68297485 technical session i

Power Consultants amp Agencies

TRAINING SESSIONS ON

CONSTRUCTION PLANNING amp

DESIGN OF EHV

TRANSMISSION LINES

BY

S M TAKALKAR PROPRIETOR

POWER CONSULTANTS amp AGENCIES A 198 VISHVAMITRY TOWNSHIP OPP - GUJARAT TRACTORS VADODARA - 390 011

Phone 0265 - 2356291 Mobile 98795994029925233951

Email smtakalkaryahoocom

TATA POWER COMPANY LTD

KALIAN

TECHNICAL SESSION ndash I

Power Consultants amp Agencies Page 2

CONSTRUCTION OF EHV TRANSMISSION LINES

10 Introduction 11 Construction of EHV Transmission line is a very specific and specialized job It involves lot of

precision and accuracy The transmission line is standing for many years in the open terrain and faces vagaries of nature The construction practice should therefore ensure that the parameters on which the design of transmission line is made are not exceeded

12 The construction mainly includes the following activities

bull Survey amp Alignment

bull Foundation Work

bull Erection of Super Structure

bull Stringing of Shield wire amp Conductor

bull Testing amp Commissioning 13 Each of above activity can be further divided into sub‐activities All the erection activities are based on the design inputs as well as site situation For example the type of tower and foundation to be adopted will depend upon the profile amp site situation where as the spandeviation angle limitations will be based on the design factors of the tower This part deals with the general specifications for construction of EHV lines

20 Survey amp Alignment 21 Whenever EHV transmission line is to be constructed between two subs‐stations the ideal route length will be the direct topographical distance between the two stations However this will not be possible as number of obstructions in the form of villages town important civil establishments big ponds rivers etc will prevent the straight run of the line The obstruction will result into line deviations It will therefore be necessary to carry out survey by various means The survey will establish the following

bull The topography of the route of the line bull The important deviation points of the line bull The approximate quantity of Towers and extension bull First hand information regarding the soil strata along the route leading to approximate

estimation of foundation work quantities bull The obstructions which may result into line deviations bull Major River Railway Road and Power line crossings and type of structures for the same bull Information regarding availability of inputs for foundation work (cement aggregates steel and

water) bull Right of way problems which are likely along the route bull Cost of transportation of material to various locations bull Tentative time frame for completing the work

22 It is also usual to make trial pits or carry out soil investigation along the proposed route of the transmission line at certain fixed interval or at the points where abrupt change in soil strata is suspected This exercise results in to the approximate estimation of the foundation types and


excavationconcrete volumes and the re‐enforcement for the foundation work The various stages of survey works are described in details as under 23 Reconnaissance and Route Alignment Survey 231 A provisional route of transmission line is initially plotted on survey maps (topo sheets) and a reconnaissance walkover survey is carried out This is essential to fix up angle tower positions tentatively since many of the physical features on the ground may not be clearly available in the survey map due to developments that might have taken place subsequent to the preparation of the maps by department of survey of India The topo sheets are obtained from the office of The Survey of India Deharadoon by indicating the Longitude amp the Lattitude of the proposed route of the transmission line In most of the cases more than one Topo sheets are required to cover the route of the line

SCHEMATIC ROUTE ALIGNMENT SURVEY

ROUTE MAP

22deg1

5

EXISTIN

G 400 KV TO

WER LI

NE

DAM

DAM

198 VISHWAMITRI TOWN SHIP OPP GUJARAT TRACTORS VADODARA-390 011

SURVEYED amp PREPARED BY-

POWER CONSULTANTS amp AGENCIES VADODARA

BY CHKD APPD PROJENGR

DRAWING NO REV

REVISIONS

0E

DATE

PCAACKBPL400kVRECCAYRM-01

RECONNAISSANCE SURVEY OF 400 kV DC

1 50000

SCALE

Project

Title

NO

wwwpowerconsultantinfo

EXISTING 400 KV DC LI

NE

TREE PLANT

Dhadhipara

Batra

Lahrapara

Nagrahi

T-05

T-05

T-05

T-05

T-05

CA

RT

TR

AC

K

Metal Road

Cart

Trac

k

METAL ROAD

CA

RT

TRA

CK

RCC

RCC

CA

RT

TR

AC

K

ROAD

L 05

3

22deg2

022

deg25

22deg2

522

deg20

22deg1

5

82deg3082deg2582deg2082deg1582deg10


Borewells

200

200

PO

PS

RF PF

Tree

Police station

ReservedProtected forest

Post office

Bench-mark

Heights point

Heights triangulated

Hutment

Wells lined unlined

SYMBOLSYMBOLDESCRIPTION DESCRIPTION

Forest

Pond

Temple Mosque

Development

Roads metalledAsphalted road

Roads unmetalled

Railways broad gauge

200Contours with heights

PowerTelephone line

Railways other gauge

Towns or Villages

RiverProposed route with AP

N

Industries

LEGEND -

Cart-track

Canal

Stream

Scrub

Boundary state

Boundary tahsil

Boundary district

400KV DC KASAIPALLI TO BHARARI TRANSMISSION LINE

INDIA(NTS)

BAY OF BENGAL

TAM

ILNA

DU

INDIAN OCEANLANKA

KERALA

SRI

HIMACHAL

CHHATISGARH

MADHYA PRADESH

KARNATAKA

PRADESH

ANDHRA

MAHARASHTRA ORISSA

UTTARANCHAL

NEPALUTTARRAJASTHAN PRADESH

PUNJAB

HARYANA

PRADESH

DELHI

ASSAMPRADESH

BHUTAN

MEGHALAYA

BANGLADESH

JHARKHAND

BENGALWEST

BIHAR

MIZORAM

MANIPUR

NAGALAND

ARUNACHAL

KASHMIRJAMMU amp

N

AR

AB

IAN

SEA

GUJARAT

Coal Bearing Area

Coal Zone Alotment Area

82deg35

82deg35

CHAPI WATER SCHEME

END POINTPROPOSED BHARARI

SUB POOLING STATION

EAST OFKARTALI

AREA BETWEENKARTALI amp DIPKA

NUNBERA

RATIJA

DIPKA

GEVRA

PONRI

NARAIBODH

SITE FOR DIPKA COLONY

KARTALIBLOCK

SARAIPALIBLOCK

DUMARKACHHARBLOCK

BANKI

BAGDEWA DILWADIH

SINGHALIBLOCK

BLOCKBLOCK

BLOCK

PROPOSED COALEXTENSION AREA

COALEXTENSIONAREA

PROPOSED

BHILAI

N O N C O A L Z O N E A R E A

COAL BEARING AREA

COAL BEARING AREA

COAL BEARING AREA

COAL BEARING AREA

COAL BEARING AREA

CO

AL BEARIN

G AREA

EXISTING POWER PLANTCKBD 2 x 30 MW

START POINTPROPOSED 400 kV

SWITCH YARD

132 kV POWER STATIONPROPOSED 2x50 MW RATIJA

SWITCH YARD

ROUTE OF PROPOSED 400kV

TRANSMISSION LINE

TOTAL LENGTH STATEMENT

DESCRIPTION ROUTE Length(Km)

1

SrNo

54867PROPOSED 400kV DC TRANSMISSION LINE

FROM KASAIPALI TO BHARARI

20

3060

40

7080

90

100

170

180

200210

220

240

250

260

270

300

290

280

310

320

340

350

360

370

380

390400

410

420

430440

450

460

10110

120

150

50

130140

160

190

230

330

GANTRY

181182183184185186221

222

223

224

303 301

302

191192

201

202

203

204

211212213214215

231232

233234

235

241

242

243

251

252

253

271

272

281282

283284

291292293294304

305

306

331

332

333

341

342

343

344

345

346

347

348

351

361

362

371

372

373

381382

383391392393394

401402

403404

405406

407408

4094010

4011

411412413421

422

431432

433441

442

451452

171

161141

111

101102

103

91

92

81827172

6A0

4A0

2122

23

232 The reconnaissance survey helps in collecting the first hand information regarding various important field data required for transmission line works The reconnaissance survey is carried out

COMPAQ

COMPAQ
Route Mapdwg
COMPAQ
SCHEMATIC ROUTE ALIGNMENT SURVEYdwg


by using GPS (Geographical Positioning System) The general points to be kept in view while establishing the preliminary route at the time of reconnaissance survey are as under a) The route should be as short and as straight as possible b) Where ever possible attempt should be made to lay the line near to or along roadway Alternatively the line should be approachable to the extent possible c) The number of angle towers should minimum and within these the number of heavier angle towers shall be as less as possible d) Cost of securing and clearing right of way (ROW) making access roads and time required for these works should be minimum e) Corridor through which line is taken should be free from Encumbrances such as non‐Agricultural land notified area Defense establishment oil amp gas establishment acquired mining areas etc f) Care is also required to be taken that the line route avoids any big planned development in the region such as Airport State Industrial Estate Mega Power Projects etc If this is not done shifting of the line may be required later or objection to the construction may occur g) Crossing with permanent objects such as Railway lines and roads should be made preferably at right angles h) In case of hilly terrain it is necessary to conduct detailed survey and locate the tower positions suitable to the topography Detailed survey is recommended for such terrain i) The reconnaissance survey will also establish if we can avoid the following

bull Marshy areas low lying lands river beds earth slip zones etc involving risk to stability of foundation amp the tower

bull Areas subjected to floods gushing ndash culverts during rainy seasons tanks ponds lakes snow blizzards

bull Inaccessible areas where approach roads are not possible bull Areas which will create problems of right of way and way leave bull Route involving abrupt changes in levels too many long spans river or power line crossings or

near parallelism to telecommunication lines bull Thick forest or areas involving heavy compensatory payments for the ROW

j) The reconnaissance survey is useful for collecting the first hand information about various important field data required for transmission line construction which are as under

bull Major power line crossing details (66 KV and above) bull Railway crossing details bull Major river crossing details bull Source of construction materials viz metal sand water etc along the line bull Important rail heads for the purpose of receipt of materials bull Important villages or Railway stations along the route for the purpose of selection of labor

camps bull Nature of soil strata likely to be encountered along the route and the terrain bull Availability of skilled semiskilled and un‐skilled labor their present rate on daily basis or on

contract basis bull Names of the major towns for the purpose of selection of site offices bull Likely local support or hindrance from various section of population along the route of the line


For fixing the final alignment and angle points on the ground as per the reconnaissance survey route alignment survey shall be carried out with the help of Theodolite andor Total Station survey chainsmeasuring tapes etc 24 Detailed Survey 241 The main objective of carrying out detailed survey is to prepare longitudinal and cross section profiles on the approved route alignment and to prepare the route plan showing details of deviation angles important objects coming within the right of way and show the landmark pointsobjects along the route with their distance from the alignment of line Work of detailed survey is normally done in two stages

1 By actual field observation taking level readings and calculating distances level differences deflection angles offset distances etc

2 By plotting of profiles on graphed tracing papers of mm x mm size 242 The use of Total Station facilitates quick measurement of distance ground levels and the angles between the two reference points The Total Station is located at fixed point and there after the prism mounted in a stand is moved along the route of the line preferably at an interval of 20 metres Each reading gives the distance and level difference These readings are stored in the memory of Total Station (TS) The data is there after transferred to the computer 243 Field Observation Recording and Calculations 2431 The method of taking level readings for preparation of longitudinal and cross section profile can be one of the following

bull By chain and dumpy level bull By tachometric survey with Theodolite bull By using Total Station and the prism

First method is more useful in plain areas where chaining can be done easily with the help of semiskilled surveyors Tachometric method offers a great advantage in hilly regions and such other inaccessible places where chaining is not possible This method needs skilled surveyors having good understanding of the use of Theodolite and basic knowledge of trigonometry In this method both traversing and leveling is done by means of a tachometric Theodolite The horizontal and vertical distances are computed with the help of readings of the stadia wires taken on the staff held at the reading point The accuracy of the work will depend upon the quality and cost of the equipment The range of operation of Theodolite is much higher than the dumpy level The surveyor and his team will move on an approved route and take ground levels in the field book at an interval of 20 to 30 meters 2432 As stated in 242 above the Total Station is the most modern equipment for surveying It saves lot of time and the observations are highly accurate This equipment is very expensive and needs lot of precautions in handling If the length of line is very short Theodolite can also serve the purpose 25 Plotting of Profiles 251 From the field book entries route plan and longitudinal profile commonly referred to as ldquoroute profilerdquo or ldquosurvey chartrdquo is prepared in the drawing office These charts are prepared and plotted on 1mm5mm1cm square paper of formed drawing sheets of graphed tracing paper The scale normally preferred is 1200mm‐vertical 12000mm‐horizontal 252 The profile shall include the following


bull The longitudinal profiles along the centre‐line of the transmission line route including the bottom conductor catenaries

bull The cross‐section profile wherever appreciable difference in level exists with references to centre‐line level In such cases the cross‐section levels shall be taken at each 50100m intervals

bull Route plan giving details of all objects lying within the right of way and just along the boundary of right of way

bull Angle of line deviation duly marked left (L) or right (R) as the case may be bull Objects and their distances along the route within the right of way from centre line nearby

villages important pucca roads amp or riverscanals cart tracks etc should be marked on the route profile

bull Crossing details with any other power or telecommunication lines roads railway lines canals or rivers should be marked as clearly as possible

bull Readings should be taken and charts should show levels of roads canal embankments maximum waterflood levels railway rail top levels heights of supportslines being crossed all trees coming within the clearance zone

bull It is advisable to prepare an independent route profile for Major River crossing section deploying tall special towers or normal towers on piles in the river crossing section as the river crossing is a special task in the construction process which involves special design

26 Tower Spotting 261 The work of tower spotting is a very precise job as it has an implication on overall cost After the tower designs are finalized the tower spotting chart or structure limitation charts are prepared Similarly the drawing of the sag template and its replica is prepared on Acrylic sheet Application of Sag Template helps to decide optimum tower position on Survey Chart which ultimately helps in finalizing the quantity of each type of tower and their extensions (3 meter amp 6 meter etc) 27 Preparation of Sag Template 271 Sag template is a very important tool for the surveyor by the help of which Tower spotting can be done Depending upon the maximum specified permissible temperature of the conductor and zero wind condition the ground clearance is to be maintained by the line Similarly under the specified minimum temperature of the conductor surface with zero wind condition the tower tensions should be within the specified limits The sag template curves are first prepared on tracing paper and the blue print is taken out from the tracing Their replicas on Acrylic sheets are prepared with the itching process The Acrylic sheets are normally 25 to 3 mm thick 272 The sag templates have the following curves itched on them

bull lsquoCold or Uplift Curversquo‐Showing sag of conductor at specified minimum temperature and zero wind

bull lsquoHotrsquo or lsquoMaximum Sag Curversquo showing maximum sag of conductor under zero wind and maximum temperature and sag tolerances are also allowed to take care of stringing error conductor creep or snow incidences

bull Ground clearance Curve‐Drawn parallel to hot curve and at a distance equal to specified minimum ground clearance


bull Tower footing Curve‐For normal tower drawn parallel to hot curve under ground clearance curve and separated by a distance equal to maximum sag at design span

