Ts for Transmission Line

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SECTION - III

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SECTION-III

(PART-A)

TECHNICAL SPECIFICATIONS

1. GENERAL INFORMATION AND SCOPE

1.1 SCOPE

1.1.1 This Specification covers detailed survey, check survey, tower

spotting/optimization of tower location, soil resistivity measurements and

geotechnical investigation, fabrication and supply of all type of 220kV double

circuit transmission line towers (as per PSTCL design) including bolts, nuts

(normal & Anti-Theft) and washers, U-bolt, D-shackle and all type of tower

accessories like phase plate, circuit plate, number plate, danger plate, anti-

climbing device (with barbed wire) etc. and casting of foundation for tower

footing, erection of towers, tower earthing, fixing of insulator string, stringing

of conductors and earthwire along with all necessary line accessories and

testing and commissioning of the erected transmission lines.

1.1.2 This specification also covers the fabrication and supply of gantry structures

for under-crossing the 220kV and 400kV Transmission Lines including bolts,

nuts and washer, D-shackle and all type of accessories like phase plate,

circuit plate, number plate, danger plate, etc. casting of foundation for gantry

footing, erection of gantries, gantry earthing, fixing of Insulator string, stringing

of conductors and earth wires along with all necessary line accessories. All

the clauses in the specification will be relevant for the gantry structures also

unless stated otherwise.

1.1.3 This Specification includes the supply of insulators and their hard wares,

ACSR Zebra, earthwire of size 7/3.15 mm, earthwire suspension and tension

clamps and all other line accessories for conductor & earthwire like mid-span

compression joints for conductor and earth wire, repair sleeve for conductor,

vibration damper for conductor & Earth wire, flexible copper bond which shall

be supplied by the bidder during execution of the project.

1.1.4 All the raw materials such as steel, zinc for galvanizing, reinforcement steel

and cement for tower foundation, coke and salt for tower earthing etc. bolts,

nuts, washers, D-shackles, hangers, links, danger plates, phase plate, number

plate, circuit plate, anti climbing devices etc. required for tower manufacture

and erection shall be included in the bidder’s scope of supply. Bidder shall

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clearly indicate in the offer, the sources from where he proposes to procure

the raw materials and the components.

1.1.5 The entire stringing work of conductor shall be carried out by standard

stringing practice. The scope of the work includes both single circuit stringing

on DC towers and double circuit stringing on DC Towers and towers are

designed for this. The bidder shall indicate in the offer, the detail description of

the procedure to be deployed for stringing operation.

1.1.6 The Special River crossing towers or any other special type of tower required

as per approved route plan, if any shall be fabricated and supplied by the

Contractor. The construction of river crossing section including casting of

foundation shall also be in the scope of bidder.

1.1.7 The fabrication & inspection of Tower Proto assemblies, wherever required,

shall also be within the scope of the Bidder and no extra payment for the

same shall be made.

1.1.8 The following Package of 220KV transmission lines are included in the scope

of the bidder under this specification:

Package 1:

S.No Name of the line Aprx. Line Length (Km)

A 220 KV D/C line from 400 KV S/Stn. Mukatsar to 220 KV S/Stn Abohar on ACSR Zebra conductor.

46

B 220 KV D/C line from 400 KV S/Stn. Mukatsar to 220 KV S/Stn Kotkapura (new) on ACSR Zebra conductor.

35

C 220 KV S/C line on D/C towers from 400 KV S/Stn. Mukatsar to 220 KV S/Stn Ghubaya on ACSR Zebra conductor.

40

The proposed completion period for this package is 14 months from Letter of Award.

Package 2:


A LILO of both circuits of 220 KV Sunam – Dhuri D/C line at 400 KV S/Stn. Dhuri on ACSR Zebra conductor.

2 X 15

B 220 KV D/C line from 400 KV S/Stn. Dhuri to 220 KV S/Stn Mandvi on ACSR Zebra conductor.

50

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C 220 KV S/C line on D/C towers from 400 KV S/Stn. Dhuri to 220 KV S/Stn Nabha on ACSR Zebra conductor.

50


Package 3:


A 220 KV D/C line from 400 KV S/Stn. Rajpura to 220 KV S/Stn Devigarh on ACSR Zebra conductor.

20

B LILO of both circuits of 220 KV D/C Patiala – M.Gobindgarh line at 400 KV S/Stn. Rajpura on ACSR Zebra conductor.

2 X 25

C 220 KV D/C line from 400 KV S/Stn. Rajpura to 220 KV S/Stn Lalru on ACSR Zebra conductor.

20


Package 4:


A 220 KV D/C line from 400 KV S/Stn. Nakodar to 220 KV S/Stn Kartarpur on ACSR Zebra conductor.

45

B 220 KV D/C line from 400 KV S/Stn. Nakodar to 220 KV S/Stn Nur Mehal on ACSR Zebra conductor.

11

C 220 KV D/C line from 400 KV S/Stn. Nakodar to 220 KV S/Stn Rehana Jattan on ACSR Zebra conductor.

35


Package 5:


A 220 KV D/C line from 400 KV S/Stn. Makhu to 220 KV S/Stn Majitha on ACSR Zebra conductor.

50

B 220 KV D/C line from 400 KV S/Stn. Makhu to 220 KV S/Stn Taran Tarn on ACSR Zebra conductor.

30

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Package 6:


A 220 KV D/C line from 220 KV S/Stn. Goindwal Sahib to 220 KV S/Stn Khassa on ACSR Zebra conductor.

50

B 220 KV D/C line from 220 KV S/Stn. Goindwal Sahib to 220 KV S/Stn Sultanpur on ACSR Zebra conductor.

20

C 220 KV D/C line from 220 KV S/Stn. Goindwal Sahib to 220 KV S/Stn Botianwala on ACSR Zebra conductor.

60


1.1.9 LOCATION DETAILS :

The 220KV transmission lines mentioned in the above packages pass

through the plain terrain of Punjab. The contractor shall have to erect the

220kV transmission line completely up to terminal arrangements as per

approved route of the line, based on the detailed & check survey to be

carried out by the Contractor.

1.2 DETAILS OF TRANSMISSION LINE ROUTES AND TERRAIN

The transmission line will be running partly through plain irrigated farm

lands/cultivated area and partly barren lands. There are few small rivers/

distributaries/ nalas, etc. to be crossed by lines in the above packages.

However, these Rivers /Nalas etc. are envisaged to be crossed by Normal

towers or strengthened Normal tower to suit specific locations.

1.3 PRELIMINARY AND DETAILED SURVEYS :

The details collected through preliminary surveys viz line route, general

soil characteristics, crossings, accessibility and infra-structure details & the

location of all obligatory points will be within the scope of the bidder. The

detailed survey shall be within the scope of the Contractor and the same

shall be carried out using the latest survey techniques such as Total

Station and GPS etc. along the approved route alignment based on

preliminary survey. Bidders may visit the line area to know about the

terrain details and the following officers may be contacted for the same:

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S.no Officer concerned Contact No. Area covered

(Circlewise)

1 The Sr.XEN, TLSC Division, PSTCL, Patiala

096461-17808

Patiala & Sangrur

2 The Sr.XEN, TLSC Division, PSTCL, Mohali

096461-17811

Mohali, Ropar, Ludhiana, Khanna

3 The Sr.XEN, TLSC Division,PSTCL,Bathinda

096461-17809

Faridkot, Ferozpur, Bathinda, Mukatsar

4. The Sr.XEN, TLSC Division,PSTCL,Jalandhar

096461-17812

Amritsar, Tarntaran, Jalandhar, Gurdaspur

1.4 ACCESS TO THE LINE AND RIGHT OF WAY

Right of way and way leave clearance shall be arranged by the Employer

in accordance with work schedule. The Employer shall also secure way

leave and right of way in the forest area.

1.5 DETAILED SURVEY, OPTIMISATION OF TOWER LOCATION

1.5.1 The detailed survey for the line(s) route, optimisation of tower locations

alongwith profiling and tower spotting shall be carried out by successful

bidder as stipulated herein. The provisional quantity for detailed survey

has been indicated in Schedule of prices.

1.5.2 The bidder should note that Owner will not furnish the topographical maps

prepared by survey of India but will provide assistance that may be

required in obtaining the topographical maps.

1.5.3 Soil resistivity, along the route alignment, shall be measured in dry

weather by four-electrode method keeping inter-electrode spacing of 50

meters. The megger reading and soil characteristics shall also be

indicated in the soil resistivity results.

1.5.4 ROUTE MARKING:

At the starting point of the commencement of route survey, an angle iron

spike of 65 x 65 x 6 mm section and 1000 mm long shall be driven firmly

into the ground to project only 150 mm above the ground level. A punch

mark on the top section of the angle iron shall be made to indicate location

of the survey instrument. Teak wood peg 50x50x650 mm size shall be

driven at prominent position at intervals of not more than 750 meter along

the transmission line to be surveyed upto the next angle point. Nails of

100mm wire should be fixed on the top of these pegs to show the location

of instrument. The pegs shall be driven firmly into the ground to project

100mm only above ground level. At angle position stone/concrete pillar

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with PSTCL marked on them shall be put firmly on the ground for easy

identification.

1.5.5 PROFILE PLOTTING & TOWER SPOTTING :

From the field book entries, the route plan with enroute details and level

profile shall be plotted and prepared to scale of 1:1000 horizontal & 1:100

vertical on 1.0, 10 mm squared paper as per approved procedure.

Reference levels at every 20 meters along the profile are also to be

indicated on the profile besides, reduced levels at undulations. Areas

along the profile which in the view of the Contractor, are not suitable for

tower spotting, shall also be clearly marked on the profile plots. If the

difference in levels be too high, the chart may be broken up according to

requirement. A 10 mm overlap shall be shown on each following sheet.

The chart shall progress from left to right. Sheet shall be 594 mm wide in

accordance with the IS. For ‘as built’ profile these shall be in A1 size.

1.5.6 TOWER LOCATION

1.5.6.1 SAG TEMPLATE

The print of the sag template as per PSTCL design will be provided to the

successful bidder.

1.5.6.2 TOWER SPOTTING

With the help of approved sag template and tower spotting data, tower

locations shall be marked on the profiles. While locating the towers on the

profile sheet, the following shall be borne in mind.

a. SPAN

The number of consecutive spans between the section points shall not

exceed 10. The section point shall comprise of tension point with B (2-D-

30) or C (2-D-60) type towers as applicable.

b. EXTENSION

An individual span shall be as near to the normal design span as

possible. In case an individual span becomes too short with normal

supports on account of undulations in ground profile, one or both the

supports of the span may be extended by inserting standard body

extension designed for the purpose according to technical specification.

c. LOADING

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There shall not be any upward force on suspension towers under

normal working conditions and the suspension towers shall support atleast

the minimum weight span as provided in the design. In case uplift is

unavoidable, it shall be examined if the same can be overcome by adding

standard body extensions to the towers failing which tension towers

designed for the purpose shall be employed at such positions.

d. ROAD CROSSING

At all important road crossings, the towers shall be fitted with normal

suspension or tension insulator strings depending on the type of towers

but the ground clearance at the roads under maximum temperature and in

still air shall be such that even with conductor broken in adjacent span,

ground clearance of the conductor from the road surface will not be less

than 7.015 meters. At all national highway tension towers with double

insulator strings on crossing side shall be used.

e. RAILWAY CROSSINGS

At the time of detailed survey, the railway crossings shall be finalized

as per the regulations laid down by the Railway Authorities. The following

are the important features of the prevailing rules & regulations:

i The crossing shall be supported on B(2-D-30) or C (2-D-60) type towers

on either side depending on the merits of each case and Double Tension

insulator string shall be used on both the towers on the side of the

crossing.

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

iii The minimum distance of the crossing tower shall be at least equal to the

height of the tower plus 6 meters away measured from the centre of the

nearest railway track.

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

station, traction Sub Station or a track cabin location in an electrified area.

V Minimum ground clearance above rail level of the lowest portion of any

conductor under condition of maximum sag shall be maintained at 17.90

meters.

The approval for crossing railway track shall be obtained by the Employer

from the Railway Authorities, however six copies of profile and plan, tower

and foundation design and drawings / any other document required for the

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approval from the Railway Authorities shall be supplied by the Contractor

to the Employer.

F RIVER CROSSING

In case of Major River crossing, towers shall be of suspension type and

the anchor towers on either side of the main river crossing shall be C (2-D-

60) type tower. For navigable river, Clearance required by navigation

authority shall be provided. For non navigable river, clearance shall be

reckoned with respect to highest flood level (HFL).

G POWER LINE CROSSING

Where this line is to cross over another line of the same voltage or lower

voltage, the tower with suitable extensions shall be used. Where the line

is to cross under the power lines, gantries may be used. Provisions to

prevent the possibility of its coming into contact with other overhead lines

shall be made in accordance with the Indian Electricity Rules, 1956 as

amended upto date. In order to reduce the height of the crossing towers it

may be advantageous to remove the ground wire of the line to be crossed

(if this is possible and permitted by the Owner of the line to be crossed).

All the works related to the above proposal shall be deemed to be included

in the scope of the Contractor except if modifications are required to line

below, in which case, the conditions shall be as agreed upon.

H TELECOMMUNICATION LINE CROSSING

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

deviation to the extent of 30 o may be permitted under exceptionally

difficult situations.

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

referred to the authority in charge of the telecommunication system. On a

request from the Contractor, the permission of the telecommunication

authority may be obtained by the Employer. Also, in the crossing span,

power line support will be as near the telecommunication line as possible,

to obtain increased vertical clearance between the wires.

I DETAILS ENROUTE

All topographical details, permanent features, such as trees, buildings etc

17.5 m on either side of the alignment for 220kv Line shall be detailed on

the profile plan.

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1.5.7 CLEARANCE FROM GROUND BUILDING, TREES ET C.

Clearance from ground, buildings, trees and telephone lines shall be

provided in conformity with the Indian Electricity Rules 1956 as amended

upto date.

1.5.8 The tree cutting shall be the responsibility of the Employer except for that

required during survey. However, the Contractor shall count, mark and put

proper numbers with suitable quality of paint at his own cost on all the

trees that are to be cut by the Employer at the time of actual execution of

the work. Contractor may please note that Employer shall not pay any

compensation for any loss or damage to the properties or for tree cutting

due to Contractor’s work.

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

arranged by the Employer as required by work programme.

1.5.10 To evaluate and tabulate the trees and bushes coming within 17.5 m on

either side of the central line alignment, the trees will be numbered and

marked with quality paint serially from angle point 1 onward and the

corresponding number will be painted on the stem of trees at a height of 1

meter from ground level. The tree list should contain the following:

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

b. Approximate height of the tree with an accuracy of ± 2 meters.

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

d. The bushy and under ground encountered within the 35m belt should also

be evaluated with its type, height, girth and area in square meters, clearly

indicating the growth in the tree/bush statement.

1.5.11 Payment of compensation towards the clearances etc. will be the

responsibility of the Employer.

1.5.12 PRELIMINARY SCHEDULE

The profile sheets, duly spotted, alongwith preliminary schedule indicating

type of towers, type of foundations, wind span, weight span, angle of

deviation, river or road crossing and other details shall be submitted for the

approval of the Employer. After approval, the Contractor shall submit six

more sets of the approved reports along with one set of reproducible copy

of final profile drawings to the Employer for record purpose.

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1.5.13 DETAILED SURVEY OF TOWER LOCATION

1.5.13.1 The detailed survey shall be conducted to locate and peg mark the tower

position on ground conforming to the approved profile and tower schedule.

In the process, it is necessary to have the pit centers marked according to

the excavation marking charts. The levels up or down of each pit center

with respect to the center of the tower location shall be noted and recorded

for determining the amount of earth work required to meet the approved

design parameters.

1.5.13.2 Changes, if required after detailed survey in the preliminary tower

schedule shall be carried out by the Contractor and he shall thereafter

submit a final tower schedule for the approval of Employer. The tower

schedule shall show position of all towers, type of towers, span length,

type of foundation for each towers and the deviation at all angles as set

out with other details.

1.6 ENVIRONMENTAL CONDITIONS

1.6.1 GENERAL CLIMATIC CONDITIONS

The area is in the extreme climate belt. Monsoons are generally active

from the months of July to September.

The maximum temperature during summer shall be of the order of 500 C

and the minimum temperature shall be of the order of (–) 2.50 C. Normal

everyday temperature is 320 C.

1.7 TECHNICAL DATA

Bidders shall furnish all technical data as per relevant schedules in four (4)

copies.

1.8 STATUTORY REGULATIONS AND STANDARDS

1.8.1 STATUTORY REGULATIONS

The contractor is required to follow local statutory regulations stipulated in

Electricity Act 2003, Electricity supply Act 1948 and Indian Electricity Rules

1956 as amended and other local rules and regulations referred to in this

specification.

1.8.2 REFERENCE STANDARDS

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

cases wherever such references are made. In case of a conflict between

such codes and/or standards and the specification, latter shall govern.

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Such codes and/or standards, referred to shall mean the latest revision,

amendments/ changes adopted and published by the relevant agencies.

1.8.2.2 Other internationally acceptable standards which ensure equivalent or

better performance than those specified shall also be accepted.

1.9 QUALITY ASSURANCE, INSPECTION AND TESTING

1.9.1 QUALITY ASSURANCE

1.9.1.1 To ensure that the supply and services under the scope of this Contract

whether manufactured or performed within the Contractor’s works or at his

Sub-contractor’s premises or at Site or at any other place of work are in

accordance with the specifications, the Contractor shall adopt suitable

quality assurance programme to control such activities at all points

necessary. A quality assurance programme of the Contractor shall

generally cover but not limited to the following:

a. His Organisation structure for the management and implementation of the

proposed quality assurance programme.

b. Documentation control system.

c. Qualification data for bidder’s key personnel.

d. The procedure for purchases of materials, parts/components and selection

of sub-contractor’s including vendor analysis, source inspection, incoming

raw material inspection, verification of material purchase etc.

e. System for shop manufacturing including process controls and fabrication

and assembly controls.

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

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

h. Inspection and test procedure for manufacture.

i. System for indication and appraisal of inspection status.

j. System for quality audits.

k. System for authorizing release of manufactured product to the Employer.

l. System for maintenance of records.

m. System for handling storage and delivery.

n. A quality plan detailing out the specific quality control procedure adopted

for controlling the quality characteristics relevant to each item of supply.

The Quality Plan shall be mutually discussed and approved by the

Employer after incorporating necessary corrections by the Contractor as

may be required.

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1.9.1.2 QUALITY ASSURANCE DOCUMENTS

The Contractor shall be required to submit all the Quality Assurance

Documents as stipulated in the Quality Plan at the time of Employer’s

inspection of material.

1.9.1.3 The Employer, through his duly authorised representatives, reserves the

right to carry out Quality Audit and Quality Surveillance of the system and

procedures of the Contractor’s/ his Sub-contractor’s Quality Management

and Control Activities.

1.9.2 INSPECTION, TESTING AND INSPECTION CERTIFICATE

The provision of the clause regarding Inspection, Testing and Inspection

Certificate as described in General Conditions shall be applicable to the

supply and erection portion of the works. The employer shall have the right

to re-inspect at his expenses any material though previously inspected

and approved by him at the Contractor’s works, before and after the same

are erected at site. If following the latter, material is found defective, then

the Contractor shall bear the cost of this inspection and reinstatement

according to specification.

1.10 TECHNICAL PARAMETERS 220kV LINE

Electrical System Data

a. Nominal voltage. 220kV

b. Maximum system voltage. 245kV

c. BIL (impulse) 1050kV (Peak)

d. Power frequency withstand voltage (wet). 460kV

2. DETAILS OF LINE MATERIAL FOR 220KV LINE

2.1 Particulars of Conductor and Earthwire.

Sr No

Particulars. Conductor Earthwire

1. Type ACSR Zebra Galvanized steel stranded.

2.

Stranding and wire dia

a. Aluminium

b. Steel

mm

mm

54/3.18 7/3.18

7/3.15

3. Total sectional area Sq.mm 484.50 54.55

4. Apprx. overall dia. mm 28.62 9.45

5. Approximate mass Kg/km 1623 428

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6. Calculated DC resistance At 20o C (max) Ohm/km 0.0680 3.41

7. Ultimate Tensile Strength KN 130.30 54 KN

8. Modulus of elasticity GN/sqm 68.9 186

9. Co-efficient of linear expansion

Per degree Centigrade 19.35 x10 –6 11.5x10-6

10 Mass of zinc coating gm/sq.m 250 240

11 Configuration of conductor.

S/C on D/C & D/C on D/C Line

Near vertical on each side of tower.

12 Location of earthwire

One continuous earthwire to run horizontally above the conductor.

2.2 PARTICULARS OF INSULATOR STRINGS

2.3 INSULATOR STRING HARDWARE( FOR 220KV LINE)

a. Anchor shackle

b. Ball Hook

c. Chain link

d. Yoke plate

e. Ball clevis

f. Socket clevis

g. Clevis eye

Sr no Particulars.

Single Suspension string

Double Suspension string

Double tension string.

Single tension string

1. No. of standard insulator discs 1 x 14 2 x 14 2 x 15 1 x 15

2. Size of disc mm 255 x 145 255 x 145 255 x 145 255 x 145

3. E&M Strength of each insulator disc. KN

70 70 160 160

4. Size and designation of ball & socket in mm

16 16 20 20

5. Minimum creepage distance of each disc mm (for Anti-Fog)

292 ( 432) 292 (432) 330 330

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h. Free center type suspension clamp.

i. Compression type dead end clamp.

2.4 ACCESSORIES FOR CONDUCTOR AND EARTHWIRE( for

220KVLINE)

a. Mid span compression joints

b. Repair sleeves for conductor

c. Flexible copper bonds

d. Vibration dampers

e. Suspension clamps for earthwire

f. Tension clamps for earthwire.

g. Preformed armour rods for Conductor

3. TRANSMISSION TOWERS

3.1 Qualifying Requirements &General Description of the Towers.

3.1.1 Incase the Contractor is a Conductor Manufacturer then the manufacturer

from whom he proposes to procure Tower material should have

manufacturing facility for Transmission Lines towers with minimum

manufacturing capacity of 4000 MT per financial year. The average

quantity manufactured per financial year during the last three financial

years should not be less than 2000 MT. Documentary proof in the form of

certificate from Chartered Accountant/ Engineer for the required

manufacturing capacity and performance certificate from any SEB / Utility

for at least 300 MT 132 KV or higher rating Transmission Lines Towers

during last 3 years shall be submitted. On Financial side, the average

Turnover of the manufacturer for the last three financial should be min.20

Crores and he should have liquid assets and / or evidence of access to or

availability of credit facilities of not less than Rs. 2 Crores. Documentary

proof for these shall also be attached with the bid.

3.1.2 The towers are of the following types:

a. Double Circuit (A, B,C, )

b. Special Towers ( if need be)

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

line conductors with necessary insulators, earthwire and all fittings under

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all loading conditions. Outline diagrams of double circuit towers are

enclosed with the Specification.

3.1.4 The tower shall be fully galvanized structure.

3.2 Type of Towers

3.2.1 The towers are classified as given below for 220 KV Lines

Type Deviation Limit Typical use

A(`2-D-2) 0deg-2deg To be used as tangent tower

B( 2-D-30) 2 deg-30deg a)Angle tower with tension insulator

b) Also designed for any two of the

power cond. Broken the same side of

the span or any of the power

conductors & ground wire broken on

the same span.

c) Also designed for up-lift force

resulting from an up-lift span up to

280m

C(2-D-60) 30deg-60deg a) Angle tower with tension

String

b) Also designed for up-lift

forces resulting from an up-lift

span of 280m

c) Dead end with 0 deg.

deviation.

NOTE: - The above towers can also be used for longer span with smaller

angle of deviations.

3.2.2 SPECIAL TOWERS

The towers which will be specially designed for very long spans such as

Major River crossing etc. which can not be crossed by normal tower with

extension shall be called special tower.

3.2.3 EXTENSIONS

The B&C type towers have 3/6 Meter body extensions for maintaining

adequate ground clearances. Besides above 9/14/19 m body extensions

may also be used with appropriate reduction in spans in case of 2-D-2

tower type A.

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3.3 SPAN AND CLEARANCES

3.3.1 NORMAL SPAN

The normal ruling span of these towers shall be 350m.

3.3.2 WIND SPAN

Wind span is the sum of the two half spans adjacent to the support under

consideration. For normal horizontal spans this equals to the ruling span.

3.3.3 WEIGHT SPAN

The weight span is the horizontal distance between the lowest point of the

conductors on the two spans adjacent to the tower. For design of the

structures, the limits given below shall prevail (in meters).

TOWER NORMAL CONDITION BROKENWIRE CONDITION TYPE

A,B&C 350X1.5 350X0.6

3.3.4 In case of certain locations actual spotting spans exceed the design spans

and cross arms and certain members of the tower shall be modified /

reinforced.

3.3.5 ELECTRICAL CLEARANCES

3.3.5.1 GROUND CLEARANCES

The min. ground clearances from the bottom conductor shall not be less

than 7015mm at the max. sag conditions i.e. at max. temperature and still

air. However to achieve the above clearance the height of the tower is

increased in the following manner.

a. A positive allowance of 150 mm shall be provided to account for error in

stringing.

b. Conductor creep shall be compensated by over tensioning the conductor

at temperature of 26oC lower than the stringing temperature for ACSR

ZEBRA.

For river crossing tower, the minimum electrical clearance including

ground clearance will be same as normal tower except an allowance of

4% of maximum sag of conductor instead of 150mm for normal towers

shall be provided to account for errors in stringing.

3.3.5.2 RAILWAY CROSSING

In case of railway crossing, the min. height above rail level to the lowest

portion of any conductor under condition of max. sag in accordance with

the regulations for Electrical Crossing of railway tracks as prevailing at the

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time of construction of line shall be applicable. However, as per existing

Indian Electricity Rules, the minimum clearance is stipulated as 15.40

meters.

3.3.5.3 POWER LINE CROSSING

Minimum clearance between the lowest at power conductor of crossing

line over the crossed line shall be in line with IS 5613 (Part II/ Sec1) as

follows.

Voltage level of crossed line (KV) Voltage level of

crossing line (kV) 33 KV 66 KV 132 KV

220 KV

400 KV

800 KV

220KV 4.58m 4.58m 4.58m 4.58m 5.49m 7.94m

3.3.5.4 LIVE METAL CLEARANCE

The minimum live metal clearance to be provided between the live parts

and steel work of super structure shall be as per IS: 5613 (Part-II/Sec-1)

1985 as given below:

Sr.No. Type of Insulator string Swing in degree

Minimum live metal clearance

in mm

Nil 2130

15 1980

30 1830

45 1675

1. Single suspension insulator

string

60 -

2. Tension insulator string Nil 2130

Nil 2130

10 2130

20 1675 3. Jumper

30 -

Nil 2130 4. Double suspension string

15 1980

Page 19 of 143

30 1830

45 1675

3.4 Drawings

3.4.1 After award of contract, the contractor shall made proto assembly as per

structural drawing of each type of tower as supplied by employer and get it

inspected and then prepare BOM and shop drawings. The contractor shall

furnish the following in ten (10) copies to the employer for necessary

within fifteen (15) days after approval of drawings.

a Bill of materials, indicating cutting and bending detail against each

member.

b Shop drawings showing all details relevant to fabrication

c. All the drawings for the tower accessories.

d. The contractor should also submit one copy of reproducible drawing/Bill of

materials as mentioned above within 15 days after final approval.

