Construction EHV Transmission Line
92,749 views
151 slides
Dec 16, 2014
Slide 1 of 151
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
About This Presentation
Complete details of EHV Transmission Line. Consolidated this presentation from those experts who had contributed separately on slider share and other web pages.Thanks for their valuable inputs.
Slide Content
Transmission of Power
Transmission Lines
3/30
Introduction
Introduction
Transmission of Power
What is Power Transmission ?
Power transmission is the movement of energy from its
place of generation to a location where it is applied to
performing useful work.
Electric power is normally generated at 11-33 kV in a power
station. To transmit over long distances, it is then stepped-
up to 400kV, 220kV or 110 kV as necessary.
Power is carried through a transmission network of high
voltage lines. Usually, these lines run into hundreds of
kilometers and deliver the power into a power grid.
What is Power Transmission ?
Power transmission is the movement of energy from its
place of generation to a location where it is applied to
performing useful work.
Electric power is normally generated at 11-33 kV in a power
station. To transmit over long distances, it is then stepped-
up to 400kV, 220kV or 110 kV as necessary.
Power is carried through a transmission network of high
voltage lines. Usually, these lines run into hundreds of
kilometers and deliver the power into a power grid.
Transmission of Power
What is Power Transmission ?
The grid is connected to load centres (cities) through a
sub-transmission network of normally 33kV (or
sometimes 66kV) lines.
These lines terminate into a 33kV (or 66kV) substation,
where the voltage is stepped-down to 11kV for power
distribution to load points through a distribution
network of lines at 11kV and lower.
What is Power Transmission ?
The grid is connected to load centres (cities) through a
sub-transmission network of normally 33kV (or
sometimes 66kV) lines.
These lines terminate into a 33kV (or 66kV) substation,
where the voltage is stepped-down to 11kV for power
distribution to load points through a distribution
network of lines at 11kV and lower.
Transmission of Power
Efficiency of transmission Line
Whatever may be the category of transmission line, the
main aim is to transmit power from one end to another.
Like other electrical system, the transmission network
also will have some power loss and voltage drop during
transmitting power from sending end to receiving end.
Hence, performance of transmission line can be
determined by its efficiency and voltage regulation.
Efficiency of transmission Line
Whatever may be the category of transmission line, the
main aim is to transmit power from one end to another.
Like other electrical system, the transmission network
also will have some power loss and voltage drop during
transmitting power from sending end to receiving end.
Hence, performance of transmission line can be
determined by its efficiency and voltage regulation.
Transmission of Power
Efficiency of transmission Line
Every transmission line will have three basic
electrical parameters.
The conductors of the line will have electrical
resistance, inductance, and capacitance.
As the transmission line is a set of conductors
being run from one place to another supported
by transmission towers, the parameters are
distributed uniformly along the line.
Efficiency of transmission Line
Every transmission line will have three basic
electrical parameters.
The conductors of the line will have electrical
resistance, inductance, and capacitance.
As the transmission line is a set of conductors
being run from one place to another supported
by transmission towers, the parameters are
distributed uniformly along the line.
Transmission of Power
Efficiency of transmission Line
Power sent from sending end - line losses
=
Power delivered at receiving end.
Efficiency of transmission Line
Power sent from sending end - line losses
=
Power delivered at receiving end.
Transmission of Power
The transmission lines are categorized as three types:
1)Short transmission Line – the line length is up to 80 km.
2)Medium Transmission Line – the line length is between
80km to 160 km.
3)Long Transmission Line – the line length is more than
160 km.
The transmission lines are categorized as three types:
1)Short transmission Line – the line length is up to 80 km.
2)Medium Transmission Line – the line length is between
80km to 160 km.
3)Long Transmission Line – the line length is more than
160 km.
Transmission Lines
Extra High Voltage
110 kV, 132 kV, 220 kV, 400 kV
Ultra High Voltage
765kV
High Voltage Direct Current
±500kV
Extra High Voltage
110 kV, 132 kV, 220 kV, 400 kV
Ultra High Voltage
765kV
High Voltage Direct Current
±500kV
Transmission Line Execution
Survey
&
Profile Plotting
Survey
&
Profile Plotting
Transmission Line Survey
A transmission line is one of essential infrastructures of
the power supply system.
