Transmission Line Towers and details

Engineering

mahesh-sontyal
  • 132 KV Note: All in meters SC DC/SC (B/B) MC (B/B) NB (B/B) A P/D(4.2) K(8) 0 (1.3) B R(7.15) L(8.7) 30 (1.31) C&D S(7.75) M(11.5) 60 (3.174) Bot Xarm Ht Bot Xarm ht 12.283 12.35 12.3 Total Height Total height 27.381 38.46 27.1
  • 220 KV Note: All in mesters L&T TSP M/C NB A AV/AS X 0 B BS Y 30 C CS(8) Z(17) 60 (3.3) D(11) BotXarm Ht 16.85 19.085 17.45 11.79 Total Ht 33.5 38.035 51.4 29
  • Special towers NB MCNB(220KV) MCNB(132KV) 120m 250m 300m 60 0, 30 & 60 Deg 0, 30 & 60 2.2 5.4 3.936 14 13.1 12.15
  • Mono pole 180m 0, 30 & 60 Bot Xarm Ht 15.8
  • JC For river crossing suspension towers only Height(m) Base width (B/B) (m) Bot Xram(m) Wt. (MT) Full JC 88.2 12.38 69 32.5 Trunk JC 72.15 10.4 52.5 28.9
  • b) After 14 days of curing Built-up method:- This method consist of erection of towers member by member. The 4 main leg members of first section of the tower are first erected and guyed of. The cross braces then assembled. For assembling second section a light gin pole is placed on top of the corner legs for raising the second section of the tower. Afterwards the gin pole is shifted to top of second section leg to raise third section this process is continued till complete tower is erected.
  • Section method :- Major sections of the tower are assembled on the ground and same are erected as units. Either mobile crane or gin pole of 10m long is used. Ground assembly(Proto) :- This method consist of assembling the tower on ground and erecting it as a complete unit. The complete tower is assembled in line wise position to allow Xarms to fitted. After assembly is completed tower is picked up from ground with the help of crane and carried to is location and set on its foundation. This method is not is useful when the towers are large and heavy and the locations are difficult.
  • Helicopter method :- In this method the tower is erected in section. Bottom section is first lifted on to the stub and then the upper section is lifted and bolted to first section and the process is repeated till the tower is erected. Some times complete assembled tower is raised with the help of helicopter. This method is adopted when approach is impossible.
  • Decreasing Bath Hard HCL Pickling HCL Rinsing Water Fluxing Ammonia and Zinc Chloride Hot plate Zinc batch Dychromizing Finishing & Filling
  • Tightening of B&N The bolts & nuts are used to join the tower parts The bolts are of 16mm diameter and 20mm diameter The length of bolts are various from 35mm to 80mm multiple of 5mm 17.5mm/21.5mm dia hole is provided on tower part for fixing bolt & nut Spring washers - 16 x 3.5 mm- to tighten the bolt&nut Flat washers 4, 5, 6, 8, 10,20 and 25mm to fill up gaps between the tower parts Check for tight of B&N using torque wrench
  • The threads of bolts projecting out side shall be punched at 3 positions and do half round welding to ensure that nuts are not loosened in course of time and avoid theft of angles. Zinc epoxy painting is applied on welded portion to avoid rusting.
  • Grounding : - *
  • earthing is provided for D leg only For Railway crossing double earthing is to be provided. Normally earth pipe is placed vertically & in difficult places earth pipe placed in slant position with prior approval. A pit of 300mm dia and 3.2m depth is excavated to place earth pipes. *
  • Tower Accessories: - Danger boards Number plate Phase plate Anti Climbing Device Step bolts 16x175 mm Antiperch / Bird guards for suspension towers Hanger rods
