Erection Manual of ERS (Disaster Management)

7/22/2019 Erection Manual of ERS (Disaster Management)

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FOR INTERNAL CIRCULATION ONLY

DOC. NO. D-2-02-70-02-00 (REVISION-0)

ERECTION MANUAL OF

EMERGENCY RESTORATION SYSTEM

(DISASTER MANAGEMENT)

CORPORATE OPERATION SERVICES

POWERGRID CORPORATION OF INDIA LIMITED(A Government of India Enterprise)

NEW DELHI 110 019


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INDEX

SL.NO.

CONTENTS PAGE

1.0 INTRODUCTION 1

2.0 DISASTER MANAGEMENT STRATEGY 3

3.0 COMPONENTS OF STRUCTURES 4

4.0 TYPES OF ASSEMBLED STRUCTURES 10

5.0 SITE PLANNING AND SURVEY 12

6.0 FAILURE AND RESTORATION SCENARIOS 14

7.0 TRANSPORTATION ARRANGEMENT 22

8.0 COMPUTER PLANNING 24

ERECTION OF ERS

9.0 EXCAVATION OF PITS 32

10.0 GUY ANCHORING 33

11.0 GENERAL ASSEMBLY AND ERECTIONINSTRUCTIONS FOR THE STRUCTURE

35

12.0 ERECTION PROCEDURE USING A GIN POLE 45

13.0 ERECTION PROCEDURE USING A BOOM-TRUCK OR LIGHT DUTY CRANE

51

14.0 ERECTION TECHNIQUE INVOLVING TILTING UPOR WHIPPING UP THE ERS COLUMN WITH AWINCH LINE

54

15.0 SPECIALISED ERECTION PROCEDURE USING AHELICOPTER

56


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SL.NO.

CONTENTS PAGE

16.0 CLIPPING-IN PROCEDURES 64

17.0 DISASSEMBLY OF ERS 70

18.0 PACKING AND STORING OF ERS 71

19.0 MAINTENANCE OF ERS 72

20.0 SAFETY GUIDELINES DOS AND DONTS 73

21.0 TROUBLE SHOOTING 75

22.0 ANNEXURE I: BILL OF ERS MATERIALS IN

ONE SET

77

ANNEXURE II: LIST OF ADDITIONAL TOOLSAND PLANTS

83

ANNEXURE III: DETAILED GUIDELINES FORTRANSPORTATION OF ERSSTRUCTURE IN TRUCKS OF 18FEET LONG BODY

85

ANNEXURE IV: SAMPLE ERS COMPUTERPRINT-OUTS 89

ANNEXURE V: DEMONSTRATION OFERECTION OF COMPLETE ERSTOWER BY HELICOPTER

101

ANNEXURE VI : IMPORTANT EXAMPLES OF USEOF ERS AT CRITICALLOCATIONS (220 KV D/CBAIRASUL-PONG LINE AT

TOWER LOCATION NO. 59)

109

23.0 REFERENCES 118


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1.0 INTRODUCTION


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1.0 INTRODUCTION

For disaster management in case of natural calamities and sabotage, theEmergency Restoration System (ERS) which is used world wide wasadopted by POWERGRID to enable quick restoration of Power Supply

by erecting the ERS and by-passing the damaged portion of TransmissionLines.

Its application is effective and is economically viable specially for PowerSystems where redundancies of transmission system are lacking. TheERS structures require no special foundation and can be used at anyvoltage level. There are various chapters, each covering step-wiseprocedure for restoration work along with safety guidelines, troubleshooting and illustrations/ demonstrations.

The ERS consists of number of standardised modular, high strength, lightweight aluminium alloy components/ blocks which can be easily andquickly erected to form a full scale guyed tower at an alternate locationnear the affected towers. With these components, 15 type of structures ofSuspension and Tension/Angle type can be assembled suiting to specificneed based on site details and computer planning. With suitable Designand Computer Planning, ERS can also be effectively used to By-passdamaged special tall towers and special pile/ well foundations. Effortshave been made to illustrate typical failure scenarios and also theirrestoration scenarios so that site people can adopt the restorationscenarios suiting to them for quick restoration.

This document contains some general guidelines/ suggestions and

recommended practices which, should be followed when usingEmergency Restoration Structures mainly of the type covered in thismanual only. In order to maximise the potential benefit which can bederived from using these structures in an emergency situation, it isessential that sufficient computer planning and site training has beenaccomplished prior to the occurrence of an emergency.

In the procedure for assembly and erection of the ERS, detailed methodof work has been mentioned for different types of erection procedures.The complete tower is erected on a nailed base foundation plate. TheGimbal Joint arrangement pivoted with the foundation bearing base plateminimises the column eccentricity and eliminates torsional loading due to

its rotational capability in various directions. All column section are simplyassembled and the ERS structure is erected with the support of guy wiresthat are attached to the guy plates using anchors, shackles andpreformed grips. Light weight high dielectric strength polymer suspensioninsulators/ post insulator strings are used for re-stringing of the existingline conductors or new conductor. With the completion of aboveoperations, the line is ready for restoration. The most commonly usederection procedure is by using Gin Pole. However, this is time consuming


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and restoration depends on number of technicians/engineers deployed forthe work. In case of emergency, boom truck/light duty crane had beenused and based on the experience gained, procedure has been outlinedin the document. It was also thought to acquire expertise in erection ofERS with the help of helicopter in case of extreme emergency and inunapproachable areas. The procedure for helicopter erection has alsobeen given. Based on the demonstrations, erection of completeassembled ERS tower in one step has been illustrated at Annexure-VIofthis document.

As with any other piece of equipment or tool, all normal safetyprecautions should be followed when working on or around thesestructures. Care should be taken to ensure that the structures are nothandled or used in a manner which may cause damage. Any and allnational, state or local safety requirements need to be observed at alltimes. Safety guidelines (DOs and DONTs), trouble shooting,Packing/storage and maintenance of ERS have also been covered. In the

last list of ERS materials, Tools & Plants required for construction andguidelines for transportation in the trucks have been given alongwith thesample ERS computer print-outs and the important example of use ofERS.

The successful application of ERS for the first time is a step ahead inPOWERGRIDs march for excellence in finding innovative solutions andstate of the art technology in the field of extra high voltage transmissionmaintenance technology and disaster management in the country.


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2.0 DISASTER MANAGEMENT STRATEGY


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2.0 DISASTER MANAGEMENT STRATEGY

Failure of transmission line towers due to natural calamities and sabotagecannot be ruled out. However, to tackle the situation arising out of thesefactors, we should be able to manage the disaster as quickly as possible

so that power supply can be maintained to the consumers. As a strategyto disaster management, one of the State-of-Art technique is to deployEmergency Restoration System for restoration of collapsed towers. Thistechnique is also used to by-pass critical/damaged towers andfoundations.

POWERGRID have following sets of ERS at different locations to managethe disaster through out the India.

Region Location Quantity

NR-I Ballabhgarh

Kanpur

1 set

1 set

NR-II Jammu / Hissar/ Wagoora 1 set

WR Dehgam (Ahmedabad)

Itarsi

1 set

1 set

SR Vijayawada/ Vaizac

Bangalore

1 set

1 set

ER Durgapur

Rourkela

1 set

1 set

NER Misa 1 set

T O T A L 10 SETS

Each set consist of various components which have been mentioned innext chapter number 3. Further, each set is capable of erecting 12 nos. ofERS towers upto 400kV (twin conductors) of different types as indicatedin chapter number 4. Moreover, in an emergency situation the ERS andthe man power is pooled from various locations so that the entire damage

can be tackled effectively. POWERGRID have also developed expertisefor transportation and erection of ERS using helicopters. In a situationwhere requirement of power is extreme, helicopters can be deployed forerection of ERS as per procedure given in chapter no.15.


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3.0 COMPONENTS OF STRUCTURES


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3.0 COMPONENTS OF STRUCTURES

3.1 FOUNDATION PLATE

This is designed for placement (Fig-1) directly on the flat/ slope (400max.)

ground. The plate weighs 250 kg and provides 2.32 square meter of bearingsurface and can be pinned to normal ground (dry soil) using 25 mm diameterreinforcing rods approximately 1.5 meter long. In case of loose soil,foundation plate can be placed on the 4 numbers screw/marsh anchorsdriven in the ground to increase the bearing strength of the soil. The height ofthe foundation plate is 0.36 meter. Normally four numbers of reinforcing rodsare to be used to secure the foundation when the column is erected.Foundation secured in this manner can also be remained in service for longtime.

Figure-1

3.2 GIMBAL JOINTS

The first section above the foundation plate is the Gimbal Joint (Fig-2) whichcan rotate 900 in four major axis (in four directions) as indicated by arrowattached on the Gimbal allowing horizontal column assembly. Above theGimbal, the required column sections can be bolted together. Once theGimbal Joint is assembled with column section horizontally, the cranes/ winch


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line/ helicopter can be used to lift the column into position using the GimbalJoint as a pivot. The Gimbal Joint can be locked rigid for initial erection,storage, handling and for transportation with the help of turn-buckles. TheGimbal weighs only 252 kg. The length of Gimbal Joint is 2.13 meter (7 feet).