In the site evaluation process for those facilities, it is
necessary to carefully consider not only technical issues,
but also the impact on natural environment, the influence
on local communities, and various regulations.
To achieve optimum line length, minimise rocky and
water terrains, reduced tower angle cut points, ROW
issues etc; it is necessary to have detailed survey, profile
of transmission line route.
A transmission line is one of essential infrastructures of
the power supply system.
In the site evaluation process for those facilities, it is
necessary to carefully consider not only technical issues,
but also the impact on natural environment, the influence
on local communities, and various regulations.
To achieve optimum line length, minimise rocky and
water terrains, reduced tower angle cut points, ROW
issues etc; it is necessary to have detailed survey, profile
of transmission line route.
Transmission Line Survey
Why Surveying Is Important ?
To optimize cost of transmission line
Line length, number of locations, deviations.
Minimum river crossings.
Minimum forest areas.
Accessibility, right of way considerations.
To assess route constraints and do construction
planning.
To ensure statutory clearances
Ground clearance.
Horizontal/Right of way clearance.
Clearances from power lines, railway lines, road
crossings etc.
Why Surveying Is Important ?
To optimize cost of transmission line
Line length, number of locations, deviations.
Minimum river crossings.
Minimum forest areas.
Accessibility, right of way considerations.
To assess route constraints and do construction
planning.
To ensure statutory clearances
Ground clearance.
Horizontal/Right of way clearance.
Clearances from power lines, railway lines, road
crossings etc.
UHV Transmission Lines - 765 kV ,
Requiring Large ROW
Requiring Large ROW
Transmission Lines through Agricultural fields
Transmission Lines in Hilly areas
Transmission Line River Crossings
Multiple Transmission Lines
Through Same Corridor
Through Same Corridor
Transmission Line Survey :
Project Conceptualization / Project Feasibility Stage:
Faster and accurate techniques required to evaluate
various line routes .
Pre-Construction Stage:
Route alignment, Detailed Mapping of right of way,
ground profiling, finalisation of tower locations.
Detailed contouring of undulated terrain for estimation
of benching and revetment quantities
Project Construction Stage
Check Survey only
Project Conceptualization / Project Feasibility Stage:
Faster and accurate techniques required to evaluate
various line routes .
Pre-Construction Stage:
Route alignment, Detailed Mapping of right of way,
ground profiling, finalisation of tower locations.
Detailed contouring of undulated terrain for estimation
of benching and revetment quantities
Project Construction Stage
Check Survey only
Detailed Survey – Modern Techniques
Route Alignment using latest satellite imageries
superimposed on Survey of India Topographical Maps.
Digital terrain modeling in hills using contouring data.
Detailed Survey using GPS, Total stations or ALTM.
Digitized contouring at undulated / hilly tower locations.
Identification of Route constraints.
Identification of infrastructure details .
Tower spotting & optimization of locations using
commercial software like PLS CADD.
Estimation of BOQ & Preparation Of Survey reports.
Soil Investigation.
Route Alignment using latest satellite imageries
superimposed on Survey of India Topographical Maps.
Digital terrain modeling in hills using contouring data.
Detailed Survey using GPS, Total stations or ALTM.
Digitized contouring at undulated / hilly tower locations.
Identification of Route constraints.
Identification of infrastructure details .
Tower spotting & optimization of locations using
commercial software like PLS CADD.
Estimation of BOQ & Preparation Of Survey reports.
Soil Investigation.
Detailed Survey – Modern Techniques
Global Positioning System
Total Station
PLS CADD
Global Positioning System
Total Station
PLS CADD
Detailed Survey – Modern Techniques
Global Positioning System
The Global Positioning System
(GPS) is a space-based satellite
navigation system that provides
location and time information in
all weather, anywhere on or
near the Earth, where there is
an unobstructed line of sight
GPS satellite.
It is a modern technology that
improves survey engineering to
Global orientation.
Global Positioning System
The Global Positioning System
(GPS) is a space-based satellite
navigation system that provides
location and time information in
all weather, anywhere on or
near the Earth, where there is
an unobstructed line of sight
GPS satellite.
It is a modern technology that
improves survey engineering to
Global orientation.
Detailed Survey – Modern Techniques
Total Station
A Total Station is a modern
surveying instrument that
integrates an electronic
theodolite with an electronic
distance meter.
A theodolite uses a movable
telescope to measure angles in
both the horizontal and vertical
planes.