3.4.2 The Contractor is required to submit four copies of the drawings as

mentioned in clause 3.4.1 for employer’s approval. While submitting the

bill of material and any other drawings pertaining to the subject

transmission line, the Contractor shall clearly indicate on each drawing

PSTCL Specification No., Name of the transmission line and project, letter

reference No. and date on which the submission are made.

3.4.3 The design and drawings as covered in clause above shall be

approved/commented by the Employer as the case may be within 21

(twenty one) days of receipt of designs/drawings in PSTCL Transmission

Design Office. If the design /drawings are commented on by the employer,

the Contractor shall submit 4 sets of revised designs /drawings within 10

(ten) days of date of issue of comments.

3.4.4 The Contractor is required to furnish the progress of submissions and

approvals of drawings on twenty fifth of every month till the completion of

all the design activities.

3.4.5 The details shall include description of drawings, schedule date of

submission, actual date of submission, schedule date of approval, actual

date of approval, schedule date of submission of distribution copies, and

‘Remarks’ column. Provision of six additional columns shall also be made

Page 20 of 143

in the above progress report to indicate date of comments issued by the

Employer and details of submission of revised drawings.

3.5 GANTRIES

3.5.1 The entire clauses relating to towers will be relevant for gantries in general

unless otherwise stated.

3.5.2 The structural drawings for gantries will be provided by employer.

3.6 MATERIALS

3.6.1 TOWER STEEL SECTIONS

Indian Standard steel sections of tested quality in conformity with IS:2062

1980 (Grade A), with latest amendments, or any other equivalent grade of

structural steel angle sections and plates conforming to latest International

standard are to be used in towers, extensions and stub setting templates.

Preferably steel sections used should be as supplied by main producer

like SAIL/TISCO/IISCO etc. However, in case of non availability, if

purchased from secondary re-rollers, the re-rollers must ensure use of

billet of main producer used for manufacture of steel section. Also re-roller

should be a reputed manufacturer having ISI certification mark/license on

its product as per IS:2062 Grade-A. PSTCL reserves the right to witness

the rolling process and to test the billets & sections at the premises of the

Re-roller for which all testing facilities shall be ensured by the bidder free

of cost.

3.6.2 FASTENERS: BOLTS, NUTS AND WASHERS

3.6.2.1 All bolts and nuts (including Anti-Theft) shall conform to IS:12427-1988. All

bolts and nuts shall be galvanized as per IS 2629-1985 with coating as per

IS-1367 Part XIII 1983 and shall have hexagonal head (round in case of

Anti-Theft) and nuts, the heads being forged out of the solid steel rods and

shall be truly concentric, and square with the shank, which must be

perfectly straight. In case of Anti-Theft nuts , the shape & size shall be as

per the attached drawing. The difference between the two minimum

measurement from bolt head size edge on bearing face on the shank of

bolt taken for any to opposite side shall not exceed maximum limit of

0.84mm for M16 type bolts .Similarly the difference between the minimum

wall thickness measured between minor thread diameter and the flats of

any 2 opposite sides of nuts shall not exceed the maximum limit of 0.42

Page 21 of 143

mm for M 16 size of nuts .Further the bearing face shall be square to

shank with the tolerance of 2 degree.

3.6.2.2 The bolt shall be of 16 mm dia and of property class 5.6 as specified in IS:

1367 (part-III) 1979 and matching nut of property class 5 as specified in

IS:1367 (Part-VI) 1980.

3.6.2.3 Bolts upto M 16mm and having length upto 10 times the diameter of the

bolts should be manufactured by cold forging and thread rolling process to

obtain good and reliable mechanical properties and effective dimensional

control. The shear strength of bolts for 5.6 grade should be 310-MPa

minimum as per IS:12427, bolts should be provided with washer in

accordance with IS:1363 Part-1 to ensure proper bearing.

3.6.2.4 Nuts should be double chamfered as per the requirement of IS:1363 Part-

III, 1984. The manufacturer should ensure that nuts should not be over-

tapped beyond 0.4mm oversize on effective diameter for size upto M 16.

3.6.2.5 Fully threaded bolts shall not be used. The length of bolts shall be such

that the threaded portion will not extend into the place of contact of the

members.

3.6.2.6 All bolts shall be threaded to take the full depth of the nuts and threaded

for enough to permit firm gripping of the members, but not further. It shall

be ensured that the threaded portion of each bolt protrudes not less than

3mm and not more that 8 mm when fully tightened. All nuts shall fit and

tight to the point where the shank of the bolt connects to the head.

3.6.2.7 Flat and tapered washers shall be provided wherever necessary. Spring

washers shall be provided for insertion under all nuts. These washers shall

be of spring steel electro-galvanised steel, positive lock type and 3.5mm

in thickness for 16-mm dia bolt as per IS 3063 (latest edition)

3.6.2.8 To obviate bending stress in bolts or to reduce it to minimum, no bolt shall

connect aggregate thickness of more than three (3) times its diameter.

3.6.2.9 The bolt position in assembled towers shall be as per IS:5613 (Part-

II/Section-2-1976).

3.6.2.10 Bolts at the joints shall be so staggered that nuts may be tightened with

spanners without fouling.

3.6.2.11 The bidder shall use Anti-Theft nuts & bolts on the first storey of the tower

(Drg. attached)

Page 22 of 143

3.6.2.12 To ensure effective in-process Quality control, it is essential that the

manufacturer should have all the testing facilities for tests like weight of

zinc coating, shear strength, other testing facilities etc. in house. The bolts

should have ISI certification mark as per IS 12427-988 & Nuts as per

1363-Part III-1984 with latest amendments.

3.7 Tower Accessories

3.7.1 Step Bolts

Each tower shall be provided with step bolts conforming to IS:10238 of not

less than 16mm diameter and 175 mm long, spaced not more than 450

mm apart and extending from about 3.5metres above the ground level to

the top of the tower. For double circuit tower the step bolt shall be fixed on

one leg from 3.5M above ground level to top of the towers. Each step bolt

shall be provided with two nuts on one end to fasten the bolt securely to

the tower and button head at the other end to prevent the feet from

slipping away. The step bolts shall be capable of withstanding a vertical

load not less than 1.5 KN.

3.7.2 Insulator Strings and Earthwire Clamps Attach ments

a. Suspension Insulator string assemblies under the bidder’s scope of supply

shall be used for suspension towers as per drawings enclosed with

Specification. For the attachment of suspension insulator string, a

swinging D-Shackle on the tower shall be provided as per drawings

enclosed with Specification. The supply of D-shackle is within scope of the

Bidder.

b. At tension towers, strain plates of suitable dimensions on the underside of

each cross arm tip and at the top of earthwire peak should be provided for

taking the hooks or D-Shackle of the tension insulator strings or earthwire

tension clamps, as the case may be.

3.7.3 Earthwire Clamps

a Suspension clamp :Earthwire suspension clamps will be supplied by the

bidder as per the reference drawing enclosed with specification.

b Tension Clamps:The bidder shall supply earthwire tension clamps for use

on the towers. The reference drawings for the same is enclosed with the

specification. However, the contractor shall supply the U-bolts wherever

required.

3.7.4 Anticlimbing Device

Page 23 of 143

Anticlimbing device/fencing as per enclosed drawings shall be provided

and installed by the Contractor for all towers/gantries. The height of the

anticlimbing device shall be provided approximately 3m above ground

level.

3.7.5 Danger, Number, Circuit and Phase plate

Danger, Number, Circuit and Phase Plates shall be provided and

installed by the Contractor with design & shape as per relevant IS.

a) Each tower shall be fitted with a number plate and danger plate. Each

tension tower shall be provided with a set of phase plates also. All the

double circuit towers are to be provided with circuit plate fixed near the

legs.

b) The letters, figures and the conventional skull and bones of danger plates

shall conform to IS:2551-1963 and shall be in a single red on the front of

the plate.

3.7.6 Bird Guards

To prevent birds perching immediately above the suspension insulator

strings and fouling the same with droppings, suitable bird guards shall be

provided at cross arm tips of all suspension towers. The bird guard

arrangement shall be such that it shall either prevent bird from perching in

position where they are liable to cause the damages or ensure that if birds

do perch, droppings will fall clear of the insulator string.

3.7.7 Aviation Requirements

3.7.7.1 The river crossing towers and any other towers in the vicinity of airport

shall be painted and the crossing span shall be provided with markers to

caution the low flying aircraft as per statutory provisions.

3.7.7.2 The full length of the towers shall be painted over the galvanized surface

in contrasting bands of orange or red and white. The bands shall be

horizontal. The width of the colour band shall be as per the relevant

aviation regulation clauses, prevalent at the time of execution of the

project.

a) Surface Preparation

The etching of galvanized surface of erected tower members with suitable

etching or wash primer is to be done as per IS:1477-1977 to enhance the

Page 24 of 143

adhesion of subsequently applied paint coating. After etching of

galvanized surface of tower one coat of zinc primer is to be applied.

b) Painting of Towers

Two coats of international orange or red and white paint at alternate

interval (bands) as explained above are to be applied. The painting of

towers shall generally confirm to relevant provisions in IS:1477-1977 Part I

& II. The paints to be used for painting shall be in accordance with

IS:2074-1962 with latest amendment.

c) Span Markers

Sphere type span marker of 600 mm diameter shall be provided on the

earthwire. The sphere shall be vertically divided into four quadrants and

each quadrants shall be alternatively painted in orange or red and white.

These markers shall be suspended from earthwire at interval of 36 meters.

The design of the markers and their fixing arrangement should be such

that they can withstand the wind pressure and shall not induce excessive

amount of vibration strain on earthwire. Detail of this arrangement shall be

submitted by the bidder along with Bid.

3.8 Tower Fabrication

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

3.8.1 Except where hereinafter modified, details of fabrication shall conform to

IS:802 (Part-II) 1978, with latest amendments or the relevant international

standards.

3.8.2 Butt splices shall be used and the inside cleat Angle and outside plate

shall be designed to transmit the load. The inside cleat Angle shall not be

less than half the thickness of the heavier member connected plus 2mm.

Lap splice may be used for connecting members of unequal size and the

inside angle of lap splice shall be rounded at the heel to fit the fillet of the

outside angle. All splices shall develop full stress in the member

connected through bolts. Butt as well as lap splice shall be made as above

and as close to the main panel point as possible. Pack plates of 3mm and

4mm thick can be used as per IS:1079 (1994) grade 0.

3.8.3 The use of filler in connection shall be avoided as far as possible. The

diagonal web members in tension may be connected entirely to the gusset

plate wherever necessary to avoid the use of filler and it shall be

connected at the point of intersection by one or more bolts.

Page 25 of 143

3.8.4 The tower structures shall be accurately fabricated to connect together

easily at site without any undue strain on the bolts.

3.8.5 All similar parts shall be made strictly inter-changeable. All steel sections

before any work is done on them, shall be carefully leveled, straightened

and made true to detailed drawings by methods that will not injure the

materials so that when assembled, the adjacent matching surfaces are in

close contact throughout. No rough edges shall be permitted in the entire

structure.

3.8.6 Drilling and Punching

3.8.7.1 Before cutting work is started, all steel sections shall be carefully

straightened and trued by pressure and not by hammering. They shall

again be trued after being punched and drilled.

3.8.7.2 Holes for bolts shall be drilled or punched with a jig but drilled holes shall

be preferred. Punching may be adopted for thicknesses upto 16mm.

Tolerances regarding punched holes are as follows:

a. Holes must be perfectly circular and no tolerance in this respect is

permissible.

b. The maximum allowable difference in diameter of the holes on the two

sides of plates or angle is 0.8mm i.e. the allowable taper in a punched

hole should not exceed 0.8mm in diameter.

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

parallel.

3.8.7.3 All burrs left by drills or punch shall be removed completely. When the

tower members are in position, the holes shall be truly opposite to each

other. Drilling or reaming to enlarge holes shall not be permitted.

3.8.8 Erection mark

3.8.8.1 Each individual member shall have an erection mark conforming to the

component number given to it in the fabrication drawings. This mark shall

be made with marking dies of 16mm size before galvanising and shall be

legible after galvanising.

3.8.8.2 Erection Mark shall be

A-BB-CC-DDD

Where

A = Employer’s code assigned to the Contractor-Alphabet

BB = Contractor’s Mark-Numerical

Page 26 of 143

CC = Tower Type-Alphabet

DDD = Number mark assigned-Numerical.

3.8.9 Quantities and Weights

3.8.9.1 The provisional quantities required are mentioned in the schedule of

Prices. Final quantities shall be determined after completion and approval

of the detailed route survey. The final quantities of tower and line materials

shall be confirmed by the Employer based on the requirement of quantities

of various towers furnished by the Contractor after completion of detailed

survey. Hence, it will be responsibility of the Contractor to intimate the

exact requirements of all towers and various line materials required for line

immediately after the survey as per the attached Bill of Quantities (BOQ)

sheets. The Employer will order the final quantities at the unit rates quoted

in the Bid.

3.8.9.2 The estimated weight of tower material and Bolts & Nuts , given in Price

Schedules, is based on unit weight of each type of tower, stubs and

extensions as well as bolts and nuts along with spring washers and step

bolts to be supplied by the contractor .The weight of tower shall mean the

weight of tower calculated by using the black sectional (i.e. ungalvanised)

weight of steel members of the size indicated in the approved fabrication

drawings and bills of materials, without taking into consideration the

reduction in weights due to holes, notches and bevel cuts etc.The

payment of complete tower structure / Stub Set shall be made which will

include the weight of the structural members including pack washers, D-

shackle, U- Bolt & links to complete the tower / Stub Set as per the weight

of the respective item mentioned in the respective approved Bill of

Material. But anti climbing devices including cleats and barbed wire shall

be covered in ACD set, however, the procedure of calculation of weights

of cleat shall remain the same.

3.9 Galvanising

Fully galvanised towers and stub (partly galvanised) shall be used for the

lines. Galvanising of the member of the towers shall conform to IS:2629-

1985 and IS:4759-1968. All galavanised members shall withstand tests as

per IS:2633-1986. For fasteners, the galvanising shall conform to IS:1367

(Part-13). The galvanising shall be done after all fabrication work is

completed, except that the nuts may be tapped or re-run after galvanising.

Page 27 of 143

Threads of bolts and nuts shall have a neat fit and shall be such that they

can be turned with finger throughout the length of the threads of bolts and

they shall be capable of developing full strength of the bolts. Spring

washers shall be electro-galvanised as per Grade 4 of IS: 1573-1970.

3.10 Earthing

3.10.1 The footing resistance of all towers shall be measured by the Contractor in

dry weather after tower erection but before the stringing of earthwire. All

the towers are to be earthed, however, in no case tower footing resistance

shall exceed 10 ohms. Pipe type earthing and counterpoise type earthing

wherever required shall be provided in accordance with the stipulations

made in IS:3043-1987 and IS:5613 (Part-II/Section-2) 1985. The details

for pipe and counterpoise type earthing are given in drawing enclosed with

the specification.

3.10.2 The provisional quantities for pipe type earthing and counterpoise earthing

are furnished in Price Schedule. The Bidders are required to furnish unit

rates also for adjustment purpose with actual quantities. The quoted price

shall include fabrication, supply and installation of earthing material

including supply of coke, salt etc. In case of counterpoise type earthing,

the quotation shall be based on 100 meters of wire per tower.

3.11 Inspection and Tests

3.11.1 General

All standard tests, including quality control tests, in accordance with

appropriate Indian/International standard, shall be carried out unless

otherwise specified herein.

3.11.2 Inspection

In addition to the provision of Clause regarding Inspection in General

conditions, the following shall also apply:

3.11.2.1

a) The Contractor shall keep the Employer informed in advance about the

time of starting and of the progress of manufacture and fabrication of

various tower parts at various stages, so that arrangements can be made

for inspection.

b) The acceptance of any part of items, with or without inspection, shall in no

way relieve the Contractor of any part of his responsibility for meeting all

the requirements of the Specification.

Page 28 of 143

3.11.2.2 The Employer or his representative shall have free access at all

reasonable times to those parts of the Contractor’s works which are

concerned with the fabrication of the Employer’s material for satisfying

himself that the fabrication is being done in accordance with the provisions

of the specifications.

3.11.2.3 Unless specified otherwise, inspection shall be made at the place of

manufacture prior to despatch and shall be conducted so as not to

interfere unnecessarily with the operation of the work.

PSTCL reserves the right to re-inspect the material after it has reached

the site / has been erected to check that the material inspected has

reached the site and / or erected.

3.11.2.4 Should any member of the structure be found not to comply with the

approved design, it shall be liable to rejection. No member once rejected

shall be resubmitted for inspection, except in cases where the Employer or

his authorised representative considers that the defects can be rectified.

3.11.2.5 Defect which may appear during fabrication shall be made good with the

consent of and according to the procedure proposed by the Contractor and

approved by the Employer.

3.11.2.6 All gauges and templates necessary to satisfy the Employer shall be

supplied by the Manufacturer.

3.11.2.7 The correct grade and quality of steel shall be used by the Contractor. To

ascertain the quality of steel used, the inspector may at his discretion get

the material tested at an approved laboratory.

3.12 Packing

3.12.1 Angle section shall be wire bundled.

3.12.2 Cleat angles, gusset plates, brackets, fillet plate and similar loose pieces

shall be securely wired in multiples through holes.

3.12.3 Bolts, nuts, washers and other attachments shall be packed in double

gunny bags accurately tagged in accordance with the contents.

3.12.4 The packing shall be properly done to avoid losses/damages during

transit. Each bundle or package shall be appropriately marked.

3.13 Standards

3.13.1 The manufacturing, fabrication, galvanising, testing, erection procedure

and materials used for manufacture and erection of towers, design and

construction of foundations shall conform to the following Indian Standards

Page 29 of 143

(IS)/International Standards which shall mean latest revisions, with

amendments/changes adopted and published, unless specifically stated

otherwise in the specification. In the event of supply of material to

Standards other than specified, the Bidder shall confirm in his bid that

these Standards are equivalent to those specified. In case of award,

salient features of comparison between the Standards proposed by the

Contractor and those specified in this document will be provided by the

Contractor to establish their equivalence.

3.13.2 The material and services covered under these specifications shall be

performed as per requirements of the relevant standards/codes (with latest

revision) referred hereinafter against each set of equipment and services.

Other Internationally acceptable standards which ensure equal or higher

performance than those specified shall also be accepted.

Sr. No.

Indian Standards

Title International & Internationally recognized Standards.

1. IS:209-Rev Specification for Zinc. ISO/R/752-1968 ASTM B6

2. IS:2062-1992 Steel for general structural purpose.

3. IS:269-1976 Ordinary rapid hardening & low heat Portland Cement.

ISO/R/597-1967

4. IS:383-1970 Coarse and find aggregates from natural sources for concrete.

CSA A23.1/A 23.2

5. IS:432-1966 (Part I&II)

Mild steel and medium tensile bars and hard drawn steel wire for concrete reinforcement.

BS-785-1938 CSA-G-30

6. IS:456-1978 Code of practice for plain and reinforced concrete.

ISO/3893-1977

7. IS:800-1962 Code of practice for use of structural steel in general Building construction.

CSA S 16.1

8. a) IS:802 b)IS:802 (Part-II)-1978

Code of Practice for use of structural steel in overhead transmission Line: Part 1: Load and Permissible stresses. Code of Practice for use of structural steel in overhead transmission line: Fabrication, Galvanising,

IEC 826 ASCE 52 BS 8100 ACSE 52

Page 30 of 143

c) IS:802 Part-III-1978

Inspection and packing. Code of Practice for use of structural steel in overhead transmission line towers: Testing.

ASCE 52

9 IS:808 Dimensions for Hot Rolled steel Beam, Column channel and Angle sections.

10 IS:875 Code of practice for design loads (other than earthquakes) for Buildings & structures.

11. IS:1139-1966 Hot rolled mild steel, medium tensile steel and high yield strength deformed bars for concrete reinforcements.

CAN/CSA G 30.18 ASTM A615.

12. IS:1367-1967 Technical supply conditions for threaded fasteners.(First Revision).

13. IS:1489-1976 Portland Pozzolena Cement. ISO/R/863-1968

14. IS:1786-1966 Cold twisted steel bars for concrete reinforcement.

15. IS:1893-1965 Criteria of Earthquake resistant design of structures.

IEEE 693

16. IS:2016-1967 Plain Washers ISO/R/887-1968. Ansi B 18.22.1

17. IS:2131-1967 Method of Standard penetration test for soils.

ASTM D 1883.

18. IS:2251-1982 Danger Notice Plates.

19. IS:2629-1966 Recommended practice for hot dip galvanising of iron & Steel.

ASTM A 123 CAN/CSA G 164

20. IS:2633-1972 Method of testing uniformity of coating of zinc coated articles.

ASTM A 123 CAN/CSA G 164.

21 IS:3043-1972 Code of Practice for earthing (with amendment No. 1 &2).

22. IS:3063-1972 Single Coil Rectangular Section spring washers for bolts, nuts, screws.

DIN-127-1970

23. IS:4091-1967 Code of practice for design and construction of foundation for transmission line towers and poles.

ASCE/ IEEE 691

24. IS:5358-1969 Hot dip galvanized coatings on fasteners.

ASTM A 153 CAN/CSA G 164.

25. IS:5613(Part-

II/Sec-1)1976

Code of practice for Design, installation & maintenance of overhead power lines(Section-1: Designs).

ASCE 52.

26. IS:5613 (Part-

II/Sec-2)-1976

Code of practice for Design, installation & maintenance of over head power lines(Section

Page 31 of 143

2: installation & Maintenance). 27. IS: 6610-1972 Specification for heavy

washers for steel structures.

28. IS:6639-1972 Hexagonal bolts for steel structures.

ASTM A 394 CSA B 33.4

29. IS:6745-1972 Methods for determination of weight of zinc coating of zinc coated iron and stel articles.

ASTM A90

30. Indian Electricity Rules-1956/ Electricity Act-2003.

31. Publication No.19(N)/700-1963

Regulation for Electrical Crossing of Railway Tracks.

32. IS:8500-1977 Specification for weldable structural steel(Medium and High strength qualities).

BS:4360

4 Tower Foundations

4.1 Foundation Types

4.2.1 General

These specifications provide general guide lines for towers for

construction of foundations for transmission and gantry towers for the

transmission lines covered in the tender. The foundation shall be

constructed as per design/drawings to be supplied by the employer.

Drawings for foundations of various tower type upto 6 mtr. extension and

gantry towers are attached.

4.2.2 Before start of work, trial bore holes upto 6 mtr. below ground level shall

be carried out by successful bidder at every kilometer or as desired by

employer. The bore log data comprising of information like position of sub

soil water table, soil strata shall be submitted to the employer for

classification of foundation type to be provided at each location.

4.2.3 Reinforced Cement concrete or special foundations shall be used for all

types of normal towers in conformity with the present day practice followed

in the country and the specifications laid herein. All the four footings of the

tower and their extension shall be similar, irrespective of down thrust and

uplift.

Foundation includes supply of materials such as cement, reinforcement

steel, sand, coarse aggregates etc. Rates quoted for foundations in

appropriate schedules shall include all items of work related to supply and

Page 32 of 143

installation of foundations such as form work, excavation and backfilling,

stub setting, providing reinforcement etc.

4.2.4 Classifications of Foundations

The foundation designs shall depend upon the type of soil, sub-soil water

level and the presence of surface water which have been classified as

follows:

4.2.4.1 Normal dry

To be used for locations where normal dry cohesive or non-cohesive soils

are met & water table is at a depth equal to or more than the width of the

foundation below the foundation level.

4.2.4.2 Partially submerged

To be used at locations where sub-soil water table is met between 0.75 m

to 1.5 m below the ground level.

4.2.2.3 Fully Submerged:

To be used at locations where sub-soil water table is met at less than 0.75

m below ground level.

4.2.2.4 Special Foundation:

For the locations not covered above, the contractor shall refer to employer

soil details/ test results from a Govt. approved test house. The employer

will supply the result.

4.2.3 Properties of concrete & Reinforcement.

The cement concrete used for the foundations shall be of grade M-20.

All the properties of concrete regarding its strength under compression,

tension, shear, punching and bend etc as well as workmanship will

conform to IS:456-1978 (with latest amendments).

4.2.3.1 The Portland Cement used in concrete shall conform to IS:269-1967.

The Pozzolena cement used in concrete shall conform to IS:1489-1976.

4.2.3.2 Concrete aggregates shall conform to IS:383-1970

4.2.3.3 The water used for mixing concrete shall be fresh, clean and free from oil,

acids and alkalies, organic materials or other deleterious substances.

Potable water is generally preferred.

4.2.3.4 Reinforcement shall conform to IS:432-1966 for M.S. bars and hard drawn

steel wires and IS:1139-1966 and IS:1786-1966 for deformed and cold

twisted bars respectively. All reinforcement shall be clean and free from

Page 33 of 143

loose mill scales, dust, loose rust, and coats of paint, oil or other coatings,

which may destroy or reduce bond. Contractor shall supply, fabricate and

place reinforcement too shapes and dimensions and indicated or as

required to carry out the intent of drawings and specifications. Only one

type of steel shall be used for the design.

4.3 Design of foundations

The employer will provide the complete design of the foundation. Normally

following type of foundations are laid as per prevailing practice in PSTCL.

1 RCC open pit dry type

2 Semi – Submerged type : Is laid where sub soil water is not permanent

and as such does not hinder in lying of foundations therefore the

foundation may be laid without de-watering otherwise de-watering is

required.

3 Fully Submerged : This foundations will cover de-watering etc. for lying

of this foundation.

4.3.1 Unit rates and measurements

The bidders are required to furnish unit rates in the Price Schedule.

4.3.1.1 The scope of work for foundation per tower shall include excavation, stub

setting, concreting, reinforcement, if any, timbering & shoring, shuttering,

dewatering, stock-pilling, dressing, curing, backfilling the foundation after

concreting with excavated/borrowed earth (irrespective of leads) and

consolidation of earth, carriage of surplus earth to the suitable point of

disposal as required by the Employer or any other activities related to

completion of foundation works.

4.3.1.2 The excavation volumes for each tower footing shall be estimated

assuming the faces of surrounding earth as vertical keeping a distance of

150mm clearance from the extreme edge of the base slab of footing.

4.3.1.3 The concrete volume and dimensions of the foundation shall be

determined from the PSTCL drawings. Measurement of concrete volume

shall be in cubic meters and shall be worked out to the second place of

decimal.

4.3.1.4 The Contractor shall provide the steel required for reinforcement of special

foundation. Measurement will be based on the calculated weights of steel

actually used in MT corrected to third place of decimal, no allowance being

made for wastage. No payments will be made for wire required for binding

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the reinforcement chairs, bolsters and spacers, as the cost of these is

deemed to be included in the unit rate quoted for the item of

reinforcement.

4.4 Construction of Tower Foundations

4.4.1 Excavation

4.4.1.1 Excavation work must not be started until the tower schedule and profile

has been approved by the Employer.

