity on the surface of the conductor or shield wire which can be
detected by eye or by feel and shall be repaired by whichever the following methods is
appropriate:
(i)
(ii)
(iii)
(iv)
Repair by manual polishing

Installation of repair sleeves over the damaged part
Installation of compression joints
Replacement with new conductor or shield wire
Slight damage such as superficial scratches or abrasions, which are not deeper than
one-third the strand diameter, can be repaired by dressing with a fine emery cloth.
Severe cuts which cannot be repaired with emery cloth due to their depth or extension,
and cause increase in the resistance of the external layers shall be repaired by use of
repair sleeves, provided that not more than one-third of the outer layer is cut or damaged
over a length of less than 10 centimeters.
Damages of extent greater than described in above paragraphs shall be repaired by
replacing the damaged length of the cable using compression joints.
When there is repeated damage in the same span or in consecutive spans, the Project
Manager or his nominated person may require all conductors in these spans to be
replaced.
In the case when signs of corrosion are detected during the stringing operation, the reels
containing corroded conductors shall be set aside, the operation shall be interrupted and
the Project Manager or his nominated person shall be informed immediately.

113
Whenever a repair sleeve is installed, a rope cage shall be placed on the sleeve to
ensure that there will be no damage from sub-conductor slapping prior to installation of
the spacer-dampers.
For the repair of the shield wires, only compression joints shall be used.
(c)
Jumper Connections
Where compression type dead-ends are used, the jumper shall be one continuous piece,
and compression-type jumper terminals bolted to the compression-type dead-ends shall
be used.
At overhead shield wire dead-ends with bolted strain clamps and OPGW with thimble
clevis and grip dead end, sufficient length of wire to form the jumper loop to clear the
tower shall be allowed. Parallel groove bolted clamps will be used for connection.
(12) OPGW Jointing/Splicing and Installation of OPGW Joint Boxes

OPGW jointing/splicing and joint boxes installation will be carried out by the Contractor.
However, following general instructions should be followed:
No mid span joint shall be allowed in the OPGW. All joints shall be performed in a joint box
located on the tower just above the location of anti-climbing device. OPGW jointing (splicing) and
joint boxes installation including supporting device for joint boxes shall be executed by the
Contractor. OPGW shall be dropped to the joint boxes along with tower braces by installing
OPGW attaching clamps at about one meter interval.
9.8
Installation of Dampers
(1)
Spacer Dampers
The four sub-conductors of each phase shall be secured to each other by means of spacer
dampers installed strictly in accordance with data furnished.
The intervals, measured along the length of the conductors at which spacers are installed shall be
as shown on the data sheets with tolerances not more than plus/minus 1.0 meter.
Spacer-dampers shall be installed in a span only after that span has been dead-ended and
clipped-in. The installation of spacer dampers shall be completed in each section within 72 hours
after the sub-conductors have been sagged.
The clamps shall be properly aligned on the conductors. Distorted shape of the spacer dampers
will be considered an unsatisfactory installation and shall be corrected or the spacer damper
replaced.
The bolts of the breakaway type shall be tightened until the outer head breaks off.
Spacer dampers shall be installed with the bolt heads in a downward position for viewing from the
ground.
(2)
Vibration Dampers
Vibration dampers shall be attached to the overhead shield wires and OPGW at the ends of all
spans and as designated on the data sheets. The vibration dampers shall be fastened securely to
overhead shield wires & OPGW so that they will hang in vertical planes. Spacing of dampers shall

114
be in accordance with the Drawings. Breakaway type bolts shall be tightened until the outer head
breaks off.
10
Pre Commissioning and Commissioning Tests
10.1
Pre Commissioning Tests