Coordinates of an unknown point
relative to a known coordinate
can be determined using the
total station.
Total Station
A Total Station is a modern
surveying instrument that
integrates an electronic
theodolite with an electronic
distance meter.
A theodolite uses a movable
telescope to measure angles in
both the horizontal and vertical
planes.
Coordinates of an unknown point
relative to a known coordinate
can be determined using the
total station.
Detailed Survey – Modern Techniques
PLS CADD Power Line Systems –
Computer Aided Design and Drafting
PLS-CADD is the most powerful overhead power line
design program.
PLS-CADD is a sophisticated three-dimensional
engineering model.
The model can be viewed in a number of different
ways: profile views, plan views, plan & profile sheets,
3-D view etc.
PLS-CADD supports both automatic and manual
spotting.
PLS CADD Power Line Systems –
Computer Aided Design and Drafting
PLS-CADD is the most powerful overhead power line
design program.
PLS-CADD is a sophisticated three-dimensional
engineering model.
The model can be viewed in a number of different
ways: profile views, plan views, plan & profile sheets,
3-D view etc.
PLS-CADD supports both automatic and manual
spotting.
Detailed Survey – Modern Techniques
PLS – CADD software - Some views
PLS – CADD software - Some views
Transmission Line
Sample route Profile through Google Earth
Sample route Profile through Google Earth
Transmission Line
Sample route Profile
Sample route Profile
Transmission Line
Sample route Profile
Sample route Profile
Topo Map
Sending end
SS
Receiving end
SS
AP
1
AP
2
AP
3
AP
4
Bee Line
Sending end
SS
Receiving end
SS
AP
1
AP
2
AP
3
AP
4
Bee Line
Digitized Toposheet
Survey of India Topo Sheet
Corresponding Digitized Map
indicating relevant information
Survey of India Topo Sheet
Corresponding Digitized Map
indicating relevant information
Computerized Route Optimization by Study of
Alternative Routes
Bee
Line
Existing Line
Alternative
3
Alternative
2
Alternative 1
Alternative Routes
Bee
Line
Existing Line
Alternative
3
Alternative
2
Alternative 1
Digital Terrain Model –
Computerized Three Dimensional Image
Computerized Three Dimensional Image
Plan & Profile Drawing
Transmission Line Survey:
The detailed survey is taken up on the line route
approved by the concerned Electricity board.
Detailed survey should cover:
Fixing of Alignment
Fixing of Line Points
Fixing of Angles of deviation
Fixing of Angle Points
Fixing of Direction Points
Measuring of distance between Angle Points
Levels at every 10 M interval or where there is level
difference of 30 Cm
The detailed survey is taken up on the line route
approved by the concerned Electricity board.
Detailed survey should cover:
Fixing of Alignment
Fixing of Line Points
Fixing of Angles of deviation
Fixing of Angle Points
Fixing of Direction Points
Measuring of distance between Angle Points
Levels at every 10 M interval or where there is level
difference of 30 Cm
Transmission Line Survey:
Detailed survey should include:
Details of Roads
Details of Villages
P & T Lines Crossings
All Power Lines Crossings – LT to 765 kV
Railway Crossings
River Crossings
Agricultural wells, Field bunds & Earth bunds etc.
Measuring Soil resistivity at 1 Km interval
Trial Pits
Crop & Tree enumeration
Detailed survey should include:
Details of Roads
Details of Villages
P & T Lines Crossings
All Power Lines Crossings – LT to 765 kV
Railway Crossings
River Crossings
Agricultural wells, Field bunds & Earth bunds etc.
Measuring Soil resistivity at 1 Km interval
Trial Pits
Crop & Tree enumeration
Transmission Line Survey:
Detailed survey Obligatory Points
AVOID:
Reserve Forest Area
Military Firing Ranges
Aerodromes
Inhabited and thickly populated areas
Hilly terrain
Marshy, Low lying & Submersible areas
Higher & 90 degrees angle turnings
Oil & Gas storage areas
Detailed survey Obligatory Points
AVOID:
Reserve Forest Area
Military Firing Ranges
Aerodromes
Inhabited and thickly populated areas
Hilly terrain
Marshy, Low lying & Submersible areas
Higher & 90 degrees angle turnings
Oil & Gas storage areas
Transmission Line Profile:
Detailed Profile should be
From the details of route survey, route plan and ‘Profile’, is
prepared. Profile is also termed as Longitudinal profile or
route profile.