  • NO TOWER SHALL BE ERECTED ON FOUNDATION BEFORE 10 DAYS AFTER CONCRETING. CHECK THE CORRECTNESS OF DIAGONAL AND LEVEL OF THE STUB OF THE FOUNDATION. TOWERS ARE TO BE ERECTED AS PER ERECTION DRAWING ASSEMBLY OF TOWER PARTS SHALL BE MADE AS PER MARK NUMBER WISE ENGRAVED ON THE TOWER MEMBER CORRESPONDING TO NUMBER IN THE ERECTION DRAWING. SPECIAL CARE SHALL BE TAKEN IN SELECTION OF MARK NUMBER FOR TRANSVERSE AND LONGITUDINAL FACE OF THE SQUARE BASE TOWER. ANY BUCKLING, DAMAGE TO STEEL MEMBER, DAMAGE TO GALVANIZING SHALL BE AVOIDED * FINAL
  • NO MEMBER SHALL BE SUBJECTED TO UNDUE STRESS. REASON CAN BE: (i) DEFECTIVE FABRICATION. (ii) DEFECTIVE FOUNDATION. (iii) DEFECTIVE ERECTION METHOD. COLLECT MATERIAL FROM STORE TALLYING WITH BOM. PREFERABLY TRANSPORT COMPLETE TOWER OR COMPLETE SECTION. THE TOWER MEMBER AT LOCATION SHALL BE KEPT ON GROUND SERIALLY ACCORDING TO THE NEED FOR FOLLOWING UP ERECTION SEQUENCE. * FINAL
  • TOWER ERECTION
  • * FINAL
  • WHILE LOADING AND UNLOADING THE TOWER PARTS, CARE SHOULD BE TAKEN FOR STACKING SYSTEMATICALLY. HANDLE THE TOWER PARTS CAREFULLY. WHILE HANDLING THEM WEAR SUITABLE GLOVES. ESTABLISH CLEAR SIGNAL/COMMUNICATION BETWEEN THE PERSONS WORKING ON THE TOP AND THE PEOPLE SUPPLYING TOWER PARTS, WATCHING GUYS PULLING ETC SPECIAL CARE SHALL BE TAKEN FOR R.C. TOWER. ALL LIFTING TOOLS AND TACKLES SHOULD BE LOAD TESTED AS PER STANDARD. * FINAL
  • ENSURE THE DERRICK USED BEFORE TOWER ERECTION HAS BEEN CHECKED FOR ADEQUATE STRENGTH / SIZE. KEEP WATCH ON ALL GUYS USED DURING ERECTION ANY SLIPPAGE/FAILURE IF THE GUY CAN CAUSE ACCIDENT. POLYPROPYLENE ROPE FROM 20MM TO 25MM SIZE SHOULD BE USED FOR GUYING & LIFTING. AFTER 5 OPERATIONS CHECK THE CONDITION OF THE ROPE. IF WORN OUT THEN REJECT. * FINAL
  • ALL TOWER MEMBERS TO BE FITTED WITH APPROPRIATE SIZE OF NUTS & BOLTS OF THE SECTION ERECTED BEFORE THE ERECTION IS TAKEN UP FOR THE NEXT SECTION. AVOID ALL TOWER ERECTION IN RAINY DAY. HEAVILY CLOUDY DAYS AVOID ALL TYPE TOWER ERECTION. STOP TOWER ERECTION OF R.C.TOWER. IN CASE OF HEAVY WIND OR APPROACHING STORM STOP ALL TOWER ERECTION. EVERY ONE SHOULD BE AWAY FROM THE TOWER. PPE LIKE HELMET, SAFETY BELT OF PROPER QUALITY IS USED. FOR CLIMBING TOWER USE SAFETY BELT WHICH CAN BE FITTED TO THE TOWER. * FINAL
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  • LINE MATERIALS Conductors Conductor Amps Kg/KM AL59 INVAR Panther 489 974 734 Amp. Double Panther 30+7/3.00 Zebra 737 1621 930 Amp. Double Zebra 54+7/3.18 Moose 840 1998 54+7/3.53
  • Layer No. of wires Total Centre 1 1 1st 6 7 2nd 12 19 3rd 18 37
  • II. Lay Ratio = Lay/OD ; Where OD = Outer diameter=(2N+1)d; where d= Dia of single strand 18 wires 10 – 12 12 wires 12 -14 6 wires 13 -18
  • Voltage Suspension Angle 132KV 9Nos 10Nos 220KV 13Nos 14Nos 400KV 23Nos 24Nos
  • Insulator hoisting Suspension insulators shall be used upto deviations of 2 degrees on all tangent type towers on the line and strain insulators on all angle type towers. For ensuring insulation co-ordination the suspension or tension strings on approach and terminal towers near the station ends upto a length of 1.5 Km shall be provided with adjustable arcing horns on tower side and fixed arcing horns on line side, keeping the arcing gap as may be stipulated by the Engineer at site. Insulator strings shall be assembled on the ground. These shall be cleaned and examined before hoisting. All accessories shall be properly fitted. Those having glazing defects exceeding half centimeter square shall not be used.