(a)
Mechanical Tests
1.
For steel structures, ensure that structure type is as per specification/drawings/structure list.
2.
Check galvanizing and thickness (rust is not acceptable).
3.
Check bolt types and tightness (torque wrench method).
4.
Ensure anti-climbing guards are correctly installed.
5.
Check step bolt tightness.
6.
For porcelain insulators, check insulators for chips, cracks, etc. Ensure correct number of
insulators have been installed in each string. Ensure that cotter keys have been properly
installed.
7.
Make sure that insulators are clean and line is safe to be energized.
8.
Check that all line hardware and fittings (insulators, corona rings, vibration dampers, spacer
dampers, conductor clamps, armor rods, etc) is installed correctly and in correct locations as
per specifications and drawings.
9.
Check that all splices are correct and installed in correct span locations.
10.
Check that all jumpers are installed correctly. Ensure correct clearances between jumper and
structure as well as with other phases at acute angle locations.
11.
Ensure there is no twist in the insulator string.
12.
Check that overhead shield wire and OPGW are grounded to towers as specified.
13.
Ensure that sags for phase and overhead ground conductors are even and according to the
specification.
14.
Check that ground clearances are as per specification.
15.
Check circuit/phase identification plates, structure number plates, danger sign plates, etc
have been correctly installed at each structure and aerial markers at the required structures.
16.
Check line/phase correctly transposed at the specified locations and clearance between the
phases is as per specification.
(b)
Electrical Tests
1.
Check tower footing resistance as per specification.
2.
Verification of physical phase arrangement.

10.2
115
3.
4.
Perform sequence impedance test (both zero and positive sequence).

Perform continuity and insulation test of complete transmission line with appropriate test
equipment.
5.
Tests on OPGW:
OTDR test of each fiber
Attenuation test
Continuity test
Commissioning Tests
1.
Perform phase sequence/rotation check.
2.
Inspection of Facilities for any visual/audible abnormality.

APPENDIX - A
Sheet 1
INSULATOR PERFORMANCE DATA

FOR
16,300 kg E&M STRENGTH
Contamination
Level
ESDD-mg/cm
Single String
200 Strings in Parallel
Vertical String
FOV50 - kV/Unit FOV5 -kV/Unit
FOV50 - kV/Unit
FOV5 -kV/Unit
V-String
FOV5 - kV/Unit
FOV50 - kV/Unit
0.06
0.12
0.50
0.75
1.00
1.
ESDD
Equivalent Salt Deposit Density
2.
FOV5
5% probability flashover voltage (withstand)

0.835 CFO (For normal distribution and 10 percent
deviation)
3.
FOV50
50% probability of flashover (critical flashover

voltage = CFO)
4.
For 200 Strings in parallel

FOV50
and
CFO(Single String)
FOV5
CFO(Single String)
0.725 (see Transmission Line Reference Book

345kV and above - EPRI - 1982)
1.105 fov (Vertical String)
4.
FOV (V-String)
1.
The performance of these insulators is based on the 5% flashover probability (withstand voltage) for 200
multiple strings.
2.
FOV (5% or 50%) = kV (5% or 50%)/Unit x No. of insulators for string
TESTS
NOTE:
For contamination test following contaminants simulating the site condition were used:
ESDD (mg/cm)
Percentage Constitution of Salt

Contaminants
Tonoko deposit density (mg/cm)
Procurement of Plant: Design, Supply, Installation, Testing & Commissioning of 500

kV Transmission Line 3rd Circuit Jamshoro-Moro-Dadu to Rahim Yar Khan
APPENDIX - A
Sheet 2
INSULATOR PERFORMANCE DATA

FOR
8,200 kg E&M STRENGTH
Contamination
Level
Single String
200 Strings in Parallel
ESDD-mg/cm
Vertical String
FOV5 -kV/Unit
FOV50 - kV/Unit FOV5 -kV/Unit
FOV50 - kV/Unit
V-String
FOV5 - kV/Unit
FOV50 - kV/Unit
0.06
0.12
0.50
0.75
1.00
1.
ESDD
Equivalent Salt Deposit Density
2.
FOV5
5% probability flashover voltage (withstand)