Figure 2

3.3 COLUMN SECTIONS

Figure-3


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All column sections (Fig-3) are made of light weigh, high strength structuralaluminium alloy. The column section ensures easy handling and eliminatesthe loss of small bolted pieces such as diagonal bracing etc in view of weldedbracing. The column sections are in three standard sizes 2.13(7 feet), 4.26(14 feet), 6.4(21 feet) meter long weighing 123, 189, and 256 kg respectively.

Locating pins and alignment holes are provided in each flanged end plate fora easy assembly and erection.

3.4 GUY PLATES

Figure-4

The guy plates are made from structural aluminium plate. Guy plates weigh23 kg and are available in three types (Fig-4), 00- 450 is used for guying andfull tension dead end structures; 450- 450 guy plate is used for suspensionstructures, intermediate guying is the most commonly used guy plate foranchoring and 00- 00 guy plate is used for In-line tensionstructures. Each ofthe six guy plate attachment holes are rated for ultimate load of 134 kN. Guyplates assembled between two column sections is used for intermediateguying. Guy wires are typically attached to the guy plates using anchorshackles and preformed grips.

3.5 BOX SECTION

Box section (Fig-5) is made from structural aluminium and used for mountinghorizontal post insulators. Box section weigh 120 kg and are installed in-between column sections and have pre-drilled holes on two sides to allowmounting of any line post insulator. It is used for mounting post insulator in H-Frame, Horizontal Vee and Delta Horizontal Vee type of structure geometry.


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In addition to this, box sections are used on tension towers for connectingjumper through line post insulators.

Figure-5

3.6 INSULATORS AND HARDWARE

The suspension and post polymer insulators (Fig-6) are used on account oftheir high strength, lightweight and durability. Hardware components areprovided for greatest number of assemblies with the least number ofcomponents. The advantages of polymer insulators is that, a lineman cancarry easily due to lightweight i.e. 10 kg. for suspension insulators and 27 kgfor post insulator suitable for use up to 400 kV line.

Figure-6


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3.7 ANCHORING SYSTEM

Anchoring System (Fig-7) is a critical element of the guyed ERS. Depending

on the prevailing soil conditions, a number of different anchoringarrangements can be provided. Cross plate anchor for normal soil(dry) is themost common and universal anchoring method that require minimalinstallation equipment. In most cases, cross plate anchoring (Fig-8) is thequickest and easiest type of anchoring. Screw anchors for loose soil and


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Rock-anchoring system for hard rock can also be used to meet specificrequirements. Dead weigh anchoring is used where other anchoring will notwork. In case of heavy dead weight made of concrete blocks are notavailable, locally fabricated crate made of steel angles filled with sand bags/stones can be used.

3.8 GIN POLE (DERRICK)

Gin pole is basic tool for erection of ERS modular structures by putting oneabove another. The length of Gin pole is 7.3 meter which can erect ERSstructures even up to 50 meter tall.

3.9 6 TON CHAIN HOIST

This is used to connect guy wire with the anchor rod. With the help of chainhoist, the guy wire can be loosened and tightened. After proper tension in guywire, chain hoist can be removed and guy wire is clamped with the anchor rod

using preformed Armour grips.

3.10 PRE-FORMED ARMOUR GRIPS

This is used to finally clamp, one end of guy wire with the Anchor rod andother end of the guy wire with the guy plate. This Pre-formed armour gripsare consumable and shall not be used after 2-3 applications.3.11 OTHER ACCESSORIES

There are other accessories/ hardware alongwith each set of ERS. The list isgiven in Annexure-I.


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4.0 TYPE OF ASSEMBLED STRUCTURES


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4.0 TYPE OF ASSEMBLED STRUCTURES

When we assemble components of structures supplied with each ERS set, itresults into 15 types of structures as given in figure number 9. These aremainly Tangent structures, Angle structures and Dead end structures. Seventypes of Tangent structures, four types of Angle structures and four types ofDead end structures can be assembled. The most commonly used structureswith 400kV are Horizontal Vee (Suspension and Angle type), SnubbingandIn-line anglestructures. Single phase or two phases or three phases can betaken on Dead end structures depending upon length and tension of thespan.

Though Horizontal Vee is tangent structure as well as angle structure but itcannot be used at 0 degree line deviation. Small angle around five degreeshould always be provided so as to increase stability and strength of tangenttype Horizontal Vee structure.

In-line Dead end structures are most suitable for longer spans such as riverand valley crossing.

Before using any of these structures, it is essential that proper site planningand survey is carried out based on route of the line as given in next chapternumber 5.


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Figure-9


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5.0 SITE PLANNING AND SURVEY


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5.0 SITE PLANNING AND SURVEY

Survey the site and study the technical feasibility for installation of varioustypes of ERS structure (Figure-9). One of the main criteria for locating thetowers is to maintain electrical clearance from the existing transmissionline and from the ground. Procedure for survey is given below :

PROCEDURE FOR SURVEY:-

Visit tower location(s) which are required for bypassing circuit throughERS.

See availability of space required for ERS structure and guy, depend ontype of failure.

Choose the location for Foundation plate (base) and the anchoring point.

Measure the angle of ERS structure and span(s)

Decide on type of structure

6. Following T&P shall be required for carrying out the above survey work.

S. No. Name of T&P Quantity

1. Theodolite As per siterequirement

2. Chains

3. Arrows/ Marking Pins/ Steel Marker

4. Dumpy Level

5. Tripod stand

6. Wooden pegs

7. Ranging rod/ Nail/ Spikes

8. Offset rods

9. Plumb bob

10. Tape (Cloth or linen tape/ Metallic)

11. Shoulder pad

12. Field Book

13. Cross staff/ Optical square


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Co-ordinate with local administration, forest authorities, Railwayauthorities for railway crossing, power utilities for power crossing and alsomake boarding & lodging arrangement of crew members at site.

Based on site planning and survey, there may be possibility of restoring

the line using different restoration scenarios. Each restoration scenariohas certain advantages and its application depends on site conditions.


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6.0 FAILURE AND RESTORATION SCENARIOS


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6.0 FAILURE AND RESTORATION SCENARIOS

Restoration of collapsed towers depends on type of failures. This is inview of the fact that many types of tower design have been used in

different wind zones. While restoring the collapsed towers with the help ofERS structure the strength and capability of first and last permanent towerwhich would support ERS columns has to be kept in mind. This calls forvarious failure and restoration scenarios which is specific to each site.Following are the examples based on the experience along with theirmerits and de-merits.

6.1 SCENARIO NO. 1

In case the failed tower is suspension or tension type but the adjacentintact towers are tension type. There are 3 possibilities of restoring thecollapsed tower which is shown in Figure 10 and 11. Normally, option 1 is

most suitable with least no. of towers as the adjacent intact towers are oftension type. Other options may be necessitated only in view of siteconstraints but with advantage of reduced shut down period forpermanent restoration.


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6.2 SCENARIO NO. 2

In this scenario failure of more than one suspension tower and theirrestoration have been shown keeping the adjacent tower as tensiontowers only. This case is similar to scenario no. 1 except no. of ERSstructures required will depend on no. of permanent towers collapsed andcondition of the site (Figure 12 and 13).


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6.3 SCENARIO NO. 3

On one side intact tower is tension type and on the other side the intacttower is suspension type. In this case the first ERS tower & intact

suspension tower should be almost in line of the existing route conductor.This is required as large angle cannot be allowed on suspension tower.However, by reducing span & tension the angle on intact suspensiontower may be slightly increased as per tower design. On the other sideintact tension tower, the angle of line conductor can be very close tocapability of the tower or may be slightly higher in case span is slackedand reduced as per tower design ( tower spotting data).(Figure 14 and15)


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6.4 SCENARIO NO. 4

Both sides of collapsed towers are the suspension type of towers. In thiscase the options 1 or 2 given in tower failure scenario no. 3 may befollowed. However, small or large angle as shown for suspension towershave to be maintained both sides of intact towers.

6.5 SCENARIO NO. 5

This scenario is applicable for by-passing critical towers on the bank ofRivers. In this case given option is considered by using the dead-end inline structures of ERS. This can take longer span by providingintermediate guys to enhance the capability of the ERS structures.


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In all the above, scenarios, only single circuit restoration has been shownwhich is normally sufficient in emergency. However, if double circuitrestoration is required, the same can be done by following similarprocedure on another side of failed line.

On finalising the restoration scenario, i.e. route of erection of ERS towers,tentative bill of materials required at site can be prepared fortransportation. Bill of materials available in each set of ERS is given inAnnexure-I. Now the Material can be transported to the erection site.