273 In erecting an overhead line all the spans cannot be kept equal to normal design span because of the profile of the ground and proper ground and object clearance considerations A constant tension is calculated which will be uniform throughout the Section (from one tension tower to other tension tower) however the sags in individual spans will vary according to their respective spans The lsquoCold and Hotrsquo Template Curves are plotted as parabola to the same scale as the survey chart for the minimum and maximum sags for the normal span (specified in the tender specifications)

28 Application of Sag Template for Tower Spotting 281 The Sag Template is an important tool for correct spotting of the towers after the detailed survey work is completed The following are the steps to be followed for correct application of sag template

bull The acrylic sag template is applied to the ground profile by moving the same horizontally while always ensuring that the vertical axis is held vertical with reference to graphed lines of the tracing paper below

bull The structure positions are marked where the tower footing curve just touches the profile while the ground clearance curve is just clear and above the profile to the left or right of the centre line up to a distance equal to maximum cross area spread on either side

bull Besides normal ground clearance the clearances between power conductor and objects like other power or telecommunication lines houses trolley wires roads railway tracks canal embankments etc shall be checked

bull Extra clearance can be obtained either by reducing the span or providing extension to tower body depending on which alternative is most economical

bull The weight span on either side of a tower can be easily obtained by marking the low points of sags (Null Point) in two adjacent spans and then reading the distance between the two

bull On inclined spans null point may be outside the span


bull This indicates that the total weight of conductor is taken up by the higher tower and the lower tower is being pulled up by a force equal to the weight of conductor between lower support and the null point

bull Should the upward pull of the uphill span becomes greater than downward load of the next adjacent span actual uplift will be caused and the conductor would tend to wing clear of the tower upwards

bull For any easy check of whether a tower is under uplift or not the following method may be adopted

bull The Template is applied horizontally until the tops of alternate supports coincide with the Cold Curve

bull If the support is under uplift and has to be extended so as to be above it and in case requisite standard body extension do not suffice for doing this tower which is designed to take uplift will have to be used

bull However for the stability of the line it is not desirable to place a tower in such a position where it is always under permanent uplift condition

bull In case it becomes mandatory due to route compulsion the cross‐arms of the tower subjected to up lift shall be designed to take the extra upward pull

bull The intermediate spans shall be as near as possible to the normal design span bull In case an individual span becomes too short on account of undulations in ground

profiles one or more line supports of the Section may be extended by inserting standard body extensions

bull Even if the line does not deviate for a long run sections have to be provided after every 12 to 15 tangent towers (ie 3 to 4 km length)

bull For this purpose a small angle tension tower designed for 15deg should only be used bull This is mandatory to afford better stability of the line against Transverse wind forces

and to facilitate easy stringing bull Besides 15deg angle tension tower is most economical amongst the standard angle tension

towers 29 Use of computer for preparing sag template and the tower spotting 291 Before taking up the tower design on hand Sag and Tension charts are required to be prepared These charts indicate the values of sag and tension of conductor and the earth wire at Maximum temperature minimum temperature and every‐day temperature under 10036(66) and 0 wind pressure Normally in plain terrain in India the maximum minimum and every‐day temperatures are considered as 0 DegC 75 Deg C and 32Deg C These values may change in the region experiencing snow or Sub‐Zero temperatures If the conductor is required to carry large block of power the maximum surface temperature of conductor can be taken up to 95Deg C For Earth wires the maximum temperature is taken as 53Deg C 292 Based on the sag tension charts the sag template curves can be plotted on the computer through a specific programme The full scale print out of the curves is then used to prepare the Acrylic Sag Template by itching process 210 Towers Spotting Data 2101 Since each tower is designed to withstand a definite load only in each of transverse vertical and longitudinal directions the surveyor must know these limitations for the various types of towers


available for use on line so than he can spot an appropriate type of tower structures along the route These limits are given in a chart form called lsquoStructure Limitation Chart or ldquoTower Spotting Datardquo which is prepared by the design department of the utility contractor These charts define the limits for permissible ruling span weight span wind span individual span and the degree of the deviation allowed on each of the standard towers These charts are made for normal towers only

For all special crossings individual tower checking is essential by the design department These charts also indicate the additional angle of deviation which can be allowed in the tower by limiting the spans so that the design load limits of the tower are not exceeded

TOWER SPOTTING

V-1 200H-1 2000

SCALE DRAWING NO REV

0A

Title CLIENT - Project

TOWER SPOTTING amp SAG CURVE OF 400kV DC TRANSMISSIONLINE

DATUM 2620m

AP4

8 - C

H5

3612

02m

AP4

9 - C

H5

4867

67m

PROPOSED SUB STATION

AP-45(14deg4823)R AP-46(75deg4341)L

422

41166

422

A 198 VISHVAMITRY TOWNSHIP OPP GUJARAT TRACTORSVADODARA - 390 011 Ph(0265) 2343001 Fax(0265) 2356291E-mail smtakalkarpowerconsultantinfo smtakalkarpcagmailcomWeb wwwpowerconsultantinfo

POWER CONSULTANTS amp AGENCIESCONSULTANT -

CUMULATIVE

LEVELS(M)REDUCED

DETAILS

amp INTERFERENCECROSSING

CHAINAGES(M)

+3M

+6M

+9M

Ground Clearanceat 1326 Mtr

Conductor stringingpoint at 2221 Mtr

+3M

+6M

+9M



+3M

+6M

+9M



+3M

+6M

+9M



Hot Curve 85deg C

Ground Clearance Curve

Hot Curve 85deg C


Hot Curve 85deg C


Cold Curve 0deg C

Cold Curve 0deg C

Cold Curve 0deg C

Wind Span

TL R

Weight Span (Cold)L R

T

Weight Span (Hot)L R

T

Loc No-

2058321141683

42716206462207

43112072622384

DA+6451

157

Wind Span

TL R


T


T

Loc No-

2112058341683

41948214282052

42341219012044

DA+3452

158

Wind Span

TL R


T


T

Loc No-

00000211211

207720000020772

202990000020299

DD+0460

159

Wind Span

TL R


T


T

Loc No-

211211422

41336201321206

411821981621366

DB+3450

156

COMPAQ

COMPAQ
Tower Spottingdwg


211 Preparation of Tower Schedule 2111 In order to decide the tower type for a particular location following information is required from the design department

bull Angle of line deviation on tower bull Whether it is to be used as section tower or dead end tower bull Sum of adjacent spans bull Weight span on tower bull Whether an immediate lower size of tower can be used in place of the actual angle tower by

limiting the span bull Whether a river can be crossed using normal tower withwithout extensions or by providing

special tower or by locating towers in mid stream by providing the pile foundations bull Whether a hill side extension will be required

212 Check Survey 2121 Check survey is carried out for the following

bull To reconfirm the work carried out during detailed survey bull To locate and peg mark the tower position on ground corresponding to the route profiles bull To give direction pegs

213 Checking and Line Alignment 2131 In this operation traversing is done from the known fixed angle point (the starting point or any other obligatory point fixed by the purchaser) in the direction of given line deviation and up to a distance equal to the section length between the starting point and the next angle point If next angle point is firmly marked in field by means of a permanent peg mark (concrete burjee) then the closing error is noted both in longitudinal and transverse directions If the error is within 1 of the total section length it can be ignored and the permanent mark made during detailed survey is taken as correct and necessary correction in the line deviation angle at the starting point is made and noted in the survey chart 2132 If the second angle point reached is not marked in field by the detailed survey gang (or the mark is missing) the angle point is tentatively fixed at the place reached as per deviation angle at starting point and first sectional length and line alignment is carried to the next deviation angle and next section length as per survey chart This process is continued till an angle point is reached which is fixed in field either by a permanent burjee (pillar) or by means of identification marks given in survey charts Intermediate checks can also be made by measuring offsets from the line to well defined objects are shown in survey charts very accurately (but much reliance cannot be given for correct alignment based on offset distance) 2133 These objects only guide the surveyor in moving as closely on the correct alignment as possible If the time span between the detailed survey and the check survey is too long care is required to keep the proper track of the original profile bench mark and offset distances Once the known angle point is reached then closing error is judiciously distributed in all the previous temporary sections and all angle points are finally marked on ground by means of concrete pillars Once the angle points are marked correct angle of deviation and section length are measured and noted on survey charts 214 Spotting and Peg Marking of Tower Locations 2141 Once each angle is fixed in field by the help of permanent concrete burjees and exact section length is known the surveyor proceeds to mark all intermediate tower positions on the straight line


joining the two angle points spaced at distance equal to individual span length as given on survey chart and after the same is duly adjusted for the closing error

bull In order to achieve correct alignment of all the intermediate towers between two angle points a number of alignment pegs are driven at the time of exact distance measurement of the section

bull The more the number of alignment pegs the better it will be for the readings as instrument errors are less if similar distances are measured in one reading

bull These pegs are also very useful when main tower marking burjees are found missing at a later date (due to mischief of local people or negligence of excavation marking gang or any other reason)

30 Foundation Work 31 After the survey work is over the activity of foundation is taken on hand The foundation work mainly includes Pit marking Excavation Stub setting Concreting Back filling and Curing They are described in brief as under 32 Directional Peg Marking for Excavation Pit Marking 321 Before the activity of excavation is taken up it essential to accurately mark the centre point of the tower centre point of each leg of the tower and the periphery of pit to be excavated for each leg foundation This is described in brief as under

bull Directional pegs are essential for correct alignment of tower centre line along longitudinal and transverse directions

bull On suspension tower pegs are set along the centre line of route alignment and perpendicular to it

bull On angle towers these are rotated by an angle equal to half the angle of line deviation and then the perpendiculars are marked

COMPAQ
ALLIGNMENT OF TRANSMISSION LINEdwg


33 PreparationStudy of Excavation Plan Suitable For the Proposed Type of Foundation 331 Trial Pit At the location of the tower a trial pit shall be made within the base of the proposed tower width This shall be generally 1 x 1 x 3 m size 332 Examination of trial pit The soil strata will be examined by EIC or an expert nominated by him who has expertise in the matter of soil classification The detailed examination report of the trial pit will be made then 333 Decision for type of foundation The EIC or the authorized engineer of the purchaser and the engineer of the contractor shall then decide upon the type of foundation to be adopted for that particular location Normally the design department contractor is equipped with the set of foundation design and the excavation plan for standard type of soils rocks and their combinations including sub‐ soil water bound strata Any one of the readily available foundation design for the particular type of tower which fits in to the classification of soilrock should be adopted If the strata are too strange special type of foundation has to be adopted with the approval of Design department of the purchaser There are many types of tower foundation which are in vogue these days They also relate to various types of soil classification such as normal soil clayey soil hard rock soft rock deformated soil etc The pile type amp well type foundations are generally used in river crossing and crossing sections of the line Plate type and grill type foundations are not being used these days as their reliability is low The type foundations can be used for smaller towers

34 Excavation 341 Pit marketing shall be carried out according to pit marking chart The pit size in the case of open cast foundations shall be determined after allowing a margin of 150mm round No margin is necessary in the case of undercut foundations The depth of the excavation at the pit enter shall be measured with reference to the tower center level The design office will furnish the survey gang with an lsquoExcavation pit Marking Chartrsquo or lsquoExcavation Planrsquo which gives distance of pit centers sides and


corners with reference to center point of the tower These distances are measured and each pit boundary is marked in the field by means of chalk spade or pick axe along the side of the pits While excavating care should be taken that earth is cut verticallytaperedin steps as per the site requirement to avoid any mishap during the course of excavation and foundation work 342 Actual excavation Before commencement of the excavation work corrected and applicable excavation plan in accordance with the soilrock classification should be obtained by the construction crew members The excavation wall shall be vertical and the pit dimensions shall be strictly as per the excavation plan and foundation drawing All excavation shall be protected so as to maintain a clean surface until the footing is placed In case of collapsible soil precaution should be taken by providing shuttering and supports for the safety of the crew members