4.4.1.2 Except as specifically otherwise provided, all excavation for footing shall

be made to the lines and grades of the foundation. The excavation wall

shall be vertical and the pit dimensions shall be such as to allow a

clearance of 150 mm on all sides from the foundation pad. The Contractor

should ensure clearance of 150 mm from the foundation pad for quality

work. All excavation shall be protected so as to maintain a clean

subgrade, until the footing is placed, using timbering/ shuttering, shoring

etc., if necessary. Any sand, mud, silt or other undesirable materials which

may accumulate in the excavated pit shall be removed by the Contractor

before placing concrete. The water table shall be kept 0.5m below the

footing level for 24 hrs.from the last hour of concrete is placed.

4.4.1.3 No extra charge shall be admissible for the removal of the fallen earth in

the pit, when once excavated. Shoring and timbering/ shuttering as

approved by authorized representative of the Employer shall be provided

by the Contractor when the soil condition is so bad that there is likelihood

of accident due to the falling of earth.

4.4.2 Setting of Stubs

4.4.2.1 The stubs shall be set correctly in accordance with standard methods at

the exact location and alignment and precisely at correct levels with the

help of stub setting template and leveling instrument. Stubs shall be set in

the presence of Employer’s representative available at site and for which

adequate advance intimation shall be given to the Employer by the

Contractor. All precautions shall be taken that stubs once finally set are

not disturb. If these are disturbed due to any reasons the same shall be

re-set in the presence of Employer’s representative without any extra cost.

4.4.2.2 The Employer’s representative shall approve setting of stub at each

location.

4.4.4 Stub setting template

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4.4.4.1 Stub setting template shall be arranged by the contractor at his cost for all

types of tower with or without extension as per approved drawings. The

stub templates shall be red oxide painted.

4.4.4.2 The contractor will furnish sufficient number of templates for the timely

completion of line without any extra cost to employer.

4.4.4.3 Following number of stub setting templates shall be deployed by the

contractor for each Package:

Template For Tower Type Nos to be deployed

For A – Type 12 Nos

For each of B and C Type 3 Nos each

However, if employer feels that more number of templates are

required for a timely completion of a particular line the contractor shall

have to deploy the same without any extra cost to employer.

4.4.5 MIXING, PLACING AND COMPACTING OF CONCRETE

4.4.5.1 The concrete shall be mixed in a mechanical mixer. However, in case of

difficult terrain hand mixing may be permitted at the discretion of

Employer. In case of hand mixing 10% extra cement shall be used without

any extra cost. The water for mixing concrete shall be fresh, clean and

free from oil, acids and alkalies. Saltish or blackish water shall not be

used.

4.4.5.2 Mixing shall be continued until there is uniform distribution of material and

the mix is uniform in colour and consistency, but in no case the mixing be

done for less than two minutes. Normally mixing shall be done close to the

foundation, but in case it is not possible, the concrete may be mixed at the

nearest convenient place. The concrete shall be transported from the

place of mixing to the place of final deposit as rapidly as practicable by

methods, which shall prevent the segregation or loss of any ingredient.

The concrete shall be placed and compacted before setting commences.

4.4.5.3 Form boxes shall be used for casting all type of foundations. The concrete

shall be laid down in 150 mm layers and consolidated well, so that the

cement cream works upto the top and no honey-combing is left in the

concrete. The mechanical vibrator shall be employed for compaction of

the concrete. However, in case of difficult terrain, manual compaction may

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be permitted at the discretion of Employer. After concreting the chimney

portion to the required height, the top surface should be finished smooth

with a slight slope towards the outer edge, to drain off any rainwater falling

on the coping.

4.4.5.4 In wet locations, the site must be kept complete dewatered, both during

the placing of the concrete and for 24 hours thereafter. There should be

no disturbance of concrete by water during this period.

4.4.5.5 After the formwork has been removed if the concrete surface is found to

be defective, the damage shall be repaired with rich cement and sand

mortar to the satisfaction of the Employer’s representative before the

foundation pits are backfilled at no extra cost.

4.4.6 Back-Filling and Removal of Stub Template

4.4.6.1 After opening of form work and removal of shoring and timbering, if any,

backfilling shall be started, after repairs, if any, to the foundation concrete.

Backfilling shall normally be done with excavated soil, unless it consists of

large boulders/stones, in which case the boulders shall be broken to a

maximum size of 80 mm. At such locations where borrowed earth is

required for backfilling, this shall be done by the Contractor at his own

cost, irrespective of lead.

4.4.6.2 The backfilling materials should be clean and free from organic or other

foreign materials. The earth shall be deposited in maximum 200 mm

layers, leveled and wetted and tampered properly before another layer is

deposited. Care shall be taken that the backfilling is started from the

foundation ends of the pits, towards the outer ends. After the pits have

been backfilled to full depth, the stub template may be removed.

4.4.6.3 The backfilling and grading shall be carried to an elevation of about 75

mm above the finished ground level to drain out water. After backfilling 50

mm high earthen embankment (bandh) will be made along the sides of

excavation pits and sufficient water will be poured in the backfilled earth

for at least 24 hours.

4.4.7 Curing

The concrete after setting for 24 hours shall be cured by keeping the

concrete wet continuously for a period of 10 days after laying. The pit may

be back filled with selected earth sprinkled with necessary amount of

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water and well consolidated in layers not exceeding 200 mm of

consolidated thickness after minimum period of 24 hours and thereafter

both the backfilled earth and exposed chimney top shall be kept wet for

the remainder of the prescribed time of 10 days. The uncovered concrete

chimney above the backfilled earth shall be kept wet by providing empty

cement bags dipped in water fully wrapped around the concrete chimney

for curing and ensuring that the bags are kept wet by the frequent pouring

of water on them.

4.4.8 Benching

When the line passes through hilly/undulated terrain, for a few tower

locations it may be required to level the ground for casting of tower

footings on same elevation. All the activities related to make the required

area of ground in same elevation for casting of foundation, shall be termed

as benching work. Benching work shall include cutting of excess earth and

removing the same to a suitable point of disposal as required by the

Employer. Benching shall be resorted to only after getting specific

approval from the Employer. Volume of the earth to be cut shall be

measured before cutting and got approved from the Employer. This

volume of earth shall be considered for the purpose of payment against

the head of benching work.

4.4.9 Protection of Tower Footing

4.4.9.1 The work shall include all necessary brick, stone masonry (in cement

mixture 1:5) revetments, concreting and earth filling above ground level

and the clearance from stacking on the site of all surplus excavated soil,

special measures for protection of foundation close to or in nallahas, river

bed hilly/undulated terrain etc, wherever required shall be done after

getting prior approval of the Employer.

4.4.9.2 The quantity of excavated earth obtained from a particular location shall

generally be utilised in back-filling work in protection of tower footing of

same location, unless it is unsuitable for such purpose. In the latter case,

the back filling shall be done with borrowed earth of suitable quality

irrespective of lead and the same shall be to the contractor’s account.

4.4.9.3 The unit rates shall be applicable for adjusting with the actual quantities of

protection works done.

5. Tower Erection, Stringing and Installation of Line Materials

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5.1 General

5.1.1 The details of the scope of erection work shall include the cost of labour,

all tools and plants and all other incidental expenses in connection with

erection and stringing work.

5.1.2 The Contractor shall be responsible for transportation of all the materials

to be provided by the Contractor as per the scope of work to site, proper

storage and preservation at their own cost till such time the erected line is

taken over by the Employer. The Contractor shall be responsible for

transportation, proper storage, safe custody, loss or damage of all

supplied items for incorporation in the lines and shall maintain and render

proper account for all such materials at all times.

5.1.3 Contractor shall set up required number of stores along the line at his own

cost and the exact location of such stores shall be discussed and agreed

to between the Contractor and the Employer. The employer shall not be

liable for any unpaid rents of the space taken for storing of material or any

damage or liability arising out of such arrangement.

5.2 Treatment of Minor Galvanising Damage

In case any minor damage to galvanising is noticed, the same shall be

treated with zinc rich paint (commercial grade) (having at least 90% zinc

content) before erection.

5.3 Assembly

5.3.1 The method followed for the erection of towers, shall ensure the points

mentioned below:

(a) Straining of the members shall not be permitted for bringing them into

position. It may, however, be necessary to match hole positions at joints

and to facilitate this, tommy bars not more than 450 mm long may be

used.

(b) Before starting erection of an upper section, the lower section shall be

completely braced and all bolts provided and tightened adequately in

accordance with approved drawings to prevent any mishap during tower

erection.

(c) All plan diagonals relevant to a section of tower shall be placed in position

before assembly of upper section is taken up.

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(d) The bolt position in assembled towers shall be as per IS:5613 (Part-

II/Section 2)-1976.

(e) Tower shall be fitted with number plate, danger plate, phase plate, circuit

plate and anti climbing device as described.

(f) All blank holes, if any left, after complete erection of the tower, are to be

filled up by bolts and nuts of correct size.

5.4 Tightening and Punching of Bolts and Nuts

5.4.1 All nuts shall be tightened properly using correct size spanner/torque

wrench. Before tightening, it will be seen that filler washers and plates are

placed in gaps between members wherever applicable bolts of proper size

and length are inserted, and one spring washer is inserted under each nut.

In case of step bolts, spring washers shall be placed under the outer nut.

The tightening shall progressively be carried out from the top downwards,

care being taken that all bolts at every level are tightened simultaneously.

The threads of bolts projecting outside the nuts shall be punched at their

position on the diameter to ensure that the nuts are not loosened in course

of time. If during tightening a nut is found to be slipping or running over the

bolt threads, the bolt together with the nut shall be replaced.

5.4.2 Anti-Theft type nuts & bolts shall be provided upto first storey of tower to

avoid pilferage of tower members.

5.5 Insulator Hoisting

5.5.1 Suspension insulator strings shall be used on suspension towers and

tension insulator strings on angle and dead end towers. These shall be

fixed on all the towers just prior to the stringing. Damaged insulators and

fittings, if any, shall not be employed in the assemblies. Before hoisting, all

insulators shall be cleaned in a manner that will not spoil, injure or scratch

the surface of the insulator, but in no case shall any oil be used for the

purpose. Torque wrench shall be used for fixing different line materials

and their components, like suspension clamp for conductor and earthwire

etc.

5.6 Handling of Conductor and Earthwire

5.6.1 The Contractor shall be entirely responsible for any damage to the towers

or conductors during stringing. While running out the conductors, care

shall be taken that the conductors do not touch or rub against the ground

or objects, which could cause scratches or damages to the strands. The

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conductors shall be run out of the drums from the top in order to avoid

damage due to chafing. Immediately after running out, the conductor shall

be raised at the supports to the levels of the clamps and placed into the

running blocks. The groove of the running blocks shall be of such a design

that the seat is semi-circular and larger than the diameter of the

conductor/earthwire and it does not slip over or rub against the sides. The

grooves shall be lined with hard rubber or neoprene to avoid damage to

conductor and shall be mounted on properly lubricated bearings.

5.6.2 The running blocks shall be suspended in a manner to suit the design of

the cross arm. All running blocks, especially those at the tension end, will

be fitted on the cross-arm with jute cloth wrapped over the steel work and

under the slings to avoid damage to the slings as well as to the protective

surface finish of the steel work. In case suspension, or section towers are

used even for temporary terminations, if this be unavoidable, they shall be

well guyed and steps shall be taken by the Contractor to avoid damage.

Guying proposal alongwith necessary calculations shall be submitted by

the Contractor to Employer for the approval. Proper T&P shall also be

made available to the Employer by the Contractor for checking the

tensions in the guy wires. The drums shall be provided with a suitable

braking device to avoid damages, loose running out and kinking of the

conductor. The conductor shall be continuously observed for loose or

broken strands or any other damage. When approaching end of a drum

length, at least three coils shall be left when the stringing operations are to

be stopped. These coils are to be removed carefully, and if another length

is required to be run out, a joint shall be made as per the

recommendations of the manufacturers.

5.6.3 Repairs to conductors, if necessary, shall be carried out during the running

out operations, with repair sleeves. Repairing of conductor surface shall

be done only in case of minor damage, scuff marks etc. keeping in view

both electrical and mechanical safe requirements. The final conductor

surface shall be clean smooth and without any projections, sharp points,

cuts, abrasions etc.

5.6.4 Conductor splices shall be so made that they do not crack or get damaged

in the stringing operation. The Contractor shall use only such

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equipment/methods during conductor stringing which ensures complete

compliance in this regard.

5.6.5 Derricks shall be used where roads, rivers, channels, telecommunication

or overhead power lines, railway lines, fences or walls have to be crossed

during stringing operations. It shall be seen that normal services are not

interrupted or damage caused to property. Shut down shall be obtained

when working at crossing of overhead power lines. The Contractor shall

be entirely responsible for the proper handling of the conductor, earthwire

and accessories in the field.

5.6.6 The sequence of running out shall be from top to downwards i.e. the

earthwire shall be run out first, followed by the conductors in succession.

Unbalances of loads on towers shall be avoided as far as possible.

5.6.7 The proposed transmission line may run parallel for certain distance with

the existing Transmission lines, which may remain, energised during the

stringing period. As a result there is a possibility of dangerous voltage

build up due to electromagnetic and electrostatic coupling in the pulling

wire, conductors and earthwires which although comparatively small

during normal operations can be severe during switching. It shall be the

Contractor’s responsibility to take adequate safety precautions to protect

his employees and others from this potential danger.

5.6.8 Towers during stringing shall be well guyed and steps may be taken by

Contractor to avoid damage. Proper T&P shall be made available to the

Employer by the Contractor for checking the tensions in the guy wires. All

the expenditure on account of the above work is deemed to be included in

the bid price and no extra payment shall be made for the same.

5.7 STRINGING OF CONDUCTOR AND EARTHWIRE

5.7.1 The stringing of the conductor shall be done by standard stringing method.

5.7.2 After being pulled, the conductor/earthwire shall not be allowed to hang in

the stringing blocks for more than 96 hours before being pulled to the

specified sag.

5.7.3 The stringing of Conductor shall be done as per initial stringing chart

provided by the Employer.

5.8 JOINTING

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5.8.1 All the joints on the conductor and earthwire shall be compression type, in

accordance with the recommendations of the manufacturer for which all

necessary tools and equipment like compressors, dies, processes etc.

shall have to be arranged by the Contractor. Each part of the joint shall be

cleaned by wire brush to make it free from rust or dirt etc. and properly

greased with anti corrosive compound if required, and as recommended

by the Contractor before the final compression is done with the

compressors.

5.8.2 All joints or splices shall be made at least 30 metres away from the

structures. No joints or splices shall be made in spans crossing over main

roads, Railways, small rivers with tension spans. During compression or

splicing operation the conductor shall be handled in such a manner as to

prevent lateral or vertical bearing against the dies. After pressing the joint

the aluminium sleeve shall have all corners rounded, burrs and sharp

edges removed and smoothened.

5.8.3 During stringing of conductor to avoid any damage to the joint, the

Contractor shall use a suitable protector with mid span compression joints

in case joints are to be passed over pulley blocks/aerial rollers. The size of

the groove of the pulley shall be such that the joint alongwith protection

can be passed over it smoothly.

5.9 Sagging-in-Operation

5.9.1 The conductor shall be pulled upto the desired sag and left in running

blocks for atleast one hour after which the sag shall be re-checked and

adjusted, if necessary before transferring the conductors from the running

blocks to the suspension clamps. The conductors shall be clamped within

36 hours of sagging in.

5.9.2 The sag will be checked in the first and the last span of the section in case

of sections upto eight spans and in one intermediate span also for

sections with more than eight spans. The sag shall also be checked when

the conductors have been drawn up and transferred from running blocks

to the insulator clamps.

5.9.3 The running blocks, when suspended from the transmission structure for

sagging shall be so adjusted that the conductors on running blocks will be

at the same height as the suspension clamp to which it is to be secured.

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5.9.4 At sharp vertical angles, the sags and tensions shall be checked on both

sides of the angle, the conductor and earthwire shall be checked on the

running blocks for equality of tension on both sides. The suspension

insulator assemblies will normally assume vertical positions when the

conductor is clamped.

5.9.5 Tensioning and sagging operations shall be carried out in calm weather

when rapid changes in temperatures are not likely to occur.

5.10 Tensioning and Sagging of Conductors and Earth wire

The tensioning and sagging shall be done in accordance with the

approved stringing charts before the conductors and earthwire are finally

attached to the towers through the earthwire clamps for the earthwire and

insulator strings for the conductor. The ‘Initial’ stringing chart shall be used

for the conductor and ‘final’ stringing chart for earthwire should be

employed for this purpose. Dynamometers shall be employed for

measuring tension in the conductor and earthwire. The dynamometers

employed shall be periodically checked and calibrated with the standard

dynamometer.

5.11 Clipping In

5.11.1 Clipping of the conductors in position shall be done in accordance with the

recommendations of the manufacturer. Conductor shall be fitted with

Preformed Armor Rods where it is made to pass through suspension

clamps.

5.11.2 The jumpers at the section and angle towers shall be formed to parabolic

shape to ensure maximum clearance requirements.

5.11.3 Fasteners in all fittings and accessories shall be secured in position. The

security clip shall be properly opened and sprung into position.

5.12 Fixing of Conductor and Earthwire Accessories

Vibration dampers for conductor & earthwire and other conductor &

earthwire accessories which are in bidder’s scope of supply, shall be

installed by the Contractor as per the design requirement and respective

manufacturer’s instructions within 24 hours of the conductor/earthwire

clamping. While installing the conductor and earthwire accessories, proper

care shall be taken to ensure that the surfaces are clean and smooth and

no damage shall occur to any part of the accessories.

5.13 Replacement

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If any replacements are to be effected after stringing and tensioning or

during maintenance, leg members and bracings shall not be removed

without reducing the tension on the tower with proper guying or releasing

the conductor. If the replacement of cross arms becomes necessary after

stringing, the conductor shall be suitably tied to the tower at tension points

or transferred to suitable roller pulleys at suspension points.

5.14 Permitted extra consumption of Line Materials

5.14.1 The bidder shall make every effort to minimise the breakages, losses, &

wastages of the line materials during erection. However while working out

the quantities of line materials, Employer shall permit the bidder extra

consumption of Conductor and Earthwire only upto the limit of 1%

The permitted extra consumption limit of 1% is inclusive of sag, stringing,

damage, losses & wastages etc. The quantity of conductor and earthwire

shall be worked out as per following norms.

(a) Quantity of Conductor = Line length as per detailed survey x

No. of phases (3) x No. of circuits.

(b) Quantity of Earthwire = line length as per detailed survey.

For other line materials, i.e. Disc Insulators, Hardware and Accessories for

Conductor and Earthwire, the actual quantity incorporated on transmission

line shall be approved.

5.14.2 The Contractor shall not be required to return to the Employer empty

Conductor and Earthwire drums as the same shall be deemed to become

his property.

5.15 Final Checking, Testing and Commissioning

After completion of the works, final checking of the line shall be done by

the Contractor to ensure that all the foundation works, tower erection, and

stringing have been done strictly according to the specifications and as

approved by the Employer. All the works shall be thoroughly inspected

keeping in view of the following main points:

(a) Sufficient backfilled earth is lying over each foundation pit and it is

adequately compacted.

(b) Concrete chimneys and their copings are in good finely shaped conditions.

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(c) All the tower members are correctly used, strictly according to final

approved drawing and are free of any defect or damage, whatsoever.

(d) All bolts are properly tightened and punched/tack welded.

(e) The stringing of the conductors and earthwire has been done as per the

approved sag and tension charts and desired clearances are clearly

available.

(f) All conductor and earthwire accessories are properly installed.

(g) All other requirements to complete the work like fixing of danger plate,

phase plate, number plate, anti climbing device, aviation signal (wherever

required) etc. are properly installed.

(h) Wherever required it should be ensured that revetment is provided.

(i) The original tracings of profile route alignment and tower, bill of material,

shop drawings of all towers are submitted to the Employer for reference

and record.

(j) The insulation of line as a whole is tested by the Contractor by providing

his own equipment, labour etc. to the satisfaction of the Employer.

(k) All towers are to be properly grounded as per requirements of the

specification.

(l) The line is tested satisfactorily for commissioning purpose.

6. General Technical Conditions

6.1 The following provisions shall supplement all the detailed technical

specifications and requirements brought out herein. The Contractor’s

proposal shall be based on the use of materials complying fully with the

requirements, specified herein.

6.2 Engineering Data

6.2.1 The furnishing of engineering data by the Contractor shall be in

accordance with the Schedule as specified in the Technical Specifications.

The review of these data by the Employer will cover only general

conformance of the data to the specifications and not a thorough review of

all dimensions, quantities and details of the materials, or items indicated or

the accuracy of the information submitted. This review by the Employer

shall not be considered by the Contractor, as limiting any of his

responsibilities and liabilities for mistakes and deviations from the

requirements, specified under these specifications.

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6.2.2 All engineering data submitted by the Contractor after review by the

Employer shall form part of the Contract document.

6.3 Drawings

In addition to those stipulated in clause regarding in general conditions,

the following also shall apply in respect of Contractors drawings.

6.3.1 All drawings submitted by the Contractor including those submitted at the

time of Bid shall be with sufficient detail to indicate the type, size,

arrangement, dimensions, material description, bill of materials, weight of

each component, break-up for packing and shipment, fixing arrangement

required, the dimensions required for installation and any other information

specifically requested in these specifications.

6.3.2 Each drawing submitted by the Contractor shall be clearly marked with the

name of the Employer, the specification title, the specification number and

the name of the Project. All titles, noting, markings and writings on the

drawings shall be in English. All the dimensions should be to the scale and

in metric units.

6.3.3 The drawings submitted by the Contractor shall be reviewed by the

Employer as far as practicable within 21 days and shall be modified by the

Contractor if any modifications and/or corrections are required by the

Employer. The Contractor shall incorporate such modifications and/or

corrections and submit the final drawings for approval within ten days. Any

delays arising out of failure by the Contractor to rectify the drawings in

good time shall not alter the contract completion date.

6.3.4 The drawings submitted for approval to the Employer shall be in

quadruplicate. One print of such drawings shall be returned to the

Contractor by the Employer marked "approved/approved with corrections".

The Contractor shall thereupon furnish the Employer additional prints as

may be required alongwith one reproducible in original of the drawings

after incorporating all corrections.

6.3.5 The work shall be performed by the Contractor strictly in accordance with

these drawings and no deviation shall be permitted without the written

approval of the Employer, if so required.

6.3.6 All manufacturing, fabrication and erection work under the scope of

Contractor, prior to the approval of the drawings shall be at the

Contractor’s risk. The Contractor may make any changes in the design

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which are necessary to conform to the provisions and intent of the

Contract and such changes will again be subject to approval by the

Employer.

6.3.7 The approval of the documents and drawings by the Employer shall mean

that the Employer is satisfied that:

(a) The Contractor has completed the part of the Works covered by the

subject document (i.e. confirmation of progress of Work).

(b) The Works appear to comply with requirements of Specifications.

In no case the approval by the Employer of any document does imply

compliance with all technical requirements nor the absence of errors in

such documents.

If errors are discovered any time during the validity of the Contract, then

the Contractor shall be responsible of their consequences.

6.3.8 Copies of drawings returned to the Contractor will be in the form of a print

with the Employer’s marking.

6.3.9 The following is the generic list of the documents and drawings that are to

be approved by the Employer:

(a) Detailed survey report and profile drawings showing ground clearance and

tower locations.

(b) Tower schedule for individual tower locations.

(c) Bill of material of towers and shop drawings.

(d) Soil investigation report.

6.4 Design Co-ordination

The Contractor shall be responsible for the selection and design of

appropriate material/item to provide the best co-ordinated performance of

the entire system. The basic design requirements are detailed out in this

Specification. The design of various components, sub-assemblies and

assemblies shall be so done that facilitates easy field assembly and

maintenance.

6.5 Design Review Meeting

The Contractor will be called upon to attend review meetings with the

Employer during the period of Contract. The Contractor shall attend such

meetings at his own cost at Patiala or at mutually agreed venue as and

when called for. Such review meeting will be held generally four times in a

year.

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6.6 Packing & Marking

6.6.1 All the materials shall be suitable protected, coated, covered or boxed and

crated to prevent damage or deterioration during transit, handling and

storage at Site till the time of erection. The Contractor shall be responsible

for any loss or damage during transportation, handling and storage due to

improper packing.

6.6.2 Each package shall be legibly marked by the Contractor at his expenses

showing the details such as description and quantity of contents, the name

of the consignee and address, the gross and net weights of the packages,

the name of the Contractor etc.

7. Erection Conditions

7.1 The following shall supplement the conditions already contained in the

other parts of these specifications and documents and shall govern that

portion of the work on this Contract to be performed at Site.

7.2 Regulation of Local Authorities and Statutes

7.2.1 The Contractor shall comply with all the rules and regulations of local

authorities during the performance of his field activities. He shall also

comply with the Minimum Wages Act, 1948, the payment of Wages Act

and of EPF act (all of the Government of India) and the rules made there

under in respect of any employee or workman employed or engaged by

him or his Sub-Contractor.

7.2.2 All registration and statutory inspection fees, if any, in respect of his work

pursuant to this Contract shall be to the account of the Contractor.

However, any registration, statutory inspection fees lawfully payable under

the provisions of the statutory laws and its amendments from time to time

during erection in respect of the transmission line, ultimately to be owned

by the Employer, shall be to the account of the Employer. Should any

such inspection or registration need to be re-arranged due to the fault of

the Contractor or his Sub-Contractor, the additional fees to such

inspection and/or registration shall be borne by the Contractor.

7.3 Contractor’s Field Operation

7.3.1 The Contractor shall keep the Employer informed in advance regarding his

field activity plans and schedules for carrying-out each part of the works.

Any review of such plan or schedule or method of work by the Employer

shall not relieve the Contractor or any of his responsibilities towards the

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field activities. Such reviews shall also not be considered as an

assumption of any risk or liability by the Employer or any of his

representatives and no claim of the Contractor will be entertained because

of the failure or inefficiency of any such plan or schedule or method of

work reviewed. The Contractor shall be solely responsible for the safety,

adequacy and efficiency or tools and plants and his erection methods.

7.4 Progress Report

7.4.1 Appropriate visual charts shall accompany the monthly progress report

detailing-out the progress achieved on all erection activities as compared

to the schedules. The report shall also indicate the reasons for the

variance between the scheduled and actual progress and the action

proposed for corrective measures, wherever necessary.

7.4.2 Facilities to be Provided by the Contractor

7.4.2.1 The Contractor shall provide all the construction equipment, tools, tackle

and scaffoldings required for construction, erection, testing and

commissioning of the transmission line covered under the Contract.

7.4.2.2 The Contractor shall provide necessary first-aid facilities for all his

employees, representatives and workmen working at the site.

7.5 Fire Protection

The work procedures that are to be used during the erection shall be

those, which minimise fire hazards to the extent practicable in line with

applicable laws, rules & regulations.

7.6 Security, Materials Handling and Storage

7.6.1 The Contractor shall have total responsibility for all equipment and

materials in his custody, stored, loose, semi-assembled and/or erected by

him at Site.

7.6.2.1 For all the supplies the Contractor shall be solely responsible for any

shortages or damages in transit, handling and/or in storage and erection at

Site. Any demurrage, wharfage and other such charges claimed by the

transporters, railways etc. shall be to the account of the Contractor.