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7.0 TRANSPORTATION ARRANGEMENT


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7.0 TRANSPORTATION ARRANGEMENT

After tower failure, a team has to visit site to look into the feasibility oflocation of ERS installation. Then number of towers to be By-passed on

ERS are to be identified along with the type of structure (geometry).Subsequently the anchoring location and number of anchoring point hasto be decided.

However, after finalisation of Restoration scenario, mode oftransportation can be decided, depending upon the location of storeswhere ERS components and T&P are stored.

Different mode of transportation that can be adopted are as follows:-

7.1 BY ROADS

Broadly there are two type of road transportation that are undertaken:-

By Trailer

ERS container containing all ERS components are loaded on Trailer.The Container has been designed in such a way that duringtransportation, no damage occurs. For Trailer, its availability andsuitability of road condition is important.

By Truck

In case a Trailer is not available, else trailer is available but roadcondition to the erection site of ERS is not suitable then it can betransported by trucks also which are readily available and arecomparatively cheaper. Depending upon the requirement more no. oftruck can be used. With the help of trucks, ERS materials can bedelivered to the nearest possible location of ERS erection site. Fromthere onwards, it can be transported by head loading with the help oflabourers to work site.

7.2 BY AIRIn case of hilly terrain, snow bound area and flooded area wheretransportation by above modes is difficult, ERS can be transported tonearest erection site from store by Air. In such case, erection can also bedone by a helicopter. As helicopter usage is more expensive ascompared to conventional method, but very fast, the same can bedeployed in urgent situation like backing down the generation and foravoiding insurmountable suffering of public at large . Also in case of flood/


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storm, if the roads are damaged and there is no other possibility totransport material/ man then helicopter can be used. Further more if thelocation is on the top of the hill or the location is not easily approachablethen also helicopter can be used. By helicopter, ERS erection gang canalso be transported if required. However again the availability ofhelicopter and the distance from Airport to ERS store is to be looked into

along with the clear area to enable the helicopter to land. In such case,the clearance from the local authorities is to be obtained. If the distance ismore, then the helicopter has to stop in between stations for refuellingwhich has to be kept in mind.

Detailed guidelines for transportation of ERS structure in trucks of 18 feetlong body are given in Annexure-III.

While transportation is in progress, computer planning for each ERS towercan be taken up.


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8.0 COMPUTER PLANNING


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8.0 COMPUTER PLANNING

Computer analysis programs are a critical part of the Modular EmergencyRestoration System. Registered copy of the complete set of computerprograms is available with each regional head quarter/ site office ofPowergrid. A copy of floppy containing ERS Program has been provided

in the pocket of the folder.

8.1 THE PROGRAM :

The program is on a single 3 HD floppy disk. The program is DOSbased, although it can also be run in a DOS Window. The program canbe run from the floppy or, if desired, it can be copied to the hard drive forfaster operation. If copying to the hard drive, create a separate directory,such as ERS, and copy the entire contents of the floppy disk to thatdirectory on the hard drive.

The following programs are contained on the disk :ATCHAIN.EXEAT4POLE.EXEATHVEE.EXEDEADEND.EXEMENU1.EXEERS.EXEBRUN30.EXE

HVEEDC.EXEDELTAHV.EXEHBONESC.EXEHFRAME.EXEPCRIT.EXEMENU2.EXEBRUN30.EXE

Each program is compiled and in executable format. BRUN30.EXE is acopyrighted product of Microsoft that enables the compiled programs torun.

8.2 SYSTEM REQUIREMENTS :

The programs are designed to run on most any IBM or compatiblepersonal computer. There are no special features, such as graphics, inorder to keep the programs as universally usable as possible. Theminimum system requirements are :

IBM PC/XT/AT or compatible computer 256K RAM

One 3-1/2, double sided, double density (360K) disk drive Display Monitor (Graphics capability not required) MS-DOS or PC-DOS 2.1 or higher

A hard disk drive in recommended since the programs will operatequicker. Approximately 500K is required to store the programs.

8.3 OPERATION :

To run the program, type ERS. A menu showing the various types ofstructures analysed by the programs is displayed.


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Selecting Units:To select the desired units, go to the Utilities optionfrom the main menu. Select either E for English units or M for metricunits. The program will ask whether to reset the data files. On the initialtime through, select Y, yes. If you go through utilities again later,selecting Y to reset will erase any saved information.

Example:From the main menu screen, select C to analyze a Chainettestructure. This takes you to the main chainette menu. The informationrequired to analyze a Chainette, or any structure type, is broken down intoConductor/OHGW information, Loading information, Span/ConductorHeight information and Geometry/Guying information.

Selecting any of these categories will allow you to view and edit theinformation. The program saves the most recent information as Default.It is possible to save up to 20 data sets for each type of information. TheGeometry information is used only with the Chainette program; however,the other three categories are common to all of the structures.

The E, edit, option in each of the information categories gives a moredetailed explanation of the desired information, including sketches andworksheets to assist you in entering the correct information.

Once all of the information has been entered, selecting A, analyze, willhave the program evaluate the Chainette structure based on theinformation that you have provided. If a G, general solution, has beenselected in the Span/Conductor Height information category, the programwill display a simple graph of allowable conductor height versus span. Ifthe guy loads or insulator loads exceed the pull-out strength of the guyplates, the graph will reflect this information. Selecting S, specific,enable you to enter a specific height and span and receive a moredetailed analysis, with the option of printing the results (sample attached).Selecting S specific, from the Span/Conductor Height informationcategory skips the general graph and goes directly to the specific solution.

8.4 STRUCTURAL ANALYSIS COMPUTER PROGRAMS

This manual explains how to analyze the Modular Emergency Restorationstructures, including the general analysis theory as well as information onthe operation of the enclosed computer programs.

It is highly recommended that a copy of the original disks be made andthe original disks stored in a safe location. The programs can either berun from the floppy disks or from a hard disk drive.

For analysing the structure on computer, following definitions shall beused.


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8.5 DEFINITIONS

Additional Assumed Eccentricity (in): Typical value of e3 eccentricityfor additional column eccentricity range from 0 to 6 inches.

Conductor Diameter (in): The bare sub-conductor diameter, in inches.For example 795mcm ACSR Drake conductor has a diameter of 1.108inches.

Conductor Weight Per Foot (lbs/ft) : The bare sub-conductor weight perunit length, in pounds per foot. For example 795mcm ACSR Drake has aweight of 1.094 lbs/ft.Conductor Tension (lbs): The sub-conductor tension, in pounds, includingany effect of ice and wind that might increase the tension but excludingthe line tension overload factor. Typical values are 15 to 25 percent of theultimate strength of the sub-conductor. This value is not requested in

programs that are used as tangents only.

Horizontal Overload Factor (Ratio): The overload capacity factor appliedto transverse loads caused by wind. In the National Electric Safety Code(NESC), Table 261-2, the horizontal overload factor is 2.50. For extremewind conditions a horizontal overload factor of 1.0 can be used.

Initial Guy Tension (lbs): The initial construction tension of the guy wiresprior to raising the conductors, given in pounds. Typical values are 500to 1000 pounds.

Line Tension Overload Factor (Ratio): The overload capacity factorapplied to line tension loads. In NESC, Table 261-2, the line tensionoverload factor is 1.65. For extreme wind conditions a line tensionoverload factor of 1.0 can be used. This value is not requested inprograms that are used as tangents only.

Maximum Vertical or Compressive Load (lbs): For a given set ofconditions (i.e. weight span, tower height, etc.), the resulting compressiveload on the foundation, in pounds. Dividing the value by the area of thefoundation, 25 ft2, gives the soil bearing pressure under the foundation inlb/ft2.

NESC: National Electrical Safety Code. The minimum general loadingrequirements (i.e. wind and ice) and strength requirements (i.e. overloadfactors) that a permanent transmission structure in the United Statesshould withstand.

Number of Conductors Per Phase : The number of sub-conductor perphase, typically 1,2,3 or 4. For example, the input value for a triple bundleconductor arrangement per phase would be 3.


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OHGW (Overhead ground wire): Also referred to as the shield wire,static wire, lightning wire, etc.

OHGW Diameter (in):The bare overhead ground wire diameter in inches.

OHGW Weight per Foot (lbs/ ft):The bare overhead ground wire weightper unit length in pounds per foot for values of commonly used strandedsteel cable.

OHGW Tension (lbs): The overhead ground wire tension, in pounds,including any effect of ice and wind that might increase the tension butexcluding the line tension overload factor. Typical values are 15 to 25percent of the ultimate strength of the OHGW. This value is not requestedin programs that are used as tangents only.

Post Insulator Angle from Horizontal (deg) :The upward slope of thepost insulator when mounted on a vertical surface. Post insulators

typically used with ERS have angles between 0 and 15 degrees.