The profile is prepared and plotted paper rolls of graphed
tracing paper.
The profile shall progress from left to right.
A typical profile is enclosed.
Detailed Profile should be
From the details of route survey, route plan and ‘Profile’, is
prepared. Profile is also termed as Longitudinal profile or
route profile.
The profile is prepared and plotted paper rolls of graphed
tracing paper.
The profile shall progress from left to right.
A typical profile is enclosed.
Transmission Line Profile
Transmission Line Profile
Transmission Line Profile
Transmission Line Profile:
Detailed Route Profile should be
Graphical representation
Preferably be in the Scale of
X-axis 1 Cm = 20 M
Y-axis 1 Cm = 2 M
Plot Plan of Alignment of Line from AP to AP
Plot Distances
Plot Levels with respect to distance
Detailed Route Profile should be
Graphical representation
Preferably be in the Scale of
X-axis 1 Cm = 20 M
Y-axis 1 Cm = 2 M
Plot Plan of Alignment of Line from AP to AP
Plot Distances
Plot Levels with respect to distance
Transmission Line Profile:
Detailed Profile should include & indicate
All Power Lines crossings: LT to 765 kV
All P & T Lines crossings
All Railway crossings
All River crossings
All Roads: Cart Tracks to National Highways
All Villages
All Agricultural wells
All Field bunds & Earth bunds
All Ponds & Lakes
Type of Soil
Crops & Trees
Detailed Profile should include & indicate
All Power Lines crossings: LT to 765 kV
All P & T Lines crossings
All Railway crossings
All River crossings
All Roads: Cart Tracks to National Highways
All Villages
All Agricultural wells
All Field bunds & Earth bunds
All Ponds & Lakes
Type of Soil
Crops & Trees
Transmission Line Profile
Transmission Line Profile:
Tower Spotting
Identify the position of Terminal Tower.
Start from Terminal Tower.
Match the tower footing curve with the position of TT.
Adjust the position of template.
Ensure Ground Clearance.
Identify the position of next tower.
Move the template to the next tower.
Repeat the procedure.
Tower Spotting
Identify the position of Terminal Tower.
Start from Terminal Tower.
Match the tower footing curve with the position of TT.
Adjust the position of template.
Ensure Ground Clearance.
Identify the position of next tower.
Move the template to the next tower.
Repeat the procedure.
Transmission Line Profile:
Tower Spotting
NORMAL SPAN:
It is the design span
ACTUAL SPAN:
It is the actual distance between two adjacent towers
NULL POINT:
It is a point in a span where the position of the conductor is
lowest (or) It is a point in a span where the sag is maximum
WEIGHT SPAN:
The distance between two adjacent null points
WIND SPAN:
It is the distance between two centre points of adjacent spans.
Tower Spotting
NORMAL SPAN:
It is the design span
ACTUAL SPAN:
It is the actual distance between two adjacent towers
NULL POINT:
It is a point in a span where the position of the conductor is
lowest (or) It is a point in a span where the sag is maximum
WEIGHT SPAN:
The distance between two adjacent null points
WIND SPAN:
It is the distance between two centre points of adjacent spans.