  • For suspension towers 70 KN insulators are hoisted with Aerial rollers. The Aerial rollers are like single sleeve pulley .Before hoisting of insulators the M pins should be checked thoroughly for their opening so that the insulation will not detached during stringing. *
  • CORRECT METHODS WRONG METHOD * FINAL
  • SELECT CONTINUOUS STRETCH AND STARTING TYPE OF TOWER FOR STRINGING WITH ADEQUATE CARE. PREPARE DRUM SCHEDULE FOR CONDUCTOR WITH CARE TO REDUCE WASTAGE. SELECT PROPERLY THE PLACEMENT SCHEDULE FOR TENSIONER AND PULLER. SELECT THE PLACE CAREFULLY FOR PLACEMENT OF TENSIONER AND PULLER TAKING SITE CONDITION INTO CONSIDERATION. CHECK CORRECTNESS OF ERECTED TOWER AS PER DRAWING AND SPECIFICATION FOR ALL TOWERS. CHECK COMPLETION OF EARTHING AND RECORD TOWER FOOTING RESISTANCE OF EACH LOCATION. ALL TREES ENROUTE THE LINE SHOULD BE CLEARED AND REMOVED FROM THE TRAVELLING PATH OF CONDUCTOR. CERTIFY AFTER VERIFICATION JOINTLY. * FINAL
  • STRINGING Paving out of conductor Rough sag Final tension / stringing
  • METHOD SLACK OR LAY OUT METHOD. PAYING BY TENSIONER PULLER. * FINAL
  • T&P required :- Tractor/Tensioner Turn table (5T or 10T) Conductor socks Automatic come along clamp for conductor and earth wire 20mm and 25mm D shackles Wooden packs Ground rollers Aerial rollers Crowbars Hacksaw blade Cutting pliers Screw driver Spanners
  • Generally drum lengths are Panther 2KM Zebra 1KM Moose 1KM Earth wire 2KM
  • * FINAL
  • Rough sag T&P required:- Rough sag leads Steel ropes 10mm, 12mm, 15mm and 16mm Come along clamp (7 bolts) Slings (20mm) 4 Sheave pulley 2 Sheave pulley Single Sheave pulley Manila ropes 12mm, 16mm, 18mm and 20mm Single and double end socks Turn buckle D shakles 20 mm Dead man 1to 1.2 m
  • Final tension /Stringing T&P required:- Leg winch Sag boards 100 MT joint compressor with die sets suitable for panther, Zebra Moose and earth wire. Earth wire flat clamps D shackles 16mm/25mm Binoculars Tractor / Tension puller
  • A A A * FINAL
  • BACK FILLED EARTH A A A * FINAL
  • TOOLS & PLANT REQUIRED PER CONDUCTOR 1. 20mm dia wire Rope Slings 40m length - 1 No. 2. 20mm 'D' Shakles - 2 Nos 3. Come along Clamp (Bolted Type) - 1 No. 4. 20mm Sling 10m length - 1 No. 5. Deadmen wood (1000mm-1200mm long) - 1 No. DETAIL – ‘B’ * FINAL
  • DETAIL – ‘C’ NOTE: Sling size = 20mm. Depending upon the Tension load rope size should be selected which is dependent on no of conductors type and the tension applied during the sagging. Arrangement should be capable of 1.5 times of the total tension load. * FINAL
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  • After stringing ensure the following Any departures from the correct sag in any span does not exceed 4 percent. The sag of any conductor does not depart by more than 3% from the mean sag of all the conductors in the same span subject of a maximum of 150mm.
  • BACK TENSION OF BOTH THE TENSION TOWERS OF SAG SECTION IS MOST IMPORTANT. PROVIDE BACK TENSION BY PAID OUT CONDUCTOR OF THE NEXT ADJACENT SECTION OF BOTH TENSION TOWERS. BACK TENSION ON THE TOWER WITH GUY WIRE SHOULD BE AVOIDED. IF REQUIRED PREPARE A SCHEME AND GOT IT APPROVED BY THE TECHNICAL CELL. GUY WIRE CAPACITY SHOULD BE 1½ TIMES OF MAXIMUM TENSION OF THE CONDUCTORS. INSPECT THOROUGHLY THE CONDITION OF GUY WIRES BEFORE USED. GUY FIXING ANGLE SHOULD BE BETWEEN 45o TO 50o TO THE VERTICAL. GUY BLOCKING ARRANGEMENT SHOULD BE VERY CAREFULLY DONE. RESPONSIBLE PERSONS SHOULD BE DEPLOYED DURING ENTIRE SAGGING OPERATION. MEN ON BACK STAY SHOULD BE PROVIDED WITH APPROPRIATE WHISTLE AND COMMUNICATION. MEN ON BACK STAY SHOULD BE IN CONSTANT TOUCH WITH FINAL SAGGING PERSON. * FINAL