Various types of foundations used for tower are shown here under

TYPES amp SHAPES OF FOUNDATION

COMPAQ

COMPAQ
TYPES amp SHAPES OF FOUNDATIONSdwg


35 Classification of Soil 351 Normal Soil Soil which can be removed by an ordinary pick axe spade and shovel easily 352 Wet Soil (Submerged Soil) Where the subsoil water table is encountered within the range of foundation depth orand where pumping or bailing out of water is required due to presence of surface water will be treated as wet soilsubmerged soil 353 Rocky Soil (Strata) 3531 Fissured RockSoft Rock Lime stone laterite hard conglomerate or other soft or fissured rock which can be quarried or split with crow bars wedges or pickaxes will be classified as fissured rocksoft rock However if required light blasting may be resorted to for loosening the material and hasten the excavation activity However this will not in any way entitle the material to be classified as hard rock 3532 Hard Rock Any rock excavation other than specified under fissured rocksoft rock above for which blasting drilling chiseling are required Where the soil is of composite nature classification of foundation will be according to the type of soil which is predominant in the footing The decision of the Engineer‐in‐charge shall be final and binding with reference to classification of soil and foundation to be adopted at that particular location The adoption of footing depends upon the type of Soil and the tower loadings The foundation to be adopted therefore depends upon the type of soil quantum of tower loading and preference for structural arrangements of footing 36 Hard Rock Excavation Where rock is encountered the holes for tower footings shall preferably be drilled but where blasting is to be resorted to as an economy measure it shall be done with the utmost care to minimize the use of concrete for filling up the blasted area All necessary precautions for handling and use of blasting materials shall be taken If inadvertently large quantities are excavated blasted the full volume excavatedblasted shall be filled with the structural concrete If this is not adhered to there are chances of reduction of reliability of foundation against upward loads In case where drilling is done the stubs may be shortened suitably with the approval of the owner or his authorized representatives The excavation shall be carried out strictly as per the excavation plan approved by the ownercustomer for the particular type of structure withwithout extension and the particular type of Soil Rock However while re‐working the CC distance between the two pits will be with reference to the junction of reduced chimney and footing 37 Blasting Material The Contractor shall procure requisite blasting material and be responsible for the purpose of the storage and use of this material Necessary permissionapprovals from the concerned Government department may be obtained by the contractor 38 Shoring and Shuttering If pits excavated in sandy soil or water bearing strata and particularly black cotton soil where there is every likelihood of pit collapse shoring and shuttering made out of timber planks of 30‐35mm


thickness or steel frames of adequate strength to suit the requirement will be provided Sand beddingstone bedding will be provided in foundation of marshy and wet black cotton foundations which will work as a sub‐grade 39 Dewatering Dewatering shall be carried out manually or by mechanical means or power driven pumps to facilitate excavation and casting of foundation The pumps shall be suitable for handling muddy water Dewatering is not necessary in case of bored foundations extending below water table The size of the mechanicalelectrical pump will depend upon the quantum of water required to be handled per hour In areas where sub‐soil water recoupment is heavy and where water cannot be controlled even by use of power driven pumps well point system is used for controlling water In this system a grid of pipes are laid around the area where the pits are excavated and the system is very effective in pumping water particularly in sandy soils After commencing pumping operation the pit can be excavated avoiding risk of collapse of earth 310 Setting of Stubs The stubs shall be set correctly in accordance with approved method at the exact location and alignment and precisely at correct levels with the help of stub setting templates and leveling instrument Stubs shall be set in the Presence of Ownerrsquos representative available at site where required The stubs are set in such a manner that the distance between the Stubs the alignment and slope are as per the approved misfit and design so as to permit assembling of the superstructure without undue pre‐stress strain or distortion in any part of the structure There are three methods by which this is generally accomplished

bull Use of combined Stub‐setting Template for all the four stubs of the tower including extension portions

bull Use of individual Leg Template for each stub bull Use as a Template the lowermost tower section or extension where Stub‐setting Template is

not available The first method is the most commonly used

bull The Stub‐setting Template comprises a light rigid square framework which holds the four stubs at the correct alignment and slope in four corners

bull The Stub‐setting Template generally of adjustable type which can suit the standard tower as well as towers with standard extensions of 3 meter amp 6 meter height

bull The Template is centered and leveled by sighting through transit bull The anchors or stubs are bolted to this Template one at each corner of the Template and are

held in their proper position until the concrete is poured and gets hardened The second method is adopted for casting the foundation locations having individual leg extensions or locations having broad base of Tower

bull In such case it is not possible to use the four legged stub setting template for various reasons related to design and construction

bull The answer to this problem is individual leg stub‐setting template bull The individual Leg Template comprises a steel channel or joist having a length more than the

size of the pit by about 2 to 3 meters bull A chamfered cleat is welded in centre of the channeljoist to provide the slope to the stub


bull The stub is bolted to the cleat of the Template with holes as required for the slop of the stub is provided

bull The individual Leg Templates are initially set on each pit approximately to the required position with reference to the centre point of the tower and with the help of a Theodolite (or Total Station) Dumpy level and a measuring tape before fixing form boxes and pouring concrete

bull The other version of individual leg extension is cut corner sections of conventional stub‐setting template

bull This is easy to fabricate and deploy at site bull This type of Template are very useful for casting the foundations of individual leg extensions in

which the foundation pits are staggered and use of either a normal Stub‐setting Template or the first section of the tower is not feasible

In the third method lower section of the tower or extension is used for setting stub bull In this method two opposite sides of the lower section of the tower are assembled horizontally

on the ground and the stubs are bolted to the same with correct slope and alignment bull Each assembled side is then lifted clear of the ground with a gin pole and is lowered into the

four pits excavated at four corners of the tower to their proper size and depth bull The assembly is lifted in such a manner that stubs are not damaged bull One side is held in place with props while the other side is being erected bull The two opposite sides are then laced together with cross members and diagonals bull Then the assembled section is lined up made square with line and level after the proper

elevation and leveling have been done the bolts are tightened to make the frame as rigid as is reasonably possible

bull Thereafter the form boxes for foundations are built and the concrete is poured bull For heavy towers use of this method is not recommended bull For heavy towers use of Stub‐setting Template is recommended as propping jacking leveling

etc will be very difficult

COMPAQ
CUNSTRUCTION OF UNEQUAL LEG EXTENTIONSdwg


311 Mixing Placing and Compacting Of Concrete It is normal practice to use coarse and fine aggregates available along the line route andof nearest locations to the route so as to have economy and better progress Ordinary plain or reinforced cement concrete given in IS 456‐1978 shall be used in overhead line foundations For main foundation M15 or 124 mix cement concrete shall be used For lean concrete sub basis or pads M 10 or 136 mix cement concrete may be used The properties of concrete and mix proportions shall be as given in IS 456‐1978 It shall be permissible to proportionate the concrete as follows Prepare a wooden measuring box of 35 lit capacity (ie equal to 1 bag of 50 kg of cement) with inside dimensions of 30 cm x 30cm x 39cm alternatively a cylinder of 34 cm diameter and 39 cm height shall be made ready for the proportioning

bull The mix quantities according to the measuring box shall be as follows M20 (1153) M15 (124 mix) M10 (136 mix) bull Cement 10 1 Bag 1 Bag bull Sand 15 2 Boxes 3 Boxes bull Metal 30 4 Boxes 6 Boxes

The required quantity of water shall be used for concrete mix The water should be free from oilacid and any other impurities Saline water or sea water should not be used for the concrete work The concrete shall be mixed in the mechanical mixer only However in case of difficult terrain hand mixing may be permitted at the discretion of Engineer In charge Mixing shall be continued until there is uniform distribution of material and the mix is uniform in color 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 or setting The concrete shall be placed and compacted before setting commences Mechanicalpneumatic vibrator shall be used for obtaining homogenous concrete work and for better finish as well as avoiding honey combing 312 Specification For From Box 3121 The general requirements of form box are as under

bull The form work shall conform to the shape lines and dimensions as shown on the approval foundation design drawings and be as constructed as to the rigid during the lacing and compacting of concrete and shall be sufficiently tight to prevent loss of liquid from concrete

bull It shall be of right design easily removable without distortions and shall be of steel or suitable materials

bull The inner surface coming in contact with concrete shall be smooth and free from projections bull Window on one face shall be provided for pyramid forms to facilitate concreting in the lower

parts which shall be fixed after concrete in the bottom part is placed bull The form work for slabs and pyramids shall be made symmetrical about the base of the

chimney to ensure interchangeable faces


3122 Clearing and Treatment of Forms bull All rubbish particularly chippings sawdust and traces of residual concrete if anyshall be

removed from the interior of the forms before the concrete is placed bull The surface in contact with the concrete shall be wetted and spread with the fine sand or

treated with an approved compositions such as black or waste oil etc before use every time bull The concrete shall be poured in 150mm layers and consolidated well so that the cement cream

works up to the top and no honey‐combing is left in the concrete bull The mechanical vibrator shall be employed for compaction of the concrete bull However in case of difficult terrain manual compaction may be permitted at the discretion of

site Engineer bull 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 rain water falling on the coping

3123 Wet Location bull In wet locations the site must be kept completely dewatered both during the placing of the

concrete and for 24 hours thereafter bull There should be no disturbance to concrete by water during this period

3124 Removal of From Box After the form work 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 Ownerrsquos representatives before the foundation pits are backfilled 313 Back Filling and Removal of Stub Template 3131 Process of bake filling The back filling work is very important for the stability of the foundation Following is recommended

bull Backfilling shall normally be done with the excavated soil if the excavated material includes large bouldersstones the boulders shall be broken to a maximum size of 80mm

bull At such locations where borrowed earth is required for backfilling this shall be done by the Contractor as per the rates terms and conditions laid down in the contract

bull If the foundation cast is rocky type backfilling with the borrowed earth may not serve the purpose


bull In such a case backfilling with chipped stones mixed with the cement slurry would be a better option

bull However this would be done as per the instructions of the engineers in change 3132 Material for bake filling The following is required to be noted for the back filling material

bull The backfilling materials should be clean and free from organic or other foreign materials bull The earth shall be deposited in maximum 200mm layers leveled and wetted and tampered

properly before another layer is deposited bull Care shall be taken that the backfilling is started from the foundation ends of the pits towards

the outer ends bull After the pits have been backfilled to full depth the stub template may be removed bull In case of urgency the template can be removed even after 50 of backfilling of the soil bull The backfilling and grading shall be carried to an elevation of about 75mm above the finished

ground level to drain out water bull After backfilling 50mm 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 3133 Curing The strength of concrete work depends upon the curing provided to it Following requires to be noted

bull The concrete after setting for 24 hours shall be cured by keeping the concrete wet continuously for a period 10 days after lying

bull The curing will be done from the top of the pit within the embankment area bull No saltish or brackish water shall be utilized for curing

3134 Earthing Earthing of tower is very important for the performance of insulators and conductor of the transmission line Each tower shall be earthed after the foundation has been cast For this purpose earth strip shall be fixed to the stub during concreting of the chimney and taken out horizontally below the ground level In normal circumstances the earth strip shall be provided on No1 stub leg as given in the structural drawings Normally the tower leg whish has the step bolt is provided with the earthing strip Following may be noted

bull The footing resistance of all towers shall be measured by the Contractor in dry weather after the erection of superstructure but before the stringing of earth wire

bull In no case the tower footing resistance shall exceed 10 ohms bull In case the resistance exceeds the specified values multiple pipe earthing or counterpoise

earthing shall be adopted in accordance with the following procedure but without interfering with the foundation concrete even though the earth stripcounterpoise lead remains exposed at the tower end

bull The connections in such case shall be made with the existing lattice member holes on the leg just above the chimney top

Pipe type earthing and counterpoise type earthing wherever required shall be done in accordance with the stipulations made in IS3043‐1966 and IS5613 (Part IISection 2) 1976

bull Pipe type earthing The installation of the pipe type earthing shall be in accordance with IS 5613‐ 1985 (part IIsection 2) A typical example of pipe type of earthing is given


bull Counter poise type earthing

Counterpoise type earthing consists of four lengths of galvanized steel stranded wires each fitted with a plug for connection to the tower leg at one end The wires are connected to each of the legs and taken radially away from the tower and embedded horizontally 450mm below ground level The length of each wire is normally limited to 15 m but may be increased if the resistance requirements are not met (ie 10 ohms or less) Galvanized steel stranded wire preferably of the same size of the overhead ground wire may be used for this purpose Such type of earthing is provided for hilly terrain locations where earth pit excavation to a depth of about 25 to 3 m is not feasible and the resistivity of the earth is very high

40 Erection of Super Structure and Fixing Of Tower Accessories 41 The towers shall be erected on the foundations only after 10 days of pouring of concrete or till such time that the concrete has acquired sufficient strength The towers are erected as per the erection drawings furnished by the manufacturers to facilitate erection For the convenience of assembling the

COMPAQ
PIPETYPE TOWER EARTHING FOR LOW RESISTIVTY ZONEdwg
COMPAQ
COUNTER POISE TYPE TOWER ESRTHINGdwg


tower parts during erection operations each member is marked in the factory to correspond with a number shown in the erection drawing Any damage to the steel and injuring of galvanizing shall be avoided while the stringing work is in progress No member shall be subjected to any undue over stress during erection 42 Method of Erection There are four main methods of erection of steel transmission towers which are described below

bull Build‐up method or piecemeal method bull Section method bull Ground assembly method bull Helicopter method

43 Build up Method This method is most commonly used in this country for the erection of 66KV 132KV 220KV and 400KV transmission line towers due to the following advantages

bull Tower materials can be supplied to site in knocked down condition which facilitates easier and cheaper transportation loading and unloading

bull It does not require any heavy machinery such as cranes etc bull Tower erection activity can be done in any kind of terrain and mostly throughout the year (save

difficult time of heavy rain) bull Availability of workmen at reasonable rates bull In this method the tower is erected member by member bull The tower members are kept on ground serially according to erection sequence bull The erection progresses from the bottom upwards bull The four main corner leg members of the first section of the tower are first erected and guyed

off bull Sometimes more than one continuous leg sections of each corner leg are bolted together at the

ground and erected bull The cross braces of the first section which are already assembled on the ground are raised one

by one as a unit and bolted to the already erected corner leg angles bull First section of the tower thus built and horizontal struts (belt members) if any are bolted in

position bull For assembling the second section of the tower two gin poles are placed one each on the top

of diagonally opposite corner legs bull These two poles are used for raising parts of second section bull The leg members and bracings of this section are then hoisted and assembled bull The gin poles are then shifted to the corner leg members on the top of second section to raise

the parts of third section of the tower in position for assembly bull Gin poles are thus moved up as the tower grows This process is continued till the complete

tower is erected bull Cross‐arm members are assembled on the ground and raised up and fixed to the main body of

the Cross‐arm members


For heavier towers a small boom is rigged on one gin pole is used instead of two gin poles In order to maintain speed and efficiency a small assembly party goes ahead of the main erection gang and its purpose is to sort out the tower members keeping the members in correct position on the ground and assembling the panels on the ground which can be erected as a complete unit

COMPAQ

COMPAQ
tower under bottom cross-arm erectiondwg


44 Section Method bull In the section method major sections of the tower are assembled on the ground and the same

are erected as units bull Either a mobile crane or a gin pole is used bull The gin pole used is approximately 10 m long and is held in place by means of guys by the side

of the tower to be erected bull The two opposite sides of the section of the tower are assembled on the ground bull Each assembled side is then lifted clear of the ground with the gin or derrick and is lowered into

position on bolts to stubs or anchor bolts bull One side is held in place with props while the other side is being erected bull The two opposite sides are then laced together with cross members and diagonals and the

assembled section is lined up made square to the line bull After completing the first section gin pole is set on the top of the first section bull The gin rests on a strut of the tower immediately below the leg joint bull The gin pole then has to be properly guyed into position bull The first face of the second section is raised bull To raise the second face of this section it is necessary to slide the foot of the gin on the strut of

the opposite face of the tower bull After the two opposite faces are raised the lacing on the other two sides is bolted up bull The last lift raises the top of the towers