7.7 Construction Management

Time is the essence of the Contract and the Contractor shall be

responsible for performance of his Works in accordance with the specified

construction schedule. If at any time, the Contractor is falling behind the

schedule for reasons attributable to him he shall take necessary action to

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make good for such delays by increasing his work force or by working

overtime or otherwise to accelerate the progress of the work and to comply

with schedule and shall communicate such actions in writing to the Employer,

satisfying that his action will compensate for the delay. The Contractor shall

not be allowed any extra compensation for such action.

7.8 Work and Safety Regulations

7.8.1 The Contractor shall ensure safety and well being of all the workmen,

materials plant and equipment belonging to him or to the others, working at

the Site and of Public at large. The Contractor shall comply with all safety

norms, rules & regulations as per Law / relevant legislations and as deemed

necessary by the Employer.

7.8.2 If the Contractor does not take all safety precautions and/or fails to comply

with the Safety Rules as prescribed under the applicable law for the safety of

the equipment, plant and personnel and the Contractor does not prevent

hazardous conditions which may cause injury to his own employees or

employees of other Contractors, or Employer or any other person at Site or

adjacent thereto, the Contractor shall be responsible for payment of

compensation to the Employer as per the following schedule:-

a) Fatal injury or Rs. 1,00,000/- Accident causing Death b) Major injuries or Rs. 20,000/- accident causing 25% per person or more permanent disability.

The above compensation will be applicable for death/ Injury to

any person whosoever.

Permanent disability shall have the same meaning as indicated in

Workmen’s Compensation Act. The compensation mentioned above shall

be in addition to the compensation payable to the workmen/employees

under the relevant provisions of the Workmen’s Compensation Act and

rules framed there under or any other applicable law as applicable from

time to time. In case the Employer is made to pay such compensation, the

Contractor will be liable to reimburse the Employer such amount (s)

addition to the compensation indicated above.

8.0 MANDATORY CONDITION

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The bidder or the authorised representative must visit the site of works

and its surroundings and obtain himself at his own responsibility and

expense, all information regarding terrain of the proposed lines, line route,

general site characteristics, crossings, accessibility, infrastructure details

and the factual position in respect of existing foundations/substations for

coordination purpose. The bidder is essentially required to furnish a

certificate in support of his having visited the site and acquainted himself

fully with the related conditions as per above, without which his tender will

not be considered.

The employer will assist the interested bidder to see and inspect the

site of works. For this purpose bidders are requested to contact the

following office:

CHIEF ENGINEER/TL,

Design Directorate Transmission,

B-2, Shakti Vihar, PSTCL,

Patiala.

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Activity Schedule for Package 1

The activity schedule, stating tentative completion period of each activity is

given below. In case the bidder wants to change this schedule, the

reasons for the same should be given.

Sr.No. Description of work. Tentative Completion Period.

1. Establishment of site office

1 month from the date of award of contract.

2. Detailed survey 3 month from the date of award of contract. 3. Approval of detailed

survey maps/profiles by PSTCL

2 weeks from the date of submission of correct route plan after removing objections, if any of this office.

4. Geo-technical & Soil Investigation and submission of reports.

2 weeks from the date of approval of survey maps/profiles.

5. Approval of soil investigation reports.

1 week from receipt of soil investigation reports.

6. Fabrication & testing of prototype of each type of tower/structure.(if req.)

2 months from the date of award of contract.

7. Submission of BOM & shop drawing of towers.

1 week from the approval of proto type.

8. Approval of BOM & shop floor drawings.

1 week from the date of submission.

9. Completion of foundation work.

Within 10 months of award of contract.

10. Completion of erection of towers and supply of complete line material.


11. Completion of stringing work.


12. Testing & Commissioning Within 14 months of award of contract.

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1 week form receipt of soil investigation reports.











11 Completion of stringing work.



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6. Fabrication & testing of prototype of each type of tower/structure(if req.)













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SECTION – III

PART – B

SCOPE FOR CONTRACTOR SUPPLIED LINE MATERIALS

1. General Information

The general scope for supply of all the material / equipment to be used for

complete execution of the 220 KV transmission lines packages is given in

this section.

2. Scope

2.1 The material to be supplied as covered in this volume shall be designed,

manufactured and tested as per the requirement specified.

2.2 The materials covered shall be supplied complete in all respects,

including all components, fittings and accessories which are necessary or

are used for their efficient performance and satisfactory maintenance

under the various operating and atmospheric conditions. Such parts shall

be deemed to be within the scope of the Contract, whether specifically

included or not in the Specification or in the Contract Schedules. The

Contractor shall not be eligible for any extra charges for such fittings etc.

The details of the material required for the above mentioned lines

under this specification are as follows and the tentative quantity of the

same are mentioned in Price Schedules of respective Packages on line-

wise basis.

i) Conductor / Tower material

ii) Earthwire

iii) Insulators

iv) Hardware Fittings

v) Accessories for Conductor and Earthwire

3 Weights and Measures

All weights and measures shall be in System International (S.I.) units. All

fasteners shall be of Metric size only.

4 General Technical Conditions

4.1 The following provisions shall supplement all the detailed technical

specifications and requirements brought out in the accompanying

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Technical Specifications. The Bidder’s proposal shall be based on the use

of equipment and materials complying fully with the requirements,

specified herein

4.2 Equipment Performance Guarantee

4.2.1 The performance requirements of the items are detailed separately in this

Specification. These guarantees shall supplement the general

performance guarantee provisions covered under General Terms and

conditions of Contract in stipulated in the bidding documents.

4.2.2 Penalties for not meeting specified performance shall be assessed and

recovered from the Contractor. Such penalties shall be in addition to

damages, if any payable under any other clause of Conditions of Contract.

4.3 Engineering Data

4.3.1 The furnishing of engineering data by the Contractor shall be in

accordance with the provisions of the contract specifications. The review

of these data by the Employer will cover only general conformance of the

data to the specifications and drawings. This review by the Employer may

not indicate to thorough review of all dimensions, quantities and details of

the equipment, materials, any devices or items indicated or the accuracy

of the equipment, materials, any devices or items indicated or the

accuracy of the information submitted. This review and/or approval by the

Employer shall not be considered by the Contractor, as limiting any of his

responsibilities and liabilities for mistakes and deviations from the

requirements, specified under this Specifications and documents.

4.3.2 All engineering data submitted by the Contractor after final process

including review and approval by the Employer shall form part of the

Contract Document and the entire works performed under these

Specifications shall be performed in strict conformity, unless otherwise

expressly requested by the Employer in writing.

4.4 Drawings

4.4.1 All drawings submitted by the Contractor including those submitted at the

time of bid shall be in sufficient detail to indicate the type, size

arrangement, dimensions, material description. Bill of Materials, weight of

each component, break-up for packing and shipment, fixing arrangement

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required, the dimensions required for installation and any other information

specifically requested in the Specifications.

4.4.2 Each drawing submitted by the Manufacture shall be clearly marked with

the name of the Employer, the unit designation, the specification title, the

specification number and the name of the Project. All titles, notings,

markings and writings on the drawing shall be English. All the dimensions

should be to the scale and in metric units.

4.4.3 The drawings submitted by the Manufacturer shall be reviewed by the

Employer as far as practicable within three (3) weeks and shall be

modified by the Manufacturer if any modifications and/or corrections are

required by the Employer. The Manufacturer shall incorporate such

modifications and/or corrections and submit the final drawings for approval

within shortest possible time / as per directions of the PSTCL.

4.4.4 The drawings submitted for approval to the Employer shall be in

quadruplicate. One print of such drawings shall be returned to the

Manufacturer by the Employer marked “approved/approved with

corrections”. The Manufacturer shall there upon furnish the Employer

additional print, as stipulated in Technical Specification, of the drawings

after incorporating all corrections.

4.4.5 Further work by the Manufacturer shall be strictly in accordance with these

drawings and no deviation shall be permitted without the written approval

of the Employer, if so required.

4.4.6 All manufacturing and fabrication work in connection with the

equipment/material prior to the approval of the drawings shall be at the

Manufacturer’s risk. The Manufacture may make any changes in the

design which are necessary to make the equipment conform to the

provisions and intent of the Contract and such changes will again be

subject to approval by the Employer. Approval of Manufacturer’s drawing

or work by the Employer shall not relieve the Manufacturer of any of his

responsibilities and liabilities under the Contract.

4.5 Manufacturing Schedule

The Manufacturer shall submit to the Employer his manufacturing, testing

and delivery schedules of various items within thirty (30) days from the

date of the Letter of Award in accordance with the delivery requirements

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stipulated. Schedules shall also include the materials and items purchased

from outside Manufacturers, if any.

4.6 Reference Standards

4.6.1 The Codes and/or Standards referred to in Specifications shall govern, in

all cases wherever such references are made. In case of a conflict

between such codes and/or Standards and the specifications, latter shall

govern. Such codes and/or Standards, referred to shall mean the latest

revisions, amendments/changes adopted and published by the relevant

agencies. In case of any further conflict in this matter, the same shall be

referred to the Employer whose decision shall be final and binding.

4.6.2 Other internationally acceptable Standards which ensure equipment or

better performance than those specified shall also be accepted. The

copies of the same shall have to be furnished by the Bidder.

4.7 Quality Assurance

To ensure that the equipment under the scope of this Contract whether

manufactured within the Contractor Works or at his Sub-Contractor’s

premises is in accordance with the specifications, the Contractor shall

adopt suitable Quality Assurance Programme to control such activities at

all points necessary.

4.7.1 A Quality Assurance Programme of the Contractor shall generally cover but

not be limited to the following:-

a) His organization structure for the management and implementation

of the proposed Quality Assurance Programme

b) Documentation control system.

c) Qualification data for key personnel.

d) The procedure for purchases of materials. Parts /components and

selection of sub-contractor’s services including vendor analysis, source

inspection, incoming raw material inspection, verification of material

purchases etc.

e) System for shop manufacturing including process controls.

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

g) Control of calibration and testing of measuring and testing

equipments.

h) Inspection and test procedure for manufacture.

i) System for indication and appraisal of inspection status.

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j) System for quality audits.

k) System for authorizing release of manufactured product to the

Employer.

l) System for maintenance of records.

m) System for handling, storage and delivery and

n) A Quality Plan detailing out the specific quality control procedure

adopted for controlling the quality characteristics of the product.

4.7.2 Quality Assurance Documents

The Contractor shall be required to submit all the Quality Assurance

Documents as stipulated in the Quality Plan at the time of Employer’s

inspection of equipment/material. The Employer or his duly authorized

representatives reserves the right to carry out Quality Audit and Quality

surveillance of the systems and procedures of the Contractor’s/his

vendor’s Quality Management and Control Activities.

4.7.3 Employer’s Supervision

To eliminate delays and avoid disputes and litigation, it is agreed between

the parties to the Contractor that all matters and questions shall be

resolved in accordance with the provisions of this document.

The manufacturing of the product shall be carried out in accordance with

specifications. The scope of the duties of the Employer, pursuant to the

contract, will include but not be limited to the following:-

a) Interpretation of all the terms and conditions of these Documents and

Specifications.

b) Review and interpretation of all the Contractor’s drawings, engineering

data, etc.

c) Witness or authorize his representative to witness tests at the

manufacture’s works or at site, or at any place where work is

performed under the Contract.

d) Inspect, accept or reject any equipment, material and work under the

Contract, in accordance with the Specifications.

e) Issue certificate of acceptance and/or progressive payment and final

payment certificate.

f) Review and suggest modification and improvement in completion

schedules from time to time; and

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g) Supervise the Quality Assurance Programme Implementation at all

stages of the works.

4.7.4 Inspection, Testing and Inspection Certif icate

i) The Employer, his duly authorized representative and/or outside

inspection agency acting on behalf of the Employer shall have at all

reasonable times access to the Contractor’s premises or works and shall

have the power at all reasonable times to inspect and examine the

materials and workmanship of the product during its manufacture and if

part of the product is being manufactured or assembled at other premises

or works, the Contractor shall obtain from the Employer and/or his duly

authorized representative permission to inspect as if the

equipment/materials were manufactured or assembled on the Contractor’s

own premises or works.

ii) The Contractor shall give the Employer fifteen (15) days written notice

of any material being ready for testing. Such tests shall be to the

Contractor’s account except for the expenses of the Inspector. The

Employer , unless witnessing of the tests is virtually waived, will attend

such tests within fifteen(15) days of the date of which the equipment is

notified as being ready for test/inspection of on a mutually agreed date,

failing which the Contractor may proceed with the test which shall be

deemed to have been made in the Inspector’s presence and he shall

forthwith forward to the Employer duly certified copies of tests in triplicate.

iii) In case of any objection to any drawings and all or any equipment and

workmanship which in Employer’s opinion is not in accordance with the

Contract the same shall be brought out in the Inspection Report by the

Employer at the time of Inspection and the Contractor shall give due

consideration to such objections and shall make the modifications that

may be necessary to meet the said objections / offer the material afresh.

iv) In all cases where the Contractor provides for tests, whether at the

premises or works of the Contractor or of any Sub-Contractor, the

Contractor except where otherwise specified shall provide free of charge

items such as labour, materials, electricity, fuel, water, stores, apparatus

and instruments, as may be reasonably demanded by the Employer

Inspector or his authorized representative to carry out effectively such

tests of the equipment in accordance with the Contract and shall provide

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facilities to the Employer Inspector or to his authorized representative to

accomplish testing.

v) The inspection by Employer and acceptance of material shall in no way

limit the liabilities and responsibilities of the Contractor in respect of the

requirements of the Contract.

5. Technical Description

The technical description of Conductor, Earthwire, Insulators, Hardware

fittings and Accessories shall be as specified in other parts of the

Technical Specifications .

6 Tests and Standards

6.1 Tests

The following type, acceptance and routine tests and tests during

manufacture shall be carried out on the material. For the purpose of this

clause:

6.1.1 Type Tests shall mean those tests which are to be carried out to prove the

process of manufacture and general conformity of the material to this

Specification. Type test certificates indicating conformity of the material as

per relevant Standard/PSTCL specification are required to be submitted

alongwith the bid as per requirement of this specification.

6.1.2 Acceptance Tests shall mean those tests which are to be carried out on

samples taken from each lot offered for pre-despatch inspection, for the

purposes of acceptance of that lot.

6.1.3 Routine Tests shall mean those tests, which are to be carried out on the

material to check requirements which are likely to vary during production.

6.1.4 Tests during Manufacture shall mean those tests, which are to be carried

out during the process of manufacture and end inspection by the

Contractor to ensure the desired quality of the end product to be supplied

by him.

6.1.5 The norms and procedure sampling for these tests will be as applicable

ISS / these specifications.

6.1.6 The standards and norms to which these tests will be carried out are listed

against them. Where a particular test is a specific requirement of this

Specification, the norms and procedure of the test shall be as specified in

Annexure-‘A’ .

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6.1.7 For all type and acceptance tests, the acceptance values shall be the

values specified in this Specification or guaranteed by the Bidder, as

applicable. The tests and standards are specified in the other

parts of the Technical Specification.

7.0 Technical Particulars.

7.1 Technical Particulars of the various items shall be furnished as per the

relevant schedules in all copies of bid. The Bidders shall also furnish any

other schedule informations as in their opinion is needed to give full

description and details to judge the items(s) offered by them.

7.2 The data furnished in Technical Particulars should be the minimum or

maximum value (as per the requirement of the specification) required. A

Bidder may guarantee a value more stringent than the specification

requirement. However, for testing purposes or from performance point of

view, the material shall be considered performed successfully if it achieves

the Minimum/Maximum value required as per the technical specification.

No preference whatsoever shall be given to the bidder offering,

better/more stringent values than those required as per specification.

8.0 Service Condition

Equipment/material to be supplied against this specification shall be

suitable for satisfactory continuous operation under tropical conditions as

specified below:

1. Max. ambient temperature (°Celsius) 50

2. Min. ambient temperature (°Celsius) (- )2.5

3. Relative humidity (%) – Range 10-100

4. Max. wind velocity (m/sec) 47

5. Max. altitude above mean sea level (meters) 1000

6. Isokeraunic level 50

7. Moderately hot and humid tropical climate Yes

conducive to rust and fungus growth.

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SECTION – III

Part -C

SURVEY & SOIL INVESTIGATION

1. General Information & Scope Of Work

1.1 The technical specifications covers detailed survey including route

alignment, profiling, tower spotting, optimization of locations, check

survey, contouring, and soil investigation for the transmission lines/ part

of the transmission lines covered under this specification .

1.1.1 The scope of work inter-alia shall include the following:-

a. Detailed Survey using GPS, Total Work stations, long range scanners

& Digital theodolites of reasonable accuracies , inter-alia including :

i. Digitised profiling along the selected route along with plan details.

ii. Computer aided tower spotting & optimization

iii. Soil resistivity measurement along the route

b. Check survey with contouring wherever required

c. Soil Investigation

d. Preparation of Survey reports including estimation of Bill of Quantities,

identification and explanation of route constraints (like Forest,

Animal/Bird sanctuary,oil pipe line/underground inflammable pipe lines

etc.), infrastructure details available en-route etc.

1.2 The Provisional quantities for the scope of work are indicated in relevant

Price Schedules. The final quantities for route alignment & detailed survey

(quantities in “kms” unit) shall be the route length along the approved route

alignment. For contouring at undulated/hilly tower locations and soil

investigations (quantities in “Locs.” unit), the actual quantities to be

executed shall be decided by Site Engineer-in-charge (Sr.XEN of

Concerned TLSC Division) during execution stage and the final quantities

shall be as approved by Superintending Engineer of concerned TLSC

Circle. The route alignment, detailed survey, including profiling & tower

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spotting, contouring, soil investigation etc shall be carried out by the

Contractor as per the technical specifications stipulated herein.

1.3 The Contractor must note that the Employer shall not be responsible for

loss or damage to properties, trees etc. due to contractor’s work during

survey. The Contractor shall indemnify the Employer for any loss or

damage to properties, trees etc. during the survey work.

1.4 The Contractor should note that Employer will not furnish the NRSA

satellite imageries or topographical maps prepared by survey of India but

will make available assistance that may be required in obtaining these by

providing letters of recommendation to the concerned authorities.

1.5 The work shall be carried out by the contractor using modern surveying

techniques. The bidder shall indicate in his offer, the detailed description of

the procedure to be deployed. The details of the equipment & facilities

including soft wares for image processing, computer aided tower spotting

etc. available with the bidder or his associates shall also be furnished with

the bid.

1.8 After carrying out the detailed survey and soil investigations, the contractor

shall estimate complete BOQ (Bill of Quantities) of the transmission lines

on Package-wise basis and submit the same (as per the BOQ format

enclosed with the Specifications) to the Employer.

2. Route Alignment

2.1 Wherever the route Alignment has already been carried out for the line

using satellite imageries of NRSA (PAN & LISS-III merged product) and

Survey of India topographical maps (scale 1:50000), any changes

necessitated during execution stage in the route alignment, same shall be

carried out by the contractor using satellite imageries / topographical

maps.

2.2 Requirement of Transmission Line Routing (for changes if any

necessitated on account of site constrains etc.):

2.2.1. The Re-alignment, if any required, of the transmission line shall be most

economical from the point of view of construction and maintenance. The

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contractor shall identify & examine alternative route alignments and

suggest to the Employer the optimal route alignment.

2.2.2. Routing/Re-routing of transmission line through protected/reserved forest

area should be avoided. In case it is not possible to avoid the forests or

areas having large trees completely, then keeping in view of the overall

economy, the route should be aligned in such a way that cutting of trees is

minimum.

2.2.3. The route should have minimum crossings of Major river, Railway lines,

National/State highways, overhead EHV power line and communication

lines.

2.2.4. The number of angle points shall be kept to minimum.

2.2.5. The distance between the terminal points specified shall be kept shortest

possible, consistent with the terrain that is encountered.

2.2.6. Marshy and low lying areas, river beds and earth slip zones shall be

avoided to minimize risk to the foundations.

2.2.7. It would be preferable to utilize level ground for the alignment.

2.2.8. Crossing of power lines shall be minimum. Alignment will be kept such as

to avoid induction problems on the lower voltage lines.

2.2.9. Crossing of communication line shall be minimized and it shall be

preferably at right angle. Proximity and parallelism with telecom lines shall

be eliminated to avoid danger of induction to them.

2.2.10. Areas subjected to flooding such as nalah shall be avoided.

2.2.11. Restricted areas such as civil and military airfield shall be avoided. Care

shall also be taken to avoid aircraft landing approaches.

2.2.12. All alignment should be easily accessible both in dry and rainy seasons to

enable maintenance throughout the year.

2.2.13. Certain areas such as quarry sites, gardens & nurseries which will present

the Employer problems in acquisition of right of way and way leave

clearance during construction and maintenance should be avoided.

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2.2.14. Angle points should be selected such that shifting of the point within 100 m

radius is possible at the time of construction of the line.

2.2.15. The line routing should avoid large habitations, densely populated areas,

Forest, Animal/Bird sanctuary, reserve coal belt areas, oil pipe

line/underground inflammable pipe lines etc. to the extent possible.

2.2.16. The areas requiring special foundations and those prone to flooding

should be avoided.

2.3 For examination of the alternatives & identification of the most appropriate

route, besides making use of information/data/details available/extracted

through Survey of India Topographical maps and computer-aided

processing of NRSA’s satellite imagery, the contractor shall also carryout

reconnaissance/preliminary survey as may be required for verification &

collection of additional information /data /details.

2.4 The contractor shall submit his preliminary observations & suggestions

along with various information/ data / details collected and also processed

satellite imagery data, scanned topographical map data marked with the

alternative routes etc. The final evaluation of the alternative routes shall be

conducted by the contractor in consultation with concerned Sr.XEN/ SE

TLSC and optimal route alignment shall be proposed by the contractor.

During Site visit and field verification to be conducted by the contractor the

Employer’s representative may join for the proposed route alignment.

2.5 Final digitized route alignment drawing with latest topographical and other

details/features including all rivers, railway lines, canals, roads etc. up to 4

kms on both sides of selected route alignment shall be submitted by the

contractor for Employer’s approval along with report containing other

information/details as mentioned above.

2.6 Changes in the route alignment, if any, during detail survey, shall be

incorporated in the final digitized route alignment drawings.

3. Detailed Survey

3.1 The detailed survey shall be carried out using GPS, Total stations, digital

theodolites etc. along the approved route alignment.

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3.2 Soil resistivity, along the route alignment shall be measured in dry weather

by four electrode method keeping inter-electrode spacing of 50 mtrs. For

calculating soil resistivity formula 2πar ( Where a=50 m and r= megger

reading in ohms) shall be adopted. Measurement shall be made at every 2

to 3 km along the length of the route. In case soil characteristics changes

within 2 to 3 km, values shall have to be measured at intermediate

locations also. Megger reading and soil characteristics should also be

indicated in the soil resistivity results.

3.3 Route Marking

3.3.1. The route of the transmission line shall be recorded using GPS of

positional accuracy less than 3m.

3.3.2. The co-ordinates of all the angle points as well as other important

crossings, landmarks etc. shall be recorded using GPS for easy relocating.

3.3.3. At the starting point of the commencement of route survey the co-

ordinates shall be recorded. The co-ordinates of the location of the survey

instrument shall also be recorded. Further, the co-ordinates at prominent

position at intervals of not more than 750 meter along the transmission line

to be surveyed up to the next angle point shall also be recorded. Wherever

the line alignment crosses the EHT line, Railway line, P&T line or roads,

the contractor shall record co-ordinates on the points of crossing.

Wherever line route alignment passes over permanent land marks such

as rock, boulders, culverts etc. suitable white paint marks with directional

markings shall be made and co-ordinates recorded.

3.4 Profiling

3.4.1. The complete profiling along the route shall be carried out using modern

surveying equipments viz. total stations, GPS, digital theodolite, long

range scanners etc. Reference levels at every 20 metres along the route

are to be recorded. R/Ls at other undulations along the route as well as in

the route plan and other enroute details viz. crossings, building &

structures, trees & other infrastructure etc shall also be recorded. Areas

along the route, which in the view of the contractor, are not suitable for

tower spotting, shall also be marked.

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3.4.2. The complete profiling details shall be digitized and the data shall be

prepared & stored in the format compatible to computer-aided tower

spotting software.

A printed/plotted output of the digitized profiling shall be submitted by the

contractor to Employer’s site-in-charge (Sr.XEN of concerned TLSC Divn.)

for review before taking up computer-aided tower spotting.

3.5 Optimisation of Tower Location / Tower Spotting

3.5.1. Optimisation of tower locations shall be done by the contractor using

computer-aided tower spotting software .

3.5.2. The sag-tension characteristics of the conductor as well as tower spotting

data shall be furnished by the Employer to the contractor during execution

stage. Sag template curves, if any required for tower spotting, shall be

prepared by the contractor.

3.5.3. Tower Spotting

While profiling & spotting the towers, the following shall be borne in mind:

a) Span

The number of consecutive spans between the section points shall not

exceed 10 spans. A section point shall comprise of tension point with B

type (2-D-30) or C Type (2-D-60) as applicable.

b) Extension/Truncation

An individual span shall be as near to the normal design span as possible.

In case an individual span becomes too short with normal supports on

account of undulations in ground profile, one or both the supports of the

span may be extended by inserting standard body.

c) Loading

There shall not be any upward force on suspension towers under normal

working conditions and the suspension towers shall support at least the

minimum weight span as provided in the designs. In case uplift is

unavoidable, it shall be examined if the same can be overcome by adding

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standard body extensions to the towers failing which tension towers

designed for the purpose shall be deployed at such positions.

d) Road Crossing

At all important road crossings, the tower shall be fitted with tension

insulator strings but the ground clearance at the roads under maximum

temperature and in still air shall be such that even with conductor broken

in adjacent span, ground clearance of the conductor from the road

surfaces will not be less than specified. At all national highways crossing

span will not be more than 250 meters.

e) Railway Crossings

All the railway crossings coming-enroute the transmission line shall be

identified by the Contractor. At the time of detailed survey, the railway

crossings shall be finalised as per the regulation laid down by the Railway

Authorities / Indian Electricity Rules. The following are the important

features of the prevailing rules & regulations :

i) The crossings shall be supported on B(2-D-30) or C(2-D-60) type tower on either side depending on the merits of each case.

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

iii) The minimum distance of the crossing tower shall be at least equal to the height of the tower plus 6 meters away measured from the centre of the nearest railway track.

iv) No crossing shall be located over a booster transformer, traction switching station, traction sub-station or a track cabin location in an electrified area.

v) Minimum ground clearance above rail level of the lowest portion of any conductor under condition of maximum sag shall be maintained at 15.40 m for 220 kV transmission lines.

vi) The crossing span will be limited to 300 meters.

f) River Crossings

In case of major river crossing, towers shall be of suspension type along

with anchor towers of C type tower on either side of the main river

crossing. For navigable rivers, clearance required by navigation authority

shall be provided. For non navigable river, clearance shall be reckoned

with respect to highest flood level (HFL).

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g) Power line Crossings

Where the line is to cross over another line of the same voltage or lower

voltage, A type tower with suitable extensions shall be used. Provisions to

prevent the possibility of its coming into contact with other overhead lines

shall be made in accordance with the Indian Electricity Rules, 1956 as

amended up-to-date. In order to reduce the height of the crossing towers,

it may be advantageous to remove the ground-wire of the line to be

crossed (if this is possible and permitted by the Employer of the line to be

crossed).