Transmission Line Profile – SAG TEMPLATE
Transmission Line Profile – Span Limitations
SPAN 110 /
132 kV
220 kV 400 kV
NORMAL SPAN 320 M 350M 400 M
WIND SPAN
Both 320 M 350 M 400 M
Single 192 M 210 M 240 M
WEIGHT SPAN
Both 400 M 450 M 600/800 M
Single 240 M 270 M 300/400 M
SPAN 110 /
132 kV
220 kV 400 kV
NORMAL SPAN 320 M 350M 400 M
WIND SPAN
Both 320 M 350 M 400 M
Single 192 M 210 M 240 M
WEIGHT SPAN
Both 400 M 450 M 600/800 M
Single 240 M 270 M 300/400 M
Transmission Line Profile – Clearances
Details
110/
132 kV
220 kV 400 kV
Ground Clearance 6.1 M 8.5 M 9.0 M
LT to 132 kV and
P& T Lines
3.1 M 4.6 M 5.5 M
220 kV 4.6 M 4.6 M 5.5 M
400 kV 5.5 M 5.5 M 5.5 M
Details
110/
132 kV
220 kV 400 kV
Ground Clearance 6.1 M 8.5 M 9.0 M
LT to 132 kV and
P& T Lines
3.1 M 4.6 M 5.5 M
220 kV 4.6 M 4.6 M 5.5 M
400 kV 5.5 M 5.5 M 5.5 M
Transmission Line Profile – Clearances
Details
110 /
132 kV
220 kV 400 kV
Highway Crossing 9 M 9 M 9M
Railway Crossing 14.6 M 15.4 M 17.9 M
Railway Crossing
Span (Max)
2/3 of NS 2/3 of NS 2/3 of NS
Distance between
Tower & Railway
Track (Min)
TH+6 M TH+6 M TH+6 M
Details
110 /
132 kV
220 kV 400 kV
Highway Crossing 9 M 9 M 9M
Railway Crossing 14.6 M 15.4 M 17.9 M
Railway Crossing
Span (Max)
2/3 of NS 2/3 of NS 2/3 of NS
Distance between
Tower & Railway
Track (Min)
TH+6 M TH+6 M TH+6 M
Transmission Line – Tower Schedule
Location
No.
Type
of
Tower
Angle of
Deviation
(degrees)
Span
(M)
Left
Wt.
Span
(M)
Right Wt.
Span
(M)
Total Wt.
Span (M)
Remarks
SS Boom - - - -
Boom at sending
end SS
70
1 TT S 35 L - 75 -
Terminal tower at
sending end SS
210
2 P - 135 150 285
300
3 R 22 R 150 130 280 Near village
280
4 P+3 - 150 125 255 33 kV Line crossing
250
Location
No.
Type
of
Tower
Angle of
Deviation
(degrees)
Span
(M)
Left
Wt.
Span
(M)
Right Wt.
Span
(M)
Total Wt.
Span (M)
Remarks
SS Boom - - - -
Boom at sending
end SS
70
1 TT S 35 L - 75 -
Terminal tower at
sending end SS
210
2 P - 135 150 285
300
3 R 22 R 150 130 280 Near village
280
4 P+3 - 150 125 255 33 kV Line crossing
250
Transmission Line Profile:
Check Survey
Marking of Tower Location
Forward & Backward Line Points
Pit Marking
Excavation
Check Survey
Marking of Tower Location
Forward & Backward Line Points
Pit Marking
Excavation
Transmission
Line
Foundation
Line
Foundation
Transmission Tower Foundation
Type of loads on foundation :
The foundation of towers are normally subjected to three
types of forces. These are:
a)The compression or downward thrust.
b)The tension or uplift.
c)The lateral forces of side thrusts in both transverse
and longitudinal directions.
Type of loads on foundation :
The foundation of towers are normally subjected to three
types of forces. These are:
a)The compression or downward thrust.
b)The tension or uplift.
c)The lateral forces of side thrusts in both transverse
and longitudinal directions.
Transmission Tower Foundation
Depending on the type of soil and the presence of surface
water table , four types of foundation will be used for each
type of tower location.
Normal dry type :
To be used for location in normal day cohesive or non-
cohesive soils.
Partially sub-merged type :
To be used at locations where sub soil water table is
met between 0.75 metre below the ground line.
Depending on the type of soil and the presence of surface
water table , four types of foundation will be used for each
type of tower location.
Normal dry type :
To be used for location in normal day cohesive or non-
cohesive soils.
Partially sub-merged type :
To be used at locations where sub soil water table is
met between 0.75 metre below the ground line.
Transmission Tower Foundation
Fully sub-merged type :
To be used at locations where sub-soil water table is met
at less than 0.75 metre below the ground line.
Wet type :
To used for locations:
1.Where sub-soil water is met at 1.5 m or more below
the ground line.
2.Which are in surface water for long periods with water
penetration not exceeding one metre below the ground
3.In black cotton soils.
Fully sub-merged type :
To be used at locations where sub-soil water table is met
at less than 0.75 metre below the ground line.
Wet type :
To used for locations:
1.Where sub-soil water is met at 1.5 m or more below
the ground line.
2.Which are in surface water for long periods with water
penetration not exceeding one metre below the ground
3.In black cotton soils.
Transmission Tower Foundation
In addition, depending on the site conditions, other types of
foundations may be introduced suitable for:
Intermediate conditions under the above classification to
effect more economy, or
- For locations in hilly and rocky areas.