COMPAQ

COMPAQ
tower cross-arm under erectiondwg


bull After the tower top is placed and all side lacings have been bolted up all the guyes are thrown off except one which is used to lower the gin pole

bull Sometimes whole one face of the tower is assembled on the ground hoisted and supported in position

bull The opposite face is similarly assembled and hoisted and then the bracing angles connecting these two faces are fitted

45 Ground Assembly Method bull The complete tower is assembled in a horizontal position on an even ground bull The tower is assembled along the direction of the line to allow the cross arms to be fitted bull On slopping ground however elaborate packing of the low side is essential before assembly

commences After the assembly is complete the tower is picked up from the ground with the help of a crane and carried to its location and set on its foundation

bull For this method of erection a level piece of ground close to footing is chosen from the tower assembly

bull This method is not useful when the towers are large and heavy and the foundations are located in arable land where building and erecting complete towers would cause damage to large areas or in hilly terrain where the assembly of complete tower on sloping ground may not be possible and it may be difficult to get crane into position to raise the complete tower

bull In India this method is not popular because of prohibitive cost of mobile crane and non availability of good approach roads to tower locations

46 Tightening Of Nuts amp Punching of Threads and Tack Welding of Nuts 461 Following are the requirements for tightening of nuts and bolts

bull All nuts shall be tightened properly using correct sized spanners bull Before tightening it is ensured that filler washers and plates are placed in relevant gaps

between members bolts of proper size and length are inserted and one spring washer is inserted under each nut

bull In case of step bolts spring washer shall be placed under the outer nut bull The tightening shall be carried on progressively from the top downwards care being taken that

all bolts at every level are tightened simultaneously bull It may be better to employ four personnel (fitters) each covering one leg and the face to his

right bull The threads of bolts shall be projected outside the nuts by one to two threads and shall be

punched at three positions on the top inner periphery of the nut and bolt to ensure that the nuts are not loosened in course of time due to the effect of the vibration

bull If during tightening process a nut is found to be slipping or running over the bolt threads the bolt together with the nut shall be changed outright

bull To prevent the pilferage of the tower members it is a common practice these days to tack weld the nut with the bolt in threaded portion

bull The welding is generally done for lowermost two sections of the tower bull The galvanization of nuts and bolts is lost due to welding bull This has to be made good by the application of zinc rich paint


462 Painting of Joints For galvanized tower in coastal or highly polluted areas the joints shall be painted with zinc rich paint on all contact surfaces during the course of erection 463 Checking the Verticality of Erected Towers The finally erected tower shall be truly vertical and no straining is permitted to bring it in alignment Tolerance limit for vertical shall be one in 360 of the tower height 47 Tower Testing and Protomodel 471 Introduction Transmission line towers are highly indeterminate structures In the analysis of design of these structures and their detailing a number of theoretical assumptions are made The structures are mass produced and the quality of materials fabrication and the assembly require checking It is desirable that the Designers and Users both are convinced that the tower can stand and most critical loads for which it is designed and are therefore subjected to full scale prototype test For a Prototype test the material used shall be made to the same standards as those that will apply to all towers during mass production 472 Testing Requirements This full scale testing of tower is generally termed as Prototype Test and for conducting Prototype tests a tower testing station is required where it is possible to measure the applied loads and deflections and observe the behavior of the tower on application of the external design loads 473 Description of a Tower Testing Station A tower Testing Station shall consist of (i) A Test Bed to withstand maximum possible compression and uplift loads and shear resulting from the external loads on a prototype tower with the highest voltage and noofr circuits which has to be subjected to testing at the Testing Station (ii) Permanent Anchors of adequate capacity to take the Transverse Longitudinal and Vertical Pulls applied to the tower of maximum expected with height and strength proposed to be tested on a test bed Longitudinal Mast(P) is a structure of adequate dimension and height constructed at a sufficient distance from the tower bed and equipped with all Riging arrangements for applying longitudinal loads The Transverse loads are applied through pulleys positioned on the Transverse Mast (B) Vertical loads are applied by means of dead weight or through anchors on the test bead (iii) The arrangements for applying the combination of given loads at a specified rate of increase if required with the help of a Multi Sheave Pulley to take mechanical advantage and reduce load on the winch (iv) Electrical Winches operated by remote control from a Central Control Room used for applying loads at the different points of tower structure as far as possible simultaneously Instruments used for recording the load applied are either Mechanical Spring Gauges or ElectricalElectronic TransducersDynamometers The dials of the respective DynamometersTransducers indicate the load in the particular wire Transverse amp longitudinal deflection readings are taken by Theodolities on scales fitted at appropriate positions on the tower (v) Remote control of loading mechanisms (vi) Remote and precise reading of measuring instruments like Mechanical Spring Gauges or ElectricalElectronic TransducersDynamometers


(vii) Arrangement for calibration of the measuring instruments From Control Room the winches and the dynamometers are operated controlled Control room shall have the facility to have the complete view of transverse and longitudinal testing arrangements of the test tower All the electrically operated machines and instruments shall be connected to and controlled from the Control Room 474 Calibration In order to ensure the correctness and reliability of all measuring instruments and in turn the validity of the tests the calibration of all instruments before the test is conducted Calibration of the load cells is done with the use of UTM the UTM shall be periodically (once in every six months) calibrated by an external third party 475 Assembly of Prototype Tower The prototype tower fabricated as per structural drawings approved by the Purchaser shall be assembled and erected on a fixed base Fitment of any member shall be easy natural and shall not be a forced one The Bolts should be tightened simultaneously on all four faces 476 Rigging Arrangements And Location of The Load cells To enable application of the external loads in the most representative manner and to simulate tower design conditions the tower structure is rigged suitably impact of any variance in inclination of rigging wires with respect to the directions accounted for in designs is considered while preparing Rigging Chart Loads are applied as per these approved rigging charts The load cells shall be attached to the tower through the rigging wires positioned as close as possible to the test tower so that frictional losses do not cause impact on the load cells 477 Test Procedure The Prototype Tower is erected on the test bed and all the rigging arrangements are completed The Tower is examined carefully to see that all the bolts and nuts are tightened properly The tower is made truly plumb and square All its members are checked for freedom from any visible defect Two graduated metallic scales are fixed at Peak and Top Cross arm level on the transverse face Readings on these scales with reference to the plumb line are taken by Theodolite 478 Testing of Prototype Tower 4781 Bolt‐Slip Test In order to eliminate as far as possible the play between the bolts and the holes throughout the structure Bolt take‐up test is done in the beginning Under this test all the transverse and vertical loads are increased simultaneously as far as possible to 50 of the ultimate normal condition (Reliability Condition) loads The loads on the tower are held for 1 minute Transverse deflection readings are taken for NO LOAD and LOADED conditions The loads on the tower are then reduced to zero or to as low a value as possible The deflection reading is once again taken for this Zero loading The differences between the two zero readings are the permanent deflections on tower For subsequent test purposes the readings with zero loads taken after the Bolt Slip Test taken are considered as the initial readings 4782 Sequence of Test Loading Cases Sequence of test loading cases shall be pre‐determined The choice of the test sequence shall largely depend upon simplification of the operations necessary for carrying out the test programme


4783 Details of Tests Test 1 (Broken wire Condition) Security and Safety Conditions as well as Anti‐cascade conditions Under this condition (all conditions involving longitudinal loads in addition to the transverse and vertical loads) all the transverse and vertical loads are first increased to about 100 Longitudinal loads are then increased in steps of 50‐75‐90‐95 of the ultimate loads At all stages of loading it shall be ensured that the transverse and vertical loads are not less than the values for corresponding step of the longitudinal load At each step the loads are maintained for one minute and the deflections are noted All loads are then increased to 100 At this final 100 loading stage towe3r is observed for 2 minutes and deflections are noted The tower is required to withstand these loads without showing any failure After every test the loads are brought down and deflection readings are taken for no load condition Test 2 (Normal Condition) Reliability Condition These loads are applied as far as possible simultaneously at all points in steps of 50‐75‐90 amp 95 The waiting period of one minute shall be maintained at each step The waiting period at the final 100 loading stage shall be 2 minutes Throughout the process of loading under all tests the tower shall be closely observed for any visual sign of deformation Whenever such deformation is observed the loads shall be brought down and remedial measures shall be taken It is pointed out here that the tendency of bowing in bracings shall not be considered as a sign of failure even though it is during the final waiting period Test 3 Destruction Test If no Destruction Test is required by the Purchaser the loads on tower after 100 under Test‐2 above shall be gradually brought down to zero If desired by the Purchaser in continuation to test 2 after the final waiting period the transverse loads only are increased in steps of 5 till the failure occurs The Destruction test however ca be discontinued beyond a certain limit on mutual agreement between the Purchaser Design amp Testing Station Authority The point of failure is detected from the sudden drop of load indication in the instrument dials in the Control Room 478 Special Requirements

bull The test tower shall be black or galvanized tower as desired by Purchaser

bull The tower which has been tested shall not be part of supply and is not to be used online

bull Test tower shall be provided with unbraced portion of stub equivalent to distance of chimney top to the point of connection of bracing with leg

bull During the process of tower test when a number of tests have been completed satisfactorily and a failure occurs as a subsequent test the design will be reviewed and tower will be reinforced if required The reinforced tower will be put to test again and subjected to balance tests unless the failure is of major nature which will require all the tests to be repeated or as mutually agreed between the Purchaser and the Supplier

bull Application of Loads on Test‐Tower As considered in design

Transverse longitudinal and vertical loads At peak and respective cross‐arm points (i) Wind load from top at peak and respective cross‐arm points upto bottom cross‐arm will be simulated suitably at ground‐wire Top Cross‐arm Middle cross‐arm and Bottom cross‐arm levels


(ii) Wind loads on tower below bottom cross‐arm will be simulated to act at bottom cross‐arm point and test will be carried out accordingly (iii) For tower with extension wind load on extension will be simulated on Top of Extension

479 Acceptance of Test Results Test is considered as passed if tower is able to withstand the specified ultimate loads (100 step) with no visible sign of deformation for the specified waiting period A detailed report incorporating test data and the results of complete tests along with photographs of the tower shall be prepared by the test‐authority in quadruplicate 4710 Presentation of Test Results

50 Conductor amp Conductor Accessories 51 Conductors The different types of conductors are used on the transmission line depending upon the voltage class and amount of current to be handled In India it is a standard practice to use following conductors for different voltages 1 66kV ‐ACSR ldquoDogrdquo conductor 2 66 132kV ‐ACSR ldquoPantherrdquo conductor 3 220kV ‐ACSR ldquoZebrardquo Conductor 4 400kV ‐ACSR Twin Bundle ldquoMoose ldquoConductor

TABLE ‐1

Sr No

Name of

Conductor

Normal operating voltage

kV

Size amp stranding

Alu Steel Nomm Nomm

Current carrying

capacity at 75ordmC (Amp)

Over all

dia cm

UTS Kg

Unit

weight KgMtr

1 ACSR Dog

3366 6472 7157 300 12

3299 0394

2 ACSR Panther

66132 3030 730 480 210 9177 0976

3 ACSR Zebra

220 54318 7318 735 286 13316 162

4 ACSR Moose

220400 54353 7353 800 318 16250 202

For special industrial connections at EHV the conductor size shall be worked out on the basis of maximum system current The insulation is provided in accordance with the voltage 52 Insulators 521 The standard type of conductor if used has also an advantage that the current carrying capacity voltage loading limit and impedances are also standardized and well defined Thus there is an easy access for a system analyzing engineer for evaluation and assessment of power flow and optimum line loading Thus the current loading limit and power transfer capability of various transmission lines are given in Table‐2 They are based on the allowable voltage regulation on EHVUHV lines

SrNo Line Voltage Power Transfer capability per 3‐phase Circuit(MW)

50kM 100kM 200kM 300kM


1 66kV 22 11 55 36

2 132kV 120 60 30 20

3 220kV 400 200 100 67

4 400kV 1500 750 375 250

522 In case of transmission line having a concentrated load and low voltage it may become mandatory to use higher size of conductor eg system having 33kv line voltage with two loads of 10 and 30MW at end of 4 to 5kM long feeder may require ldquoZebrardquo conductor to be strung on it Since with reduction in voltage the current to be carried becomes very high and use of lower size of conductor may be hazardous Similarly a lightly loaded 132kV lines can also be strung with ACSR ldquoDogrdquo conductor The thermal loading limits of the conductor are increasing day by day Of‐late it has been customary to consider 75ordmC as a maximum surface temperature of the conductor Operating lines at high thermal limits is not advisable due to two reasons i) Line losses increase with increase in temperature ii) Sag may increase bringing down the statutory clearance below the conductor to non acceptable level With this in view the conductors used in the substation buses are one size up in diameter or in bundle configuration Thus the 220kV side bus of 400kV substations may have quadruple ldquoMooserdquo conductor and 66kV bus of 220kV substation may have a Twin ldquoZebrardquo or Twin ldquoMooserdquo conductor (Bus) 53 Choice of Insulators The glazed disc type porcelain insulators have been a standard material in use for last 50 years in this country The insulator string consist of No of disc unit in optimum width at about 135kV per disc up to


a voltage of 220kV For 400kV class of line the insulator size and creep age distances are higher and thus No of insulators to be used are 23 for suspension and 24 for tension tower The important parameters for disc insulator string used in various voltage of transmission line are given in Table‐3

Table‐3

Sr No

Line

Voltage

Size of each

insulator disc(D x H)

mm x mm

Electro‐mech

StrengthKg

Noof insulators per string

Single Double

No No

Weight of Insulator

String Single

Double Kg Kg

Length of insulator

string Single

Double mm mm

1 66kV Suspension Tension

255 x 146 255 x 146

7000 8180

5 6

10 12

75 85

150 170

1000 1140

1300 1280


255 x 146 255 x 146

8180

11500

9

10

18 20

120 130

240 260

1600 1790

1716 2190


255 x 146 255 x 146

8180 11500

14 15

28 30

130 140

260 280

2340 2850

2640 3200


255 x 146 255 x 146

11500 16500

23 24

46 48

275 640

550

1280

4200 5900

4400 6200

531 Other insulator types in vogue these days are a solid core insulator stack and high density polymer insulator Even though the polymer long rod insulators are simpler and low weight they are yet to be popular in this country because of very high cost 532 The design of insulators does not only depend upon the creep age `distances but they have many intricacies such as the type of material used in the insulators capacitance grading thermal capability back flash over etc 533 The insulators used on the line are also governed by the basic insulation level selected in power system 534 The choice of disc insulators to be used depend upon the terrain amp the pollution level through which the transmission line has to pass and thus fog type and antifog type disc insulator are in use for different applications The antifog type insulators are in use for different applications The anti‐fog type insulators are found most suitable in the polluted atmosphere 54 Conductor Accessories 541 Mid span Joint ndash It is used to provide joint in the conductor For AC Conductor the joint comprises one small steel tube and the other bigger Aluminum tube The steel tube is compressed (crimped) against the two ends of Steel which are exposed by peeling of the Aluminum Strands for half the length of steel tube strands of ACSR amp the Aluminum strands Hydraulic equipments are used for crimping For AAAC or AAC conductor only Aluminum tube is used which is also crimped after steel tube is crimped after sliding over the crimped steel tube