Minimum clearance in meters between lines when crossing each other:

Sl. No.

Nominal System Voltage

66 KV 132KV 220KV 400KV 765KV/ 800 KV

1 66 KV 2.44 3.05 4.58 5.49 7.94

2 132KV 3.05 3.05 4.58 5.49 7.94

3 220KV 4.58 4.58 4.58 5.49 7.94

4 400KV 5.49 5.49 5.49 5.49 7.94

5 765 / 800 KV 7.94 7.94 7.94 7.94 7.94

For power line crossings of voltage level of 132 kV and above, angle

towers shall be provided adjacent to A type tower on either side of the

Power line crossing which can be used in temporary dead end condition

with proper guying to facilitate stringing of the power line crossing

sections separately on obtaining line shutdowns.

h) Telecommunication Line Crossings

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

deviation to the extent of 30 degree may be permitted under exceptionally

difficult situations.

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

referred to the authority in charge of the telecommunication System. On a

request from the Contractor, the permission of the telecommunication

authority may be obtained by the Employer.

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Also, in the crossing span, power line support will be as near the

telecommunication line as possible, to obtain increased vertical clearance

between the wires.

i) Details En-route

All topographical details, permanent features, such as trees, building etc.

17.5 m for 220 KV D/C line on either side of the alignment shall be detailed

on the profile plan.

3.6 Clearance from Ground, Building, Trees etc.

Clearance from ground, buildings, trees and telephone lines shall be

provided in conformity with the Indian Electricity Rules, 1956 as amended

upto date.

3.6.1. The Contractor shall count, mark and put proper numbers with suitable

quality of paint at his own cost on all the trees that are to be cut by the

Employer at the time of actual execution of the work as detailed below.

Contractor may please note that Employer shall not pay any compensation

for any loss or damage to the properties or for tree cutting due to

Contractor’s work.

3.6.2. To evaluate and tabulate the trees and bushes coming within 17.5 m for

220 KV D/C line on either side of the central line alignment the trees will

be numbered and marked with quality paint serially from angle point 1 (I)

onwards and the corresponding number will be painted on the stem of

trees at a height of 1 meter from ground level. The trees list should contain

the following:

a) Girth (circumferences) measured at a height of 1 meter from ground

level.

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

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

d) The bushs and under growth encountered within the 35 m for 220 kV

line should also be evaluated with its type, height, girth and area in

square meters, clearly indicating the growth in the tree/bush statement.

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3.6.3. The contractor shall also intimate the Employer his assessment about the

likely amount of tree & crop compensation etc. required to be paid by the

Employer during execution stage. This assessment shall be done

considering prevailing practices/guidelines, local regulations and other

enquiries from local authorities.

3.6.4. The Contractor shall also identify the forest/non forest areas involved duly

authenticated by concerned authorities.

a) A statement of forest areas with survey/compartment Nos.(all type of

forest RF/PF/Acquired forest/Revenue forest/Private forest/Forest as

per dictionary meaning of forest etc.)

b) A statement of non-forest areas with survey/compartment nos.

c) Tree cutting details(Girth wise & specie wise)

d) Marking of forest areas with category on topo sheets 1:2,50,000

showing complete line route, boundaries of various forest divisions and

their areas involved.

e) Village forest maps of affected line and affected forest area and

marking of the same.

f) Forest division map showing line and affected forest area.

3.6.5 The Contractor shall finalize the forest clearance proposal on the

prescribed format duly completed in all respects for submission by the

Employer to the Forest Department.

3.7 Preliminary Schedule

The profile sheets showing the locations of the towers together with

preliminary schedules of quantities indicating tower types, spans, angle of

deviation, crossing & other details etc. shall be submitted by the contractor

for review & approval by the Employer’s site-in-charge ( concerned

Sr.XEN /TLSC)

3.8 Check Survey of Tower Locations

3.8.1. The check survey shall be conducted to locate tower locations on ground

conforming to the approved profile and tower schedule.

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3.8.2. The co-ordinates of all the tower locations shall also be recorded using

GPS of positional accuracy less than 3 m for easy relocating. The position

of all tower locations shall be marked in the final digitized route alignment

drawing with relative distances from any permanent bench mark area.

3.9 Contouring at hilly/undulated locations

3.9.1. The levels up or down of each pit centre with respect to centre of tower

location shall be recorded at intervals of 2m using total

stations/GPS/digital theodolite and digitized contour plans shall be made.

Based on the digitized elevation plans, the quantities of benching &

protection work shall be optimized using suitable computer-aided

techniques/software.

3.10 The changes desired by the Employer in the preliminary tower schedule

or as may be required based on detailed survey of tower locations &

contouring by the contractor, shall be carried out by the contractor and the

final tower schedule shall be submitted for approval of Employer. The

tower schedule shall show position of all type of towers, span length, type

of foundation for each tower, benching & revetment requirement, deviation

at all angles, crossings & other details etc.

3.11 Survey Report

3.11.1. Complete BOQ of the transmission lines as per format enclosed with this

technical specifications shall be furnished in the survey report.

3.11.2. Each angle point locations shall be shown with detailed sketches showing

existing close by permanent land marks such as specific tree(s), cattle

shed, homes, tube wells, temples, electric pole/tower, telephone pole,

canal, roads, railway lines etc. The relative distance of land marks from the

angle points and their bearings shall be indicated in the sketch. These

details shall be included in the survey report.

3.11.3. Information w.r.t infrastructure details available en-route, identification and

explanation of route constraints, etc shall also be furnished in the Survey

report and shall inter-alia include the following:

3.11.3.1. Information regarding infrastructural facilities available along the final route

alignment like access to roads, railway stations, construction material

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sources (like quarry points for stone, sand and availability of construction

water), labour, existing transport facilities , fuel availability etc. shall be

furnished in the survey report.

3.11.3.2. All observations which the Contractor thinks would be useful to the

construction of the transmission lines mentioned under scope of work are

to be reported.

3.11.3.3. Suggestions regarding location for setting up stores during line

construction in consultation with Employer’s representative shall also be

provided by the contractor.

3.11.3.4. Some portions of the line may require clearance from various authorities.

The Contractor shall indicate the portion of the line so affected, the nature

of clearance required and the name of concerned organizations such as

local bodies, municipalities, P&T (name of circle), Inland navigation,

Irrigation Department, Electricity Boards and Zonal railways, Divisional

Forest Authorities etc.

3.11.4. All the requisite data for processing the case for statutory clearances such

as PTCC, Forest and Railway shall be provided along with the report.

4. Geotechnical Investigations

4.1 General

4.1.1. These specifications provide general guidelines for geotechnical

investigation of normal soils. Information required for locations with special

foundations shall be obtained by Contractor and furnished to Employer.

4.2 Scope

4.2.1. The scope of work includes soil investigations/ furnishing bore log data at

various tower locations. The Soil investigation report/ bore log data will be

submitted to the SE/ Transmission Design, PSTCL, Patiala for foundation

decision in case sub-soil water level is found to be above 6 m. The bore

log data shall indicate the sub-soil water level, nature of soil strata and

bearing capacity of the soil. The bore log data shall be furnished for all

locations on the approved route plan.

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4.2.2. Contractor shall carry out all work expressed and implied in these

specifications in accordance with requirements of the specification.

4.2.3. It is essential that equipment and instruments be properly calibrated at the

commencement of the work. If the Employer desires to witness such tests,

Contractor shall arrange for the same.

4.3 Codes and Standards for Geotechnical Investigat ions

All work shall be carried out in accordance with the relevant Indian

Standards and Codes.

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SECTION –III

PART – D

TECHNICAL SPECIFICATION OF ACSR ‘ZEBRA’

1. SCOPE & QUALIFYING CRITERIA :

This specification covers manufacture, testing before dispatch, supply

& delivery of ACSR Zebra having Nominal Aluminium Area 420 mm sq.,

54/7/3.18mm to be delivered in good condition at any destination railway

station in Punjab. The supplier shall be responsible for the said delivery of

material to the correct railhead in accordance with the dispatch instructions to

be issued after successful material inspection. The conductor should bear

either ISI certification or PQM (Punjab Quality Mark)

The tendered prices shall cover the cost of material utilized/destroyed

while carrying out various tests as specified in this specification or in the

relevant ISS to which the material offered shall conform and no extra payment

shall be due for the material so destroyed during testing .

In case the Contractor is a Tower Manufacturer then the manufacturer

from whom he proposes to procure Conductor should have capacity to

manufacture at least 2000 Km 61 strand ACSR / AAAC per year and should

have supplied at least 500 Km ACSR Zebra and/or Moose during the last two

years. Certificate of a Chartered Accountant / Engineer for capacity shall be

furnished with the bid. In addition to this Performance Certificate for supply of

at least 300 Km ACSR Zebra and/or Moose from any SEB / utility shall also

be furnished with the Bid. On Financial side, the average Turnover of the

manufacturer for the last three financial should be min.20 Crores and he

should have liquid assets and / or evidence of access to or availability of

credit facilities of not less than Rs. 2 Crores. Documentary proof for these

shall also be attached with the bid.

2. STANDARDS:

The conductor shall comply in all respects with the IS-398 (Part-2):1996 with

latest amendments, if any, and also the technical specification detailed

therein. Offers conforming to the standard other than IS-398(Part-2): 1996

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shall be accompanied by the English version of the relevant standard in

support of the guaranteed particulars as given in GTPs.

3. MATERIAL:

3.1 The conductor shall be constructed of hard drawn aluminium and

Galvanized steel wires which have the mechanical and electrical properties

specified in table 1&2 of IS 398 (Part-2) 1996. The conductor to be procured

against this specification is to be installed on 220 KV transmission lines,

hence special care shall be taken during its manufacture to avoid any defects

on conductor. The raw material used for the manufacture of the conductor

shall be EC Grade Aluminium rods conforming to IS-5484, 1978 and

Galvanised steel wire drawn from high carbon steel rods procured by either

acid or base open hearth process, electric furnace or basic oxygen process.

The Mechanical properties of wire shall comply with requirements, given in

table 2 of IS-398(Part-2)1996. The zinc used for galvanizing should be

electrolyte high grade zinc having purity not less than 99.95%. It shall conform

to satisfy all the requirements. IS 209:1992. Zinc coating on steel wire may

be applied by the hot process or electrolytic Process. The stranding of

conductor be completed in single operation . The tenderer shall submit

documentary proof of their capability of making 54 strands conductor in single

operation. The conductor drum should bear ISI Monogram mark or PQM

mark in conformation to ISI/PQM material supplied.

3.2 The responsibility for procurement of good quality raw material shall be

solely of supplier and in any case assistance for the procurement of raw

material not controlled by the Govt. shall not be provided by the Board and

delivery programme shall not be affected due to non supply of raw material.

The supplier will have to ensure adequate quantity of good quality un-

controlled raw material in their stock so that the progress of work is not

hampered. No extension in delivery period will be allowed on the pretext of

non-availability of or short supply of raw material not controlled by Govt. and

this will not constitute a valid reason of Force Majeure. The material used for

finished product shall be of best quality and shall conform to specific details

as laid down in IS:398(Part-2):1996 for tolerances, mechanical properties,

surface conditions, joints in wire and stranding.

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3.3 The aluminium wires(strands) shall be hard drawn from electrolytic aluminium

rod having purity not less than 99.5% and shall conform to relevant ISS. Cut ends

of the conductor shall be properly treated to avoid ingress of moisture. The producer

test certificate in respect of impurity contents of Aluminium conductivity etc. shall

have to be furnished in order to assess whether Aluminium rod of correct quality

has been used for aluminium strands.

The steel wires(strands) shall be drawn from steel produced by either acid or

basis open hearth process by the electric furnace process or basic oxygen

process and shall conform to the requirement as regards to chemical

composition. The steel produced by BESSEMER process shall not be used

for drawing the steel wire strands.

3.4 The steel core wire shall hot dip galvanised conforming to IS:2629/1980

and shall have zinc coating of minimum 250 gms/m2 of the un-coated inner wire

surface as per IS:4826/1968 for hard heavily coated wires. The zinc coated

steel wire after stranding shall successfully withstand 2 dips of one minute duration

and 1 dip of ½ minute duration under Preece test. The zinc coating shall be

reasonably smooth, continuous and of reasonably uniform thickness and free from

imperfections, consistent with good commercial practice and shall meet all the

relevant tests as per the standards. The steel wires shall be for such quality and

purity that when drawn to the size of wire specified and coated with zinc, the

finished strands shall have the same properties and characteristics as prescribed

in the relevant Indian standards. The quality of zinc used for coating of steel wire

shall be as-per IS-209/1992 i.e. electrolytic High grade zinc of 99.95 purity.

3.5 The responsibility to arrange raw material shall be solely of the firm. EC

grade Aluminium ingots or rods of relevant size shall be procured only from

the main producers such as Hindalco , Balco & Nalco. Similarly in case of

HTGS wire of relevant size, the material shall be procured main / reputed

producers like Ratlam Wires, Tata Steel, Usha Martin, Arti Steels, Bajrang

Wires, Bharat Wires & Ropes and Ramsarup industrial Corp.

4. SURFACE CONDITIONS:

The wires used for standard conductor shall be smooth and free from

all imperfections, such as spills and splits. The surface of the conductor shall

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be free from sharp edges, abrasion or other departures from smoothness of

uniformity of surface counter that would increase radio interference and

corona losses. When subjected to tension upto 50% of the ultimate strength of

conductor the surface shall not depart from its cylindrical form nor any part of

the component parts, or strands move relative to each other in such a way so

as to get out of place and disturb the longitudinal smoothness of the

conductor.

The defects like scratches, die marks, surface cuts, abrasion, stuff

mark and deposition of dust, dirt and grit, non-uniformity in diameter, un-even

and loose stranding, discontinuity in steel core wire, overlapping of strands,

joints in individual wires in the outer most layer of the conductor, etc. should

be avoided during manufacturing.

Even though the conductor may pass the relevant tests specified in

this specification or IS but if any of the above defects during visual inspection

are found to exist in the conductor offered, the same shall not be accepted.

5. JOINT IN WIRE:

I) ALUMINIUM WIRES : It would be preferable if no joints are made in Aluminium wires.

However, in case joints are made ,no two joints in any layer are permitted within

15 meters of each other in complete stranded conductor. The joint shall be made by

cold pressure welding as per IS:398/1996(Part-II). There will be no joints in

outermost layer of conductor.

II) GALVANISED/STEEL CORE WIRE:

There shall be no joints or weld of any kind in the finished wire entering into

constructions of strands. There shall also be no strand joints or strand splices

in any length of the completed stranded steel core wire of conductor.

6. LENGTHS AND VARIATION IN LENGTHS .

The conductor shall be supplied in standard length of 1300 meters. 90%

of the total ordered quantities of the conductor can be supplied in standard

lengths with +/- 5% tolerances. Further supply of 10% ordered quantities can

be supplied in shorter lengths but none of which shall be less than 650 meters

or 50% of the standard length.

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7. TEST CERTIFICATES AND TEST :

a) The firm shall supply the following type test certificates for ACSR ZEBRA

carried out as per the relevant ISS from Govt. Test House/Govt. Accredited

Test House/Tag Corporation, Chennai alongwith the tender. Type test

certificates from any other agency will not be acceptable:

i) Surface condition

ii) Test for ultimate breaking load on stranded conductor.

iii) Stress strain Tests

b) Individual wire and finished steel cored Aluminium conductor shall be

subjected, before dispatch from the works, to the test as specified in the IS-

398(Part-2) 1996 with latest amendments or any other authoritative standard.

Samples of individual wire for test shall be taken before stranding from

not less than 10% of the spools in the case of Aluminium wires and 10% of

the wire coiled in the case of steel wires. If samples are taken after stranding,

they shall be obtained by cutting 1.2 meters lengths from the outer end of the

finished conductor from not more than 10% of the finished reels or drums.

The tests will have to be performed in the presence of Employer upto

his entire satisfaction without any extra charges. Steel wire shall be tested

both for torsion and elongation and it shall pass both the tests.

8. REJECTION AND RE-TESTS

Should any one of the test pieces first selected fails to pass the tests,

three further samples from the same batch shall be selected for testing one of

which shall be from the length from which the original test samples was taken

unless that length has been withdrawn by the supplier.

Should all of the three test pieces from these additional samples satisfy

the requirements of the tests, the batch represented by these samples shall be

deemed to comply with the standard, should the test piece from any of the

three additional samples fail, the batched represented shall be deemed not to

comply with the standards and shall be rejected.

9. PACKING & MARKING :

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a) Supplier will be required to pack and protect the material securely so as to

avoid damage in transit under normal conditions. The conductor in the drum

shall be properly lagged due to abrasion during transport.

b) Supplier shall also be responsible for all losses or damages caused or

occasioned to by defect in the packing drum. The conductor shall be wound

in non-returnable wooden reels or drums.

c) The wooden drum and reels shall be manufactured according to Drg.

No.DD/TS-990R1 (Attached) and as per details given hereafter.

The drums shall be marked with the following:

i) Trade Name, if any

ii) Name of the manufacture

iii) Contract/Specification No.

iv) Size and type of conductor

v) Length of conductor

vi) Net weight

vii) Gross weight

viii) Certification mark ISI/PQM as per Approved ISI Monogram.

ix) Name and address of the consignee.

x) Drum Number and lot No.

xi) To check the sturdiness (or otherwise) of the packing reels a few

drums selected at random would be subjected to rolling for distance of

50 Mtrs. on the floor out of which 20 Mtrs. would be bricked floor. The

protective lagging should not break and drum should not get distorted

from the original shape during this process.

xii) The direction of rolling of drum shall be marked on the drum .

xiii) The conductor shall be tightly and uniformly spooled in the drum. Each

wrap shall be laid snugly against the side of the proceeding wrap.

xiv) The outside surface of the conductor drum flanges shall be painted with

double coat of enamel paint, the inner surface of the flanges including

the Barrel the inner surface of the flanges including the Barrel shall be

painted with double coat of Aluminium paint and thereafter bituminised

paper shall be provided.

d) No extra charges will be paid for these reels or drums.

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e) The reels shall be sufficiently strong to ensure delivery of conductor in

field free from displacement and damage shall be able to with stand all

stresses due to handling and stringing operations so that conductor surface

is not dented scratched or damaged in any way during manufacture,

transport and erection. It shall be notched to suite the conductor and to be

held in place by steel strapping. The drum shall be suitable for wheel

mounting. Before reeling the card board or other suitable material shall be

secured to the drum along the inside flange. The outside flange surface shall

be painted with two coats of paint. The conductor wound on the drum shall

be covered with polythene paper. The drum shall be properly lagged with at

least 50mm thick wood so as to avoid damage due to abrasion during

transport. Any loose space between top conductor layer and cross-wooden

battens shall be securely filled with straw or other waste packing material.

The protective lagging shall be closely fitted. There shall be hoop iron or

galvanized steel wire outside the protective lagging. A gap of min. 100mm

shall be kept between last conductor layer and wooden battens to avoid any

damage to conductor.

11. GUARANTEED TECHNICAL PARTICULARS:

The Bidder shall submit the GTPs with his bid.

IMPORTANT : Material shall be accepted only from those manufacturers who

have got the ISI/PQM mark and facility to manufacture 54 strands conductor

in single operation. Documentary proof for having such facility shall be

submitted with the tender.

WOODEN DRUM DETAILS

1. WOODEN COMPONENTS:

Wood used for manufacture of drum shall be seasoned wood preferably soft

wood. It shall be sound and free from visual defects, which may impair its

strength.

2. FLANGES ;

All Flanges shall be constructed with two thickness of timber, each ply being

at approximately right angle to the other, nailed, clenched together. Nails shall

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be driven from the inside face of flange, punched and the clenched on the

outer face. Flange boards shall be not less than the nominal thickness by

more than 2mm. There shall be not less than two nails per Board in each

circle. Where a slot is cut in the flange to receive the inner end of the

conductor, the entrance shall be in line with the periphery of the barrel. The

flanges of drum shall be large enough to prevent any possible contact

between the conductor and the ground during handling or transport. The

projection of flanges beyond the outer-most of the conductor shall be at least

100mm.

3. SPINDLE HOLE:

The spindle hole shall be cut through the centre of the middle flange board

and either spindle steel plates or cast iron bushings shall be fitted by bolts and

nuts.

4. BARREL END SUPPORTS

The supports shall be securely fixed to the flanges by nailing and shall be of

segmental type.

5. BARREL

Each batten shall be nailed to the barrel end support with one nail at each

side for 50mm wide Boards and at least two nails for all wider boards. The

battens shall be closely butted & provided with a smooth and round external

surface to the barrel. The edges of the battens shall be chamfered.

6. STRETCHERS;

Stretchers shall be used in the construction of drums and the middle end

supports when provided shall be slotted to receive them.

7. The protective lagging shall be closely fitted. Out-side the protective lagging there shall

be hoop iron or galvanized steel wire. A gap of min.(100mm) shall be kept between last

conductor layer and wooden battens to avoid any damage to conductor. The wooden

battens shall be nailed to the flanges.

8. PROTECTION TO CONDUCTOR;

The barrel surface and inner surfaces of the flanges of the drums shall be

painted with Aluminium Paint. A layer of water proof material shall be provided

over the barrel and inner surfaces of flanges. Another layer of water proof

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material shall be provided over the last layer of conductor and under the

laggings.

The wooden drum shall be constructed as per following details

(All dimensions in mm).

Drum dimension suitable Zebra

for conductor size

Flange diameter 1725 mm

Barrel diameter 710 mm

Transverse 900 mm

Flange thickness 3x33 mm

Bore diameter 90 mm

Nail circle -

Nail length 89 mm

Nail size 3.65 mm

Thickness of barrel end lagging 50 mm

No. of stretchers 6 mm

Stretcher size 100x50 mm

No. of bolts 6 mm

Diameter of spindle plate hole 90 mm

No. of spindle bolt plate 4

Spindle plate diameter 12 mm

Thickness of external lagging 50 mm

No. of binders over the external lagging. 3

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GUARANTEED TECHNICAL PARTICULARS OF ACSR “ZEBRA”

1. CONDUCTOR

a) Nominal Alumn. Area 420mm2

b) Stranding 54/3.18Al.+7/3.18 Steel

2. Sectional area of aluminium 428.9mm2

3. Total sectional area 484.5mm2

4. Appx. Overall diameter 28.62mm

5. Appx. Mass 1621Kg/Km.

6. Calculated resistance at 200 0.06868 Ω/km

7. Appx. Calculated breaking load 130.32KN

8. Lay ratio

a)Steel core Min.-13 Max.-28

b)Aluminium Wires

1. 12 wire layers Min.-10 Max.-17 2. 18wire layers Min.-10 Max.-16 3. 24wire layers Min.-10 Max.-14 9. Modulus of elasticity 69GN/m2

10. Co-efficient of linear expansion 19.3x10-6 /0C

2.DATA FOR INDIVIDUAL WIRE OF ALUMINIUM AND STEEL

USED IN ACSR ‘ZEBRA’

1. DIAMETER STEEL ALUMINIUM Max. 3. 24mm 3.21mm Min. 3.12mm 3.15mm 2. Cross sectional Area 7.942mm2 7.942mm2

3. Weight 61.95kg/km 21.47kg/km 4. Breaking Load

Before stranding 10.43KN 1.29KN After stranding 9.91KN 1.23KN

5. Resistance at 200C 3.626Ω/km 6. Zinc Coating. a) No. & duration of dips 2 dips of One minute each & 1 dip of half minute b) Min. weight of coating gm/mm2 250gm/m2

Page 90 of 143

SECTION-III

PART - E

SPECIFICATIONS FOR DISC INSULATORS

1.0 Scope & Qualifying Criteria :

2.1 The scope of the Bidder includes the supply of Normal and Anti-Fog

Porcelain Disc Insulators complete in all respect. The use of Anti-fog

type disc insulators is envisaged at those suspension points where the

level of pollution is very high. Areas having high pollution level are to

be identified by the bidder during detailed survey so as to ascertain the

actual quantum of Anti-fog type insulators required on the lines under

the packages covered by this specification.

2.2 The bidder shall ensure that the manufacturer of the Disc Insulators

fulfills the following Qualifying Criteria:

i) The manufacturer should have production capacity of at least

2,00,000 nos. porcelain disc insulators of 70 KN and above

voltage rating per annum. A certificate to this effect from a

Chartered Accountant / Engineer must accompany the Bid.

ii) The manufacturer must have supplied a total of at least 1,00,000

nos.70 KN & 160 KN porcelain insulators during the last three

years. A certificate to this effect from a Chartered Accountant /

Engineer must accompany the Bid.

iii) Performance certificate(s) from SEBs/ Utilities for satisfactory

supply & operation of at least 20,000 nos. porcelain disc

insulators of 70 KN and above ratings for normal type & 5,000

nos. for Anti-Fog type must be furnished with the Bid .

iv) The average annual turnover of the manufacturer for the last

three years shall not be less than Rs. 10 crores. He should have

liquid assets and / or evidence of access to or availability of

credit facilities of not less than Rs. 2 Crores. Documentary proof

for these shall also be attached with the bid.

2.0 Details of Disc Insulators

a) The insulator strings shall consist of standard discs for a three phase, 50 Hz,

effectively earthed 220KV transmission system in a moderately polluted

Page 91 of 143

atmosphere and Anti-fog type for heavily polluted areas at suspension points.

The discs shall be cap and pin, ball and socket type.

b) Bidder may quote for disc insulators made of electro-porcelain .

c) The size of disc insulator, minimum creepage distance, the number to be

used in different type of strings & their electromechanical strength shall be as

follows :

S No. Type of string Size of disc insulator (mm)

Minimum creepage distance of each disc (mm)

No. of discs

Electro- mechanical strength of insulator disc (KN)

1. Single suspension

255 X 145 292 (432 for

Anti-fog)

1x14 70

2. Single Tension 280 X 145 330 1x15 160

3. Double Tension 280 X 145 330 2x15 160

4. Double Suspension

255 X 145 292 (432 for

Anti-fog)

2x14 70

2.1 Pin and Cap

i) Pin and Cap shall be designed to transmit the mechanical stresses to the

shell by compression and develop uniform mechanical strength in the

insulator. The cap shall be circular with the inner and outer surfaces

concentric, of such design that it will not yield or distort under load conditions.

ii) The pin shall move freely in the cap socket but without danger of accidental

uncoupling during erection or in position. The design of the disc should be

such that stresses due to expansion or contraction in any part of the insulator

shall not lead to deterioration.

2.2 Security Clip

2.2.1 Security clip for use with ball and socket coupling shall be of R-shaped hump

type which shall provide positive locking of the coupling as per IS:2486-(Part-

iii)/IEC:372. The legs of the security clips shall be spread after installation to

prevent complete withdrawal from the socket. The locking device should be

resilient, corrosion resistant and of suitable mechanical strength. There shall

be no risk of the locking device being displaced accidentally or being rotated

Page 92 of 143

when in position. Under no circumstances shall locking device allow

separation of insulator units or fittings. 3% extra clips are to be provided.

2.2.2 The hole for the security clip shall be countersunk and the clip shall be of such

design that the eye of clip may be engaged by a hot line clip puller to provide

for disengagement under energized conditions. The force required to pull the

security clip into its unlocked position shall not be less than 50 N (5 Kg) or

more than 500 N (50 Kg).