  • ANY WHISTLE OR COMMUNICATION FROM THE PERSON AT BACK STAY, STRINGING SHOULD BE STOPPED. IF NECESSARY CONDUCTOR SHOULD BE RELEASED TO DE-TENSION. FINAL SAGGING SHOULD BE DONE AS PER APPROVED SAG TENSION CHART. ANY CHANGES IN THE SECTION, SPAN MADE DURING THE CONSTRUCTION THE SAG TENSION CHART SHOULD BE GOT CORRECTED. THE PERSON IN-CHARGE OF FINAL SAGGING SHOULD HAVE COPIES OF FINAL PROFILES, SAG TENSION CHART, FINAL TOWER SCHEDULE, SAG TEMPLATE, PROPER RECORDING REGISTER, FORMATS, ALL DRAWINGS OF HARDWARE AND ACCESSORIES. TWO THERMOMETERS SHOULD BE CLAMPED ON THE TOWER IN ADVANCE ON THE SAG SPAN. TEMPERATURE SHOULD BE CONSTANTLY MONITORED. NECESSARY CORRECTION OF SAG BOARD SHOULD BE DONE BEFORE FINAL MARKING OF CONDUCTOR. ADEQUATE AND PROPER COMMUNICATION SHOULD BE AVAILABLE AT ALL POINTS CONTROLLING SAG AND BACK TENSION POINT. * FINAL
  • ALL EQUIPMENT SHOULD BE LOAD TESTED BEFORE FINAL SAGGING OPERATION PLANNED. USE SUITABLE DYNAMOMETERS TO CROSS CHECK SAG, SHORTER SPAN, HILLY TERRAIN. CHECK CONSTANTLY EVENNESS OF THE BUNDLE CONDUCTOR. KEEP CONSTANT CHECK ON THE MOVEMENT OF AERIAL ROLLER TO ENSURE INTERMEDIATE SPAN ALSO REACHED TO DESIRED SAG. IN CASE ANY CONDUCTOR IS PULLED ABOVE SAG IN THE SAG SPAN THEN RELEASE BOTH THE CONDUCTORS TO BRING DOWN BELOW SAG AND BRING EVENNESS AND THEN RE-SAGGED. AVOID FINAL SAGGING IN WINDY DAYS, OTHER WISE ALLOWANCE IS TO BE GIVEN FOR UPLIFT. ALLOWANCE GIVING IS NOT DESIRABLE SINCE IT DEPENDS ON THE WIND AND EXPERIENCE. SPECIFIC CARE SHOULD BE TAKEN IN MEASURING FINALLY SAGGED CONDUCTOR BEFORE CUTTING & COMPRESSING THE DEAD END CLAMP. * FINAL
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  • KEEP THE CONDUCTOR FINALLY SAGGED FOR 48HRS ON ROLLER. AGAIN CHECK THE SAG AND RE-ADJUST IT IF NECESSARY. KEEP SUSPENSION STRING ABSOLUTE VERTICAL. PLUMB MARK THE CONDUCTOR BEFORE REMOVING ROLLER BY MEANS OF A PLUMB OR PLUMB MARKER MADE FOR SPECIFIC PURPOSE. THEN THE CONDUCTOR SHOULD BE LIFTED BY MEANS OF A SUITABLE LIFTING DEVICE. LIFTING DEVICE MAY CONSIST OF ONE OR TWO HOOKS DEPENDING UPON NUMBER OF CONDUCTORS. AFTER LIFTING THE CONDUCTOR FIX PREFORMED ARMOUR RODS. TAKE 2 OR 3 RODS ON EACH SIDE OF THE CENTRE MARK SUCH THAT THE HAND WILL NOT BE MORE THAN ONE OR TWO PITCH LENGTHS AWAY FROM THE CENTRE MARK. * FINAL
  • THE CENTRE MARK OF THE RODS SHOULD BE LOCATED AT THE CENTRE MARK OF THE CONDUCTOR SUPPORT. APPLY THE RODS BY ROTATING ABOUT CONDUCTOR CONTINUING FROM 1 OR 2 PITCH LENGTH OF EITHER SIDE OF THE CENTRE. FIX ARMOUR ROD APPLYING SPIRAL MOTION OF THE HANDS UNTIL THEIR ENDS ARE SNAPPED INTO POSITION. FIX SUSPENSION STRING OVER ARMOUR ROD THEN RELEASE THE LOAD. CHECK THE INSULATOR ASSEMBLY IS IN PLUMB. INSTALL VIBRATOR DAMPERS OR SPACER DAMPERS AS PER DRAWING at 1.2 to 1.3 m IF VIBRATION DAMPERS ARE USED THEN FIX THE LINE SPACER IMMEDIATELY THERE AFTER. * FINAL
  • ALLOW THE FINALLY SAGGED CONDUCTOR FOR 48HRS TO TAKE CARE THE CREEPAGE OR MINOR SAG ERROR DUE TO MOVEMENT OF AERIAL ROLLER. LIFTING DEVICE SHOULD BE FIXED IN SUCH A MANNER SO THAT LIFTING LOAD IS TRANSFERRED TO TOWER BODY. AVOID POINTED LIFTING LOAD ON THE TIP OF CROSS ARM. LIFTING HOOK SHOULD HAVE A RUBBER OR NEOPRENE LINING. MATCH THE CENTRE OF THE ARMOUR ROD WITH CENTRE MARK OF THE SUSPENSION POINT. FIX VIBRATION DAMPERS OR SPACER DAMPER IMMEDIATELY SINCE THE CONDUCTOR AT FULL LOAD / CRITICAL TENSION. FIX LINE SPACER IMMEDIATELY FOR BUNDLE CONDUCTOR TO AVOID CLASHING OF CONDUCTOR. * FINAL
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  • MEASURE THE EXACT JUMPER LENGTH REQUIRED FOR EACH TENSION TOWER. CHECK THE JUMPER DEPTH, ANGLE AS GIVEN IN THE ELECTRICAL CLEARANCE DIAGRAM. PRESS THE JUMPER CONE AND FIX ON THE TOWER. WHILE FIXING JUMPER THE CONDUCTOR SHOULD BE EARTHED PREFERABLY ON BOTH THE SIDES. IN CASE OF BUNDLE CONDUCTOR RIGID SPACER SHOULD BE FIXED AS PER THE RECOMMENDATIONS OF MANUFACTURER. * FINAL