0.835 CFO (For normal distribution and 10 percent
deviation)
3.
FOV50
50% probability of flashover (critical flashover

voltage = CFO)
4.
For 200 Strings in parallel
FOV5
CFO(Single String)
FOV50
and
CFO(Single String)
0.725 (see Transmission Line Reference Book

345kV and above - EPRI - 1982)
1.105 fov (Vertical String)
4.
FOV (V-String)
1.
The performance of these insulators is based on the 5% flashover probability (withstand voltage) for 200
multiple strings.
2.
FOV (5% or 50%) = kV (5% or 50%)/Unit x No. of insulators for string
TESTS
NOTE:
For contamination test following contaminants simulating the site condition were used:
ESDD (mg/cm)
Percentage Constitution of Salt

Contaminants
Tonoko deposit density (mg/cm)
Procurement of Plant: Design, Supply, Installation, Testing & Commissioning of 500

kV Transmission Line 3rd Circuit Jamshoro-Moro-Dadu to Rahim Yar Khan

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NATIONAL TRANSMISSION AND

DESPATCH COMPANY LIMITED (NTDCL)

ADB LOAN NO.2846-PAK: MFF 0007 POWER TRANSMISSION

BIDDING DOCUMENTS NO. ADB-65-2012 (PACKAGE-1)

MATERIAL AND WORKMANSHIP

Conductor and Shield wire

OPGW and Associated Hardware

Insulators and Hardware

Accessories and Dampers

Transmission Line Construction

Standards Other than those Specified

Cleaning and Galvanizing

Galvanizing of Nut, Bolts and Washers.

Procurement of Plant: Design, Supply, Installation, Testing & Commissioning of 500 kV

Tests for Tower Steel, Associated Hardware and Accessories

SHIELD WIRE AND OPTICAL FIBER EQUIPMENT

EHS Shield Wire

Procurement of Plant: Design, Supply, Installation, Testing & Commissioning of 500 kV

Optical Fiber Equipment

Procurement of Plant: Design, Supply, Installation, Testing & Commissioning of 500 kV

Testing and Inspection

Conductor and Shield Wire Data

Conductor Suspension Assemblies

Conductor Dead End Assemblies

Power Arc Rating

Overhead EHS Shield Wire Suspension Assembly

Overhead EHS Shield Wire Tension Assembly

Hardware and Fittings for OPGW

Parallel Groove Connectors

Grounding Connectors for Ground Rods

Bare Copper-Clad Steel Grounding Conductor

CONDUCTOR AND SHIELD WIRE ACCESSORIES

Conductor Compression Splice

Conductor Repair Sleeve

Conductor Compression Dead End Splice

Overhead Shield Wire Compression Splice

Procurement of Plant: Design, Supply, Installation, Testing & Commissioning of 500 kV

100 Ton Hydraulic Compressors (Engine Driven)

60 Ton Hydraulic Compressors (Engine Driven)

Electrical Joint Compound

SPACER DAMPERS FOR CONDUCTOR AND STOCKBRIDGE DAMPERS FOR

Electrical Resistance Test

Procurement of Plant: Design, Supply, Installation, Testing & Commissioning of 500 kV

Clamp Slippage Test at Ambient Temperature

Bolt Torque Test

Attachment of Weights to Messenger Cable Test

Attachment of Clamp to Messenger Cable Test

Damper Performance Tests

Vertical Fatigue Test

Basic Line Data and Environment

TECHNICAL PROVISIONS FOR CONSTRUCTION

Sub Soil Investigation

Installation of Insulators and Hardware

Stringing Conductors, Overhead EHS Shield Wire and OPGW

Pre Commissioning and Commissioning Tests

Pre Commissioning Tests

Procurement of Plant: Design, Supply, Installation, Testing & Commissioning of 500 kV

MATERIAL AND WORKMANSHIP