542 Repair Sleeve ndash It is used when one or two strands of the outer Aluminum strands are broken The sleeve is manufactured in two parts longitudinally and circumferentially major part is 70 on diameter and minor part is 30 on diameter The length of both the parts is the same After sliding both the parts on the conductor the sleeve is crimped on the affected part

543 Pre‐formed Armor rods ndash This is a set of twelve helical right hand ball ended Aluminum rods of appropriate length The set is wound on the conductor at suspension tower location and then the entire assembly along with the conductor is clamped in the suspension clamp The PA rods prevents damage and reduces fatigue on the conductor due to the relative movement of the clamp and the conductor and also helps in reducing the effect of conductor vibration on clamp amp the tower cross‐arm

544 Vibration Dampers ndashThey are used to damp the Aeolian vibrations on the conductor The dampers are clamped to the conductor near the cross arm point on both the sides at a distance of 3 to 5Mtr The vibration damper comprises a clamp a messenger cable and dead weight The dampers can be solenoid type or 4R type


545 Spacer cum Dampers‐ They is used for bundle conductor spacing and for damping the vibrations They comprise two arms with clamping device and a spacing yoke having a spring action They are made of Aluminum 546 Cushioned (Armour grip) spacers‐ They are used as spacers for bundle conductor with amour grip They comprise an aluminum rod two neoprene rubber jaws and two sets of armour rods (each having six rods) Rigid spacers are used for twin bundle conductor jumpers 547 Earthwire ndash The earth wire is used for protecting the conductor in the mid span It is provided at such a height which affords an angle of shield not more than 30ordm with Top conductor The common size of earth wire used is 7315 and 7366 In case of 400kV and above two earth wires are used for better protection Earth wire Accessories includes the following 5471 Suspension Clamp ‐ This is used for suspending the earth wire through the earth wire peak of the transmission tower The earth wire passes through the suspension clamp


5472 Tension Clamp ‐ This is used on tension locations of tower and provided in tension position on both the sides of the tension tower

5473 Copper Earth bond‐ This is used for providing direct passage to the lightning surge to the tower The copper bond is made out of stranded copper mesh with two lugs on the ends and is about 500mm long One end of this is connected to the suspensiontension clamp of earth wire and the other end is connected to the tower body


5474 Cross bye clips (sister wire clamps) ndash This is used for providing better continuity to the earth wire They are nothing but a sort of parallel groove clamp They are provided in set of three from either side of the tower

5475 Mid Span Joint ‐ This is used to connect the cut ends of the earth wire This is nothing but a steel tube which is crimped on the ends of the earth wire

548 The Insulators are connected in series or in series ndashparallel to form a single or double string on the tower Suitable hardware is required for securing the insulators to the tower The insulator hardware commonly used is as follows‐ 5481 Single Suspension hardware ndash This is used on suspension locations of the tower line falling in the rural areas and also falling in the agricultural field The hardware has a hook on the tower side and socket on the conductor side


5482 Double Suspension hardwaremdashthis is used on suspension tower locations which require a road crossing or a railway crossing amp river crossing They have anchor and a yoke on the tower side and yoke amp sockets on line side They also have a Suspension clamp on the line side

5483 Single Tension hardwaremdash This is used on tension tower locations This hardware has a shackle on the line side and a dead end clamp on the line side

5484 Double Tension hardwaremdash This is used on tension tower location having a major road crossing river crossing power line crossing railway crossing etc They have D‐shackle yoke on tower side and yoke dead end clamps on the line side


55 Relation of Conductor With Transmission Line Components 551 The Transmission line components described above has relation with the conductor Some salient points are described below‐ The earth wire provided on the tower provides a cover to the conductor against lightning surges if the conductor is placed within an umbrella of 30ordm degrees If earth wire is not provided or is missing the conductor will be loaded by lightning and stray discharges The conductor will carry this along the line and insulators may get damaged The earth wire accessories help in supporting the function of earth wire The transmission tower provides full support to the conductor with two extremities ndash a) To allow sufficient ground clearance and object clearance to the conductor under maximum temperature amp still air b) Absorb the maximum tension of the conductor under 0ordmC temperature with certain percentage of wind pressure Any deficiency in the tower design will lead to a catastrophe 552 The insulators keep the conductor in position on suspension and tension locations amp also insulate the conductor from the tower body Any damage to insulator will cause a short circuit on the conductor and may also lead to the break down 553 The hardware part of the insulator string is very important for the performance of the conductor Any loose end will result into damage to the conductor The hardware permits the conductor to swing to some extent and also restrains the conductor from over swing 554 The earthing system provides a safe passage to the fault current amp lightning switching surges If earthing system is poor the life of conductor and insulator will be reduced 555 The long span of River amp Creek Crossing imposes differential stresses due to variation in wind pressure and temperature along the long span The length of the catenary is very long amp therefore the conductor swing is also very big The variation in wind velocity over tall tower also steps up the vibration level

60 Stringing of Conductor and Ground Wire

61 Stringing is the last major item of construction activity The stringing activities are most important and time consuming activities in transmission line construction This requires much skill and technical know‐how The stinging crew shall include skilled laborers experienced fitters and supervisor The stinging tools and tackles should be of good quality and in good working condition


62 The stringing activities are mainly consisting of the following bull Hoisting of insulators bull Paying of conductorground wire bull Rough sagging of conductor bull Final sagging of conductorground wire bull Clippingclamping of conductor and jumpering

63 Hoisting of Insulators Following may be noted for hoisting of insulators

bull The insulators used on transmission lines are 11KV antifog type Disc insulators having capacity as 70KN 90KN 120KN and 160KN

bull The suspension insulator strings shall be used on all suspension locations (tangent towers) and tension insulator strings on all tension locations (angle towers having153060deg Deviation and Dead end towers)

bull The insulator strings shall be assembled on ground bull All the insulators shall be cleaned and examined for hair cracks or any damage bull The strings are then hoisted and fixed to the tower cross‐arm along with hardware and Arial

rollers bull The security clips (R pinW pin) should be properly placed before hoisting

COMPAQ
PROCEDURE FOR STRINGING OF CONDUCTOR WIRESdwg


64 Paying out of ConductorGround wire Following may be noted for paying of conductor

bull Before commencing of string works copies of sag tension charts (supplied by the design department) showing initial and final sag should be made available at site to EIC

bull Normally ground wire drums are mounted on turntable near tension location bull The ground wire is pulled manually or by tractor along the line The ground wire running blocks

are hoisted on the towers prior to taking up this operation bull The ground wire drums should be opened and laid carefully in such a way to avoid

cracksdamages bull It should be ensured that no joint in ground wire is within 30m from the suspensiontension

clamp bull Sufficient number of aluminum snatch blocks shall be used for paying out of conductor bull Precautions should be taken to avoid conductor rubbing on the ground by providing adequate

number of ground rollers bull Additional rollers shall be provided for crossing thorny hedges fencing and other obstructions

which are likely to cause damage to the conductor bull No joints of conductor shall be allowed within 30m from suspensiontension hardware bull In case of railwayroad crossing spans no joints shall be permitted Further not more then one

joint in a span of each conductor shall be permitted bull Prior to taking up of conductor paying activity the areal rollers are fitted to the towers along

with suspension strings bull The conductor drums should be handled carefully at site to avoid any damage to the outer

aluminum layer bull The mid span joints and tension hardware are compressed by using hydraulic compression

machine bull All the compression joints shall be carefully made and a record of initial and final lengths of the

joints signed by the contractorrsquos and purchaserrsquos representative should be maintained 65 Rough Sagging of Conductor

bull On completion of conductor paying work between two tension locations (ie is line section) the conductors of all the phases shall be anchored near the tension location

bull During the rough sagging the conductor will be lifted above the ground by about 3 meters bull Thus the tension on the wire will minimum

66 Final Sagging of ConductorGround wire Following may be noted for final sagging of conductor ground wire

bull The conductor and ground wire shall be made to sag correctly as per the approved stringing charts

bull All conductors shall be stressed to their maximum working tension at the time of stringing according to the sag tension charts

bull Dynamometers shall be used in tensioning of conductors check for sag should also be made at intervals corresponding to the ambient temperature shown by the thermometer placed at site

bull Extra sag of 150mm should be allowed at all important tension locations of railway crossing major road crossing river crossing spans


bull It should be ensured that the conductor ground wire after being pulled shall not be kept on stringing sheaves for more than 72 hours before being pulled to the specified sag

bull During the time when conductorground wire is on the stringing sheave (before final sagging) it shall be ensured no damage of conductorground wire occurs due to wind vibrations vehicles or any other reasons

bull The conductor shall be pulled up to desired sag (final sag) and left in aerial stringing sheaves for at least one hour After which the sag shall be rechecked and adjusted if required before clipping work is taken on hand

bull During final sagging of conductor the sag at intermediate spans should be verified with the help of sag board provided at suitable distances (as per the approved stringing chart and the corresponding site temperature) on the tower body of intermediate locations

bull The stringing of bundle conductor (two or more conductor) shall be carried out by using tension stringing equipment

bull Using this method the conductors are kept under tension during the stringing process to keep conductor clear of the ground and obstacles which may cause conductor surface damage as well as clear of the energized circuits

bull This method is applicable where it is desired to keep the conductor off the ground to minimize surface damaged or in areas where frequent crossings are encountered

bull The equipments involved in this method are reel stands tensioner pullers reel winder pilot line winder splicing cart and pulling vehicle

bull One more important reason to use the tension stringing equipment for stringing of bundle conductor is to release payout rough sag and final tensioning of all the sub‐conductors of the bundle under equal physical tension

bull This will ensures equal sags of each sub‐conductor in a span and sub‐span 67 ClippingClamping of Conductor and Jumpering The clippingclamping work includes fixing of suspension hard wares providing of preformed armour rods removal of aerial sheaves etc Following required for clipping clamping

bull Conductor shall be clamped within 24 hours of final sagging bull The sag before clamping should be checked in the first and last span of the section having

eight spans bull The check should be provided at intermediate span also if the section is having more than eight

spans bull At all the suspension locations the preformed armour rods shall be wrapped keeping the

centre of the preformed armour rods at the centre point of the stringing sheaves bull Care should be taken to see that all the strands of the rods are fixed on the surface of the

conductor without any void bull The suspension clamps of the suspension hardware should be fixed (bolted) at the centre of the

preformed armour rods bull The vibration dampers should be fitted on tension locations at an appropriate distance from

the tension hardware (specified by the design department) during the rough final sagging of conductors

bull The vibration dampers on suspension locations shall be fitted at an appropriate distance on either side of the suspension hardware as specified


bull The jumpering work of conductor includes cutting of proper length of jumper providing of jumper cones on both the ends of jumper fixing of the jumper to the tension hardware on either side of the tension location etc Care should be taken to compress the jumper cones with hydraulic compressor machine so as to have firm grip with the conductor

bull The tightening of boltsnuts should be proper over tightening should be avoided bull The clearance with the tower body after providing jumpers shall be checked as per the

approved tower drawing bull The ground wire jumpers are also prepared using appropriate length of ground wire having

compressed jumper cones on either side bull The prepared jumpers shall be then fitted to the tension clamps on either side of the tension

locations bull An additional ground wire piece called sister wire is fitted on the newly strung ground wire at

the top of all the locations using 2 to 3 numbers of cross by clips also known as sister wire clamps on either side of the locations

bull The bolts and nuts of cross by clips should be properly tightened bull The vibration dampers for ground wires shall be provided at appropriate distance on either side

of the location as specified bull The earth wire stringing is normally done before the stringing of conductor bull The rough sagging and final sagging is done exactly as per the procedure described for

conductor bull The approved stringing charts are used for stringing of earth wire bull After final tensioning of the earth wire the suspension clamps are provided on the suspension

locations and compression type dead end clamps are provided on the tension locations bull Jumpering work is done on the earth wire tension tower bull Sister wires and clamps are provided on each tower making an additional loop on the top of the

earth wire point which also ensures better conductivity amp continuity bull The earth wire suspension and tension clamps are connected to the main tower body using

braided copper earth band bull This earth bond gives direct path to the lightning discharges traveling on the earth wire to the

mother earth through towers and safe guards the conductors bull Vibration dampers are also provided on the earth wire to damp the Aeolian vibrations The

clamps are required to be properly tightened to ensure proper connectivity and trouble free service

68 Fixing of Tower Accessories After the stringing work is done it is necessary to fix the tower accessories such as phase plate Number plate Danger plate Circuit identification plate Anti climbing devices etc as per their respective position shown on the structural drawings 69 Protection of Towers

bull In the hilly terrain the foundations of the tower are susceptible to the damage due to the erosion of soil covering it

bull This happens because of gushing water from upstream Sometimes the tower is spotted on the ravines or river banks and one or more of the four tower legs are subjected to soil erosion

bull In both the above cases it is usual to provide retaining wall and or revetment


bull Whenever the Transmission line is passing through a corridor having major road on both the sides or the tower line is passing very near to the major road it is necessary to provide a steel barrier around the tower up to height of 3 meters

bull This barrier has to be sufficiently strong and made out of girders and channels bull The barriers have to be well founded to take the impact of the dashing vehicles

70 Details of Manpower Tools Tackles Equipment Vehicles and Infrastructure Required For the Construction of The EHV Transmission Line 71 The details of man power tool tackles equipments and vehicles required for the construction of EHV line of various voltage classes such as 66 KV 132 KV 220 KV and 400 KV etc are given here after The erection activities are spread over a long period and are mostly carried out in the rural areas and therefore appropriate infrastructure is required The activities are labor oriented and besides there are restrictions on the use of automatic machineries due to the constraint of cost and the constraint of movements in the rural and in‐accessible tower and line locations The transmission line construction activity generally includes‐

bull Survey and alignment bull Foundation work bull Erection of super structure bull Stringing of shield wire and conductor bull Testing and Commissioning