Post Insulator Buckling Load (lbs):The ultimate compressive strengthof the post insulator, in pounds. This value is used to determine themaximum span that the post insulator can hold. For insulators with a 2.5inch fibreglass rod, commonly used with ERS, values range from 20,000lbs for an 8 foot length to 10,000 lbs for a 10 foot length.

Post Insulator Length (ft):The projected horizontal length of a horizontalpost insulator measured from its base to conductor attachment point,given in feet.

Radial Ice Loading (in):The radial thickness of ice applied to each sub-conductor and OHGW in inches. The ice is assumed to have a density of57 lb/ft3.

Ratio of Wind to Weight Span (wd/wt): The ratio obtained by dividingthe wind span by the weight span. The wind span, or horizontal span, isdefined as one half the sum of the conductor spans on either side of thestructure. The weight span, or vertical span, is defined as the sum of thedistances from each side of the structure to the low point of the conductorcatenary curve. The program calculate loads based on weight span only,and use this ratio to adjust the values for the wind span. On level terrain

this ratio is 1.0. For a structure on top of a hill, the ratio would be lessthan one. For a structure in a valley, the ratio would be greater than one.

Shape Factor for Column Wind Load (Ratio): The drag ratio of a non-cylindrical surface to a cylindrical surface for the same wind pressure. InNESC, Section 252B(2)(c), the minimum factor for a square latticedstructure is 3.2.


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Total Line Angle (degrees): The total angle, in degrees, that theconductors turn at the structure when projected onto the horizontal plane.

Vertical Overload Factor (Ratio):The overload capacity factor applied tothe weight of the conductor and ice. In NESC, Table 261-2, the verticaloverload factor is 1.50. For extreme wind conditions a vertical overload

factor of 1.0 can be used.

Vertical Phase Separation (ft): The vertical separation of phases,measured in feet. For the Horizontal Vee and Delta Horizontal Veestructures, as well as Deadend structures that utilize a post insulatorjumper, this separation is a box section height (1.5 feet) plus a standardcolumn section height (7,14, or 21 feet). For the Herringbone structureand Deadend structures that do not utilize a post insulator jumper, thisseparation is a standard column section height (7,14 or 21 feet).

Weight Span (ft): The sum of the distances from each side of thestructure to the low point of the conductor catenary curve. The weight

span is multiplied by the Ratio of Wind to Weight Span to give thecorresponding wind span. This span is also commonly referred to as thevertical span.

Conductor Wind Load, without Overload (lbs/sq ft):The wind pressureon the projected area of the conductors and OHGW, excluding thehorizontal overload factor, given in pounds per square foot. The programwill automatically add the radial ice to the conductors and OHGW andcalculate the projected area. This area is multiplied by the wind pressureand by the horizontal overload factor.

Column Wind Load, with Overload (lbs/sq ft) : The wind pressure onthe projected area of the ERS column, including the appropriate horizontaloverload factor. The program multiplies the column wind load by theshape factor and the projected area, but does not multiply the windpressure on the column by the horizontal overload factor.

X-Vertical Slope of Guy Wire (X to 1): The vertical change in the guywire for a unit horizontal change. X is the rise of the guy for a run of 1.Refer to drawings of each ERS type in computer programme for a specificdefinition of the X-slope for that structure.

Y-Horizontal Slope of Guy Wire (Y to 1):The spread of multiple guys in

the plan view. Refer to drawings of each ERS type in computerprogramme for a specific definition of Y-slope for that structure.

8.6 INPUT DATA FOR COMPUTER PROGRAMS

There is no standard formula that can be identified for ERS installation.However computer analysis programs has to be used prior to finalisingfor Emergency Restoration Structures. These user-friendly programsallow the utility engineer to quickly analyse any of the Emergency


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Restoration Structures configuration. User may use laptop computer forfield analysis for different Emergency Restoration Structureconfiguration. Following input data are required to analyse the structure.

8.6.1 Input Data

a. Conductor/ OHGW Data

Quantity per phaseDiameterUnit weightEveryday TensionMaximum Tension

Units

no.cmkg/mkNkN

Conductor OHGW

---

b. Wind/ Ice/ OLF Loading Data

Wind on ConductorWind on ColumnRadial Ice (thickness)Conductor/ OHGWTensionShape FactorVertical OverloadHorizontal OverloadLine Tension OverloadAdditional Eccentricity

Units

PascalPascalcm

cm

(E-Everyday, M-Maximum)

c. Line Profile/ Span / Height Data

Total Line AngleSpan Information TypeWind SpanWeight Span

Ratio of Wind Span to weightSpanDesired Conductor Height

Units

Degrees

metersmeters

meters

General/ Specific

d. Structure Geometry/ Guying Data

Input data are different and depend on the type of structure. Theinput data are to be taken from concerned line design parametersand as given for ERS structure and also in computer floppy.


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8.6.2 Output Data

After all the data have been fed in the programme, it will give the outputregarding suitability of structure. The output data will include thefollowing information:

* Allowable conductor height and span* Insulator loads* Guy and anchor loads* Intermediate guy wire requirements* Right-of-way requirements

Sample computer planning have been carried out for each type ofstructure for guidance of users.

8.7 SAMPLE PRINT-OUTS :Attached are sample print-outs (Annexure IV) of the various structuretypes that can be analyzed, including the Horizontal Vee, Delta HorizontalVee, Deadend, Running Angle(Single Phase), Running Angle(ThreePhase), Chainette, 4 Column, Single Circuit Herringbone and DoubleCircuit Herringbone. Also included are print-outs from the P-Criticalcolumn analysis program, the various column Erection Analysis optionsand the Wind/ Weight Span Circulation Worksheet.

The above input/ output data and computer print out can be convertedbetween metric and English units of measure.

8.8 CONVERSION FACTORS

The following factors are for soft converting between Metric and Englishunits of measure.

Length:1mm = 0.0396 in1 m = 3.2808 ft1 km = 0.6214 mile

1 in = 25.40 mm1 ft = 0.3048 m1 mile = 1.609 km

Area :

1 m2= 10.76 ft

2

1 cm2= 0.155 in

2

1 ft2= 0.0929 m

2

1 in2= 6.452 cm

2

Mass :1 kg = 2.2046 lb 1 lb = 0.4536 kg

Force :1 kN = 224.82 lb 1 lb = 0.00445 kN

Pressure

1 Pa = 1 N/m2

= 0.020886 lb/ft2 1 lb/ft

2= 47.879 Pa


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Wind Speed to Pressure :

1 lb/ft2= 0.00256*(mph)

2 1 lb/ft

2= 0.0129*(m/s)

2

Other:1 kg/m = 0.672 lb/ft1 km/h = 0.6214 mph

1 lb/ft = 1.488 kg/m1 mph = 1.609 km/h


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9.0 EXCAVATION OF PITS


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9.0 EXCAVATION OF PITS

The first step of erection of ERS is excavation. The procedure and T&Prequired is given below.

Procedure:-

1. Dig hole of 1 meter X 1 meter square area and 2-3 meter deepdepending on soil.

2. In case of rock drill by drilling machine.

3. In case of anchoring in loose soil, screw marsh anchors are to bedriven up to refusal level (minimum 2-3 meter)

4. A hole or a cut at 45 degree is to be made for inserting anchors rodfrom top to bottom of pit.

5. The size of pit i.e. length & width should be as small as possible sothat soil is not much disturbed.

6. In case water level is high, additional pits shall be made to share theload on anchors.

Tools & Plants

S. N Name of T&P Quantity1. Excavator As per site

requirement2. Shovel

3. Crow bars/ Spikes (22 mm.,1.5 MTR)

4. Drilling machine (if required)

5. Excavator (to be hired, if required)

After pits are excavated, next step is anchoring for the guys.


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10.0 GUY ANCHORING


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10.0 GUY ANCHORING

The procedure for anchoring and requirement of T&P is given below:-

Procedure:-

1. Insert Tripleye anchors rod (Guy adopter) in pit hole.

2. It should come out at bottom of pit hole.

3. Fit cross plate anchor with anchor rod and tighten with nuts as perapproved drawing.

4. Now back-fill the pit with the excavated soil and compact the soilproperly.

5. The top of anchor rod is to be connected with guy wire with the helpof pre-formed armour grips. These grips should have not beenused more than 2-3 times.

6. In case of screw/ marsh anchors compaction of soil is not required.The top end of screw anchor rod/ extension rod shall be connectedwith guy wire.

Tools & Plants

S.N. Name of T&P Quantity and type1. 9/16 EHS Guy Wire As per site

requirement

2. Guy Assembly consisting of(i) Wire Rope Thimble (Guy WireThimble)

(ii) Big Grip Deadend (Preformed GuyGrip)

3. Cross Plate Anchor Assembly consisting of(i) Tripleye Anchor Rod (Guy Adaptor)(ii) Cross Plate Anchor

4. Marsh Screw Anchor Assembly consisting of

(i) Tripleye Guy Adaptor

(ii) Triple Helix Lead Section(iii) 10 Foot Extension(iv) Fork Installation Tool(v) Fork Installation Tool Body

(vi) -104 Hex head cap bolt

(vii) -10Hex Standard Nut


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5. Rock Bolt Anchor Assembly consisting of

(i) Rock Bolt Anchor Assembly Part(ii) S1 Key Hole Bearing Steel Plate

Washer

(iii) E1 Eye Bolts

Once the four anchors are ready, tower erection can be started.Remaining anchors can be made ready while carrying out erection oftowers as the same are required before stringing activity only.