  • Statutory Inspection points: S. No. Location No. Type of tower Chimney Coping Missing bolt & nuts HR weld Insulators Arcing horns Jumper bolt & nuts Jumpers Vibration Dampers Conductor Earth wire Earth wire bonds Number plates Danger boards Phase plates Step bolt & nuts Protection wall Ground clearance Tree clearance Other remarks
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  • 132 KV Note: All in meters SC DC/SC (B/B) MC (B/B) NB (B/B) A P/D(4.2) K(8) 0 (1.3) B R(7.15) L(8.7) 30 (1.31) C&D S(7.75) M(11.5) 60 (3.174) Bot Xarm Ht Bot Xarm ht 12.283 12.35 12.3 Total Height Total height 27.381 38.46 27.1
  • 220 KV Note: All in mesters L&T TSP M/C NB A AV/AS X 0 B BS Y 30 C CS(8) Z(17) 60 (3.3) D(11) BotXarm Ht 16.85 19.085 17.45 11.79 Total Ht 33.5 38.035 51.4 29
  • Special towers NB MCNB(220KV) MCNB(132KV) 120m 250m 300m 60 0, 30 & 60 Deg 0, 30 & 60 2.2 5.4 3.936 14 13.1 12.15
  • Mono pole 180m 0, 30 & 60 Bot Xarm Ht 15.8
  • JC For river crossing suspension towers only Height(m) Base width (B/B) (m) Bot Xram(m) Wt. (MT) Full JC 88.2 12.38 69 32.5 Trunk JC 72.15 10.4 52.5 28.9
  • b) After 14 days of curing Built-up method:- This method consist of erection of towers member by member. The 4 main leg members of first section of the tower are first erected and guyed of. The cross braces then assembled. For assembling second section a light gin pole is placed on top of the corner legs for raising the second section of the tower. Afterwards the gin pole is shifted to top of second section leg to raise third section this process is continued till complete tower is erected.
  • Section method :- Major sections of the tower are assembled on the ground and same are erected as units. Either mobile crane or gin pole of 10m long is used. Ground assembly(Proto) :- This method consist of assembling the tower on ground and erecting it as a complete unit. The complete tower is assembled in line wise position to allow Xarms to fitted. After assembly is completed tower is picked up from ground with the help of crane and carried to is location and set on its foundation. This method is not is useful when the towers are large and heavy and the locations are difficult.
  • Helicopter method :- In this method the tower is erected in section. Bottom section is first lifted on to the stub and then the upper section is lifted and bolted to first section and the process is repeated till the tower is erected. Some times complete assembled tower is raised with the help of helicopter. This method is adopted when approach is impossible.
  • Decreasing Bath Hard HCL Pickling HCL Rinsing Water Fluxing Ammonia and Zinc Chloride Hot plate Zinc batch Dychromizing Finishing & Filling
  • Tightening of B&N The bolts & nuts are used to join the tower parts The bolts are of 16mm diameter and 20mm diameter The length of bolts are various from 35mm to 80mm multiple of 5mm 17.5mm/21.5mm dia hole is provided on tower part for fixing bolt & nut Spring washers - 16 x 3.5 mm- to tighten the bolt&nut Flat washers 4, 5, 6, 8, 10,20 and 25mm to fill up gaps between the tower parts Check for tight of B&N using torque wrench
  • The threads of bolts projecting out side shall be punched at 3 positions and do half round welding to ensure that nuts are not loosened in course of time and avoid theft of angles. Zinc epoxy painting is applied on welded portion to avoid rusting.
  • Grounding : - *
  • earthing is provided for D leg only For Railway crossing double earthing is to be provided. Normally earth pipe is placed vertically & in difficult places earth pipe placed in slant position with prior approval. A pit of 300mm dia and 3.2m depth is excavated to place earth pipes. *