2.3 Ball and Socket Designation

The dimensions of the balls and sockets shall be of 16 mm

designation, for 70 KN disc insulator and 20 mm designation for 160 KN discs

in accordance with the standard dimensions stated in IS:2486-(Part-II)/IEC :

120.

2.4 Dimensional Tolerance of Insulator Disc

It shall be ensured that the dimensions of the disc insulators for both 70

KN and 160 KN( Normal Type) are within the limits specified below:

For Standard type disc

Std. Max. Min.

a) Diameter of Disc (mm) 70 KN

160 KN

255

280

266

293

244

267

b) Ball to ball spacing

between discs 70 KN

160 KN 145 170

149 175

141 165

2.5 Interchangeability

The disc insulators inclusive of the ball and socket fittings shall be of standard

design suitable for use with the hardware fittings of any make conforming to

relevant Indian/International Standards.

2.6 Corona And RI Performance

All surfaces must be clean, smooth, without cuts, abrasions or projections.

No part shall be subjected to excessive localized pressure. The metal parts shall

Page 93 of 143

be so designed and manufactured that it shall not generate any Radio

Interference beyond specified limit and not produce any noise generating corona

under the operating conditions.

2.7 Maintenance

2.7.1 The disc insulators offered shall be suitable for employment of hot line

maintenance techniques so that the usual hot line operations can be carried

out with ease, speed and safety.

2.7.2 Bidders shall indicate the methods generally used in the routine hot and dead

line maintenance of EHV Lines for which similar disc insulators have been

supplied by them. Bidders shall also indicate the recommended periodicity of

such maintenance.

2.8 Materials

2.8.1 Porcelain

The porcelain used in the manufacture of shells shall be sound, free

from defects thoroughly vitrified and smoothly glazed.

2.8.2 Glaze

The finished porcelain shall be glazed in brown colour. The glaze shall

cover all exposed parts of the insulator and shall have a good luster, smooth

surface and good performance under the extreme weather conditions of a

tropical climate. It shall not be cracked or chipped by ageing under the

normal service conditions. The glaze shall have the same co-efficient of

expansion as of the porcelain body throughout the working temperature

range.

2.8.3 Cement

Cement used in the manufacture of the insulator shall not cause

fracture by expansion or loosening by contraction. The cement shall not give

rise to chemical reaction with metal fittings and its thickness shall be as small

and uniform as possible. Proper care shall be taken to correctly centre and

locate individual parts during cementing.

2.8.4 Pins and Caps.

Pins and Caps shall be made of drop forged steel and malleable cast

iron/spheriodal graphite iron respectively, duly hot dip galvanized and shall

not be made by jointing, welding, shrink fitting or any other process from more

than one piece of material.

2.8.5 Security Clips

Page 94 of 143

Security clips shall be made of good quality stainless steel or phosphor

bronze as per IS:1385-1968.

3.0 Workmanship

3.1 All the material shall be of the latest design and conform to the best

modern practices adopted in the extra High voltage field. Bidders shall

offer only such insulators as are guaranteed by him to be satisfactory and

will give continued good service.

3.2 The design, manufacturing process and material control at various stages

shall be such as to give maximum working load, highest mobility, best

resistance to corrosion, good finish and elimination of sharp edges and

corners to limit corona and radio interference.

3.3 The design of the insulators shall be such that stresses due to expansion

and contraction in any part of the insulator shall not laed to deterioration.

3.4 Metal caps shall be free from cracks, seams, shrinks, air holes, burrs and

rough edges. All surfaces of the metal parts shall be perfectly smooth with

no projecting points or irregularities which may cause corona. All load

bearing surfaces shall be smooth and uniform so as to distribute the

loading stresses uniformly.

3.5 All ferrous parts shall be hot dip galvanized to give a minimum average

coating of zinc equipment to 600 gm/sq.m. and shall be in accordance with

the requirement of IS:2629-1966 and shall satisfy the tests mentioned in

IS:2633-1972. The zinc used for galvanising shall be as per IS:209-1979.

The zinc coating shall be uniform, adherent, smooth, reasonably bright,

continuous and free from imperfections such as flux, ash, rust stains, bulky

white deposits and blisters. The galvanised metal parts shall be

guaranteed to withstand atleast four successive dips each lasting for one

(1) minute duration under the standard preece test.

3.6 Before ball fittings are galvanized, all die flashing on the shank surface of

the ball shall be carefully removed without reducing the dimensions below

the design requirements.

3.7 The design of the insulators shall be such that the shell shall not engage

directly with hard metal. The design shall also be such that when units are

coupled together there is no contact between the shell of one unit and

metal of the next adjacent unit. The design of the shell ribs shall be such

Page 95 of 143

that the security clip of the insulator can be engaged and disengaged

easily with hot stick without damaging the shell ribs.

3.8 Insulator units after assembly shall be concentric and co-axial within limits

as permitted by the relevant Indian Standards.

3.9 The manufacturer of the disc insulators shall guarantee an insulator failure

rate not exceeding 1 (one) per 10000 (ten thousand) per year. In case the

annual failure rate during the first ten years of service exceeds the above

figure, under normal operating condition, as will be determined by check to

be conducted as per mutually agreed procedure and conditions upto ten

years (as permitted by the operating situation). The manufacturer shall

supply to the Owner free of cost spare insulators equal to 10 times excess

of the failure.

3.10 The manufacturer shall guarantee that there shall not be any

decapping of insulators on line under normal operating conditions. In event

of any decapping and subsequent line drop, during the first ten years of

service the manufacturer shall have to pay Rs. 50,000/- (Rs. Fifty

thousand) per dropped string towards expenditure to be incurred by

PSTCL for this line repair.

4.0 Equipment marking

4.1 Each insulator disc shall be legibly and indelibly marked with the trade

mark of the manufacturer and year of manufacture. The guaranteed

combined mechanical and electrical strength shall be indicated in kilo

newtons followed by the word ‘kN to facilitate easy identification and to

ensure proper use.

4.2 For porcelain insulator, the marking shall be on porcelain. The marking

shall be printed, not impressed and shall be applied before firing.

5.0 Bid Drawings

5.1 The bidder shall furnish full description and illustration of the material

offered.

5.2 The bidder shall furnish along with the bid the outline drawing (4 copies) of

each insulator unit including a cross sectional view of the insulator shell.

The drawing shall include but not limited to the following information:

(a) Shell diameter and ball to ball spacing with manufacturing tolerances

(b) Minimum Creepage distance with positive tolerance

(c) Protected creepage distance.

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(d) Eccentricity of the disc

(i) Axial run out

(ii) Radial run out

(e) Unit mechanical and electrical characteristics

(f) Size and weight of ball and socket parts.

(g) Weight of unit insulator disc

(h) Materials

(i) Indentification mark

(j) Manufacturer’s catalogue number

5.3 After placement of award, the Contractor shall submit full dimensioned

insulator drawings containing all the details as given in Clause above, in

four (4) copies to Employer for approval. After getting approval from

Employer , the Contractor shall submit 10 more copies of the same

drawing to the Employer for further distribution and field use at Employer’s

end.

6.0 Tests and Standards

6.1 Tests

The following type, acceptance, routine tests and tests during

manufacture shall be carried out on the disc insulator individually . For the

purpose of this clause:-

6.1.1 Type tests shall mean those tests which are to be carried out to prove

the design, process of manufacture and general conformity of the

material to this specification. Type test certificate indicating conformity

of the material as per relevant standard/PSTCL specification are

required to be submitted along with the bid as per requirements of this

specification.

6.1.2 Acceptance tests shall mean those tests which are to be carried out on

samples taken from each lot offered for pre-despatch inspection for the

purpose of acceptance of that lot.

6.1.3 Routine tests shall mean those tests, which are to be carried out on

each disc insulator/hardware fitting to check requirements which are

likely to vary during production.

6.1.4 Tests during manufacture shall mean those tests which are to be

carried out during the process of manufacture and end inspection by

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the Contractor to ensure the desired quality of the end product to be

supplied by him.

6.1.5 The norms and procedure of sampling for these tests will be as per

applicable ISS / IEC standards.

6.1.6 The standard and norms to which these tests will be carried out are

listed against them.

6.1.7 For all types and acceptance tests, the acceptance values shall be the

values guaranteed by the Bidder in the Guaranteed Technical

Particulars of this proposal or the acceptance value specified in this

specification whichever is more stringent for that particular test.

6.1.8 For all type and acceptance tests, the Bidder shall guarantee only

minimum values in the Guaranteed Technical Particulars. Bidder shall

be required to achieve the same or higher values, as guaranteed,

during testing for all type and acceptance tests except for voltage

distribution test. Bidder shall be required to achieve the same or lower

values during testing.

6.2 Type Tests

The type test are meant to demonstrate conformity to the specification of design &

material used in the manufacture of goods. The disc insulators to be offered by

the bidders should have successfully passed the type test (As per IS 731 / relevant

IEC) given below :

a) Visual examination

b) Verification of dimension

c) Visible discharge test

d) Impulse voltage withstands test

e) Wet power frequency voltage withstand test

f) Temperature cycle test

g) Electro-mechanical failing load test

h) 24 hrs. Mechanical strength test/Electro mechanical strength test

i) Puncture test

j) Porosity test

k) Galvanising test

6.3 Acceptance Tests

a) b)

Visual examination. Verification of dimensions.

IS :731-1971

c) Temperature cycle test.

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d) e) f) g) h) i)

Galvanising test. Electro Mechanical Strength test/24 hrs. Mechanical Strength test. Test on locking device for ball and socket coupling. Puncture test Porosity test Electro-mechanical failing load test

IEC:575-1975,

Clause 4.0

IEC:373(2)-1976

6.4 Routine Tests

a) b)

c)

Visual Inspection. Mechanical routine test.

Electrical routine test (for porcelain insulator only)

IS-731-1971 Clause-10.13, 10.14 & 10.15

6.5 Testing Expenses

The entire cost of testing for acceptance and routine tests and tests during

manufacture specified herein shall be treated as included in the quoted Ex-

works/CIF Price except for the expenses of the Inspector/Employer’s

representative.

6.6 Additional Tests.

i) The Employer reserves the right of having at his own expense any

other test(s) of reasonable nature carried out at Contractor’s premises,

at site, or in any other place in addition to the afore said type,

acceptance and routine tests to satisfy himself that the material comply

with the Specifications.

ii) The Employer also reserves the right to conduct all the tests mentioned

in this specification at his own expense on the samples drawn from the

site at Contractor’s premises or at any other test centre. In case of

evidence of non-compliance, it shall be binding on the part of the

Contractor to prove the compliance of the items to the technical

specifications by repeat tests or correction of deficiencies, or

replacement of defective items, all without any extra cost to the

Employer.

6.7 Test Reports.

Page 99 of 143

i) Copies of type test reports, conducted within last five years from CPRI/ ERDA

or equivalent lab/ test house of national repute , shall be furnished alongwith

the bid.

ii) Record of routine test reports shall be maintained by the Contractor at his

works for periodic inspection by the Employer’s representative.

iii) Test Certificate of test during manufacture shall be maintained by the

Contractor. These shall be produced for verification as and when desired by

the employer.

7.0 Inspection

7.1 The Employer’s representative shall at all times be entitled to have access to

the works and all places of manufacture, where insulators, and its component

parts shall be manufactured and the representatives shall have full facilities for

unrestricted inspection of the Contractor’s and sub-contractor’s works, raw

materials, manufacture of the material and for conducting necessary test as

detailed herein.

7.2 The material for final inspection shall be offered by the Contractor only under

packed condition. The Employer shall select samples at random from the

packed lot for carrying out acceptance tests.

7.3 The contractor shall keep the Owner informed in advance of the time of starting

and the progress of manufacture of material in their various stages so that

arrangements could be made for inspection.

7.4 No material shall be dispatched from its point of manufacture before it has been

satisfactorily inspected and tested unless the inspection is waived off by the

Employer in writing. In the latter case also the material shall be dispatched only

after satisfactory testing for all tests specified herein have been completed.

7.5 The acceptance of any quantity of material shall be no way relieve the

Contractor of his responsibility for meeting all the requirements of the

specification and shall not prevent subsequent rejection, if such material are

later found to be defective.

8.0 Packing and Marking

8.1 All insulators shall be packed in strong seasoned wooden crates. The gross

weight of the crates alongwith the material shall not normally exceed 50 Kg to

avoid handling problem.

Page 100 of 143

8.2 The packing shall be of sufficient strength to withstand rough handling during

transit, storage at site and subsequent handling in the field. The heads of the pins

should be properly protected against damage.

8.3 Suitable cushioning, protective padding or spacers shall be provided to prevent

damage or deformation during transit and handling.

8.4 All packing cases shall be marked legibly and correctly so as to ensure safe

arrival at their destination and to avoid the possibility of goods being lost or

wrongly dispatched on account of faulty packing and faulty or illegible markings.

Each wooden case/crate shall have all the markings stenciled on it in indelible

ink.

9.0 Standards

9.1 The insulators strings and its components shall conform to the following

Indian/International Standards which shall mean latest revision, with


otherwise in the Specification.

9.2 In the event of supply of insulators conforming to standards other than specified

the Bidder shall confirm in his bid that these standards are equivalent to those

specified. In case of award salient features of comparison between the standards

proposed by the Contractor and those specified in this document will be provided

by the Contractor to establish equivalence.

Sr. No.

Indian Standard Title International Standard

1. IS:209-1979 Specification for Zinc BS:3436-1986

2. IS:406-1964 Method of Chemical Analysis of Slab Zinc.

3. IS:731-1971 Porcelain insulators for overhead Power lines with a nominal voltage greater than 1000 V

BS:137-1982(I&II)

4. IS:2071 Part(I)-1974 (Part(ii)-1974 (Part(iii)-1976

Methods of High Voltage Testing

IEC:60-1-1989

5. IS:2486 Specification for insulator fittings for Overhead Power Lines with a nominal voltage greater than 1000V

Page 101 of 143

Part-I-1971 General Requirements and Tests)

BS:3288-1979

Part-II-1974 Dimensional Requirements

IEC:120-1984

Part-III-1974 Locking Devices IEC:372-1984

6. IS:2629-1985 Recommended Practice for Hot, Dip Galvanization for iron and steel

ISO-1461(E)

7. IS:2633-1986 Testing of Uniformity of Coating of zinc coated articles.

8. IS:3188-1965 Dimensions for Disc Insulators.

IEC:305-1978

9. IS:6745-1972 Determination of Weight of Zinc coated iron and steel articles.

ISO:1460(E)

10. Thermal Mechanical Performance test and mechanical performance test on string insulator units.

IEC:575-1977

11. Guide for the selection of insulators in respect of polluted conditions

IEC:815-1986

12. IS-731-1971 Tests on insulators of Ceramic material or glass for overhead lines with a nominal voltage greater than 1000V

13. IS-3188 For characteristic of string

insulator units

14. IEC-383/1983 For tests on insulators of

ceramics material for

overhead lines with a

nominal voltage greater

than 1000V

Page 102 of 143

15. IS:13305-1992 Permissible limits of visual

defects for insulating

porcelain.

16. Specification for ceramic

insulating material

IEC-672

(Part-I, II &III)

Page 103 of 143

SECTION-III

PART - F

SPECIFICATIONS FOR EARTH WIRE

1. Technical Description of Earthwire

1.1 Scope & Qualifying Criteria:

i) The bidder is to arrange for supply of HTGSS wire (Earth Wire) of size

7/3.15 mm to be used on 220 KV Transmission Lines.

ii) The bidder shall ensure that the manufacturer fulfills the following

Qualifying Criteria:

a) The manufacturer must have capacity to make at least 2000 MT Earthwire

of size 7/3.15 mm & above per annum. Documentary proof in form of a

certificate from a chartered Accountant / Engineer must be attached with

the Bid.

b) The manufacturer must have supplied at least 1000 MT Earthwire of size

7/3.15mm & above during the last three years. Documentary proof in form

of a certificate from a chartered Accountant / Engineer must be attached

with the Bid.

c) Performance Cetificate(s) from any SEB/ Utility for supply of at least 250

MT Earthwire of size 7/3.15 mm or above shall be funished with the Bid.

d) The average annual turnover of the manufacturer shall not be less than

Rs. 10 crores per annum and he should have liquid assets and / or

evidence of access to or availability of credit facilities of not less than Rs. 2

Crores. Documentary proof for these shall also be attached with the bid.

1.2 Details of Earthwire

1.2.1 The galvanised steel earthwire shall generally conform to the

specification of ACSR core wire as mentioned in IS:12776-1989 & IS:

4826-1979 (latest) except where otherwise specified herein.

1.3 Workmanship

1.3.1 All steel strands shall be smooth, uniform and free from all

imperfections, such as spills and splits, die marks, scratches, abrasions

and kinks after drawing and also after stranding.

1.3.2 The finished material shall have minimum brittleness as it will be

subjected to appreciable vibration while in use.

Page 104 of 143

1.3.3 The steel strands shall be Hot dip galvanised and shall have a

minimum zinc coating of 240 gms/sqm. After stranding of the uncoated

wire surface. The zinc coating shall be smooth, continuous, of uniform

thickness, free from imperfections and shall withstand three and a half

dips after stranding in standard Preece test.

1.3.4 The steel strands shall be preformed and post formed in order to

prevent spreading of strands while cutting of composite earthwire.

Care shall be taken to avoid damage to galvanization during

preforming and post forming operation.

1.3.5 To avoid susceptibility towards wet storage strains (while rust), the

finished material shall be provided with a protective coating of boiled

linseed oil.

1.4 Joints in Wires

There shall be no joint of any kind in the finished steel wire strand

entering into the manufacture of the earth wire. There shall be no

strand joints or strand splices in any length of the completed stranded

earthwire.

1.5 Tolerances

The tolerances shall be as per the relevant ISS.

1.6 Materials

1.6.1 Steel

The steel wire strands shall be drawn from high carbon steel rods and

shall conform to the following requirements as to the chemical composition

:-

Element % Composition

Carbon Not more than 0.55

Manganese 0.4 to 1.10

Phosphorous Not more than 0.05

Sulphur Not more than 0.05

Silicon 0.15 to 0.35

1.6.2 Zinc

The zinc used for galvanising shall be electrolytic High Grade Zinc of

99.95% purity. It shall conform to and satisfy all the requirements of

IS:209-1979

1.7 Standard length

Page 105 of 143

1.7.1 The standard length of the earthwire shall be 2000 meters. The

tolerance on length shall be ± 5% on the standard length.

1.7.2 Random length will be accepted provided no length is less than 50% of

standard length and the total quantity of random lengths is not more

than ten(10)percent of the total quantity in each shipment.


2.1 Tests

The following type, acceptance and routine tests and tests during

manufacture shall be carried out on the earthwire. For the purpose of this

clause:

2.1.1 Type Tests shall mean those test which are to be carried out to prove

the process of manufacture and general conformity of the material to

this Specification. Type test certificates indicating conformity of the

material as per relevant Standard/PSEB specification are required to

be submitted alongwith the bid as per requirements of section II of this

specification.

2.1.2 Acceptance Tests shall mean those tests which are to be carried out

on samples taken from each lot offered for pre-despatch inspection, for

the purposes of acceptance of that lot.

2.1.3 Routine Tests shall mean those tests, which are to be carried out on

each strand/spool/length of the earthwire to check requirements which

are likely to vary during production.

2.1.4 Tests during Manufacture shall mean those tests, which are to be

carried out during the process of manufacture and end inspection by

the Contractor to ensure the desired quality of the end product to be

supplied by him.

2.1.5 The norms and procedure of sampling for these tests will be as per the

Quality Assurance Programme to be mutually agreed to by the

Contractor and the Employer.

2.1.6 The standards and norms to which these tests will be carried out are

listed against them.

2.1.7 For all type and acceptance tests, the acceptance values shall be the

values guaranteed by the Bidder in the guaranteed technical particulars

of his proposal or the acceptance value specified in this Specification,

whichever is more stringent for that particular test.

Page 106 of 143

2.2 Type Tests, Acceptance Tests, Routine Tests and Tes t During

Manufacture .

2.2.1 Type Tests on Earthwire

All the tests under clause 2.2.2 (Acceptance Tests)

2.2.2 Acceptance Test on Earthwire

a) Visual and dimensional check on drum

b) Visual check for joints scratches etc. and

lengths of earth wire.

c) Dimensional check

Annexure-A d) Lay length check

e) Galvanising test

f) Torsion test

g) Elongation Test

h) Wrap test.

i) DC resistance test. IS:398(Part-III)

j) Breaking load test

k) Chemical Analysis of steel

2.2.3 Routine Test on Earth wire.

a) Check for correctness of stranding.

b) Check that there are no cuts, fins etc. on the strands.

c) Check that drums are as per Specification.

2.2.4 Tests During Manufacturer on Earthwire.

a) Chemical analysis of zinc used for galvanising.

b) Chemical analysis of steel.


2.3.1 The entire cost of testing for the type, acceptance and routine tests and

tests during manufacture specified herein shall be treated as included

in the quoted unit price except for the expenses of the

inspector/Employer’s representative.

2.4 Additional Tests.

2.4.1 The Employer reserves the right of having at his own expenses any

other test(s) of reasonable nature carried out at Contractor’s premises,

Page 107 of 143

at site, or in any other place in addition to the aforesaid type,

acceptance and routine tests to satisfy himself that the materials

comply with the Specifications.

2.4.2 The Employer also reserves the right to conduct all the tests mentioned

in this specification at his own expense on the samples drawn from the

site at Contractor’s premises or at any other test center. In case of

evidence of non compliance, it shall be binding on the part of

Contractor to prove the compliance of the items to the technical

specifications by repeat tests, or correction of deficiencies or

replacement of defective item all without any extra cost to the

Employer.

2.5 Test Reports

2.5.1 Copy of type test reports ,conducted at Govt. approved / NABL

accredited labs not older than five years at the time of bid submission,

shall be furnished alongwith the Bid.

2.5.2 Record of routine test reports shall be maintained by the Contractor at

his works for periodic inspection by the Employer’s representative.

2.5.3 Test Certificates of tests during manufacture shall be maintained by the

Contractor. These shall be produced for verification as and when

desired by the Employer.

2.6 Inspection

2.6.1 The Employer’s representative shall at all times be entitled to have

access to the works and all places of manufacture, where conductor

shall be manufactured and representative shall have full facilities for

unrestricted inspection of the Contractor’s works, raw materials and

process of manufacture for conducting necessary tests as detailed

herein.(also see annex –A)

2.6.2 The Contractor shall keep the Employer informed in advance of the

time of starting and of the progress of manufacture of conductor in its

various stages so that arrangements can be made for inspection.

2.6.3 No material shall be dispatched from its point of manufacture before it

has been satisfactorily inspected and tested, unless the inspection is

waived off by the Employer in writing. In the latter case also the

earthwire shall be dispatched only after satisfactory testing for all tests

specified herein have been completed.

Page 108 of 143

2.6.4 The acceptance of any quantity of material shall in no way relieve the

Contractor of any of his responsibilities for meeting all requirements of

the Specification, and shall not prevent subsequent rejection if such

material is later found to be defective.

2.7 Packing for Earthwire in wooden drum

The Contractor shall be responsible for any loss or damage during

transportation handling and storage due to improper packing. The

drums shall generally conform to IS:1778-1980, except as otherwise

specified hereinafter. The empty drums will be the property of the

Contractor and should be disposed at Contractor’s cost.

2.7.1 The drums shall be suitable for wheel mounting and for letting off the

earthwire under a minimum controlled tension of the order of 5KN.

2.7.2 For Earthwire two standard lengths shall be wound on each drum.

2.7.3 For Earthwire, each strand shall be individually welded to prevent

parting of two lengths at a tension less than 15 KN. The two ends

where the first length finishes and the second length starts, shall be

clearly marked with adhesive tape and no weld should be present

outside these marks. The length between the two marks shall be

treated as scrap and will not be taken into account for measurement

purposes.

2.7.4 All wooden components shall be manufactured out of seasoned soft

wood free from defects that may materially weaken the component

parts of the drums.

2.7.5 The flanges shall be of two ply construction with each ply at right

angles to the adjacent ply and nailed together. The nails shall be

driven from the inside face flange, punched and then clenched on the

outer face. The thickness of each ply shall not vary by more than 3mm

from that required. There shall be at least 3 nails per plank of ply with

maximum nail spacing of 75 mm. Where a slot is cut in the flange to

receive the inner end of the earthwire the entrance shall be in line with

the periphery of the barrel.

2.7.6 The wooden battens used for making the barrel of the earthwire shall

be of segmental type. These shall be nailed to the barrel supports with

at least two nails. The battens shall be closely butted and shall provide

Page 109 of 143

a round barrel with smooth external surface. The edges of the battens

shall be rounded or chamfered to avoid damage to the earthwire.

2.7.7 Barrel studs shall be used for the construction of drums. The flanges

shall be holed and the barrel studs shall be threaded over a length on

either end, sufficient to accommodate washers, spindle plates and nuts

for fixing flanges at the required spacing.

2.7.8 Normally, the nuts on the studs shall stand protruded of the flanges.

All the nails used on the inner surface of the flanges and the drum

barrel shall be counter sunk. The ends of barrel shall generally be

flushed with the top of the nuts.

2.7.9 The inner cheek of the flanges and drum barrel surface shall be

painted with a bitumen based paint.

2.7.10 Before reeling, card board or double corrugated or thick bituminised

waterproof bamboo paper shall be secured to the drum barrel and

inside of flanges of the drum by means of a suitable commercial

adhesive material. After reeling the conductor and exposed surface of

the outer layer of earthwire shall be wrapped with water proof thick

bituminised bamboo paper to preserve the earthwire from dirt, grit and

damage during transport and handling.

2.7.11 A minimum space of 50 mm for earthwire shall be provided between

the inner surface of the external protective lagging and outer layer of

the earthwire.

2.7.12 Each batten shall be securely nailed across grains as far as possible to

the flange, edges with at least 2 nails per end. The length of the nails

shall not be less than twice the thickness of the battens. The nails

shall not protrude above the general surface and shall not have

exposed sharp, edges or allow the battens to be released due to

corrosion.

2.7.13 The nuts on the barrel studs shall be tack welded on the one side in

order to fully secure them. On the second end, a spring washer shall

be used.

2.7.14 Outside the protective lagging, there shall be minimum of two binder

consisting of hoop iron/galvanised steel wire. Each protective lagging

shall have two recesses to accommodate the binders.

Page 110 of 143

2.7.15 The earthwire ends shall be properly sealed and secured on the side of

one of the flanges to avoid loosening of the earthwire layers during

transit and handling.

2.8 Marking

Each drum shall have the following information stenciled on it in

indelible ink alongwith other essential data:

a) Contract/Award letter number.

b) Name and address of consignee.

c) Manufacturer’s name and address.

d) Drum number

e) Size of earthwire.

f) Length of earthwire in meters.

g) Gross weight of drum with earthwire.

h) Weight of empty drum with lagging.

i) Arrow marking for unwinding.

j) Position of the earthwire ends.

2.9 Verification of Earthwire Length

The Employer reserves the right to verify the length of earthwire after

unreeling at least ten (10) percent of the drums in a lot offered for

inspection.

2.10 Standards

The earthwire shall conform to the following Indian/International

Standards, which shall mean latest revision, amendments/changes

adopted and published, unless otherwise in the Specification.