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11.1 GENERAL ASSEMBLY :

Once the type of ERS structure has been determined, the materialsrequired have been secured and at least four anchors are ready,

assembly of the structure can begin. In certain cases, such as where thecolumn is being Whipped up, it may be necessary to secure thefoundation using screw anchors, in order to resist the erection loads onthe foundation. (Figure 16 shows how to calculate the erection forces onthe foundation).

If the foundation must be placed on unstable ground, one or two guyplates can be placed between the foundation and the Gimbal to attachpermanent guy wires from these guy plates to permanent anchors, inorder to stablize the foundation.

Above the Gimbal the required tower sections can be bolted together

along with any guy plates and box sections which may be called for by thedesign. The bolts used on the structures should always be the special

ERS bolts. These bolts are 5/8-11zinc-plated steel bolts with the stampERS on the head. For proper functioning of the tower, it may be

ensured that only these bolts be used and other non standard 5/8-11bolts should not be used. If a column is overloaded these speciallydesigned ERS bolts are designed to fail before any of the welds (SeeFigure 17). If no ERS bolts are available, 5/8 inch SAE grade 5 or 16 mmgrade 8.8 metric bolts can be used; however, the welds may break beforethe bolts if the section is overloaded.

For all connections including two or more guy plates, the standard ERS

bolt i.e. 3-1/2 inch or 90 mm in length with 2-1/2 inches of thread lengthcan be used. In all cases a lock washer should be included, and the boltstorqued to 70 to 90 foot-pounds or 95 to 120 Newton-meters. If highstrength non-ERS bolts are used, more than one length will be neededtypically 2-1/2 inch or 65 mm for most connections and 3-1/2 inch or 90mm for connections of two of more guy plates.

As a general rule, the shorter column sections, 7 and 14 foot, should beassembled closest to the foundation. These sections are slightly heavierper unit length than the 21 foot sections and by assembling them on thelower portion of the tower more of the weight is kept at the bottom of thestructure. The column sections should be mounted so the flat portion ofthe side lattice angles are facing up. Structurally, it makes no differencewhich end of the section is up or down, however, positioning the latticeflats up makes climbing the towers easier.Each column section has two pins, one on each end. These pins can beused to help align two sections being assembled. For structuralpurposes, the pins can be positioned in any of the three holes on thecolumn end plate, although it is recommended that they be positioneddiagonally opposite.


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Figure-16


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Positioning the pins diagonally opposite will maintain the same back andforth pattern of the lattice angles between column sections and thusprovide a more consistent climbing pattern. There is one short pin andone long pin, which allows one pin to be installed first so the columnsection can be rotated on the first pin until the second pin is inserted.

When attaching the insulator/ hardware assemblies to the ERS structure,care should be taken to prevent twisting of the polymer suspensioninsulators. Torsional loading combined with tensile loading can reducethe ultimate strength of the insulators and cause premature failure.


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Figure-17

Figure-18


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11.2 GENERAL INSTRUCTIONS FOR ERECTION OF THESTRUCTURE

There are a variety of erection techniques which can be used on the ERSstructures. Each particular utility develops their own specific techniquesdepending on the type of equipment which they have available, the type

of terrain that they must work in and the type of ERS structure that theywill be erecting. Keeping this in mind, only the most commonly usedtechniques are described. As the user gains more experience with thestructures, other techniques and methods can be tried as long as thebasic rules explained below are maintained.

A common method of erecting the structures is using Gin Pole. However,to expedite restoration work tilting up the structure with a crane orhelicopter can also be adopted. If the structure has been assembled withthe foundation in its proper location with the structure horizontal, thestructure can be picked at or near the top and tilted into place pivoting atthe Gimbal. It is important to note that the ERS structure is fabricatedfrom aluminium and is very flexible compared to steel. When picking thetop end of a 105 foot (32 meter) column, with the base fixed to theground, the top end will deflect or raise approximately 20 inches or 500mm before the Gimbal begins to rotate (see Figure 18). If the 105 ftcolumn is made up of 21 ft sections, and the maximum bending momentis calculated, 27 percent of the bending capacity of the structure is utilizedwhen tilting up as described above. For a conservative reference useFigure 19 and 20 to determine the maximum lifting load T1 and themaximum column length that can be lifted. Figure 19 assumes an ERScolumn made up of only 14 ft sections, with eight guy plates at the top,and a reasonable amount of guy wire attached to the structure. Figure 20

assumes an ERS column made up of only 14 ft sections, with eight guyplates and three box sections at the top, and a reasonable amount of guywire attached to the structure. When lifting with a helicopter, tests haveindicated that the lifting load T1 will increase by approximately 10% dueto helicopter downwash on the structure.

To minimize the bending moment on a simple column when tilting it upwith a crane, the column should be picked up approximately one third ofthe distance from the top (T2 in Figures 19 and 20). Column with boxsections, or other top-heavy loads, should be picked up closer to the top.Special caution should be taken when erecting tall columns over 120 feetor 36 meters.

If the foundation is not set in position when erection begins, the bestmethod of transporting and setting an assembled column is to choke thestructure slightly above the center of gravity (T3 in Figures 19 and 20).The structure can then be moved so that the foundation is in its properlocation and the structure can be tilted into position.


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Figure-19


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Figure-20


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Since it is very difficult to plumb the column with a crane or helicopter, it isadvisable to use the crane or helicopter to get the structure close to plumband then use chain hoists on the guys to bring the structure into plumb.Past experience has shown that some form of positive hold on the guys isessential. Chain hoists and come-along attached to the guys should be

used when adjusting the position of the tower. Block and tackle shouldnot be used. If a block and tackle is used and the column gets too far outof plumb, the force of the towers movement may be too great for theblock and tackle and the column could fall.

The allowable bending moment on a column is 140,000 foot-pounds or190,000 Newton-meters. This bending moment should not be exceededduring construction. Figure 19 and 20 should give maximum lifting loadsand maximum column lengths. If a particular application is outside ofthese parameters, the actual bending moments can be calculated byusing the ERS computer programs. If this is not available, the weight ofeach component and their length can be used to perform a simply

supported beam analysis. The end support reaction of the simplysupported beam will provide T1. The maximum bending moment canalso be found from this analysis.

As a general rule, when erecting a tall column, over 100 feet or 30 meters,and any column which will be subjected to high winds, the column shouldhave intermediate guying. This intermediate guying will reduce thebending of the column due to wind loads, and dramatically increase theloading capacity of the structure (See Figure 21). It is important to keepthe column straight when adding intermediate guying. Do not overtension the intermediate guy so that a bend is introduced into the column(See Figure 22). The intermediate guys can be attached on a guy plateinstalled between sections for this purpose. There are also four holes onthe end flange of each section, one on each side, which can be used forattaching intermediate guys after the ERS structure is installed. Thesesame four holes can and should be used as attachment points forconstruction guys when using the section method of Gin Pole erection.

Except under unusual circumstances, it is important to guy all structuresat the same height as the load. Do not connect the load to the structureat one height and guy the structure at the section below or above, as thiswill create bending loads on the structure which may limit its capacity.This rule is also true for the box section, back guy the box section to

minimize shear on the box section. In cases where a load is being appliedto both the top and bottom of a box section, such as in a heavily loaded 3bundle deadend, it is best for the structure to be guyed back at both thetop and bottom of the box section.


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Figure-21

Figure-22


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The guy plates on the ERS have 6 points where guys or loads can beattached. Each of these six attachment points can hold an ultimate loadof 30,000 pounds or 134 kN. It is important to insure that the maximumdesign load on any one of these points is below this limit (See Figure 23).In cases where the maximum load may be above this limit, multiple guysshould be attached to more than one attachment point. It is critical that

the guy attachments have a large degree of flexibility and not be rigidconnections. If a guy is attached without this degree of articulation,wedging or bending of the attachment hardware may occur, and theattachment may fail. For this reason, it is recommended that an anchorshackle with bolt nut and cotter pin and a steel wire rope thimble be usedwith a preformed guy wire grip at the guy plate.

Figure-23

It is important when tensioning the top guys as well as the intermediate

guys, that they not be over tensioned. In most cases, a pretension ofabout 500-1000 pounds or 2-4 kN, or simply taking the slack out of theline, is sufficient. In some instances, such as a deadend or angle tower,the pretension should only be enough to keep the column straight undernormal conductor loading conditions. It is not recommended that thestructure be raked back as is often done with wooden poles. After theconductor is clipped in, the guy wire tensions should be re-checked andadjusted to insure a straight column (see Figure 22).