  • Tower Accessories: - Danger boards Number plate Phase plate Anti Climbing Device Step bolts 16x175 mm Antiperch / Bird guards for suspension towers Hanger rods
  • NO TOWER SHALL BE ERECTED ON FOUNDATION BEFORE 10 DAYS AFTER CONCRETING. CHECK THE CORRECTNESS OF DIAGONAL AND LEVEL OF THE STUB OF THE FOUNDATION. TOWERS ARE TO BE ERECTED AS PER ERECTION DRAWING ASSEMBLY OF TOWER PARTS SHALL BE MADE AS PER MARK NUMBER WISE ENGRAVED ON THE TOWER MEMBER CORRESPONDING TO NUMBER IN THE ERECTION DRAWING. SPECIAL CARE SHALL BE TAKEN IN SELECTION OF MARK NUMBER FOR TRANSVERSE AND LONGITUDINAL FACE OF THE SQUARE BASE TOWER. ANY BUCKLING, DAMAGE TO STEEL MEMBER, DAMAGE TO GALVANIZING SHALL BE AVOIDED * FINAL
  • NO MEMBER SHALL BE SUBJECTED TO UNDUE STRESS. REASON CAN BE: (i) DEFECTIVE FABRICATION. (ii) DEFECTIVE FOUNDATION. (iii) DEFECTIVE ERECTION METHOD. COLLECT MATERIAL FROM STORE TALLYING WITH BOM. PREFERABLY TRANSPORT COMPLETE TOWER OR COMPLETE SECTION. THE TOWER MEMBER AT LOCATION SHALL BE KEPT ON GROUND SERIALLY ACCORDING TO THE NEED FOR FOLLOWING UP ERECTION SEQUENCE. * FINAL
  • TOWER ERECTION
  • * FINAL
  • WHILE LOADING AND UNLOADING THE TOWER PARTS, CARE SHOULD BE TAKEN FOR STACKING SYSTEMATICALLY. HANDLE THE TOWER PARTS CAREFULLY. WHILE HANDLING THEM WEAR SUITABLE GLOVES. ESTABLISH CLEAR SIGNAL/COMMUNICATION BETWEEN THE PERSONS WORKING ON THE TOP AND THE PEOPLE SUPPLYING TOWER PARTS, WATCHING GUYS PULLING ETC SPECIAL CARE SHALL BE TAKEN FOR R.C. TOWER. ALL LIFTING TOOLS AND TACKLES SHOULD BE LOAD TESTED AS PER STANDARD. * FINAL
  • ENSURE THE DERRICK USED BEFORE TOWER ERECTION HAS BEEN CHECKED FOR ADEQUATE STRENGTH / SIZE. KEEP WATCH ON ALL GUYS USED DURING ERECTION ANY SLIPPAGE/FAILURE IF THE GUY CAN CAUSE ACCIDENT. POLYPROPYLENE ROPE FROM 20MM TO 25MM SIZE SHOULD BE USED FOR GUYING & LIFTING. AFTER 5 OPERATIONS CHECK THE CONDITION OF THE ROPE. IF WORN OUT THEN REJECT. * FINAL
  • ALL TOWER MEMBERS TO BE FITTED WITH APPROPRIATE SIZE OF NUTS & BOLTS OF THE SECTION ERECTED BEFORE THE ERECTION IS TAKEN UP FOR THE NEXT SECTION. AVOID ALL TOWER ERECTION IN RAINY DAY. HEAVILY CLOUDY DAYS AVOID ALL TYPE TOWER ERECTION. STOP TOWER ERECTION OF R.C.TOWER. IN CASE OF HEAVY WIND OR APPROACHING STORM STOP ALL TOWER ERECTION. EVERY ONE SHOULD BE AWAY FROM THE TOWER. PPE LIKE HELMET, SAFETY BELT OF PROPER QUALITY IS USED. FOR CLIMBING TOWER USE SAFETY BELT WHICH CAN BE FITTED TO THE TOWER. * FINAL
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  • LINE MATERIALS Conductors Conductor Amps Kg/KM AL59 INVAR Panther 489 974 734 Amp. Double Panther 30+7/3.00 Zebra 737 1621 930 Amp. Double Zebra 54+7/3.18 Moose 840 1998 54+7/3.53
  • Layer No. of wires Total Centre 1 1 1st 6 7 2nd 12 19 3rd 18 37
  • II. Lay Ratio = Lay/OD ; Where OD = Outer diameter=(2N+1)d; where d= Dia of single strand 18 wires 10 – 12 12 wires 12 -14 6 wires 13 -18
  • Voltage Suspension Angle 132KV 9Nos 10Nos 220KV 13Nos 14Nos 400KV 23Nos 24Nos
  • Insulator hoisting Suspension insulators shall be used upto deviations of 2 degrees on all tangent type towers on the line and strain insulators on all angle type towers. For ensuring insulation co-ordination the suspension or tension strings on approach and terminal towers near the station ends upto a length of 1.5 Km shall be provided with adjustable arcing horns on tower side and fixed arcing horns on line side, keeping the arcing gap as may be stipulated by the Engineer at site. Insulator strings shall be assembled on the ground. These shall be cleaned and examined before hoisting. All accessories shall be properly fitted. Those having glazing defects exceeding half centimeter square shall not be used.
