Edison’s Dream Edison’s Dream

““We will make Electricity We will make Electricity so cheap that only the so cheap that only the

rich will burn candlesrich will burn candles” ”

--Thomas Thomas Alva EdisonAlva Edison

(1847 - (1847 -

1931)1931) 11

ENGINEERINGENGINEERING

JYOTI STRUCTURES LIMITED

TRANSMISSION LINE TOWERS

PURPOSE :

The main purpose of TRANSMISSION LINE TOWER is to hold the conductor, which is transmitting the power from generating station to distribution end. As the conductors are bare and carrying the power at high voltage need to hold it at required height as per statutory requirements moreover the structure shall be safe, reliable and shall withstand all the climatic loads during the expected life of line.

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1) Survey 2) Design & Detailing 3) Proto Manufacturing & Assembly.4) Testing. 5) Manufacturing & Supply 6) Construction & Erection 7) Stringing of line and Commissioning

(i.e. Charging the line)

TRANSMISSION LINE TOWERSWhenever a Transmission Line is to be set up, the following activities are required to be executed:

ENGINEERING

TOTAL STATIONTOTAL STATION

55

Cut-pointCut-point

66

Insulator string

a) 33 kV Towerb) 66 kV Towerc) 110 kV Towerd) 132 kV Towere) 220 kV Towerf) 400 kV Towerg) 500 kV Towerh) 765 kV Tower i) 800 kV Tower j) 1200 kV Tower etc.

Towers can be classified as below:

1] As per Voltage level

TYPE OF TOWERS

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2] Number of Circuits –

a) Single Circuit Tower

TYPE OF TOWERSENGINEERING

2] Number of Circuits –

b) Double Circuit Tower

TYPE OF TOWERSENGINEERING

2] Number of Circuits –

c) Multi Circuit Tower

TYPE OF TOWERSENGINEERING

3] On the basis of Base Width –

a) Narrow Base Tower b) Broad Base Tower

TYPE OF TOWERSENGINEERING

Multi-circuit 15° Angle Tower (Vertical formation)

4] As per Configuration –

a) Vertical (Barrel type) Tower

TYPE OF TOWERSENGINEERING

4] As per Configuration –

b) Horizontal Tower

TYPE OF TOWERSENGINEERING

5] Type of Support –

a) Self Supported Tower b) Guy Supported Tower

TYPE OF TOWERSENGINEERING

a) Standard Tower (From Power station to Sub station)b) Special tower for River crossing/Creek crossingc) Railway crossing/road crossingd) Power Line Crossinge) Transposition tower

6] Type of Use –

TYPE OF TOWERSENGINEERING

Transposition tower

7] As per Angle of Deviation –

a) A type (0 - 2 deg)

TYPE OF TOWERSENGINEERING

7] As per Angle of Deviation – b) B type (2 – 15 deg) / (0 – 15 deg)c) C type (15 –30 deg)d) D type (30 – 60 deg)/ (dead end)

TYPE OF TOWERSENGINEERING

θ = 2-15° for B

= 15-30° for C

= 30-60° for D

CROSS ARM (PLAN)

a) Light wind zone (wind zone 1 & 2)

Zone 1 : 33 m/sec Zone 2 : 39 m/secb) Medium wind zone

(wind zone 3& 4)

Zone 3 : 44 m/sec

Zone 4 : 47 m/secc) Heavy wind zone

(wind zone 5 & 6) Zone 5 : 50 m/sec

Zone 6 : 55 m/sec

8] As per Wind Zone –

TYPE OF TOWERSENGINEERING

9] As per Type of Current –

b) HVDC Lines (High voltage direct current)

TYPE OF TOWERSENGINEERING

a) EHV /UHV (A/C) Lines

10] As per Type of Insulator –

a) Suspension Tower b) Tension Tower

TYPE OF TOWERSENGINEERING

765 KV S/C Tangent tower-Delta formation

2222

DESIGN SPAN:

ENGINEERING

Normal suggested design standard spans are as follows:

Voltage Normal design spans 33kv 180-305 m 66kv 240,250,275 m

110kv 315,325,335 m132kv 315,325,335 m220kv 335,350,375 m 400kv 400 m800kv 400,450 m

PEAK

CROSS ARM

CAGE

TOWER BODY

BODY / LEG EXTENSION

Peak: The function of peak is to support the Ground wire.

Cage: It comprises tower legs interconnected by bracings between peak and waist level.Cross-Arm: The function of cross-arm is to support conductor.Tower Body: Tower Body is the main portion of tower for connecting cage to tower foundation extension.Body Extension: It is used to increase/decrease the height of tower with a view to obtaining the required minimum ground clearance.Leg Extension: Leg Extensions are used either with anyone leg or pair of legs at locations where footing of tower are at different levels.

TOWER ANOTOMYENGINEERING

Tower Parts

CROSS ARM

LEG

TIE MEMBER

BRACING/LATTICE

BELT

PEAK MEMBER

TOWER ANOTOMYENGINEERING

Tower Members

Stub/Anchor Bolts and Base Plate Assembly connect the tower body /body extension and leg extensions to foundations. Cleats are provided on the stubs to offer resistance against uprooting of stubs.

Stub/Anchor Bolts and Base Plate Assembly:

TOWER ANOTOMYENGINEERING

Tower Accessories -

TOWER ANOTOMY

1) STEP BOLTS

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Tower Accessories -

TOWER ANOTOMY

2) ‘U’ BOLT

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Tower Accessories -

TOWER ANOTOMY

3) ‘D’ SHACKLE

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Tower Accessories -

TOWER ANOTOMY

4) HANGER, BIRD GAURD

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Bird Guard

Hanger

Tower Accessories -

TOWER ANOTOMY

5) DANGER PLATE, NUMBER PLATE, CIRCUIT PLATE,

PHASE PLATE

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Phase Plate

Circuit Plate

Number Plate

Danger Plate

Tower Accessories -

TOWER ANOTOMY

6) ANTICLIMBING DEVICE

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Tower Accessories -

TOWER ANOTOMY

7) EARTHING - PIPE TYPE

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Tower Accessories -

TOWER ANOTOMY

7) EARTHING - COUNTER POISE TYPE

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