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12.0 ERECTION PROCEDURE USING A GIN POLE


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12.0 ERECTION PROCEDURE USING A GIN POLE

The Gin Pole can be used to either tilt up an ERS column or build an ERScolumn section by section. Both of these methods will be discussed;however all the items covered in section 14.0 also apply to tilting up anERS column with the Gin Pole.

12.1 TILTING UP THE ERS COLUMN WITH THE GIN POLE

Before attempting this method, determine the loads in the winch line andthe maximum length of ERS column that can be erected using thismethod. Refer to Figure 24 to determine the maximum winch or liftingload T4 and the maximum column length. In order to be conservative,Figure 24 assumes an ERS column made up of only 14 ft. sections, witheight guy plates at the top, and a reasonable amount of guy wire attachedto the structure. If a particular application is substantially different from theERS column described above, the actual lifting loads can be calculated as

demonstrated in Figure 16.

The winch line roller assembly and the Gin Pole attachment should beassembled to the aluminium Gin Pole. The attachment is designed to fiton any one of the four sides of the bottom channel, and between the 1inch reinforcing plates of ERS Gimbal Joint. Cut four pieces of rope.These ropes will be tied to the ring on the top of the Gin Pole (derrick) andwill be used to stabilize the Gin Pole during tower erection. Place thewinch line in the roller assembly of the Gin Pole and tilt up the column.The column being tilted up should be guyed to each side to prevent thecolumn from becoming unstable and rotating to one side. These two sideguys should be attached to two separate anchors that line up with the

foundation in a straight line on the ground perpendicular to the plane thatthe ERS column is being raised in. Since the ERS Gimbal axis isapproximately 2 ft. off the ground, tension in these two side guys shouldbe released as the column is raised to the vertical position. Failure toleave sufficient slack in the side guys as the tower is raised can cause theside guys to break. The column should also be guyed on the sideopposite to the winch line side to prevent the column from tipping over if itis raised past vertical.

12.2 BUILDING AN ERS COLUMN SECTION BY SECTIONWITH THE GIN POLE

An important advantage of the Modular Emergency Restoration System isthat structures and conductor can be erected and installed by hand usingthe Gin Pole (derrick). The following detailed procedure can be usedwhen no heavy equipment is available.

12.2.1 Initial preparation requirements:

1. Cut four pieces of rope. These ropes will be tied to the ring on the top


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of the Gin Pole (derrick) and will be used to stabilize the Gin Poleduring tower erection. The length of the ropes should be sufficient tobuild the entire length of the structure and have the ropes at a 45degree angle from the top to where the ropes are tied to the temporaryanchors. For a 125 foot or 38 meter high tower, the ropes should be atleast 200 feet or 61 meters in length. See Figure 25.

Figure-24


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2. Provide anchors for the Gin Pole. If permanent anchors cannot be usedthen temporary anchors need to be used to attach the 200 foot or 61meter Gin Pole mast ropes. One method of making temporary anchors isto use steel bars approximately 4 feet or 1.2 meters in length, 1 inch or 25mm in diameter and pointed on one end. Depending on soil conditions 1to 3 bars should be used at each of the four Gin Pole anchor locations.

Typically, it is the same type of bar that is used to stake down thefoundation plate. It is a good idea to have several extra bars, about 20, onthe erection site.

3. Provide a sufficient quantity of rope. Polypropylene rope, 5/8or 16 mm indiameter, is typically used to guy the Gin Pole and can be used for ahoisting rope. However, never use polypropylene rope to temporarily guythe tower. If a 125 foot or 38 meter tower were to be erected, theminimum total amount of rope required would be approximately 2,100 feetor 640 meters, the ropes should be cut into the following lengths :

(i) 200 foot (60 m) lengths 4 Nos.

(ii) 300 foot (90 m) lengths 4 Nos.(iii) 15 foot (5 m) lengths 2 Nos.

4. Provide the following miscellaneous equipment required to erect thetowers, assuming block permanent anchors and temporary stake anchorsare used;

(i) Sledge hammers (8 lb, or 3.6 kilogram) 2 Nos.

(ii) Roller sheaves with side opening and hook 4 Nos.(1 ton or 9000 Newton safe working load minimum)

(iii) Adjustable wrench (0 to 2 inch or 50 mm, jaws) 1 No.

(iv) Hydraulic wire cutters 1 No.(capacity for 9/16 inch EHS guy wire)

(v) Guy wire spool stand 1 No.

5. Precut all steel guy wires to be used on the tower.

6. Locate and mark foundation and anchor locations on the ground.

7. Dig anchor holes if plate anchors are used instead of block weightanchors. Install anchor plates. Back fill in 2 foot or 0.6 meter lifts. Be sureto use a hand tamper on each 2 foot or 0.6 meter lift. It is important thatthe back filled soil be compacted. Use water if necessary. If standardplate anchors are used, the anchor rod should be on a 45 degree angleand approximately 1 foot or 0.3 meter of the anchor rod should be aboveground.


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8. Locate and stake 4 temporary Gin Pole rope anchors (4 foot or 1.2 metersteel rods). At a minimum, these anchors should be as far from thefoundation as the tower is tall when completely erected.

9. Place one sheave on the top ring of the Gin Pole. Place 2 sheaves on awire cable or sling that has been wrapped around the foundation. String

one 300 foot or 91 meter rope through the sheaves at the base of thefoundation and through the sheave at the top of the Gin Pole.

12.2.2 Procedure for Gin Pole (derrick) erections of the ERStowers:

1. Stake foundation at its proper location.

2. Manually tip the Gimbal Joint onto the foundation and bolt it in place. Donot remove the turn buckles from the Gimbal Joint. If the top of the GimbalJoint is not level, adjust the four turn buckles to level it.

3. Tip up the Gin Pole along the Gimbal Joint. Pull back and tie the four 200foot or 61 meter Gin Pole mast ropes to their respective anchors. If theGin Pole is to be used for hoisting insulators, stringing blocks and othermaterials once the tower is built, be sure to locate the Gin Pole on themost convenient side of the tower.

4. Erect the first column section by tying the mast rope to the column sectionabove its center of gravity (see Figure 25). Do this in such a manner thatthe point of connection is centered on the side of the column that the GinPole is on. Tie two tag lines to the column being lifted (300 feet or 91meters long one on the top and one on the bottom). The column section

should be hoisted from the opposite side of the structure that the Gin Poleis attached to. To manually hoist the column section use 15 to 20 men topull the 300 foot or 91 meter hoisting line. Using the tag lines (3 men oneach tag line) to keep the column section being hoisted perpendicular tothe tower. Lower the column section onto the Gimbal. Make sure the pinguides slide into the holes properly. Bolt the connection with 8 bolts.

5. Pull the Gin Pole up the tower to its next location by attaching a sheave orsnatch block to one of the one inch holes centered on either side of thecolumn flange. Run the second 300 foot or 91 meter rope through theanother sheave at the foundation and through the sheave on the top ofthe tower flange and attach it to the ring on the bottom end of the Gin

Pole. By slacking off on the four Gin Pole guys and pulling on the secondhoist rope the Gin Pole can be safely raised to the next location. Whenthe proper height above the tower is reached, place the hook on thebottom of the Gin Pole over one of the lattice angles. This hook usuallyslides to the corner of the lattice angle. Secure the Gin Pole at the bottomring and near the top flange using the two 15 foot or 4.6 meter tie ropes(regularly inspect these ropes for wear, and replace as needed).

6. Readjust and tighten the Gin Pole rope guys so the top of the Gin Pole is


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correctly located. Repeat the hoisting procedure that was described inparagraph no.4. Note that the higher the column sections are to behoisted the farther away from the tower the tag line personnel must be.

7. Place temporary steel guys at proper intervals as the tower heightincreases. The guy wires should be attached to the permanent anchors.

When the temporary steel guys have been put in place, the turnbuckleson the Gimbal should be loosened and completely removed.

8. In difficult terrain, it may be easier to install the 21 ft. column sections first,and the smaller 7 ft. and 14 ft. column sections later, as the structureheight increases.

9. Once the entire tower has been erected it should be plumbed and theguys should be properly tightened and the performed grips should beapplied.

10. At this point, the Gin Pole can either be left in place or tipped at an angle

to assist in hoisting insulators, stringing blocks or conductors. Be sure theGin Pole is properly roped to the columns before lifting heavy loads.


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Figure-25


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13.0 ERECTION PROCEDURES USING A BOOM-TRUCK OR LIGHT DUTY CRANE


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13.0 ERECTION PROCEDURES USING A BOOM-TRUCK

OR LIGHT DUTY CRANE

There are several techniques that can be used to erect an ERS structurewith a crane. The choice of technique depends on the type and capacity ofthe crane available. One technique has already been partially discussed insection 11.2. With a large crane, the entire column can be bolted togetherhorizontally on the ground. The entire structure including foundation canbe moved to the proper location, if needed, and the crane used to raise thetop of the column to the near plumb position until the structure can besecured and plumed using chain hoists and come-along attached to theguys. This method requires the crane to lift the end of the column whilethe boom is extended at least one half the height of the ERS column awayfrom the cranes foundation, this necessitates a large crane. It alsorequires a skilled crane operator to raise a load and swing the crane boomas the end of the ERS column raises.