  • For suspension towers 70 KN insulators are hoisted with Aerial rollers. The Aerial rollers are like single sleeve pulley .Before hoisting of insulators the M pins should be checked thoroughly for their opening so that the insulation will not detached during stringing. *
  • CORRECT METHODS WRONG METHOD * FINAL
  • SELECT CONTINUOUS STRETCH AND STARTING TYPE OF TOWER FOR STRINGING WITH ADEQUATE CARE. PREPARE DRUM SCHEDULE FOR CONDUCTOR WITH CARE TO REDUCE WASTAGE. SELECT PROPERLY THE PLACEMENT SCHEDULE FOR TENSIONER AND PULLER. SELECT THE PLACE CAREFULLY FOR PLACEMENT OF TENSIONER AND PULLER TAKING SITE CONDITION INTO CONSIDERATION. CHECK CORRECTNESS OF ERECTED TOWER AS PER DRAWING AND SPECIFICATION FOR ALL TOWERS. CHECK COMPLETION OF EARTHING AND RECORD TOWER FOOTING RESISTANCE OF EACH LOCATION. ALL TREES ENROUTE THE LINE SHOULD BE CLEARED AND REMOVED FROM THE TRAVELLING PATH OF CONDUCTOR. CERTIFY AFTER VERIFICATION JOINTLY. * FINAL
  • STRINGING Paving out of conductor Rough sag Final tension / stringing
  • METHOD SLACK OR LAY OUT METHOD. PAYING BY TENSIONER PULLER. * FINAL
  • T&P required :- Tractor/Tensioner Turn table (5T or 10T) Conductor socks Automatic come along clamp for conductor and earth wire 20mm and 25mm D shackles Wooden packs Ground rollers Aerial rollers Crowbars Hacksaw blade Cutting pliers Screw driver Spanners
  • Generally drum lengths are Panther 2KM Zebra 1KM Moose 1KM Earth wire 2KM
  • * FINAL
  • Rough sag T&P required:- Rough sag leads Steel ropes 10mm, 12mm, 15mm and 16mm Come along clamp (7 bolts) Slings (20mm) 4 Sheave pulley 2 Sheave pulley Single Sheave pulley Manila ropes 12mm, 16mm, 18mm and 20mm Single and double end socks Turn buckle D shakles 20 mm Dead man 1to 1.2 m
  • Final tension /Stringing T&P required:- Leg winch Sag boards 100 MT joint compressor with die sets suitable for panther, Zebra Moose and earth wire. Earth wire flat clamps D shackles 16mm/25mm Binoculars Tractor / Tension puller
  • A A A * FINAL
  • BACK FILLED EARTH A A A * FINAL
  • TOOLS & PLANT REQUIRED PER CONDUCTOR 1. 20mm dia wire Rope Slings 40m length - 1 No. 2. 20mm 'D' Shakles - 2 Nos 3. Come along Clamp (Bolted Type) - 1 No. 4. 20mm Sling 10m length - 1 No. 5. Deadmen wood (1000mm-1200mm long) - 1 No. DETAIL – ‘B’ * FINAL
  • DETAIL – ‘C’ NOTE: Sling size = 20mm. Depending upon the Tension load rope size should be selected which is dependent on no of conductors type and the tension applied during the sagging. Arrangement should be capable of 1.5 times of the total tension load. * FINAL
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  • After stringing ensure the following Any departures from the correct sag in any span does not exceed 4 percent. The sag of any conductor does not depart by more than 3% from the mean sag of all the conductors in the same span subject of a maximum of 150mm.
  • BACK TENSION OF BOTH THE TENSION TOWERS OF SAG SECTION IS MOST IMPORTANT. PROVIDE BACK TENSION BY PAID OUT CONDUCTOR OF THE NEXT ADJACENT SECTION OF BOTH TENSION TOWERS. BACK TENSION ON THE TOWER WITH GUY WIRE SHOULD BE AVOIDED. IF REQUIRED PREPARE A SCHEME AND GOT IT APPROVED BY THE TECHNICAL CELL. GUY WIRE CAPACITY SHOULD BE 1½ TIMES OF MAXIMUM TENSION OF THE CONDUCTORS. INSPECT THOROUGHLY THE CONDITION OF GUY WIRES BEFORE USED. GUY FIXING ANGLE SHOULD BE BETWEEN 45o TO 50o TO THE VERTICAL. GUY BLOCKING ARRANGEMENT SHOULD BE VERY CAREFULLY DONE. RESPONSIBLE PERSONS SHOULD BE DEPLOYED DURING ENTIRE SAGGING OPERATION. MEN ON BACK STAY SHOULD BE PROVIDED WITH APPROPRIATE WHISTLE AND COMMUNICATION. MEN ON BACK STAY SHOULD BE IN CONSTANT TOUCH WITH FINAL SAGGING PERSON. * FINAL