Each of the above activity need different types of tools tackles man power etc The details given here under give a broad view of the tools tackles equipments man power and other infra structure required in the construction of EHV transmission lines 72 Infrastructure for Survey

bull This is the first and foremost activity in the transmission construction bull Expert surveyor assisted by helpers and suitable vehicles to carry instruments is the basic need bull This survey work is different from the survey work required to be done for civil establishments

COMPAQ

COMPAQ
RIVETMENT FOR THE TOWERdwg


bull The surveyor must have the knowledge of preparing profiles and also various methods to carry out the correct survey

bull The surveyor should also have in‐depth knowledge of tower spotting bull The infra structure required for carrying out survey work is listed below bull Average output per month per gang consisting of about 10 crew members will be

(i) Alignment survey 15 km (ii) Detailed Survey 20 km (iii) Check Survey 20 km

bull Wherever topographical survey is to be carried out the output will be less and will depend on the quantum of work and terrain

bull The output in hilly terrain may be substantially low bull Tools required for Survey Gang

Theodolite(or Total Station) with stand 1 NODumpy level with stand 1 NORanging rod 5 NOLeveling Staff 2 NOEngineers chain ‐30 m 1 NOEngineers chain ‐20 m 1 NOSteel Tape ‐30 m 1 NOSteel Tape ‐20 m 1 NOSurvey umbrella 1 NOChain pins 30 NO

Spades knives and exes for clearing the bushes and trees As per requirement

Tents buckets water drums camping cots tables chairs petromax etc As per requirement

Transport required for Survey Gang Jeep with trailers 1 NO 73 Foundation activity

bull This activity has to be carried out from location to location spread over a distance which is sometimes as large as 400 meters Excavation has to be carried out in various types of soils and rocks

bull The excavation plan will change accordingly Sometimes in hilly locations we may have to blast the rock In case sub soil water is encountered during excavations dewatering has to be resorted to In case soil collapse shoring and shuttering are required The foundation depth may vary from 1m to 5m depending upon the soilrock and decision regarding the type of foundation has to be adopted The infra structure required for this activity is as below

Average output per gang consisting of about 85 people per month will be

Excavation

60 msup3 Soft rock 400 ‐500 msup3 Normal soil

150 msup3 soft rock +180 msup3 normal

soil Output of hard rock will depend on situation


Stub‐setting amp Concreting 60 ndash 70 msup3 Tools and Plants required for Excavation Stub‐setting and Concreting Gang

Stub‐setting Templates As per

requirement Stub‐setting Jacks ‐do‐ Form boxesChimneys ‐do‐ Mixture Machine ‐Diesel engine driven 1 NO Mixture Machine ‐ Hand driven 2 NO Needle vibrator 1 NO Dewatering pump 2 NO Air compressor for drilling holes in rock 1 NO

High carbon drilling rods for drilling holes in rock As per

requirement Exploder 1 NO Water tanker trailor 1 NO Theodolite with stand 1 NO Ranging rod 3 NO Dumpy level with stand (or Total Station with Prism) 1 NO Leveling staff 1 NO Survey umbrella 1 NO Concrete cube mould (for testing the concrete) 6 NO

Wooden shuttering amp poles As per

requirement Mixing Sheets 12 NO Measuring Box 6 NO Metal screen (for course aggregate) ‐ 40 mm mesh 1 NO Metal screen (for course aggregate) ‐ 20 mm mesh 1 NO Metal screen (for course aggregate) ‐ 125 mm mesh 1 NO Sand screen ‐ 475 mm mesh 1 NO Empty barrel (200 liters capacity) 6 NO SteelAluminumWooden ladder (35m length) 5 NO 30 m metallic tape 1 NO 30 m steel tape 1 NO Engineersrsquo spirit level 2 NO Steel piano wirethread 50 m Crow bar 20 NO Pick axe 12 NO Spade 25 NO Shovel 8 NO Gamelas 30 NO Buckets 12 NO Iron rammer (45 Kg) 5 NO


Masonry trowel 6 NO Manila rope ‐ 38 mm dia 150 m Manila rope ‐ 12 mm dia 30 m Poking rod (16 mm dia) ‐ 3 m length 2 NO Poking rod (16 mm dia) ‐ 15 m length 2 NO

Blasting materials binding wire As per

requirement

Hammer Tommy bar plumb bob (045 Kg) Hook (12 mm dia) spanners (both ring and flat) etc

As per requirement

Tents buckets water drums camping cots Tables and chairs petromax etc

As per requirement

Transport required for Stub‐setting amp Concreting Gang Truck (For transportation of metal and sand from Source cement reinforcement steel and Other materials from site stores)

1 NO

Tractor with trailer 1 NO Motor cycle 1 NO

74 Tower Erection

bull Tower erection requires lot of precision Besides the material has to be lifted from the ground level to various heights depending upon the type of tower While erecting it is necessary that equilibrium is maintained and damage to the tower material and accidents are avoided The infrastructure required for this activity is given under

bull Average output per gang considering of about 50 crew members per month will be ‐ 80 MT bull Tools required for Tower Erection Gang

Ginpole Derric Pole ‐ 75100 mm dia amp 85 ndash 9 m length 2 NO Polypropylene rope ‐ 25 mm dia 700 m Polypropylene rope ‐ 19 mm dia 1000 m Single sheave pulley ‐ closed type 8 NO Single sheave pulley ‐ Open type 4 NO Crow bars (25 mm dia amp 18 m length) 16 NO Spanners (both ring and flat) Hammers Slings (16 mm dia amp 1 m length) Hooks (12 mm dia) lsquoDrsquo shackle tommy bars

As per requirement

Tents buckets water drums camping Cots tables chairs petromax etc

As per requirement

Transport required for Tower Erection Gang 1 Truck 1 2 NO 2 Tractor with trailer 1 NO 3 Motor Cycle 1 NO

75 Stringing Stringing work is almost the last activity save commissioning in the overall construction activities in the EHV transmission lines This is really a very precise and hazardous activity While stringing operations are on load balance and rigging arrangement has to be full ndash proofThe man power deployed has to be proportional to the actual physical tension


required to be given to the earth wires and conductors Excess man power may result into over tension and less man power may result into improper stringing and accidents The infrastructure required for stringing operations is given under

bull Average output per gang consisting of about 200 persons per month with Tension Stringing ndash Machine stringing method For 400 KV single circuit 15 km For 400 KV double circuit 8 km For +‐ 500 HVDC multi circuit 5 km

bull Requirement of man power and average output per gang for carrying out various types transmission lines by manual method is furnished here under Description of line Man power (NO) Average output month (km)

66 KV single circuit 75 30 66 KV double circuit 75 15 132 KV single circuit 100 30 132 KV double circuit 100 15 220 KV single circuit 125 30 220 KV double circuit 125 15 400 KV single circuit 225 15 400 KV double circuit 225 8

bull Tools and plants required for stringing Gang for TensionManual Stringing

TSE sets (Tensioner and Puller of 810 T capacity) 1 SET Running block for conductor 100 NO Running block for earth wire 60 NO Head Board 2 NO Pilot wire each of 800 m length 10 NO Pilot wire joint 12 NO Ground roller for TensionManual Stringing 30100 NO Wire mesh pulling grip (one end open) of required dia for conductor

6 NO

Wire mesh pulling grip (one end open) of required dia for earth wire

2 NO

Wire mesh pulling grip (double end open) of required dia for earth wire

4 NO

Articulated joint ndash Heavy duty (20T) 10 NO Articulated joint ndash Medium duty (10T) 10 NO Articulated joint ndash light duty (5T) 5 NO Drum mounting jack for conductor drum of 10T capacity 4 SETS Turn table (5T capacity) 2 NO Anchor plate (15 m x 10 x 8 mm) with 15 Nos anchor pins (45 mm dia amp 850 mm long)

Hydraulic compressor machine 100 T capacity with die sets 8 NO Traveling ground 12 SETS Dynamometer ‐ 10T 4 NO


Dynamometer ‐ 2 T 2 NO Pilot wire reel stand 4 NO Four Sheave pulley with 12 mm dia 300 m length wire rope 6 SETS Four sheave pulley with 9 mm dia 300 m length wire rope 2 SETS Four sheave pulley with 12 m dia 150 m length wire rope 4 SETS Equalizer pulley (10 T) capacity 16 NO Conductor lifting tackle 4 SETS Winch ndash motorized manual ndash 10 T capacity 4 NO Come along clamp for conductor (bolted type automatic) 5020 NO Come along clamp for earth wire (bolted type automatic) 1510 NO Tirfor (5 T capacity) 6 NO Aerial chair (For conductor) 6 NO Aerial Trolley 4 NO Turn Buckle ‐ 10T 16 NO Turn Buckle ‐ 3 T 6 NO TensionSag plate (for tensioning purpose) 6 NO Sag Board 8 NO Marking roller 4 NO Mismatch roller 2 NO Joint protector 6 NO Walkie talkie set 4 NO Theodolite with stand (or Total Station with Prism) 1 NO Thermometer 3 NO Survey umbrella 1 NO Hydraulic wire cutter 2 NO Binocular 3 NO Flag (red and green) 30 NO Crow bar (18 m length) 10 NO Nail puller 6 NO Wire rope ‐ 19 mm dia 1000 m Wire rope ‐ 16 mm dia 150 m Wire rope ‐ 14 mm dia 900 m Polypropylene rope ‐ 25 mm dia 500 m Polypropylene rope ‐ 19 mm dia 500 m lsquoDrsquo ndash Shackle ‐ 190 mm long 40 NO lsquoDrsquo ndash Shackle ‐ 150 mm long 125 NO Bulldog clamp ‐ 100 mm long 125 NO Bulldog clamp ‐ 100 mm long 35 NO

Hammers spanners (both flat and ring) round files flat files screw drivers cutting pliers steel and metallic tapes hacksaw frame and blades scaffolding slings etc

As per requirement

Tents buckets water drums camping cots table chair petromax etc

As per requirement


76 Transport Required for Stringing

Tension Stringing Manual Stringing Truck 4 NO 4 NO

75 hp tractor 2 NO 1 NO

35 hp45 hp Tractor and trailors 5 NO 6 NO

Jeep 2 NO 2 NO

Motor Cycle 1 NO 1 NO

80 Conclusion 81 Construction of EHV transmission line is a very precise and skillful job Proper construction practice ensures high reliability and long life of the transmission line 82 The main activities of foundation tower erection amp stringing are completely diverse from each other and require different type of skill workers as well as tools tackles and equipment


CONSTRUCTION OF EHV TRANSMISSION LINES

10 Introduction 11 Construction of EHV Transmission line is a very specific and specialized job It involves lot of

precision and accuracy The transmission line is standing for many years in the open terrain and faces vagaries of nature The construction practice should therefore ensure that the parameters on which the design of transmission line is made are not exceeded

12 The construction mainly includes the following activities

bull Survey amp Alignment

bull Foundation Work

bull Erection of Super Structure

bull Stringing of Shield wire amp Conductor

bull Testing amp Commissioning 13 Each of above activity can be further divided into sub‐activities All the erection activities are based on the design inputs as well as site situation For example the type of tower and foundation to be adopted will depend upon the profile amp site situation where as the spandeviation angle limitations will be based on the design factors of the tower This part deals with the general specifications for construction of EHV lines

20 Survey amp Alignment 21 Whenever EHV transmission line is to be constructed between two subs‐stations the ideal route length will be the direct topographical distance between the two stations However this will not be possible as number of obstructions in the form of villages town important civil establishments big ponds rivers etc will prevent the straight run of the line The obstruction will result into line deviations It will therefore be necessary to carry out survey by various means The survey will establish the following

bull The topography of the route of the line bull The important deviation points of the line bull The approximate quantity of Towers and extension bull First hand information regarding the soil strata along the route leading to approximate

estimation of foundation work quantities bull The obstructions which may result into line deviations bull Major River Railway Road and Power line crossings and type of structures for the same bull Information regarding availability of inputs for foundation work (cement aggregates steel and

water) bull Right of way problems which are likely along the route bull Cost of transportation of material to various locations bull Tentative time frame for completing the work

22 It is also usual to make trial pits or carry out soil investigation along the proposed route of the transmission line at certain fixed interval or at the points where abrupt change in soil strata is suspected This exercise results in to the approximate estimation of the foundation types and




ROUTE MAP

22deg1

5

EXISTIN

G 400 KV TO

WER LI

NE

DAM

DAM





DRAWING NO REV

REVISIONS

0E

DATE



1 50000

SCALE

Project

Title

NO



NE

TREE PLANT

Dhadhipara

Batra

Lahrapara

Nagrahi

T-05

T-05

T-05

T-05

T-05

CA

RT

TR

AC

K

Metal Road

Cart

Trac

k

METAL ROAD

CA

RT

TRA

CK

RCC

RCC

CA

RT

TR

AC

K

ROAD

L 05

3

22deg2

022

deg25

22deg2

522

deg20

22deg1

5



Borewells

200

200

PO

PS

RF PF

Tree

Police station


Post office

Bench-mark

Heights point


Hutment

Wells lined unlined


Forest

Pond

Temple Mosque

Development


Roads unmetalled



PowerTelephone line


Towns or Villages


N

Industries

LEGEND -

Cart-track

Canal

Stream

Scrub

Boundary state

Boundary tahsil

Boundary district


INDIA(NTS)