- For locations where special foundations (well type or
piles) are necessitated.
In addition, depending on the site conditions, other types of
foundations may be introduced suitable for:
Intermediate conditions under the above classification to
effect more economy, or
- For locations in hilly and rocky areas.
- For locations where special foundations (well type or
piles) are necessitated.
Transmission Tower Foundation
Testing of soil
It is desirable to undertake testing of soil for all the tower
locations and report should be obtained about the sub-soil
water table, bearing capacity of soil, possibility of
submergence and other soil properties required for the correct
casting of casing of foundations.
Testing of soil
It is desirable to undertake testing of soil for all the tower
locations and report should be obtained about the sub-soil
water table, bearing capacity of soil, possibility of
submergence and other soil properties required for the correct
casting of casing of foundations.
Transmission Tower Foundation
Testing of soil
It is desirable to undertake testing of soil for all the tower
locations and report should be obtained about the sub-soil
water table, bearing capacity of soil, possibility of
submergence and other soil properties required for the correct
casting of casing of foundations.
Testing of soil
It is desirable to undertake testing of soil for all the tower
locations and report should be obtained about the sub-soil
water table, bearing capacity of soil, possibility of
submergence and other soil properties required for the correct
casting of casing of foundations.
Transmission Tower Foundation
Tower Foundation:
1.Excavation
2.PCC
3.Stub setting
4.Template Alignment
5.Concreting
6.Curing
7.De-shuttering & Template removal.
8.Back- Filling
Tower Foundation:
1.Excavation
2.PCC
3.Stub setting
4.Template Alignment
5.Concreting
6.Curing
7.De-shuttering & Template removal.
8.Back- Filling
Transmission Tower Foundation
Excavation
Excavation
Transmission Tower Foundation
Excavated pit on hard rock
Excavated pit on hard rock
Transmission Tower Foundation
Water at Excavated pit Dewatering
Water at Excavated pit Dewatering
Transmission Tower Foundation
Stub setting & Template Assembly
Stub setting & Template Assembly
Transmission Tower Foundation
Stub setting & Template Assembly
Stub setting & Template Assembly
Transmission Tower Foundation
Base levelling with sand filling
Base levelling with sand filling
Transmission Tower Foundation
PCC
PCC
Transmission Tower Foundation
Raft Concrete
Raft Concrete
Transmission Tower Foundation
Stub Concrete
Stub Footing concrete
Stub Concrete
Stub Footing concrete
69/30
Tower Erection
Tower Erection
Transmission Tower Erection
Method of Tower Erection
There are four main methods of erection of steel
transmission towers which are described below:
1)Build-up method or Piecemeal method.
2)Section method.
3)Ground assembly method.
4)Helicopter method.
Method of Tower Erection
There are four main methods of erection of steel
transmission towers which are described below:
1)Build-up method or Piecemeal method.
2)Section method.
3)Ground assembly method.
4)Helicopter method.
Transmission Tower Erection
Build Up Method of Tower Erection
This method is most commonly used in India for the erection
of 66kV, 132kV, 220kV and 400kV transmission line towers.
This method consists of erecting the towers, member by
member. The tower members are kept on ground serially
according to erection sequence to avoid search or time loss.
The erection progresses from the bottom upwards. The four
main corner leg members of the first section of the tower
are first erected and bolted with the stub.
Build Up Method of Tower Erection
This method is most commonly used in India for the erection
of 66kV, 132kV, 220kV and 400kV transmission line towers.
This method consists of erecting the towers, member by
member. The tower members are kept on ground serially
according to erection sequence to avoid search or time loss.
The erection progresses from the bottom upwards. The four
main corner leg members of the first section of the tower
are first erected and bolted with the stub.
Transmission Tower Erection
Build Up Method of Tower Erection
The cross braces of the first section which are already
assembled on the ground are raised one by one as a unit
and bolted to the already erected corner leg angles.
The cross braces of the first section which are already
assembled on the ground are raised one by one as a unit
and bolted to the already erected corner leg angles.
The members / sections are hoisted either manually or by
winch machines operated from the ground.
After the tower top is placed and all side lacing are bolted
up. Cross – Arms are erected as complete unit .