With two cranes, ERS structures have been erected where one largercrane remains almost stationary lifting the top end of the ERS structure(which was assembled and positioned near the final location of thefoundation). At the same time, a smaller mobile crane lifts the bottom endof the ERS structure (including foundation plate) and moves the foundationto its final position. In this method the large crane never has to swing itsboom.

However, for most applications where only a small crane or boom truck isavailable or can get to the job site, the following technique is most useful.This technique can also be used with larger cranes.

The following steps are referred to in Figure 26

1. Position the foundation in the desired location and stake into place.

2. Construct the column on the ground adjacent to the foundation. Thecenter of the column should be located approximately at thefoundation. Leave the turnbuckles on the Gimbal (but loosen the locknuts).

3. Install pre-measured guys to the column, include temporary guys ifrequired.

4. Locate the center of gravity (CG) by picking-up the column at variouslocations. Pick the column by choking all four main angles with a steelor nylon strap. Locate the straps one to two feet above the center ofgravity, so that two linemen can lift the Gimbal.

5. Begin raising the column using the winch line. The boom should onlyrequire minor adjustments in position. Have two crewmen walk theGimbal section towards the foundation.


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Figure-26

6. Once the column is vertical, with the Gimbal one foot off the ground,remove all four turnbuckles from the Gimbal.

7. Position the column over the foundation and bolt the Gimbal andfoundation together. Maintain a minimal amount of tension on thewinch line, enough to keep the column vertical without pulling the


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foundation upwards.

8. Attach the guys to their anchors and begin tensioning. Use the guywires, not the boom, to plumb the column. After the guys are installedthe winch line can be slacked off.

9. Have a crewman climb the column and release the sling from thecolumn.


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14.0 ERECTION TECHNIQUE INVOLVINGTILTING UP OR WHIPPING UP THE ERS

COLUMN WITH A WINCH LINE


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14.0 ERECTION TECHNIQUE INVOLVING TILTING UPOR WHIPPING UP THE ERS COLUMN WITH AWINCH LINE

Entire ERS columns have been erected using a winch line placed over thetop of a standard Gin Pole (derrick) and attached to the top of the ERScolumn. Another method is to raise the top of the ERS column with asmall boom and simply pull or whip up the column with a winch line. Stilla third method is to use one already erected ERS column as a Gin Poleand tilt up another ERS column with the winch line.

Figure-27

When tilting up an ERS structure using a winch line and standards GinPole (derrick), another ERS structure, or when whipping up a column,the foundation will have a tendency to move horizontally in the direction ofthe pull, and to tip up during the initial stages of the lift. As more verticalweight of the column acts on the foundation the tipping will subside. Thistendency should not pose any problems, although it is recommended thatscrew anchors be used to secure the foundation when using theseerection techniques(see Figure 27). Figure 16 shows the types of loadswhich are present when tilting up or whipping up a column. This type ofanalysis should be performed to determine the winch line load, uplift andhorizontal load on the foundation as well as to insure that the capacity ofthe structure is not exceeded. In using the procedure shown in Figure 16for analyzing an ERS column being tilted up, set the dimension B to the


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height of the standard Gin Pole or the winch line attachment point on anadjacent ERS structure.

The column being tilted up or whipped up, should be guyed to eachside to prevent column from becoming unstable and rotating to one side.These two side guys should be attached to two separate anchors that lineup with the foundation in a straight line on the ground perpendicular to theplane that the ERS column is being raised in. Since the ERS Gimbal axisis approximately 2 feet off the ground, tension in these two side guysshould be released as the column is raised to the vertical position. Failureto leave sufficient slack in the side guys as the tower is raised can causethe side guys to break. The column should also be guyed on the sideopposite from the winch line to prevent the column from tipping over if it israised past vertical.


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15.0 SPECIALISED ERECTION PROCEDUREUSING A HELICOPTER


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15.0 SPECIALISED ERECTION PROCEDURE USING AHELICOPTER

Three methods are typically available for erecting an ERS column using ahelicopter. The method chosen usually depends on the type and lift

capacity of the helicopter and the skill and training of the pilots.

15.1 FLY IN AND LANDING OF AN ENTIRE ERS COLUMNUSING A HELICOPTER

This method requires the largest helicopter, of the three methods. TheERS column is usually assembled on the ground at a marshalling yard(see section 11.1). The permanent guy wires are pre cut and attached tothe column and brought down to the ERS Gimbal joint, rolled up andattached to the Gimbal with tape or a tie rope. Two metal or nylon slingsare attached to diagonally opposite corners of the top of the ERS column(as seen in Figure 28). This will ensure that the column hangs straight.

Next, these slings are attached to a lift line of approximately 100 feet or30 meters in length and to a ring with sufficient weight that will allow thering and lift line to drop off the remote control release hook mechanism onthe helicopter. For emergency conditions, and for ease of release eachhelicopter should be equipped with a remote controlled releasemechanism as shown in Figure 28.

Discuss and plan the erection procedure and emergency proceduresbefore beginning. Use a helicopter pilot with external load movingexperience. Provide adequate radio communication equipment for thehelicopter and ground crew. Provide for dust abatement around theerection site to improve visibility.

Lift the column, first pivoting about the Gimbal then lifting the entirecolumn. As the helicopter approaches the erection site, the area wherethe foundation is to be placed should be clearly marked. As the helicopterlowers the ERS structure, static electricity can be drained off by firsttouching the structure on the ground. A foundation crew will grab thefoundation and help guide it to its proper location, while the helicopterhovers. Once the foundation is located, the foundation crew should stakethe foundation. At the same time, one crew for each permanent guy wirewill detach the guy wire from the Gimbal of the ERS structure, and put theguy wire in wire grips and attach these grips to the anchors with chainhoists.

While this is taking place, the helicopter should not try to hold thestructure plumb, as the structure will be unstable, making it difficult for theguy wire crews to attach the guy wires to the anchors. Instead, thehelicopter should hold the ERS structure in one position, approximately 5-10 degrees from vertical.


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Figure-28

Once four of the permanent guy wires are attached to their anchors andtightened up, the helicopter can slowly lower to test if all the guy wires andanchors are properly installed. Once this is verified, the helicopter canrelease the ERS structure using the remote controlled release hook. It isimportant to ensure that there is enough weight on the ring of the lift line


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to release the lift line from the hook, otherwise the pilot may pull awaywithout releasing the lift line.

Once the helicopter has left, the crews can finish plumbing the structureand staking the foundation.

15.2 TILTING UP AN ERS COLUMN WITH A HELICOPTER

This method may also require a large helicopter (refer Figure 19 and 20for lifting loads). The ERS column is usually assembled on the ground atthe site (see section 11.1). The permanent guy wires are pre cut andattached to the column and brought out to the permanent anchors. Twometal or nylon slings are attached to diagonally opposite corners of thetop of the ERS column (as seen in Figure 28). Next, these slings areattached to a lift line of approximately 100 feet or 30 meters in length andto a ring with sufficient weight that will allow the ring and lift line to drop offthe remote control release hook mechanism on the helicopter. Foremergency conditions, and for ease of release, each helicopter should be

equipped with a remote controlled release mechanism as shown in Figure28.

Discuss and plan the erection procedure and emergency procedurebefore beginning. Use a helicopter pilot with external load movingexperience. Provide adequate radio communication equipment for thehelicopter and ground crew. Provide for dust abatement around theerection site to improve visibility.

Attach the lift line to the helicopter, then tilt up the column. (see section14.0).

The helicopter should not try to hold the structure plumb, as the structurewill be unstable making it difficult for the guy wire crews to attach the guywire to the anchors. Instead the helicopter should hold the ERS structurein one position approximately 5-10 degrees from vertical. If more than oneERS column is to be tilted up at this site, it is a good idea to tie markers orflags to the guy wires so that the helicopter pilot can more easily see theguy wires when additional columns are raised.

Once four of the permanent guy wires are attached to their anchors andtightened up, the helicopter can slowly lower to test if all the guy wires andanchors are properly installed. Once this is verified, the helicopter can

release the ERS structure using the remote controlled release hook. It isimportant to ensure that there is enough weight on the ring of the lift lineto release the lift line from the hook, otherwise the pilot may pull awaywithout releasing the lift line.

Once the helicopter has left, the crews can finish plumbing the structure.