In the event of the supply of earthwire conforming to standards other

than specified, the Bidder shall confirm in his bid that these standards

are equivalent to those specified. In case of award, salient features of

comparison between the standards proposed by the Contractor and

those specified in this documents will be provided by the Contractor to

establish their equivalence.

Sl. No.

Indian Standard

Title International Standards

1 IS:209-1979

Specification for Zinc BS:3436-1986

2. IS:398-1982

Specification for Aluminium Conductors for Overhead

IEC:209-1966 BS:215-1970

Page 111 of 143

Transmission Purposes. 3. IS:398-

1982 Part-II

Aluminium Conductor Galvanised Steel Reinforced.

BS:215-1970 IEC:1089-1991

4. IS:1778-1980

Reels and Drums for Bare Conductors.

BS:1559-1949

5. IS:1521-1972

Method of Tensile Testing of Steel Wire.

ISO6892-1984

6. IS:2629-1985

Recommended Practice for Hot Dip Galvanising of Iron and Steeel.

7. IS:2633-1972

Method of Testing Uniformity of Coating on Zinc Coated Articles.

8. IS:4826-1979

Galvanised Coating on Round Steel Wires.

IEC:888-1987 BS:443-1969

9. IS:6745-1972

Methods of Determination of Weight of Zinc Coating of Zinc Coated Iron and Steel Aticles.

BS:433-1969 ISO:1460-1973

10. Zinc Coated steel wires for stranded Conductors.

IEC:888-1987

Page 112 of 143

ANNEXURE-‘A’ (Earthwire)

1.1 Chemical Analysis of Steel : Samples taken from the Steel ingots

coils/strands shall be chemically/ spectrographically analysed. The same shall

be in conformity with the requirements stated in this specification.

1.2 Visual and Dimensional Check on Drums: The drums shall be visually and

dimensionally checked to ensure that they conform to the requirements of this

specification.

1.3 Visual Check for Joints, Scratches, etc.: Earth wire drums shall be rewound

in the presence of the Purchaser. The purchaser shall visually check for

scratches, joints, etc. and that the conductor generally conforms to the

requirements of this specification.

1.4 Dimensional Check on Steel : The individual strands shall be dimensionally

checked to ensure that they conform to the requirements of this specification.

1.5 Check for Lay Ratios of various Layers : The lay ratios of various layers

shall be checked to ensure that they conform to the requirements of this

specification.

1.6 Galvanising Test : The test procedure shall be as specified in IS:4826. The

material shall conform to the requirements of this specification. The

adherence of zinc shall be checked by wrapping around a mandrel four times

the diameter of the steel wire.

1.7 Torsion and Elongation Tests on Steel Strands : The test procedures shall

be as per of IS:398 (Part-II ).

Page 113 of 143

SECTION III

PART - G

SPECIFICATIONS FOR HARDWARE FITTINGS

1. Scope & Qualifying Requirements:

1.1 This specification covers design manufacture testing supply & delivery of

ACSR Zebra accessories like Single suspension and Tension string

hardware fitting, PA Rods, Straight Joints, Repair Sleeve and 4R Stock

Bridge Dampers with security clips etc. for 220KV overhead Power

transmission lines in the state of Punjab

1.2 Technical specifications contained herein are for the guidance of the

Bidders. Any deviation from Purchaser’s specification will be considered

on their relative merits in respect of performance, efficiency, durability and

overall economy, consistent with the requirements stipulated herein after.

1.3 Equipment carrying ISI Mark would be preferred.

1.4 The Bidders may not furnish particulars of Manufacturer who are not in a

position to offer material according to Purchasers specification.

1.5 The details / particulars of Manufacturer who have genuine facilities to

manufacture single piece forged fitting & galvanizing need only be

submitted.

1.6 The tendered prices shall cover the cost of material utilized/destroyed

while carrying out various tests as specified in this specification or in the

relevant ISS to which the material offered shall conform and no extra

payment shall be due for the material so destroyed during testing.

1.7 The manufacturer should have adequate capacity to manufacture

Hardware Fittings & accessories suitable for ACSR Zebra / Moose and

should have supplied at least 2000 nos. Tension Fittings, 4000 nos.

Suspension Fittings, 2000 sets of PA rods and 3000 nos. 4-R Dampers for

ACSR Zebra and/or Moose during the last two years. Certificate of a

Chartered Accountant / Engineer for the same shall be furnished with the

bid. In addition to this, Performance Certificate for supply of at least 1500

nos. Tension Fittings, 2500 nos. Suspension Fittings, 2500 sets of PA rods

and 4000 nos. 4-R Dampers for ACSR Zebra and/or Moose during the last

two years from any SEB / utility shall also be furnished with the Bid. On

Page 114 of 143

Financial side, the average Turnover of the manufacturer for the last three

financial should be min.2 Crores and he should have liquid assets and / or

evidence of access to or availability of credit facilities of not less than Rs.

50 lakhs. Documentary proof for these shall also be attached with the bid.

2.0 Technical Description of Hardware Fittings:

2.1 Details of Hardware Fittings:

The hardware fittings shall be as per the specification drawings

enclosed with this part of the specification. Each hardware fitting shall be

supplied complete in all respects and shall include the following hardware

parts:

a) Single/Double suspension and Tension hardware fittings, shall be supplied

suitable for attaching to strain plate fixed to tower.

b) Suspension and dead end assembly to suit conductor size of ACSR

ZEBRA.

c) Other necessary fittings as eye links, ball clevis, socket clevis, clevis eye,

U-clevis and chain link etc. to make the hardware fittings complete.

d) 2.5% extra fasteners.

2.2 Dimensions of Insulators String alongwith Hardw are Fitting:

The various limiting dimensions of Single/Double Suspension and

Single/Double Tension insulator strings alongwith hardware fitting shall be

as per the specification drawing enclosed with this part of the specification

2.3 Interchangeability:

The hardware for insulator strings with disc insulators together with ball &

socket fitting shall be of standard design, so that these hardware are

interchangeable with each other and suitable for use with disc insulators of

any make conforming to relevant Indian standard.

2.4 Corona and RI Performance:

Sharp edges and scratches on all the hardware fittings shall be avoided.

All surfaces must be clean, smooth, without cuts and abrasions or

projections to avoid Corona and Radio Interference.

2.5 Maintenance:

The hardware fittings offered shall be suitable for employment of hot line

maintenance techniques so that usual hot line operations can be carried

out with ease, speed and safety. The techniques adopted for hot line

maintenance shall be generally bare hand method & hot stick method.

Page 115 of 143

2.6Ball and Socket Designation

The dimensions of the ball and socket shall be of 16mm for 70 KN disc

insulators & 20mm for 160KN disc insulators. The designation should be in

accordance with the standard dimensions shall be checked by the

appropriate gauge after galvanizing only.

2.7 Security clips and Split Pins

i) Security clips for use with ball and socket coupling shall be R-shaped, hump

type, which provides positive locking of the coupling as per IS: 2486(Part-III)

1974 shall be made of Phosphorous bronze conforming to IS: 7814-1975. The

legs of the security clips shall be spread after assembly in the works to prevent

complete withdrawal from the socket. The locking device should be resilient,

corrosion resistant and of suitable mechanical strength. There shall be no risk

of the locking device being displaced accidentally or being rotated when in

position. Under no circumstances shall the locking devices allow separation of

fittings.

ii) The hole for the security clip shall be countersunk and the clip should be of

such design that the eye of clip may be engaged by a hot line clip puller to

provide for disengagement under energized conditions. The force required to

pull the security clip into its unlocked position shall not be less than 50 N (5Kg)

or more than 500 N (50 Kg).

iii) Split pins shall be used with bolts & nuts.

2.8 Suspension Assembly:

i) The suspension assembly shall be suitable for ACSR ‘Zebra’ (54/7/3.18

Conductor).

ii) The suspension assembly shall include free centre type suspension clamp

alongwith standard preformed Armour rods. The suspension clamp

alongwith standard preformed Armour rods set shall be designed to have

maximum mobility in any direction and minimum moment of inertia so as to

have minimum stress on the conductor in the case of oscillation of the

same.

iii) The suspension clamp alongwith standard preformed armour rods set

shall have a slip strength between 8-15% of breaking load of ACSR

“zebra”. The conductor should not slip at a load of 8% of breaking load of

conductor. The slip strength shall not exceed 15% of breaking load of

Page 116 of 143

conductor as per specification

iv) The suspension assembly shall be designed, manufactured and finished to

give it a suitable shape, so as to avoid any possibility of hammering

between suspension assembly and conductor due to vibration. The

suspension assembly shall be smooth without any cuts, grooves,

abrasions, projections, ridges or excrescences, which might damage

the conductor.

v) The suspension assembly/clamp shall be designed so that it shall

minimize the static & dynamic stress developed in the conductor under

various loading conditions as well as during wind induced conductor

vibrations.

2.9 Free Centre Type Suspension Clamp:

i) Free Centre Suspension Clamp shall be smoothly rounded and curved

into a bell mouth at the ends. The lip edges shall have rounded bead.

There shall be at least two U-bolts for tightening of clamp body and keeper

pieces together.

ii) The Suspension Clamp required for use on ACSR Zebra shall be of

Aluminium alloy only. The clamp body and the keeper pieces shall be of

high strength aluminium alloy, while base cotter bolt, U-bolts and nuts shall

be of stainless steel (IS: 6603-1972)

iii) The ball mouth of the Suspension Clamp shall be so designed as to

take into the account, the hypothetical catenary’s angle of the conductor

vibrations.

iv)The clamp body and the conductor groove of the keeper pieces shall

hold the conductor at mutually suitable curvature, so that the conductor

receives the maximum compression at the clamp centre, with gradually

lessening compression as it reaches the ball mouth in order that any

damage to conductor due to vibration is minimized.

v)The suspension clamp when suspended vertically by means of flexible

attachment shall not slip upto a minimum load of 2200 kg i.e 50% of the

maximum working tension of the conductor.

vi) Supplier shall indicate the tightening torque with which Nuts should be

tightened so that conductor in suspension clamps should not slip at a load

of 2200 kg i.e 50% of the maximum working tension of the conductor so as

to have the required slip strength.

Page 117 of 143

2.10 Dead end Assembly:

i) The dead end assembly shall be suitable for ACSR Zebra.

ii) The dead end assembly shall be compression type with provision for

comprising jumper terminal at one end. The angle of jumper terminal to be

mounted should be 300 with respect to the vertical line. The area of bearing

surface on all the connections shall be sufficient to ensure positive electrical

and mechanical contact and avoid local heating due to I2R losses. The

resistance of the clamp when compressed on Conductor shall not be more

than 75% of the resistance of equivalent length of Conductor.

iii) Die compression areas shall be clearly marked on each dead-end

assembly designed for continuous die compressions and shall bear the words

‘COMPRESS FIRST’ suitably, inscribed near the point on each assembly

where the compression begins. If the dead end assembly is designed for

intermittent die compression it shall bear identification marks

‘COMPRESSION ZONE’ and ‘NON COMPRESSION ZONE’ distinctly with

arrow marks showing the direction of compressions and knurling marks

showing the end of the zones. Tapered aluminium filler plugs shall also be

provided at the line of demarcation between compression & non-compression

zone. The letters, number and other markings on the finished clamp shall be

distinct and legible. The dimensional tolerances of the cross section of

aluminium /aluminium alloy for dead end assembly for ACSR Zebra shall be

as per the table given below:

Sr

No.

Item Dimensions before

Compression

Dimensions after

Compression

Inner

Dia

(mm)

Outer Dia

(mm)

Corner to

corner

(mm)

Face to

face (mm)

1 Aluminium 31 48 46 40

2 Steel 10.7 28.8 20.2 17.5

iv) The assembly shall not permit slipping or damage to, or failure of the

complete conductor or any part thereof at a load less than 95% of the ultimate

tensile strength of the conductor.

2.11 Yoke Plates

Page 118 of 143

The strength of yoke plates shall be adequate to withstand the minimum

ultimate tensile strength, as specified in the bid drawings. The plates shall be

either triangular or rectangular in shape as may be necessary. The design of

yoke plate shall into account the most unfavorable loading conditions likely to

be experienced as a result of dimensional tolerances for disc insulators as

well as components of hardware fittings within the specified range. The plates

shall have suitable holes for fixing arcing horn. All the corners and edges

should be rounded off with a radius of atleast 3mm. The holes provided for

bolts in the yoke plate should satisfy shear edge condition as per Clause

No.8.10 of IS:800-1984.

3.0 Fasteners: Bolts, Nuts and Washers:

i) All bolts and nuts shall confirm to IS:12427-1988. All bolts and nuts shall

be hot dip galvanized. All bolts and nuts shall have hexagonal heads, the

heads being forged out of solid truly concentric, and square with the

shank, which must be perfectly straight.

ii) Bolts upto M16 and having length upto 10 times the diameter of the bolt

should be manufactured by cold forging and thread rolling process to

obtain good and reliable mechanical properties and effective dimensional

control. The shear strength of bolt for 5.6 grade should be 310 Mpa min.

as per IS: 12427.Bolts should be provided with washer face in accordance

with IS: 1363 Part-1 to ensure proper bearing.

iii) Nuts should be double chamfered as per the requirement of IS:1363 Part-

III,1984.It should be ensured by the manufacturer that nuts should not be

over tapped beyond 0.4mm oversize on effective diameter for size upto

M16.

iv) Fully threaded bolts shall not be used. The length of the bolt shall be such

that the threaded portion shall not extend into the place of contact of the

component parts.

v) All bolts shall be threaded to take the full depth of the nuts and threaded

enough to permit the firm gripping of the component parts but no further. It

shall be ensured that the threaded portion of the bolt protrudes not less

than 3 mm and not more than 8mm when fully tightened. All nuts shall fit

and tight to the point where shank of the bolt connects to the head.

vi) Flat washers and spring washers shall be provided wherever necessary

Page 119 of 143

and shall be of positive lock type. Spring washers shall be electro-

galvanised. The thickness of washers shall conform to IS:2016-1967.

vii) To obviate bending stress in bolt, it shall not connect aggregate thickness

more than three time its diameter.

viii) Bolts at the joints shall be so staggered that nuts may be tightened with

spanners without fouling.

ix) To ensure effective in-process quality control it is essential that the

manufacturer should have all the testing facilities for tests like weight of

zinc coating, shear strength, other testing facilities etc, in-house.

x) Fasteners of grade higher than 8.8 are not to be used.

4.0 Materials:

i) The materials of the various components shall be as specified hereunder.

However components made of alternative materials giving equivalent or

better performance shall also be considered. The Bidder shall indicate the

material proposed to be used for each and every component of hardware

fittings stating clearly the class, grade or alloy designation of the material,

manufacturing process & heat treatment details and the reference

standards.

ii) Raw material to be used for the manufacture of various hardware fittings

made of mild steel, forged steel and aluminium alloy, nuts and bolts, cotter

pins, security clips, galvanizing or electro-plating shall conform to relevant

Indian standard and may be tested by purchaser according to the tests laid

therein.

4.1 Mild Steel:

Raw material to be used for the manufacture of various hardware

fittings made of mild steel shall be tested according to the tests laid in the

relevant Indian standard, if so desired by the purchaser.

4.2 Aluminium or Aluminium Alloy fittings :

The Aluminium or Aluminium Alloy fittings shall be of extruded sections

as mentioned against each. The type of Aluminium/ Aluminium Alloy, its

mechanical properties and chemical composition shall be indicated in the

tender.

4.3 Forgings:

Page 120 of 143

All the forged fitting shall be made from forged steel and all the tests

specified in the corresponding IS shall be performed on the test bars, if

desired by the purchaser. The Bidder shall specify whether cold or hot

process shall be used and the forging done with drop hammer or press,

alongwith the size and capacity of the forging equipment. All the forged

fittings shall be made out of one piece and these shall not be made by

joining welding or shrunk fitted or with any other process.

The Bidder shall indicate type of forging steel and its mechanical

properties, which will be used for producing forged hardware fittings.

The details of materials for different component are listed as in Table No.1

5.0 Workmanship:

i) All the equipment shall be of the latest design and conform to the best modern practices

adopted in the Extra High Voltage field.

ii) All ferrous parts including fasteners shall be hot dip galvanized, after all

machining has been completed. Nuts may, however, be tapped (threaded)

after galvanizing and the threads oiled. Spring washers shall be electro-

galvanized. The bolt threads shall be undercut to take care of the increase in

diameter due to galvanizing. Galvanizing shall be done in accordance with

IS:2629-1985 and shall satisfy the tests mentioned in IS:2633-1986.

Fasteners shall withstand four dips while spring washers shall withstand three

dips of one-minute duration in the standard preece test. Before ball fittings are

galvanized, all die flashing on the shank and on the bearing surface of the ball

shall be carefully removed without reducing the dimensions below the design

requirements.

iii) The zinc coating shall be perfectly adherent, of uniform thickness, smooth,

reasonably bright, continuous and free from imperfections such as flux,

ash, rust stains, bulky white deposits and blisters. The zinc used for

galvanizing shall be grade Zn 99.95 as per IS: 209-1979.

iv) Pin balls shall be checked with the applicable “GO” gauges in at least two

directions, one of which shall be across the line of die flashing and the

other 900 to this line. “NO GO” gauges shall not pass in any direction.

v) Socket ends, before galvanizing, shall be of uniform contour. The bearing

surface of socket ends shall be uniform about the entire circumference

without depressions of high spots. The internal contours of socket ends

shall be concentric with the axis of the fittings as per IS: 2486.

Page 121 of 143

vi) The axis of the bearing surfaces of socket ends shall be coaxial with the

axis of the fittings. There shall be no noticeable tilting of the bearing

surfaces with the axis of the fittings.

vii) In case of casting, the same shall be free from all internal defects like

shrinkage inclusion, blowholes, cracks etc. Pressure die-casting shall not

be used for casting of components with thickness more than 5 mm.

viii) All current carrying parts shall be so designed and manufactured that

contact resistance is reduced to minimum & localized heating

phenomenon is averted.

ix) No equipment shall have sharp ends or edges, abrasions or projections

and cause any damage to the conductor in any way during erection or

during continuous operation, which would produce high electrical and

mechanical stresses in normal working. The design of adjacent metal parts

and mating surfaces shall be such as to prevent corrosion of the contact

surface and to maintain good electrical contact under service conditions.

x) All the holes shall be cylindrical, clean cut and perpendicular to the plane

of the material. The periphery of the holes shall be free from burrs.

xi) All fasteners shall have suitable corona free locking arrangement to guard

against vibration loosening.

xii) Welding of aluminium shall be by inert gas shielded tungsten arc or inert

gas shielded metal arc process. Welds shall be clean, sound, smooth, and

uniform without overlaps, properly fused and completely sealed. There

shall be no cracks, voids incomplete penetration, incomplete fusion, under-

cutting or inclusions. Porosity shall be minimized so that mechanical

properties of the aluminium alloys are not affected. All welds shall be

properly finished as per good engineering practices.

xiii) The particular care shall be taken during manufacture & subsequent

handing to ensure smooth surface free from abrasion or cuts.

6.0 Bid Drawings:

i) The Bidder shall furnish full description and illustrations of materials offered.

ii) Fully dimensioned drawings of the complete insulator string hardwares and

the component parts showing clearly the following arrangements shall be

furnished in four (4) copies alongwith the bid. Weight, material and fabrication

details of all the components should be included in the drawings.

(a) Attachment of the hanger or strain plate.

Page 122 of 143

(b) Suspension or dead end assembly.

(c) Links with suitable fittings.

iii) All drawing shall be identified by a drawing number and contract number. All

drawings shall be neatly arranged. All drafting & lettering shall be legible. The

minimum size of lettering shall 3 mm. All dimensions & dimensions tolerances

shall be mentioned in mm:

The drawing shall include:

(a) Dimensions and dimensional tolerance.

(b) Materials, fabrication details including any weld details & any

specified finishes & coatings. Regarding material, designation &

reference of standards are to be indicated.

(c) Catalogue No.

(d) Marking

(e) Weight of assembly

(f) Installation instructions

(g) Design installation torque for the bolt or cap screw.

(h) Withstand torque that may be applied to the bolt or cap screw

without failure of component parts.

(i) The compression die number with recommended compression

pressure.

(j) All other relevant terminal details.

iv) After placement of award, the Contractor shall submit fully dimensioned

drawing including all the components in four (4) copies to the Purchaser for

approval. After getting approval from the Purchaser and successful

completion of all the type tests, the Contractor shall submit 10 more copies

of the same drawings to the Purchaser for further distribution and field use

at Purchaser’s end.

Table-1

Details of Materials for ACSR “Zebra”

Sr. No.

Name of item. Material Reference Standard

1. Security Clips SS/Phosphor Bronze IS: 7814:1975/ IS:6603-1972

2. U-clevis/ Anchor shackle

Forged Steel Grade-4 As per IS:2004 1978 or equivalent.

3. Ball Eye/ Ball clevis Forged Steel Grade-4 As per IS:2004 1978 or

Page 123 of 143

equivalent. 4. Socket clevis /

Clevis-clevis Forged Steel Grade-4 As per IS:2004

1978 or equivalent.

5. Tension Clamp Extruded Aliminium (99.5% pure)

As per IS:2004 1978 or equivalent.

6. Suspension Clamp High Strength Al. Alloy IS: 6051:1910 7. Dead End

Assembly

(a)Outer Sleeve (of dead end assembly)

EC grade of Extruded Aluminium (99.5% pure)

(b) Steel Sleeve Mild Steel/FS As per IS:226-1975

8. Jumper Bolts / U-bolts with flat washer & nut

Stainless Steel IS: 6603:1972

9. Bolt, Nut & Flat washer for outer parts

Mild Steel HDG

10. Spring Washer Spring steel 11. Split pin Brass with min

hardness of 160HV

7.0 Tolerance in Dimensions

The tolerance, if any, in all important dimensions, shall be indicated on

each of the drawing, otherwise the purchaser shall stick to the dimensions

given in the specification drawings, in case the offer is accepted.

8.0 Samples

The bidder who has not supplied /executed order earlier for these items to

PSTCL may submit samples within 15 days of opening of the tender free of

cost. Ordinary samples will not be returned to supplier. However expensive

samples will be returned to him & should be collected by him within 1 month

of opening of the tender at his own risk & cost .

9.0 Accessories For ACSR Zebra conductor

9.1 General

i) This portion details the technical particulars of the accessories for ACSR

“Zebra’.

ii) 2.5% extra fasteners shall be provided.

9.2 Standard Preformed Armour Rod Set

Page 124 of 143

1) The Preformed Armour Rods Set suitable for ACSR “Zebra shall be used to

minimize the stress developed in the conductor due to different static and

dynamic loads because of vibration due to wind, slipping of conductor from

the suspension clamp as a result of unbalanced conductor tension in

adjacent spans and broken wire condition. It shall also withstand power arcs;

chafing and abrasion from suspension clamp and localized heating effect due

to magnetic power losses from suspension clamps as well as resistance

losses of the conductor.

2) The preformed armour rods set shall have right hand lay and the inside

diameter of the helices shall be less than the outside diameter of the

conductor (conductor being manufactured according to IS; 398-1961-Part II)

to have gentle but permanent grip on the conductor and the loading stress

shall be evenly distributed over the entire length of the conductor through out

the length of contact. The surface of the armour rod when fitted on the

conductor shall be smooth and free from projections, cuts and abrasions etc.

3) The armour rods shall not have the tendency of loosening at the ends during

use. The armour rods shall conform to IS: 2121-1981 (Part-I) with latest

amendments.

4) The manufacture of armour rods should be free of machine marks or any

surface distortions and the ends must be smooth, so as not to cause damage

to the conductor and that corona effect is minimum.

5) The number of armour rods in each set shall be twelve. Each rod shall be

marked in the middle with paint for easy application on the line.

6) The armour rod shall not loose their resilience even after five applications.

7) Material will be supplied as per following particulars:

1. Type Performed 2. Suitable for ACSR ‘Zebra’ conductor 3. Material Aluminium Alloy (High strength in

accordance with IS: 739-1996) 4. UTS 35 kg/mm2

5. Dimensions As per IS: 2121-1981 (Part-I) 6. Tolerance in dimensions As per IS: 2121-1981 (Part-I) 7. Number of Rods in each

set 12 Nos.

8. Direction of Lay Right Hand Lay 9. Shape of ends & centre

marking Ball ended, Centre to be marked with Black paint

10. Conductivity Not less than 39% of the conductivity of the IACS.

11. Slip strength 25% of UTS of conductor

Page 125 of 143

9.3 Mid Span Compression Joint

1.Mid Span Compression Joint shall be used for joining two lengths of conductor

shall be made out of extruded aluminium tubing and of circular to hexagonal pattern.

The joint shall have a resistively less than 75% of the resistivity of equivalent length

of conductor. The joint shall not permit slipping off, damage to, or failure of the

complete conductor or any part thereof at a load less than 95% of the ultimate tensile

strength of the conductor.

2.The joint shall be made of aluminium sleeves for jointing the conductor. The

aluminium sleeve shall have aluminium of purity not less than 99.5%. Tapered

aluminium filler plugs shall also be provided on the line of demarcation between

compression and non-compression zone. The Mid Span Compression Joint should

be so designed that when installed, no air space is left within the finished joint. The

dimensions and dimensional tolerances of mid span compression joint shall be as

per Table-II.

3.The tender must accompany dimensional sketches separately for steel and

aluminium portion of the joint before and after it is installed on the conductor, along

with the inner and outer dimensions of steel and aluminium portions of the joint.

4.The Mid Span Compression Joint in all respects must comply with the

requirements laid down for such joints in IS:2121-1981(Part-II) (with latest

amendments). Tender shall be accompanied with copies of the type tests mentioned

in relevant IS in support of the guaranteed technical particulars.

1. Type Compression

2. Material

i) Outer Sleeve Aluminium (Extruded tube) 99.5%

pure

II) Inner Sleeve Steel (Hot Dip galvanized)

3. Shape of cross section

i) Before compression Round

ii) After compression Hexagonal

4. Min. failing load Not less than 95% of the breaking

load of the conductor

5. Electrical resistance of the

joint after installation

Not more than 75% of measured

resistance of the equivalent length

Page 126 of 143

of conductor

6. Marking Compression & non compression

zone to be marked clearly of the

Aluminium sleeve

7. Weight 0.4 kg (indicative only)

Page 127 of 143

Table II

Dimensions & Dimensional Tolerances for Mid Span Compression Joint

and Repair Sleeve for ACSR ‘Zebra’

Sr No.

Item Dimensions before Compression

Dimensions after Compression

Inner Dia (mm)

Outer Dia (mm)

Length (mm)

Corner to Corner (mm)

Face to Face (mm)

1 Mid Span Compression joint for ACSR Zebra

A

Aluminium

Sleeve

31+0.5 48+1 710+5 46+0.5 40+0.5

B Steel Sleeve 10.7 28.8 20.2 17.5

2 Repair Sleeve 31+0.5 48+1 275+5 46+.5 40+.5

9.4 Repair Sleeve

1. Repair Sleeve of compression type shall be used to repair conductor with not

more than one sixth of the strands broken in the outer layer. The sleeve shall be

manufactured from 99.5% pure aluminium and shall have a smooth surface. The

repair sleeve shall comprise of two pieces with a provision of seat for sliding of the

keeper piece. The edges of the seat as well as keeper piece shall be so rounded that

the conductor strands are not damaged during installation. The dimensions and

dimensional tolerances of repair sleeve shall be as per Table-II.