Build Up Method of Tower Erection
The cross braces of the first section which are already
assembled on the ground are raised one by one as a unit
and bolted to the already erected corner leg angles.
The cross braces of the first section which are already
assembled on the ground are raised one by one as a unit
and bolted to the already erected corner leg angles.
The members / sections are hoisted either manually or by
winch machines operated from the ground.
After the tower top is placed and all side lacing are bolted
up. Cross – Arms are erected as complete unit .
Transmission Tower Erection
Section Method of Transmission Tower Erection
In the section method, major sections of the tower are
assembled on the ground and the same are erected as units.
These Units are erected with the help of mobile cranes.
Ground Assembly Method of Tower Erection
This method consists of assembling the tower on ground, and
erecting it as a complete unit. The complete tower is
assembled in a horizontal position on even ground.
In India, this method is not generally adopted because of
prohibitive cost of mobile crane, and non-availability of good
approach roads to tower locations.
Section Method of Transmission Tower Erection
In the section method, major sections of the tower are
assembled on the ground and the same are erected as units.
These Units are erected with the help of mobile cranes.
Ground Assembly Method of Tower Erection
This method consists of assembling the tower on ground, and
erecting it as a complete unit. The complete tower is
assembled in a horizontal position on even ground.
In India, this method is not generally adopted because of
prohibitive cost of mobile crane, and non-availability of good
approach roads to tower locations.
Transmission Tower Erection
Helicopter Method
•In the helicopter method, the
transmission tower is erected in
section. Sometimes a completely
assembled tower is raised with
the help of helicopter.
•This method is mostly used
where access to the tower
location is limited.
1
Helicopter Method
•In the helicopter method, the
transmission tower is erected in
section. Sometimes a completely
assembled tower is raised with
the help of helicopter.
•This method is mostly used
where access to the tower
location is limited.
1
Transmission Tower Erection
Tower erection - Finishing Works
All nuts shall be tightened with one to two threads shall be
projected outside the nuts.
Punching after nut tightening and tack welding shall be
done along with bolt and nut together to ensure that the
nuts are not loosened in course of time.
The joints shall be painted with zinc paint on all contact
surfaces during the course of erection to avoid rusting.
The finally erected tower shall be truly vertical after
erection. Tolerance limit for vertical shall be one in 360 of
the tower height.
Tower erection - Finishing Works
All nuts shall be tightened with one to two threads shall be
projected outside the nuts.
Punching after nut tightening and tack welding shall be
done along with bolt and nut together to ensure that the
nuts are not loosened in course of time.
The joints shall be painted with zinc paint on all contact
surfaces during the course of erection to avoid rusting.
The finally erected tower shall be truly vertical after
erection. Tolerance limit for vertical shall be one in 360 of
the tower height.
Transmission Tower Foundation
Tower Erection in progress
Tower Erection in progress
Electrical Transmission Tower types and design
The main supporting unit of overhead transmission
line is transmission tower.
Transmission towers have to carry the heavy
transmission conductor at a sufficient safe height
from ground. In addition to that all towers have to
sustain all kinds of natural calamities.
So transmission tower designing is an important
engineering job where all three basic engineering
concepts, civil, mechanical and electrical engineering
concepts are equally applicable.
The main supporting unit of overhead transmission
line is transmission tower.
Transmission towers have to carry the heavy
transmission conductor at a sufficient safe height
from ground. In addition to that all towers have to
sustain all kinds of natural calamities.
So transmission tower designing is an important
engineering job where all three basic engineering
concepts, civil, mechanical and electrical engineering
concepts are equally applicable.
78/30
Tower Erection
Tower Erection
Electrical Transmission Tower types and design
A transmission tower consists of the following parts.
1)Peak of transmission tower
2)Cross arm of transmission tower
3)Boom of transmission tower
4)Cage of transmission tower
5)Transmission Tower Body
6)Leg of transmission tower
7)Stub/Anchor Bolt and Base plate assembly of
transmission tower.
A transmission tower consists of the following parts.
1)Peak of transmission tower
2)Cross arm of transmission tower
3)Boom of transmission tower
4)Cage of transmission tower
5)Transmission Tower Body
6)Leg of transmission tower
7)Stub/Anchor Bolt and Base plate assembly of
transmission tower.
Electrical Transmission Tower types and design
Peak of Transmission Tower
The portion above the top cross
arm is called peak of
transmission tower. Generally
earth shield wire connected to
the tip of this peak.