BAY OF BENGAL

TAM

ILNA

DU

INDIAN OCEANLANKA

KERALA

SRI

HIMACHAL

CHHATISGARH

MADHYA PRADESH

KARNATAKA

PRADESH

ANDHRA

MAHARASHTRA ORISSA

UTTARANCHAL


PUNJAB

HARYANA

PRADESH

DELHI

ASSAMPRADESH

BHUTAN

MEGHALAYA

BANGLADESH

JHARKHAND

BENGALWEST

BIHAR

MIZORAM

MANIPUR

NAGALAND

ARUNACHAL

KASHMIRJAMMU amp

N

AR

AB

IAN

SEA

GUJARAT

Coal Bearing Area


82deg35

82deg35

CHAPI WATER SCHEME


SUB POOLING STATION

EAST OFKARTALI


NUNBERA

RATIJA

DIPKA

GEVRA

PONRI

NARAIBODH


KARTALIBLOCK

SARAIPALIBLOCK

DUMARKACHHARBLOCK

BANKI

BAGDEWA DILWADIH

SINGHALIBLOCK

BLOCKBLOCK

BLOCK


COALEXTENSIONAREA

PROPOSED

BHILAI


COAL BEARING AREA

COAL BEARING AREA

COAL BEARING AREA

COAL BEARING AREA

COAL BEARING AREA

CO

AL BEARIN

G AREA



SWITCH YARD


SWITCH YARD


TRANSMISSION LINE



1

SrNo



20

3060

40

7080

90

100

170

180

200210

220

240

250

260

270

300

290

280

310

320

340

350

360

370

380

390400

410

420

430440

450

460

10110

120

150

50

130140

160

190

230

330

GANTRY

181182183184185186221

222

223

224

303 301

302

191192

201

202

203

204

211212213214215

231232

233234

235

241

242

243

251

252

253

271

272

281282

283284

291292293294304

305

306

331

332

333

341

342

343

344

345

346

347

348

351

361

362

371

372

373

381382

383391392393394

401402

403404

405406

407408

4094010

4011

411412413421

422

431432

433441

442

451452

171

161141

111

101102

103

91

92

81827172

6A0

4A0

2122

23


COMPAQ

COMPAQ
Route Mapdwg
COMPAQ

























































TOWER SPOTTING

V-1 200H-1 2000


0A



DATUM 2620m

AP4

8 - C

H5

3612

02m

AP4

9 - C

H5

4867

67m


AP-45(14deg4823)R AP-46(75deg4341)L

422

41166

422



CUMULATIVE

LEVELS(M)REDUCED

DETAILS


CHAINAGES(M)

+3M

+6M

+9M



+3M

+6M

+9M



+3M

+6M

+9M



+3M

+6M

+9M



Hot Curve 85deg C


Hot Curve 85deg C


Hot Curve 85deg C


Cold Curve 0deg C

Cold Curve 0deg C

Cold Curve 0deg C

Wind Span

TL R


T


T

Loc No-

2058321141683

42716206462207

43112072622384

DA+6451

157

Wind Span

TL R


T


T

Loc No-

2112058341683

41948214282052

42341219012044

DA+3452

158

Wind Span

TL R


T


T

Loc No-

00000211211

207720000020772

202990000020299

DD+0460

159

Wind Span

TL R


T


T

Loc No-

211211422

41336201321206

411821981621366

DB+3450

156

COMPAQ

COMPAQ
Tower Spottingdwg


















COMPAQ








COMPAQ

COMPAQ



























COMPAQ












































COMPAQ
COMPAQ


















COMPAQ

COMPAQ








COMPAQ

COMPAQ




































TABLE ‐1

Sr No

Name of

Conductor


kV

Size amp stranding

Alu Steel Nomm Nomm

Current carrying


Over all

dia cm

UTS Kg

Unit

weight KgMtr

1 ACSR Dog

3366 6472 7157 300 12

3299 0394

2 ACSR Panther

66132 3030 730 480 210 9177 0976

3 ACSR Zebra

220 54318 7318 735 286 13316 162

4 ACSR Moose

220400 54353 7353 800 318 16250 202



50kM 100kM 200kM 300kM


1 66kV 22 11 55 36

2 132kV 120 60 30 20

3 220kV 400 200 100 67

4 400kV 1500 750 375 250




Table‐3

Sr No

Line

Voltage

Size of each


mm x mm

Electro‐mech

StrengthKg


Single Double

No No

Weight of Insulator

String Single

Double Kg Kg

Length of insulator

string Single

Double mm mm


255 x 146 255 x 146

7000 8180

5 6

10 12

75 85

150 170

1000 1140

1300 1280


255 x 146 255 x 146

8180

11500

9

10

18 20

120 130

240 260

1600 1790

1716 2190


255 x 146 255 x 146

8180 11500

14 15

28 30

130 140

260 280

2340 2850

2640 3200


255 x 146 255 x 146

11500 16500

23 24

46 48

275 640

550

1280

4200 5900

4400 6200






























COMPAQ



































































COMPAQ

COMPAQ














Excavation















requirement


As per requirement


As per requirement


1 NO


74 Tower Erection




As per requirement


As per requirement










6 NO


2 NO


4 NO






As per requirement


As per requirement






Jeep 2 NO 2 NO






ROUTE MAP

22deg1

5

EXISTIN

G 400 KV TO

WER LI

NE

DAM

DAM





DRAWING NO REV

REVISIONS

0E

DATE



1 50000

SCALE

Project

Title

NO



NE

TREE PLANT

Dhadhipara

Batra

Lahrapara

Nagrahi

T-05

T-05

T-05

T-05

T-05

CA

RT

TR

AC

K

Metal Road

Cart

Trac

k

METAL ROAD

CA

RT

TRA

CK

RCC

RCC

CA

RT

TR

AC

K

ROAD

L 05

3

22deg2

022

deg25

22deg2

522

deg20

22deg1

5



Borewells

200

200

PO

PS

RF PF

Tree

Police station


Post office

Bench-mark

Heights point


Hutment

Wells lined unlined


Forest

Pond

Temple Mosque

Development


Roads unmetalled



PowerTelephone line


Towns or Villages


N

Industries

LEGEND -

Cart-track

Canal

Stream

Scrub

Boundary state

Boundary tahsil

Boundary district


INDIA(NTS)

BAY OF BENGAL

TAM

ILNA

DU

INDIAN OCEANLANKA

KERALA

SRI

HIMACHAL

CHHATISGARH

MADHYA PRADESH

KARNATAKA

PRADESH

ANDHRA

MAHARASHTRA ORISSA

UTTARANCHAL


PUNJAB

HARYANA

PRADESH

DELHI

ASSAMPRADESH

BHUTAN

MEGHALAYA

BANGLADESH

JHARKHAND

BENGALWEST

BIHAR

MIZORAM

MANIPUR

NAGALAND

ARUNACHAL

KASHMIRJAMMU amp

N

AR

AB

IAN

SEA

GUJARAT

Coal Bearing Area


82deg35

82deg35

CHAPI WATER SCHEME


SUB POOLING STATION

EAST OFKARTALI


NUNBERA

RATIJA

DIPKA

GEVRA

PONRI

NARAIBODH


KARTALIBLOCK

SARAIPALIBLOCK

DUMARKACHHARBLOCK

BANKI

BAGDEWA DILWADIH

SINGHALIBLOCK

BLOCKBLOCK

BLOCK


COALEXTENSIONAREA

PROPOSED

BHILAI


COAL BEARING AREA

COAL BEARING AREA

COAL BEARING AREA

COAL BEARING AREA

COAL BEARING AREA

CO

AL BEARIN

G AREA



SWITCH YARD


SWITCH YARD


TRANSMISSION LINE



1

SrNo



20

3060

40

7080

90

100

170

180

200210

220

240

250

260

270

300

290

280

310

320

340

350

360

370

380

390400

410

420

430440

450

460

10110

120

150

50

130140

160

190

230

330

GANTRY

181182183184185186221

222

223

224

303 301

302

191192

201

202

203

204

211212213214215

231232

233234

235

241

242

243

251

252

253

271

272

281282

283284

291292293294304

305

306

331

332

333

341

342

343

344

345

346

347

348

351

361

362

371

372

373

381382

383391392393394

401402

403404

405406

407408

4094010

4011

411412413421

422

431432

433441

442

451452

171

161141

111

101102

103

91

92

81827172

6A0

4A0

2122

23


COMPAQ

COMPAQ
Route Mapdwg
COMPAQ

























































TOWER SPOTTING

V-1 200H-1 2000


0A



DATUM 2620m

AP4

8 - C

H5

3612

02m

AP4

9 - C

H5

4867

67m


AP-45(14deg4823)R AP-46(75deg4341)L

422

41166

422



CUMULATIVE

LEVELS(M)REDUCED

DETAILS


CHAINAGES(M)

+3M

+6M

+9M



+3M

+6M

+9M



+3M

+6M

+9M



+3M

+6M

+9M



Hot Curve 85deg C


Hot Curve 85deg C


Hot Curve 85deg C


Cold Curve 0deg C

Cold Curve 0deg C

Cold Curve 0deg C

Wind Span

TL R


T


T

Loc No-

2058321141683

42716206462207

43112072622384

DA+6451

157

Wind Span

TL R


T


T

Loc No-

2112058341683

41948214282052

42341219012044

DA+3452

158

Wind Span

TL R


T


T

Loc No-

00000211211

207720000020772

202990000020299

DD+0460

159

Wind Span

TL R


T


T

Loc No-

211211422

41336201321206

411821981621366

DB+3450

156

COMPAQ

COMPAQ
Tower Spottingdwg


















COMPAQ








COMPAQ

COMPAQ



























COMPAQ












































COMPAQ
COMPAQ


















COMPAQ

COMPAQ








COMPAQ

COMPAQ




































TABLE ‐1

Sr No

Name of

Conductor


kV

Size amp stranding

Alu Steel Nomm Nomm

Current carrying


Over all

dia cm

UTS Kg

Unit

weight KgMtr

1 ACSR Dog

3366 6472 7157 300 12

3299 0394

2 ACSR Panther

66132 3030 730 480 210 9177 0976

3 ACSR Zebra

220 54318 7318 735 286 13316 162

4 ACSR Moose

220400 54353 7353 800 318 16250 202



50kM 100kM 200kM 300kM


1 66kV 22 11 55 36

2 132kV 120 60 30 20

3 220kV 400 200 100 67

4 400kV 1500 750 375 250




Table‐3

Sr No

Line

Voltage

Size of each


mm x mm

Electro‐mech

StrengthKg


Single Double

No No

Weight of Insulator

String Single

Double Kg Kg

Length of insulator

string Single

Double mm mm


255 x 146 255 x 146

7000 8180

5 6

10 12

75 85

150 170

1000 1140

1300 1280


255 x 146 255 x 146

8180

11500

9

10

18 20

120 130

240 260

1600 1790

1716 2190


255 x 146 255 x 146

8180 11500

14 15

28 30

130 140

260 280

2340 2850

2640 3200


255 x 146 255 x 146

11500 16500

23 24

46 48

275 640

550

1280

4200 5900

4400 6200






























COMPAQ



































































COMPAQ

COMPAQ














Excavation















requirement


As per requirement


As per requirement


1 NO


74 Tower Erection




As per requirement


As per requirement










6 NO


2 NO


4 NO






As per requirement


As per requirement






Jeep 2 NO 2 NO



























































TOWER SPOTTING

V-1 200H-1 2000


0A



DATUM 2620m

AP4

8 - C

H5

3612

02m

AP4

9 - C

H5

4867

67m


AP-45(14deg4823)R AP-46(75deg4341)L

422

41166

422



CUMULATIVE

LEVELS(M)REDUCED

DETAILS


CHAINAGES(M)