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15.3 SECTION BY SECTION METHOD OF ERECTING ANERS COLUMN USING A HELICOPTER:

This method is not recommended unless the helicopter pilots and crewshave previously trained together. If they have not trained sufficiently, abetter method for erecting the ERS structure would be for the smallerhelicopter to transport all the material to the erection site and use thesection by section method of erecting an ERS with the Gin Pole. (seesection 12.2).

To use the section by section method of erecting an ERS structure with ahelicopter follow the procedure below :

15.3.1 Initial preparation Requirements:

1. Cut four lengths of 9/1619 EHS guy wire approximately 330 feet or100 meters in length. Attach performed guy wire big grips with wire

rope thimbles to both ends.

2. Provide eight automatic wire grips eight 3-ton chain hoists, and sixmetal slings.

3. Discus and plan the erection procedure and emergency proceduresbefore beginning. Use a helicopter pilot with external load movingexperience. Provide adequate radio communication equipment for thehelicopter and ground crew.

4. Provide for dust abatement around the erection site to improvevisibility.

5. Discharge static electricity build up in the column sections bygrounding the column prior to lowering the tag lines to the linemen onthe tower. This can be done with a small metal wand by a lineman, orby touching the structure to the ground.

15.3.2 Procedure for Section by Section Helicopter Erection ofERS towers:

1. Level a small area for the foundation. Bring in the foundation andplace it with the helicopter. Securely stake the foundation to the

ground. Next, bring in the Gimbal and manually place it on top of thefoundation with a crew of four to six linemen. Then bolt the Gimbal tothe foundation. Generally (if space permits) the tie rods on the Gimbalare released and the Gimbal is lowered to the ground and one or twoadditional column sections are brought in, and a light-duty helicopter isused to tilt up the first 21-35 feet or 6-11 meters of column sections.However, if space is not available then the tie rods on the Gimbal areleft in place, and the top flange of the Gimbal is levelled by adjustingthe tie rods to await the next column section.


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Figure-29

2. Lift each column section with the helicopter by attaching two metal ornylon slings to diagonally opposite corners of the top flange as seen inFigure 29. This will ensure that the column hangs straight. Next, attachthe slings to a 100 foot or 30 meter lift line and to a ring with sufficientweight that will allow the ring and lift line to drop off the remote control


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release hook mechanism on the helicopter. For emergency conditions,and for ease of release each helicopter should be equipped with aremote controlled release mechanism as shown in Figure 29. 10 footor 3 meter tag lines should be attached to diagonally opposite cornersat the bottom of the column being lifted.

3. Fly in the first column above the Gimbal joint and lower the columndown onto the top of the Gimbal joint using the tag lines to guide it.This is shown on Figure 29 Some pilots prefer the linemen to pull thecolumn down onto the structure while the helicopter maintains aneutral buoyancy or only a slight lifting force on the column section.Once the column section has landed, one bolt is placed in each of thediagonally opposite corners by the linemen. While the linemen aredoing this, it is best that the helicopter pilot lowers the helicopter to putslack in the lift line. This is shown on Figure 30. If the helicopter pilottries to maintain tension in the line, quite often the helicopter will driftto the side and begin to pull the column off the top of the structure.

4. Hand tighten both bolts in the diagonally opposite corners, move awayfrom the structure and release the lift line.

5. Attach one end of the four 330 foot or 100 meter steel guy wires to thestructure on each of the four corner legs using steel slings andshackles. These guy wires should be located approximately 10 feet or3 meters below the top of the column (see Figure 29). This will ensurethat the next column section does not become tangled in theintermediate construction guys.

6. Bring in the next column section and grab the tag lines and pull thecolumn down on to the structure. Insert the long 6-inch or 152 mm pinon the column being flown in, into one of the matching holes in theerected column. Rotate the column and locate the shorter 4-inch or102 mm pin in its matching hole. Bring down the column by pulling ondiagonally opposite corners of the structure (see Figure 29). Lowerthe helicopter to put some slack in the lift line while the two linementighten the bolt and nut in diagonally opposite corners of the flanges.The linemen should climb down below the temporary guying, whichthe pilot releases the hook. It is important to ensure that there isenough weight on the ring of the lift line to release the lift line from thehook, otherwise the pilot may pull away without releasing the lift line.Once the lift line is released, the linemen can climb back up to the

flange and finish bolting all eight ERS bolts to attach the flangesection.


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Figure-30


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7. Attach the four 330 foot or 100 meter guy wires to more permanent

locations either at the mid point of the flange or at a guy plate on thestructure as the height of the column increases (refer to Figure 29).Attach the other end with preformed guy wire grips and thimbles to thematching flanges with a anchor shackle. Put the steel guy wire into

automatic wire grips, using 3-ton chain hoists to tension the guy wiresto the permanent anchors. Release the lower temporary guys,attached with slings, and use that end of the guy wire to guy at higherlocations on the structure. It is recommended that no more than 42feet or 13 meters of free standing column be erected without the guywire being moved up and re-anchored. The emergency RestorationStructure can be erected using a light-duty helicopter, by following thepreceding steps.


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16.0 CLIPPING-IN PROCEDURES


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16.0 CLIPPING-IN PROCEDURES

16.1 RESTORING CONDUCTOR AND CLIPPING-IN

Once the Lindsey Modular Emergency Restoration structures are erected,along with their associated hardware and insulators, the conductor mayhave to be restrung between the intact permanent towers and throughthe Lindsey Modular emergency Restoration Structures. Standardtension stringing methods should be used for this operation, no specialprecautions are needed for the ERS. The stringing travelers or rollerscan be attached to either the Universal Yoke Plate or the End CapAdapter with an Anchor Shackle and Chain Link, or just an AnchorShackle. Depending upon the anticipated time that the ERS are to remainin service, the conductor may be left in the stringing travelers, or theconductor can be clipped-in

If cranes and bucket trucks are available, clipping-in relatively straight

forward. The following procedures can be used if equipment access tothe ERS structure is limited.

16.2 CLIPPING-IN PROCEDURES FOR CHAINETTESTRUCTURES

1. After the two columns of the Chainette structure have been erectedand both columns are vertical and the top cross rope guy is still slack,raise the Chainette hardware and insulator assembly and attach it tothe top guy plates on each column.

2. If the conductor is to be strung through the bundle travelers, raise the

bundle travelers with the Chainette hardware insulator assembly.Connect the bundle travelers to the universal yoke plate. A tag lineshould be attached to the frame of each bundle traveler, and a pilotline should be threaded through the center sheave of each bundletraveler.

3. Once the Chainette insulator hardware assembly has been attached tothe top guy plates, use the 3-ton chain hoists at each of the anchorlocations to tilt the columns outward to take the slack out of the topcross rope guy.

4. String the 3-bundle conductor using standard tension stringingmethods. Once the conductors are sagged, the Chainette structurecan be clipped in.

5. To provide access to each phase place a ladder (or boatswains chair)with rollers on the top cross rope guy. Attach tag lines to the ladder toposition it horizontally. Attach a Chainette Clip-In Sling to the sameguy plate shackle that is used by the top cross rope guy (Refer toFigure 31).


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Figure-31

6. Attach a 3-ton chain hoist to the shackle on each of the yoke plates ofthe clipping-in sling. Referring to Figure 31, the clipping-in of a two orthree conductor bundle would require using the chain hoist and aconductor lifting hook to lift the first outside sub-conductor into theoutside position of the universal yoke plate. The U-bolts on thesuspension clamp should be tightened to approximately 35 ft-lb. or 47


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Newton-meters torque.

7. For a three conductor bundle, raise the center sub-conductor andtemporarily position it on the second hole of the universal yoke plate.(Refer to Figure 31) For additional clearance a chain link can beadded to the anchor shackle.

8. Raise the last or inside conductor using the chain hoist. Once theload is taken off the bundle traveler attach the tag line to a smallsnatch block on the fourth hole of the universal yoke plate and use it tolower the bundle traveler.

9. Once the bundle traveler is lowered, position the third conductor andclip it in to the fifth bottom hole of the universal yoke plate.

10. Once the third conductor is clipped in, lower the second conductor andattach it to the clevis eye link. This completes the 3-bundle triangulargeometry. (Refer to Figure 31).

11. Move to the next phase and repeat this process.

16.3 CLIPPING-IN PROCEDURES FOR HERRINGBONEAND FOUR-COLUMN STRUCTURES.

1. Once the 4-column or Herringbone structures are erected, and thecross guy ropes are tightened by tightening up on the anchor guys, theVee-string insulator hardware assemblies can be raised to theirappropriate positions. The single conductor or bundle conductortravelers should be attached to the universal yoke (refer to Figure 32).

A tag line should be attached to each traveler.

2. If the conductor is to be strung through the travelers, raise thetravelers with the Vee-string hardware insulator assembly. A tag lineshould be attached to the frame of each traveler, and a pilot lineshould be threaded through the center sheave of each traveler.

3. String the conductor using standard tension stringing methods. Oncethe conductors are sagged, the structure is now ready for clipp

Erection Manual of ERS (Disaster Management)

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