  • ANY WHISTLE OR COMMUNICATION FROM THE PERSON AT BACK STAY, STRINGING SHOULD BE STOPPED. IF NECESSARY CONDUCTOR SHOULD BE RELEASED TO DE-TENSION. FINAL SAGGING SHOULD BE DONE AS PER APPROVED SAG TENSION CHART. ANY CHANGES IN THE SECTION, SPAN MADE DURING THE CONSTRUCTION THE SAG TENSION CHART SHOULD BE GOT CORRECTED. THE PERSON IN-CHARGE OF FINAL SAGGING SHOULD HAVE COPIES OF FINAL PROFILES, SAG TENSION CHART, FINAL TOWER SCHEDULE, SAG TEMPLATE, PROPER RECORDING REGISTER, FORMATS, ALL DRAWINGS OF HARDWARE AND ACCESSORIES. TWO THERMOMETERS SHOULD BE CLAMPED ON THE TOWER IN ADVANCE ON THE SAG SPAN. TEMPERATURE SHOULD BE CONSTANTLY MONITORED. NECESSARY CORRECTION OF SAG BOARD SHOULD BE DONE BEFORE FINAL MARKING OF CONDUCTOR. ADEQUATE AND PROPER COMMUNICATION SHOULD BE AVAILABLE AT ALL POINTS CONTROLLING SAG AND BACK TENSION POINT. * FINAL
  • ALL EQUIPMENT SHOULD BE LOAD TESTED BEFORE FINAL SAGGING OPERATION PLANNED. USE SUITABLE DYNAMOMETERS TO CROSS CHECK SAG, SHORTER SPAN, HILLY TERRAIN. CHECK CONSTANTLY EVENNESS OF THE BUNDLE CONDUCTOR. KEEP CONSTANT CHECK ON THE MOVEMENT OF AERIAL ROLLER TO ENSURE INTERMEDIATE SPAN ALSO REACHED TO DESIRED SAG. IN CASE ANY CONDUCTOR IS PULLED ABOVE SAG IN THE SAG SPAN THEN RELEASE BOTH THE CONDUCTORS TO BRING DOWN BELOW SAG AND BRING EVENNESS AND THEN RE-SAGGED. AVOID FINAL SAGGING IN WINDY DAYS, OTHER WISE ALLOWANCE IS TO BE GIVEN FOR UPLIFT. ALLOWANCE GIVING IS NOT DESIRABLE SINCE IT DEPENDS ON THE WIND AND EXPERIENCE. SPECIFIC CARE SHOULD BE TAKEN IN MEASURING FINALLY SAGGED CONDUCTOR BEFORE CUTTING & COMPRESSING THE DEAD END CLAMP. * FINAL
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  • * FINAL
  • KEEP THE CONDUCTOR FINALLY SAGGED FOR 48HRS ON ROLLER. AGAIN CHECK THE SAG AND RE-ADJUST IT IF NECESSARY. KEEP SUSPENSION STRING ABSOLUTE VERTICAL. PLUMB MARK THE CONDUCTOR BEFORE REMOVING ROLLER BY MEANS OF A PLUMB OR PLUMB MARKER MADE FOR SPECIFIC PURPOSE. THEN THE CONDUCTOR SHOULD BE LIFTED BY MEANS OF A SUITABLE LIFTING DEVICE. LIFTING DEVICE MAY CONSIST OF ONE OR TWO HOOKS DEPENDING UPON NUMBER OF CONDUCTORS. AFTER LIFTING THE CONDUCTOR FIX PREFORMED ARMOUR RODS. TAKE 2 OR 3 RODS ON EACH SIDE OF THE CENTRE MARK SUCH THAT THE HAND WILL NOT BE MORE THAN ONE OR TWO PITCH LENGTHS AWAY FROM THE CENTRE MARK. * FINAL
  • THE CENTRE MARK OF THE RODS SHOULD BE LOCATED AT THE CENTRE MARK OF THE CONDUCTOR SUPPORT. APPLY THE RODS BY ROTATING ABOUT CONDUCTOR CONTINUING FROM 1 OR 2 PITCH LENGTH OF EITHER SIDE OF THE CENTRE. FIX ARMOUR ROD APPLYING SPIRAL MOTION OF THE HANDS UNTIL THEIR ENDS ARE SNAPPED INTO POSITION. FIX SUSPENSION STRING OVER ARMOUR ROD THEN RELEASE THE LOAD. CHECK THE INSULATOR ASSEMBLY IS IN PLUMB. INSTALL VIBRATOR DAMPERS OR SPACER DAMPERS AS PER DRAWING at 1.2 to 1.3 m IF VIBRATION DAMPERS ARE USED THEN FIX THE LINE SPACER IMMEDIATELY THERE AFTER. * FINAL
  • ALLOW THE FINALLY SAGGED CONDUCTOR FOR 48HRS TO TAKE CARE THE CREEPAGE OR MINOR SAG ERROR DUE TO MOVEMENT OF AERIAL ROLLER. LIFTING DEVICE SHOULD BE FIXED IN SUCH A MANNER SO THAT LIFTING LOAD IS TRANSFERRED TO TOWER BODY. AVOID POINTED LIFTING LOAD ON THE TIP OF CROSS ARM. LIFTING HOOK SHOULD HAVE A RUBBER OR NEOPRENE LINING. MATCH THE CENTRE OF THE ARMOUR ROD WITH CENTRE MARK OF THE SUSPENSION POINT. FIX VIBRATION DAMPERS OR SPACER DAMPER IMMEDIATELY SINCE THE CONDUCTOR AT FULL LOAD / CRITICAL TENSION. FIX LINE SPACER IMMEDIATELY FOR BUNDLE CONDUCTOR TO AVOID CLASHING OF CONDUCTOR. * FINAL
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  • MEASURE THE EXACT JUMPER LENGTH REQUIRED FOR EACH TENSION TOWER. CHECK THE JUMPER DEPTH, ANGLE AS GIVEN IN THE ELECTRICAL CLEARANCE DIAGRAM. PRESS THE JUMPER CONE AND FIX ON THE TOWER. WHILE FIXING JUMPER THE CONDUCTOR SHOULD BE EARTHED PREFERABLY ON BOTH THE SIDES. IN CASE OF BUNDLE CONDUCTOR RIGID SPACER SHOULD BE FIXED AS PER THE RECOMMENDATIONS OF MANUFACTURER. * FINAL
  • Statutory Inspection points: S. No. Location No. Type of tower Chimney Coping Missing bolt & nuts HR weld Insulators Arcing horns Jumper bolt & nuts Jumpers Vibration Dampers Conductor Earth wire Earth wire bonds Number plates Danger boards Phase plates Step bolt & nuts Protection wall Ground clearance Tree clearance Other remarks
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