+3M

+6M

+9M



+3M

+6M

+9M



+3M

+6M

+9M



+3M

+6M

+9M



Hot Curve 85deg C


Hot Curve 85deg C


Hot Curve 85deg C


Cold Curve 0deg C

Cold Curve 0deg C

Cold Curve 0deg C

Wind Span

TL R


T


T

Loc No-

2058321141683

42716206462207

43112072622384

DA+6451

157

Wind Span

TL R


T


T

Loc No-

2112058341683

41948214282052

42341219012044

DA+3452

158

Wind Span

TL R


T


T

Loc No-

00000211211

207720000020772

202990000020299

DD+0460

159

Wind Span

TL R


T


T

Loc No-

211211422

41336201321206

411821981621366

DB+3450

156

COMPAQ

COMPAQ
Tower Spottingdwg


















COMPAQ








COMPAQ

COMPAQ



























COMPAQ












































COMPAQ
COMPAQ


















COMPAQ

COMPAQ








COMPAQ

COMPAQ




































TABLE ‐1

Sr No

Name of

Conductor


kV

Size amp stranding

Alu Steel Nomm Nomm

Current carrying


Over all

dia cm

UTS Kg

Unit

weight KgMtr

1 ACSR Dog

3366 6472 7157 300 12

3299 0394

2 ACSR Panther

66132 3030 730 480 210 9177 0976

3 ACSR Zebra

220 54318 7318 735 286 13316 162

4 ACSR Moose

220400 54353 7353 800 318 16250 202



50kM 100kM 200kM 300kM


1 66kV 22 11 55 36

2 132kV 120 60 30 20

3 220kV 400 200 100 67

4 400kV 1500 750 375 250




Table‐3

Sr No

Line

Voltage

Size of each


mm x mm

Electro‐mech

StrengthKg


Single Double

No No

Weight of Insulator

String Single

Double Kg Kg

Length of insulator

string Single

Double mm mm


255 x 146 255 x 146

7000 8180

5 6

10 12

75 85

150 170

1000 1140

1300 1280


255 x 146 255 x 146

8180

11500

9

10

18 20

120 130

240 260

1600 1790

1716 2190


255 x 146 255 x 146

8180 11500

14 15

28 30

130 140

260 280

2340 2850

2640 3200


255 x 146 255 x 146

11500 16500

23 24

46 48

275 640

550

1280

4200 5900

4400 6200






























COMPAQ



































































COMPAQ

COMPAQ














Excavation















requirement


As per requirement


As per requirement


1 NO


74 Tower Erection




As per requirement


As per requirement










6 NO


2 NO


4 NO






As per requirement


As per requirement






Jeep 2 NO 2 NO




















COMPAQ








COMPAQ

COMPAQ



























COMPAQ












































COMPAQ
COMPAQ


















COMPAQ

COMPAQ








COMPAQ

COMPAQ




































TABLE ‐1

Sr No

Name of

Conductor


kV

Size amp stranding

Alu Steel Nomm Nomm

Current carrying


Over all

dia cm

UTS Kg

Unit

weight KgMtr

1 ACSR Dog

3366 6472 7157 300 12

3299 0394

2 ACSR Panther

66132 3030 730 480 210 9177 0976

3 ACSR Zebra

220 54318 7318 735 286 13316 162

4 ACSR Moose

220400 54353 7353 800 318 16250 202



50kM 100kM 200kM 300kM


1 66kV 22 11 55 36

2 132kV 120 60 30 20

3 220kV 400 200 100 67

4 400kV 1500 750 375 250




Table‐3

Sr No

Line

Voltage

Size of each


mm x mm

Electro‐mech

StrengthKg


Single Double

No No

Weight of Insulator

String Single

Double Kg Kg

Length of insulator

string Single

Double mm mm


255 x 146 255 x 146

7000 8180

5 6

10 12

75 85

150 170

1000 1140

1300 1280


255 x 146 255 x 146

8180

11500

9

10

18 20

120 130

240 260

1600 1790

1716 2190


255 x 146 255 x 146

8180 11500

14 15

28 30

130 140

260 280

2340 2850

2640 3200


255 x 146 255 x 146

11500 16500

23 24

46 48

275 640

550

1280

4200 5900

4400 6200






























COMPAQ



































































COMPAQ

COMPAQ














Excavation















requirement


As per requirement


As per requirement


1 NO


74 Tower Erection




As per requirement


As per requirement










6 NO


2 NO


4 NO






As per requirement


As per requirement






Jeep 2 NO 2 NO










COMPAQ

COMPAQ



























COMPAQ












































COMPAQ
COMPAQ


















COMPAQ

COMPAQ








COMPAQ

COMPAQ




































TABLE ‐1

Sr No

Name of

Conductor


kV

Size amp stranding

Alu Steel Nomm Nomm

Current carrying


Over all

dia cm

UTS Kg

Unit

weight KgMtr

1 ACSR Dog

3366 6472 7157 300 12

3299 0394

2 ACSR Panther

66132 3030 730 480 210 9177 0976

3 ACSR Zebra

220 54318 7318 735 286 13316 162

4 ACSR Moose

220400 54353 7353 800 318 16250 202



50kM 100kM 200kM 300kM


1 66kV 22 11 55 36

2 132kV 120 60 30 20

3 220kV 400 200 100 67

4 400kV 1500 750 375 250




Table‐3

Sr No

Line

Voltage

Size of each


mm x mm

Electro‐mech

StrengthKg


Single Double

No No

Weight of Insulator

String Single

Double Kg Kg

Length of insulator

string Single

Double mm mm


255 x 146 255 x 146

7000 8180

5 6

10 12

75 85

150 170

1000 1140

1300 1280


255 x 146 255 x 146

8180

11500

9

10

18 20

120 130

240 260

1600 1790

1716 2190


255 x 146 255 x 146

8180 11500

14 15

28 30

130 140

260 280

2340 2850

2640 3200


255 x 146 255 x 146

11500 16500

23 24

46 48

275 640

550

1280

4200 5900

4400 6200






























COMPAQ



































































COMPAQ

COMPAQ














Excavation















requirement


As per requirement


As per requirement


1 NO


74 Tower Erection




As per requirement


As per requirement










6 NO


2 NO


4 NO






As per requirement


As per requirement






Jeep 2 NO 2 NO





























COMPAQ












































COMPAQ
COMPAQ


















COMPAQ

COMPAQ








COMPAQ

COMPAQ




































TABLE ‐1

Sr No

Name of

Conductor


kV

Size amp stranding

Alu Steel Nomm Nomm

Current carrying


Over all

dia cm

UTS Kg

Unit

weight KgMtr

1 ACSR Dog

3366 6472 7157 300 12

3299 0394

2 ACSR Panther

66132 3030 730 480 210 9177 0976

3 ACSR Zebra

220 54318 7318 735 286 13316 162

4 ACSR Moose

220400 54353 7353 800 318 16250 202



50kM 100kM 200kM 300kM


1 66kV 22 11 55 36

2 132kV 120 60 30 20

3 220kV 400 200 100 67

4 400kV 1500 750 375 250




Table‐3

Sr No

Line

Voltage

Size of each


mm x mm

Electro‐mech

StrengthKg


Single Double

No No

Weight of Insulator

String Single

Double Kg Kg

Length of insulator

string Single

Double mm mm


255 x 146 255 x 146

7000 8180

5 6

10 12

75 85

150 170

1000 1140

1300 1280


255 x 146 255 x 146

8180

11500

9

10

18 20

120 130

240 260

1600 1790

1716 2190


255 x 146 255 x 146

8180 11500

14 15

28 30

130 140

260 280

2340 2850

2640 3200


255 x 146 255 x 146

11500 16500

23 24

46 48

275 640

550

1280

4200 5900

4400 6200






























COMPAQ



































































COMPAQ

COMPAQ














Excavation















requirement


As per requirement


As per requirement


1 NO


74 Tower Erection




As per requirement


As per requirement










6 NO


2 NO


4 NO






As per requirement


As per requirement






Jeep 2 NO 2 NO














































COMPAQ
COMPAQ


















COMPAQ

COMPAQ








COMPAQ

COMPAQ




































TABLE ‐1

Sr No

Name of

Conductor


kV

Size amp stranding

Alu Steel Nomm Nomm

Current carrying


Over all

dia cm

UTS Kg

Unit

weight KgMtr

1 ACSR Dog

3366 6472 7157 300 12

3299 0394

2 ACSR Panther

66132 3030 730 480 210 9177 0976

3 ACSR Zebra

220 54318 7318 735 286 13316 162

4 ACSR Moose

220400 54353 7353 800 318 16250 202



50kM 100kM 200kM 300kM


1 66kV 22 11 55 36

2 132kV 120 60 30 20

3 220kV 400 200 100 67

4 400kV 1500 750 375 250




Table‐3

Sr No

Line

Voltage

Size of each


mm x mm

Electro‐mech

StrengthKg


Single Double

No No

Weight of Insulator

String Single

Double Kg Kg

Length of insulator

string Single

Double mm mm


255 x 146 255 x 146

7000 8180

5 6

10 12

75 85

150 170

1000 1140

1300 1280


255 x 146 255 x 146

8180

11500

9

10

18 20

120 130

240 260

1600 1790

1716 2190


255 x 146 255 x 146

8180 11500

14 15

28 30

130 140

260 280

2340 2850

2640 3200


255 x 146 255 x 146

11500 16500

23 24

46 48

275 640

550

1280

4200 5900

4400 6200






























COMPAQ



































































COMPAQ

COMPAQ














Excavation















requirement


As per requirement


As per requirement


1 NO


74 Tower Erection




As per requirement


As per requirement










6 NO


2 NO


4 NO






As per requirement


As per requirement






Jeep 2 NO 2 NO




















COMPAQ

COMPAQ








COMPAQ

COMPAQ




































TABLE ‐1

Sr No

Name of

Conductor


kV

Size amp stranding

Alu Steel Nomm Nomm

Current carrying


Over all

dia cm

UTS Kg

Unit

weight KgMtr

1 ACSR Dog

3366 6472 7157 300 12

3299 0394

2 ACSR Panther

66132 3030 730 480 210 9177 0976

3 ACSR Zebra

220 54318 7318 735 286 13316 162

4 ACSR Moose

220400 54353 7353 800 318 16250 202



50kM 100kM 200kM 300kM


1 66kV 22 11 55 36

2 132kV 120 60 30 20

3 220kV 400 200 100 67

4 400kV 1500 750 375 250




Table‐3

Sr No

Line

Voltage

Size of each


mm x mm

Electro‐mech

StrengthKg


Single Double

No No

Weight of Insulator

String Single

Double Kg Kg

Length of insulator

string Single

Double mm mm


255 x 146 255 x 146

7000 8180

5 6

10 12

75 85

150 170

1000 1140

1300 1280


255 x 146 255 x 146

8180

11500

9

10

18 20

120 130

240 260

1600 1790

1716 2190


255 x 146 255 x 146

8180 11500

14 15

28 30

130 140

260 280

2340 2850

2640 3200


255 x 146 255 x 146

11500 16500

23 24

46 48

275 640

550

1280

4200 5900

4400 6200






























COMPAQ



































































COMPAQ

COMPAQ














Excavation















requirement


As per requirement


As per requirement


1 NO


74 Tower Erection




As per requirement


As per requirement










6 NO


2 NO


4 NO






As per requirement


As per requirement






Jeep 2 NO 2 NO










COMPAQ

COMPAQ




































TABLE ‐1

Sr No

Name of

Conductor


kV

Size amp stranding

Alu Steel Nomm Nomm

Current carrying


Over all

dia cm

UTS Kg

Unit

weight KgMtr

1 ACSR Dog

3366 6472 7157 300 12

3299 0394

2 ACSR Panther

66132 3030 730 480 210 9177 0976

3 ACSR Zebra

220 54318 7318 735 286 13316 162

4 ACSR Moose

220400 54353 7353 800 318 16250 202



50kM 100kM 200kM 300kM


1 66kV 22 11 55 36

2 132kV 120 60 30 20

3 220kV 400 200 100 67

4 400kV 1500 750 375 250




Table‐3

Sr No

Line

Voltage

Size of each


mm x mm

Electro‐mech

StrengthKg


Single Double

No No

Weight of Insulator

String Single

Double Kg Kg

Length of insulator

string Single

Double mm mm


255 x 146 255 x 146

7000 8180

5 6

10 12

75 85

150 170

1000 1140

1300 1280


255 x 146 255 x 146

8180

11500

9

10

18 20

120 130

240 260

1600 1790

1716 2190


255 x 146 255 x 146

8180 11500

14 15

28 30

130 140

260 280

2340 2850

2640 3200


255 x 146 255 x 146

11500 16500

23 24

46 48

275 640

550

1280

4200 5900

4400 6200






























COMPAQ



































































COMPAQ

COMPAQ














Excavation















requirement


As per requirement


As per requirement


1 NO


74 Tower Erection




As per requirement


As per requirement










6 NO


2 NO


4 NO






As per requirement


As per requirement






Jeep 2 NO 2 NO






































TABLE ‐1

Sr No

Name of

Conductor


kV

Size amp stranding

Alu Steel Nomm Nomm

Current carrying


Over all

dia cm

UTS Kg

Unit

weight KgMtr

1 ACSR Dog

3366 6472 7157 300 12

3299 0394

2 ACSR Panther

66132 3030 730 480 210 9177 0976

3 ACSR Zebra

220 54318 7318 735 286 13316 162

4 ACSR Moose

220400 54353 7353 800 318 16250 202



50kM 100kM 200kM 300kM


1 66kV 22 11 55 36

2 132kV 120 60 30 20

3 220kV 400 200 100 67

4 400kV 1500 750 375 250




Table‐3

Sr No

Line

Voltage

Size of each


mm x mm

Electro‐mech

StrengthKg


Single Double

No No

Weight of Insulator

String Single

Double Kg Kg

Length of insulator

string Single

Double mm mm


255 x 146 255 x 146

7000 8180

5 6

10 12

75 85

150 170

1000 1140

1300 1280


255 x 146 255 x 146

8180

11500

9

10

18 20

120 130

240 260

1600 1790

1716 2190


255 x 146 255 x 146

8180 11500

14 15

28 30

130 140

260 280

2340 2850

2640 3200


255 x 146 255 x 146

11500 16500

23 24

46 48

275 640

550

1280

4200 5900

4400 6200






























COMPAQ



































































COMPAQ

COMPAQ














Excavation















requirement


As per requirement


As per requirement


1 NO


74 Tower Erection




As per requirement


As per requirement










6 NO


2 NO


4 NO






As per requirement


As per requirement






Jeep 2 NO 2 NO




1 66kV 22 11 55 36

2 132kV 120 60 30 20

3 220kV 400 200 100 67

4 400kV 1500 750 375 250




Table‐3

Sr No

Line

Voltage

Size of each


mm x mm

Electro‐mech

StrengthKg


Single Double

No No

Weight of Insulator

String Single

Double Kg Kg

Length of insulator

string Single

Double mm mm


255 x 146 255 x 146

7000 8180

5 6

10 12

75 85

150 170

1000 1140

1300 1280


255 x 146 255 x 146

8180

11500

9

10

18 20

120 130

240 260

1600 1790

1716 2190


255 x 146 255 x 146

8180 11500

14 15

28 30

130 140

260 280

2340 2850

2640 3200


255 x 146 255 x 146

11500 16500

23 24

46 48

275 640

550

1280

4200 5900

4400 6200






























COMPAQ



































































COMPAQ

COMPAQ














Excavation















requirement


As per requirement


As per requirement


1 NO


74 Tower Erection




As per requirement


As per requirement










6 NO


2 NO


4 NO






As per requirement


As per requirement






Jeep 2 NO 2 NO





Table‐3

Sr No

Line

Voltage

Size of each


mm x mm

Electro‐mech

StrengthKg


Single Double

No No

Weight of Insulator

String Single

Double Kg Kg

Length of insulator

string Single

Double mm mm


255 x 146 255 x 146

7000 8180

5 6

10 12

75 85

150 170

1000 1140

1300 1280


255 x 146 255 x 146

8180

11500

9

10

18 20

120 130

240 260

1600 1790

1716 2190


255 x 146 255 x 146

8180 11500

14 15

28 30

130 140

260 280

2340 2850

2640 3200


255 x 146 255 x 146

11500 16500

23 24

46 48

275 640

550

1280

4200 5900

4400 6200






























COMPAQ



































































COMPAQ

COMPAQ














Excavation















requirement


As per requirement


As per requirement


1 NO


74 Tower Erection




As per requirement


As per requirement










6 NO


2 NO


4 NO






As per requirement


As per requirement






Jeep 2 NO 2 NO































COMPAQ



































































COMPAQ

COMPAQ














Excavation















requirement


As per requirement


As per requirement


1 NO


74 Tower Erection




As per requirement


As per requirement










6 NO


2 NO


4 NO






As per requirement


As per requirement






Jeep 2 NO 2 NO





































































COMPAQ

COMPAQ














Excavation















requirement


As per requirement


As per requirement


1 NO


74 Tower Erection




As per requirement


As per requirement










6 NO


2 NO


4 NO






As per requirement


As per requirement






Jeep 2 NO 2 NO
















Excavation















requirement


As per requirement


As per requirement


1 NO


74 Tower Erection




As per requirement


As per requirement










6 NO


2 NO


4 NO






As per requirement


As per requirement






Jeep 2 NO 2 NO














requirement


As per requirement


As per requirement


1 NO


74 Tower Erection




As per requirement


As per requirement










6 NO


2 NO


4 NO






As per requirement


As per requirement






Jeep 2 NO 2 NO










6 NO


2 NO


4 NO






As per requirement


As per requirement






Jeep 2 NO 2 NO






As per requirement


As per requirement






Jeep 2 NO 2 NO








Jeep 2 NO 2 NO



68297485 technical session i

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