2. Repair sleeves suitable for ACSR Conductor shall be of circular to hexagonal

pattern and are required to make good the severed strands of the conductor. The

repair sleeves shall be suitable for applying with 100 Ton press. The material to be

used for repair sleeve shall satisfy the requirement laid down in IS-2121-1981 (Part-

II) for ACSR Zebra conductor.

Table III

1. Type Compression type, in two parts with provision of seat for sliding of keeper piece

2. Shape of cross section

i) Before compression Generally round

ii) After compression Hexagonal

3. Dimensions As per given in Table II

Page 128 of 143

4. Suitable for ACSR ‘ZEBRA’ conductor

5. Material Extruded Aluminium 99.5% pure

6. UTS Not less than 95% of UTS of

conductor

7. Standard IS: 2121-1981 (Part-II)

8. Max. Electrical resistance

of repaired portion

Not more than 75% of measured

resistance of the equivalent length

of conductor

9. Min. failing load 95% of breaking load of conductor

10. Length As per given in Table II

9.5 Vibration Damper

1. Vibration dampers of 4R-stockbridge type with four (4) different resonance’s

spread within the specified aeolian frequency band width corresponding to wind

speeds of 1m/s to 7 m/s shall be used at suspension and tension points on each

conductor in each span to damp out aeolian vibrations as mentioned hereinafter.

2. One damper minimum on each side per conductor for suspension points and

for tension points shall be used for ruling design span of 350 meters.

3. The clamp of the vibration damper shall be made of high strength aluminium

alloy of designation 4600 as per IS:617-1994. It shall be capable of supporting the

damper and prevent damage or chafing of the conductor during erection or

continued operation. The clamp shall have smooth and permanent grip to keep the

damper in position on the conductor without damaging the strands or causing

premature fatigue failure of the conductor under the clamp. The clamp groove shall

be in uniform contact with the conductor over the entire clamping surface except for

the rounded edges. The groove of the clamp body and clamp cap shall be smooth,

free from projections, grit or other materials, which could cause damage to the

conductor when the clamp is installed. Clamping bolts shall be provided with self-

locking nuts and designed to prevent corrosion of threads of loosening in service.

4. The messenger cable shall be made of high strength galvanized

steel/stainless steel with a minimum strength of 135 Kg/mm2. It shall be of preformed

and post formed quality in order to prevent subsequent droop of weight and to

maintain consistent flexural stiffness of the cable in service. The number of strands

in the messenger cable shall be 19. The messenger cable other than stainless steel

Page 129 of 143

shall be hot dip galvanized in accordance with the recommendations of IS: 4826-

1979 for heavily coated wires.

5. The damper mass shall be made of hot dip galvanized cast iron . All castings

shall be free from defects such as cracks, shrinkage, inclusions and blowholes etc.

The surface of the damper masses shall be smooth. The bidder should indicate the

composition of the material so used for casting and give its

6. The damper mass shall be so designed so as to avoid accumulation of

rainwater in it. If necessary damper masses may be provided with holes before

galvanizing for draining out the rainwater.

7. The damper clamp shall be casted over the messenger cable and offer

sufficient permanent grip on it. The tightening torque for fitting the Damper with the

conductor shall be indicated in the tender. The clamping bolts shall be provided with

suitable locking devices to prevent loosening during service due to electrical and

mechanical stresses.

8. The threads in nuts & tapped holes shall be cut after galvanizing and shall be

well lubricated or greased. All other threads shall be cut before galvanizing.

9. The damper clamp shall be capable of being removed and reinstalled on the

conductor at the designated torque without damaging the fasteners or the conductor

surface.

10. The messenger cable shall not slip out of the grip at a load less than the mass

pull-off value of the damper. The damper masses made of material other than zinc

alloy shall be fixed to the messenger cable in a suitable manner in order to avoid

excessive stress concentration on the messenger cables, which shall cause

premature fatigue failure of the same. The messenger cable ends shall be suitably

and effectively sealed to prevent corrosion. The damper mass made of zinc alloy

shall be casted over the messenger cable and have sufficient and permanent grip on

the messenger cable under all service conditions.

11. The vibration damper shall be capable of being installed and removed from

energized line by means of hot line techniques. In addition, the clamp shall be

capable of being removed and reinstalled on the conductor at the designated torque

without shearing or damaging of fasteners & conductor.

12. The manufacturer must indicate the clamp bolt tightening torque to ensure

that the slip strength of the clamp is maintained between 2.5 KN and 5 KN. The

clamp when installed on the conductor shall not cause excessive stress

Page 130 of 143

concentration on the conductor leading to permanent deformation of the conductor

strands and premature fatigue failure in operation.

13. The vibration damper shall not have magnetic power loss more than 1 watt at

500 Amps. 50 Hz alternating current per conductor.

14. The technical particulars for damping design of the system are as follows:

----------------------------------------------------------------------------------------------

Sr. No. Description Technical Particulars. Zebra ----------------------------------------------------------------------------------------------

Configuration Double /Single Circuit

1. Span length in meters

(i) Average span 350 m

ii) Max. span 500 m

2. Tensile load in Wind Zone 4

(As per IS:875,1987 (47m/s)

a) At temperature of –2.5oC 4133 kg

and Still air

b) At temperature of –2.50C 4428 kg

and 2/3rd full wind

b) At temperature of 320C 3951 kg

and full wind

3. Armour rods used Standard performed Armour rods

4. Maximum permissible ±150 micro strain

dynamic strain

5. Max. working temperature 75oC

6.. Ultimate breaking load 130.32 KN

----------------------------------------------------------------------------------------------

18. The Contractor shall submit the damper placement chart for spans ranging

from 100m to 500m. Placement charts should be duly supported with

relevant technical documents and sample calculations.

19. The damper placement charts shall include the following:

(1) Location of the dampers for various combinations of spans and

line tensions clearly indicating the number of dampers to be

installed per span.

(2) Placement distance clearly identifying the extremities between

which the distances are measured.

Page 131 of 143

(3) Placement recommendation depending upon type of suspension

clamps (viz Free centre type)

(4) The influence of mid span compression joints, repair sleeves

and Armour rods in the placement of dampers.

(5) The dampers shall be suitable for installation and replacement

with hot line tools.

9.6 Material and Workmanship

9.6.1 All the equipments shall be of the latest proven design and conform to the

best modern practice adopted in the extra high voltage field. The Bidder

shall offer only such equipment as guaranteed by him to be satisfactory

and suitable for 220KV lines and will which give continued good

performance.

9.6.2 The design, manufacturing process and quality control of all the materials

shall be such as to achieve requisite factor of safety for maximum working

load, highest mobility, elimination of sharp edges and corners, best

resistance to corrosion and a good finish.

9.6.3 All ferrous parts shall be hot dip galvanized, after all machining has been

completed. Nuts may, however, be tapped (threaded) after galvanizing

and threads oiled. Spring washers shall be electro-galvanized. The bolt

threads shall be undercut to take care of increase in diameter due to

galvanizing. Galvanizing shall be done in accordance with IS: 2629-1985

and satisfy the tests mentioned in IS: 2633-1986. Fasteners and other

galvanized materials shall be guaranteed to withstand at least four dips

each lasting one minute under the standard Preece test for galvanizing

unless otherwise specified.

9.6.4 The zinc coating shall be perfectly adherent, of uniform thickness, smooth,

reasonably bright, continuous and free from imperfections such as flux,

ash, rust, stains, bulky white deposits and blisters. The zinc used for

galvanizing shall be of grade Zn.99.95 as per 209-1979.

9.6.5 In case of castings, the same shall be free from all internal defects like

shrinkage inclusion, blowholes, cracks etc.

9.6.6 All current carrying parts shall be so designed and manufactured that

contact resistance is reduced to minimum and localized heating

phenomenon is averted.

9.6.7 No equipment shall have sharp ends or edges, abrasions or projections

Page 132 of 143

and shall not cause any damage to the conductor in any way during

erection or during continuous operation which would produce high

electrical and mechanical stresses in normal working. The design of

adjacent metal parts and mating surfaces shall be such as to prevent

corrosion of the contact surface and to maintain good electrical contact

under all service conditions.

9.6.8 Particulars care shall be taken during manufacture and subsequent

handling ensure smooth surface free from abrasion or cuts.

9.6.9 The fasteners shall conform to the requirement of IS: 6639-1972. All

fasteners and clamps shall have corona free locking arrangement to guard


9.6.10 Pin balls shall be checked with the applicable “GO” gauges in at least two

directions, one of which shall be across the line of die flashing and the

other 90 deg. to this line. “NO GO” gauges shall not pass in any direction.

9.6.11 Socket ends, before galvanising shall be of uniform contour. The bearing

surface of socket ends shall be uniform about the entire circumference.

9.6.12 The axis of the bearing surfaces of socket ends shall be coaxial with the

axis of the fittings. There shall be no noticeable tilting of the bearing

surfaces with the axis of the fittings.

In case of casting, the same shall be free from all internal defects like

shrinkage inclusion, blowholes, cracks etc. Pressure die-casting shall not

be used for casting of components with thickness more than 5 mm.

9.6.13 All the holes shall be cylindrical, clean cut arid perpendicular to the plane

of the material. The periphery of the holes shall be free from burrs.

9.6.14 All fasteners shall have suitable corona free locking arrangement to guard


9.6.15 Welding of aluminium shall be by inert gas shielded tungsten arc or inert

gas shielded metal arc process. Welds shall be clean, sound, smooth, and

uniform without overlaps, properly fused and completely sealed. there

shall be no cracks, voids, incomplete penetration, incomplete fusion, under

cutting or inclusions. Porosity shall be minimized so that mechanical

properties of the aluminium alloys are not affected. All welds shall be

properly finished as per good engineering practices.

9.7 Compression Markings

Page 133 of 143

Die compression areas shall be clearly marked on each equipment

designed for continuous die compressions and shall bear the words

COMPRESS FIRST suitably inscribed on each equipment where the

compression begins. If the equipment is designed for intermittent die

compressions, it shall bear the identification marks ‘COMPRESSION

ZONE’ and ‘NON COMPRESSION ZONE’ distinctly with arrow marks

showing the direction of compression and knurling marks showing the end

of the zones. The letters, number and other markings on finished

equipment shall be distinct and legible.

9.8 Bid Drawings

The Bidder shall furnish detailed dimensioned drawings of the equipments

and all component parts. Each drawing shall be identified by a drawing

number and Contract number. All drawing shall be neatly arranged. All

drafting and lettering shall be legible. The minimum size of lettering shall

be 3mm. All dimensions and dimensional tolerances shall be mentioned in

mm.

The drawings shall include:

(i) Dimensions and dimensional tolerances.

(ii) Material, fabrication details including any weld details and any

specified finishes and coatings. Regarding material,

designations and reference of standards are to be indicated.

(iii) Catalogue No.

(iv) Marking.

(v) Weight of assembly.

(vi) Installation instructions.

(vii) Design installation torque for the bolt or cap screw.

(viii) Withstand torque that may be applied to the bolt or cap screw

without failure of component parts.

(ix) The compression die number with recommended compression

pressure.

(x) All other relevant technical details.

9.8.1 Placement charts for spacer/spacer damper and damper.

9.8.2 The above drawing shall be submitted in 4 copies with all the details as

stated above alongwith the bid document. After the placement of award,

the Contractor shall again submit the drawings in four copies to the

Page 134 of 143

Purchaser for approval. After Purchaser’s approval and successful

completion of all type tests, 10 more sets of drawings shall be submitted to

Purchaser for further distribution and field use at Purchaser’s end.


The type, acceptance and routine tests and tests during manufacture shall be

carried out. For the purpose of this clause:

a) Type tests shall mean those tests, which are to be carried out to prove the

design process of manufacture and general conformity of the material to

this Specification.

b) Acceptance test shall mean those tests, which are to be carried out on

samples taken from each lot offered for pre-dispatch inspection for the

purpose of acceptance of that lot.

c) Routine test shall mean those tests, which are to be carried out on each item

of the material to check requirements, which are likely to vary during

production.

d) Tests during Manufacture shall mean those tests which are to be carried out

during the process of manufacturing and end inspection by the Purchaser to

ensure the desired quality of the end product to be supplied by him.

e) The standards & norms to which these tests shall be carried out are listed

against them.

f) For all type and acceptance tests, the acceptance values shall be the values

guaranteed by the Bidder in the data requirement sheets of this proposal or

the acceptance value specified in this specification, whichever is more

stringent for that particular test.

10.0 Earthwire Accessories for 7/3.15 mm Earthwire

10.1 General

1. This portion details the technical particulars of the accessories for

Galvanised Steel Earthwire.

2. 2.5% extra fasteners shall be supplied.

10.2 Mid Span Compression Joint

Mid Span compression joint shall be used for joining two lengths of

earthwire. The joint shall be made of mild steel. The steel sleeve should

not crack or fail during compression. The Brinnel Hardness of stainless

steel should not exceed 200. The steel sleeve shall be hot dip galvanized.

The joints shall not permit slipping off, damage to, or failure of the

Page 135 of 143

complete earthwire or any part thereof at a load not less than 95% of the

ultimate tensile strength of the earthwire. The joint shall have resistivity

less than 75% of resistivity of equivalent length of earthwire. The

dimensions and the dimensional tolerances of the joint shall be as per the

table given below;

Sr.No

Item Dimension before compression

Dimensions after compression

Inner dia (mm)

Outer dia (mm)

Corner to corner width (mm)

Face to face width (mm)

1. Steel Sleeve

10+/-0.2 20+/-.2 19+/-0.5 16+/- 0.5

10.3 Vibration Dampers

i)Vibration Dampers of 4R stock bridge type with four (4) different

frequencies spread within the specified Aeolian frequency bandwidth

corresponding to wind speed of 4m/s to 7 m/s shall be used for suspension &

tension points on which each earth wire in each span to damp out Aeolian

vibration as mentioned herein after.

ii)One damper min on each side per earth wire at suspension points and at

tension points shall be used for ruling design span of 350 mtr. for Earthwire of

size 7/3.15.

iii)The bidder may offer damping system involving more number of dampers

per ruling design span than the specified.

iv)The clamp of the Vibration Dampers shall be made of aluminum alloy. It

shall be capable of supporting the damper during installation and prevent

damage or chafing of earth wire during erection or continued operation.

The clamp shall have smooth and permanent grip to keep the damper in

position on the earth wire without damaging the strands or causing

premature fatigue failure of the earthwire under the clamp. The clamp

grooves shall be in uniform contact with the conductor over the entire

clamping surface except for the rounded edges. The groove of the clamp

body and clamp cap shall be smooth, free from projections, grit or

materials which could cause damage to the earthwire when the clamp is

installed. Clamping bolts shall be provided with self locking nuts designed

to prevent corrosion of the threads or loosening during service.

v) The messenger cable shall be made of high strength galvanised

steel/stainless steel with a minimum strength of 135 kg/sq.mm. It shall be

Page 136 of 143

of preformed and post formed quality in order to prevent subsequent drop

of weights and to maintain consistent flexural stiffness of the cable in

service. The number of strands in the messenger cable shall be 19. The

messenger cable ends shall be suitably and effectively sealed to prevent

corrosion.

vi) The damper mass shall be made of hot dip galvanised mild steel/cast iron

or a permanent mould cast zinc alloy. All castings shall be free from

defects such as cracks, shrinkages inclusions and blow holes etc. the

inside and outside surfaces of the damper masses shall be smooth.

vii) The technical particulars for vibration analysis and damping design of the

system are as follows :

Sr. No.

Description Technical Particulars

1. Configuration One galvanised steel earth wires in horizontal configuration 7/3.15mm

2. Span length meters i) Ruling design span ii) Maximum span

350m 500m

3. tensile load in i) At temperature of -

2.5oC ii) At temperature of –

2.5oC and 2/3rd full wind iii) At temperature of 32oC

and full wind

Wind zone 4(As per IS:875,1987(47m/s) 1290 Kg 1415 kg 1369 kg

4. Max. permissible Dynamic strain

+/- 150 micro strain

5. Ultimate Breaking load 5710 kg. 6. Max. working temperature 75oC

viii) The damper placement chart for spans ranging from 100m to 500m shall

be submitted by the bidder. All the placement charts should be duly

supported by relevant technical documents.

The damper placement charts shall include the following :

1) Location of the dampers for various combinations as spans and lien

tension clearly indicating numbers of dampers to be installed per

earthwire per span.

2) Placement distances clearly identifying the extremities between which

the distances are to be measured.

3) Placement recommendation depending upon type of suspension

clamps (viz, free center type/trunion type etc.)

Page 137 of 143

4) The influence of mid span compression joints in the placement of

dampers.

10.4 Flexible Copper Bond

The flexible copper bond shall be circular in cross section of minimum

34 sq. mm equivalent copper area and not less than 500mm in length, it shall

consist of 259 wires of 0.417mm dia. Tinned copper conductor, it shall be laid

up as 7 stranded ropes, each of 37 bunched wires. The tinning shall be as per

relevant Indian Standard. Two tinned copper connecting lugs shall be press

jointed to either ends of the flexible copper cable. One lug shall be suitable for

122mm dia bolt and the other for 16mm dia bolt. The complete assembly shall

also include one 16mm dia 40mm long HRH MS Bolts hot dip galvanized with

nut and lock washer.

10.5 Suspension Clamp

1. Standard suspension clamp for Earthwire size 7/3.15 mm as per PSTCL

deign shall be supplied.

2. The clamps shall be of free-centre type and shall provide adequate area of

support to the earthwire. The groove of the clamp shall be smooth,

finished in a uniform circular or oval shape and shall slope downwards in

the smooth curve to avoid edge support and hence to reduce the intensity

of bending moment on earthwire.

3. There shall be no sharp point in the clamps coming in contact with

earthwire. There shall not be any displacement in the configuration of the

earthwire strands nor shall the strands be unduly stressed in final

assembly during working conditions.

4. The clamping piece and the clamp body shall be clamped by at least two

U-Bolts of size not less than 10mm diameter having one nut and one 3

mm thick lock nut with washer on each of its limbs. Suspension clamps

shall be provided with inverted type U-bolts.

5. The Contractor shall supply all the components of the suspension

assembly including shackles, bolts, nuts, washers, split pin etc. The total

drop of the suspension assembly from the centre point of the earthwire

shall not exceed 150mm. The design of the assembly shall be such that

the direction of run of the earthwire shall be same as that of the conductor.

10.6 Tension Clamp

Page 138 of 143

1. At all tension towers suitable compression type tension clamps shall be

used to hold 7/3.15mm galvanized steel earthwire. Anchor shackle shall

be supplied which shall be suitable for attaching the tension clamp to

strain plates.

2. The clamps shall have adequate area of bearing surface to ensure

positive electrical and mechanical contact and shall not permit any slip to

the earthwire under working tension and vibration conditions. The angle of

jumper terminal to be mounted should be 30 deg. with respect to the

vertical line.

3. The clamp shall be made of mild steel . The steel should not crack or fail

during compression. The Brinnel hardness of steel sleeve shall not exceed

200. The steel sleeve shall be hot dip galvanized.

4. The complete assembly shall be so designed as to avoid undue bending in

any part of the clamp and shall not produce any hindrance to the

movements of the clamps in horizontal or vertical directions.

5. The slip strength of the assembly shall not be less than 95% of the

ultimate strength of the earthwire.

6. The clamps shall be complete with all the components including anchor

shackle, bolts nuts washers, split pin, jumper arrangement etc.

11.1 Type tests

On suspension Hardware Fittings only

a) Visual Inspection IS: 2486(Part-I)

b) Verification of Dimensions “

c) Slip strength test “

d) Ultimate Tensile Strength test “

e) Mechanical strength test “

f) Magnetic power loss test for suspension

assembly

“

g) Clamp slip strength Vs torque test for

suspension clamp

“

h)

i)

Galvanizing/Electroplating tests

Chemical composition test

IS: 2633

On Tension Hardware fittings only

a) Visual Inspection IS: 2486(Part-I)


Page 139 of 143

c) Slip strength test for dead-end assembly “

d) Heating cycle test for dead end Assembly “

e) Electrical resistance test for dead end

Assembly

“

f) Ultimate Tensile Strength test “

g) Mechanical strength test “

h) Chemical composition test “

i) Galvanizing/Electroplating tests IS: 2633

Mid Span Compression joint for Conductor and Earth wire

a) Visual Inspection IS: 2121(Part-II)


c) Heating cycle test “

d) Failing Load Test “

e) Electrical resistance test “

f) Slip strength test “

g) Chemical analysis of materials

i) Galvanizing tests IS: 2633

Repair Sleeve for Conductor

a) Chemical analysis of materials

Vibration Dampers

a) Visual Inspection IS: 9708-1993


c) Resonance frequency Test “

d) Fatigue tests “

e) Mass Pull off Test “

f) Dynamic characteristics test “

g) Damper efficiency test “

h) Clamp Slip Test “

i) Clamp Bolt Tightening Test “

j) Chemical analysis of materials “

k) Magnetic power loss test “

l) Galvanizing/Electroplating tests IS: 2633

11.2 Acceptance Tests

On Both Suspension and Tension Hardware Fittings

Page 140 of 143

a) Visual Examination IS:2486-(Part-I)

b) Verification of dimensions “

c) Galvanizing/Electroplating test “

d) Mechanical strength test of each

component.

“

e) Ultimate Tensile Strength test “

f) Chemical composition test “

On Tension Hardware Fittings only

Electrical resistance test for dead end

Assembly

IS:2486-(Part-I)

Mid Span Compression joint for conductor and Earthw ire

Visual examination and dimensional

verification

IS:2121-(Part-II)-1981

Galvanising/Electroplating test IS: 2633

Failing Load Test IS: 2121

Repair Sleeve for Conductor

Visual examination and dimensional

verification

IS:2121-(Part-II)-1981

Vibration Damper for Conductor

a) Visual examination and dimensional

verification

IS: 9708-1993

b) Fatigue Test “

c) Mass pull off test “

d) Verification of resonance frequencies “

e) Clamp slip test “

f) Clamp bolt torque test “

g) Strength of messenger cable “

h) Dynamic characteristics test “

i) Galvanizing test IS: 2633

Routine Tests

For Hardware Fittings

a) Visual examination IS:2486-(Part-I) 1993

For Conductor and Earthwire Accessories

a) Visual examination and dimensional

verification

IS:2121-(Part-II)1981

Clause 6.2 & 6.3

Page 141 of 143

Tests During Manufacture

a) Chemical analysis of zinc used for

galvanizing

b) Chemical analysis, mechanical,

metallographic test and magnetic paprticle

inspection for malleable castings.

c) Chemical analysis hardness tests and

magnetic particle inspection for forgings


a) All the requisite Type Test Certificates of the material to be arranged by

the Bidder from qualifying manufacturers must be furnished with the bid and no

charges for the same shall be payable.

b) The Purchaser reserves the right of having at his own expense any other

tests(s) of reasonable nature carried out at Contractor’s premises, at site or in

any other place in addition to the aforesaid type, acceptance and routine tests to

satisfy himself that the material comply with the specification.

c) The Purchaser also reserves the right to conduct all the tests mentioned in

this specification at his own expense on the samples drawn from the site at

Contractor’s premises. In case of evidence of non compliance, it shall be binding

on the part of Contractor to prove the compliance of the items to the technical

specification by repeat tests, or correction of deficiencies, or replacement of

defective items all without any extra cost to the Purchaser.

11.4 Tests Reports

11.4.1 Record of routine test report shall be maintained by the Contractor at his

works for periodic inspection by the Purchaser’s representative.

11.4.2 Test Certificates of tests during manufacture shall be maintained by the

Contractor. These shall be produced for verification as and when desired by

the Purchaser.

12.0 Inspection

12.1 The Purchaser’s representative shall at all times be entitled to have

access to the works and all places of manufacture, where the material

and/or its component parts shall be manufactured and the representatives

shall have full facilities for unrestricted inspection of Contractor’s, sub-

Page 142 of 143

Contractor’s works, raw materials, manufacturer’s of all the material and

for conducting necessary tests as detailed herein.

12.2 The material for final inspection shall be offered by the Contractor only

packed condition as the Employer shall select samples at random from the

packed lot for carrying out acceptance tests.

12.3 The Contractor shall keep the Purchaser informed in advance of the time

of starting and of the progress of manufacture of material in its various

stages so that arrangements could be made for inspection.

12.4 Material shall not be dispatched from its point of manufacture before it

has been satisfactorily inspected and tested, unless the inspection is

waived off by the Purchaser in writing. In the latter case also the material

shall be dispatched only after all tests specified herein have been

satisfactorily completed.

13 Packing and Marking.

1. All material shall be packed in strong and weather resistant wooden

cases/crates or double gunny bags. The gross weight of the packing shall not

normally exceed 50 Kg to avoid handling problems.

2. The packing shall be of sufficient strength to withstand rough handling during

transit, storage at site and subsequent handling in the field. The bidder shall

be fully responsible for defects observed in the material on account of

improper packing.

3. All the packing cases / bags shall be marked legibly and correctly so as to

ensure safe arrival at their destination and to avoid the possibility of goods

being lost or wrongly dispatched on account of faulty packing and faulty or

illegible markings.

4. The fittings made of extrusions shall have the following identification mark

embossed/punched on them and those made of forged mild steel shall be

stamped/marked wherever possible. Castings and Forging which shall be

done at works other than that of the supplier, shall bear identification mark,

both of the manufacturer and supplier.

i) Name and trade mark of the manufacturer.

ii) Size of the conductor for which it is to be used.

iii) Month & year of manufacture.

14.0 Standard

Page 143 of 143

1. The Hardware fittings, conductor accessories shall conform to the following

Indian Standards, which shall mean latest revisions, with


otherwise in the Specification.

2. In the event of the supply of hardware fittings; accessories conforming to

standards other than specified, the Bidder shall confirm in his bid that these

standards are equivalent to those specified and acceptance of the same shall

be solely in the domain of PSTCL. In case of award, salient features of

comparison between the Standards proposed by the Contractor and those

specified in this document will be provided by the Contractor to establish their

equivalence, alongwith certified copies of those standards.

Sr No

Indian Standard

1. IS: 209-1979 Specification for Zinc 2. IS: 398-1996 (Part-2) Specification for ACSR for overhead

Transmission Purpose 3. IS: 1573-1976 Electroplated Coating of Zinc on Iron and

Steel 4. IS: 2121-1981 Part-I Specification for Conductors and Earth

wire Accessories for overhead power lines Part-II Mid-Span Joints and Repair Sleeve for

Conductors 5. IS: 2486 Specification for Insulator Fitting for

overhead power lines with nominal Voltage greater than 1000V

Part-I, 1971 General requirements and tests 6. IS: 2629-1985 Recommended practice for Hot Dip

Galvanizing of Iron and Steel 7. IS: 2633-1986 Method of testing Uniformity of coating on

Zinc Coated Articles. 8. IS: 4826-1979 Galvanized Coating on Round Steel Wires 9. IS: 6745-1972 Methods of Determination of Weight of Zinc

Coating of Zinc Coated Iron and Steel Articles.

10 IS: 6639-1976 Hexagonal Bolts for Steel Structures 11 IS: 9708-1980 Specification for Stock Bridge Vibration

Dampers for Overhead Power Lines

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