Peak of Transmission Tower
The portion above the top cross
arm is called peak of
transmission tower. Generally
earth shield wire connected to
the tip of this peak.
Electrical Transmission Tower types and design
Cage of Transmission Tower
The portion between tower body
and peak is known as cage of
transmission tower. This portion of
the tower holds the cross arms.
Cage of Transmission Tower
The portion between tower body
and peak is known as cage of
transmission tower. This portion of
the tower holds the cross arms.
Electrical Transmission Tower types and design
Cage of Transmission Tower
The portion between tower body
and peak is known as cage of
transmission tower. This portion of
the tower holds the cross arms.
Cage of Transmission Tower
The portion between tower body
and peak is known as cage of
transmission tower. This portion of
the tower holds the cross arms.
Electrical Transmission Tower types and design
Cross Arms of Transmission Tower
The portion from bottom cross arms
up to the ground level is called
transmission tower body.
This portion of the tower plays a vital
role for maintaining required ground
clearance of the bottom conductor of
the transmission line.
Cross Arms of Transmission Tower
The portion from bottom cross arms
up to the ground level is called
transmission tower body.
This portion of the tower plays a vital
role for maintaining required ground
clearance of the bottom conductor of
the transmission line.
Electrical Transmission Tower types and design
Design of Transmission Tower
During Design of transmission tower the following points
to be considered in mind.
1.The minimum ground clearance of the lowest
conductor point above the ground level.
2.The length of the insulator string.
3.The minimum clearance to be maintained between
conductors & between conductor and tower.
4.The location of ground wire with respect to outer
most conductors.
Design of Transmission Tower
During Design of transmission tower the following points
to be considered in mind.
1.The minimum ground clearance of the lowest
conductor point above the ground level.
2.The length of the insulator string.
3.The minimum clearance to be maintained between
conductors & between conductor and tower.
4.The location of ground wire with respect to outer
most conductors.
Electrical Transmission Tower types and design
Transmission Tower
To determine the actual transmission
tower height by considering the above
points, we have divided the total height of
tower in four parts.
1.Minimum permissible ground clearance
(H1).
2.Maximum sag of the conductor (H2).
3.Vertical spacing between top and
bottom conductors (H3).
4.Vertical clearance between ground
wire and top conductor (H4).
Transmission Tower
To determine the actual transmission
tower height by considering the above
points, we have divided the total height of
tower in four parts.
1.Minimum permissible ground clearance
(H1).
2.Maximum sag of the conductor (H2).
3.Vertical spacing between top and
bottom conductors (H3).
4.Vertical clearance between ground
wire and top conductor (H4).
Electrical Transmission Tower types and design
Types of Transmission Tower
According to different considerations, there are different
types of transmission towers.
The transmission line goes as per available corridors.
Due to unavailability of shortest distance straight
corridor transmission line has to deviate from its straight
way when obstruction comes.
In total length of a long transmission line there may be
several deviation points.
Types of Transmission Tower
According to different considerations, there are different
types of transmission towers.
The transmission line goes as per available corridors.
Due to unavailability of shortest distance straight
corridor transmission line has to deviate from its straight
way when obstruction comes.
In total length of a long transmission line there may be
several deviation points.
Electrical Transmission Tower types and design
Types of Transmission Tower
According to the angle of deviation there are four types
of transmission tower.
1)A – type tower – angle of deviation 0 to 2
2)B – type tower – angle of deviation 2 to 15
3)C – type tower – angle of deviation 15 to 30
4)D – type tower – angle of deviation 30 to 60
Types of Transmission Tower
According to the angle of deviation there are four types
of transmission tower.
1)A – type tower – angle of deviation 0 to 2
2)B – type tower – angle of deviation 2 to 15
3)C – type tower – angle of deviation 15 to 30
4)D – type tower – angle of deviation 30 to 60
Electrical Transmission Tower types and design
Types of Transmission Tower
As per the force applied by the conductor on the cross
arms, the transmission towers can be categorized in
another way.
1.Tangent suspension tower and it is generally A - type
tower.
2.Angle tower or tension tower or sometime it is called
section tower. All B, C and D types of transmission
towers come under this category.
Types of Transmission Tower
As per the force applied by the conductor on the cross
arms, the transmission towers can be categorized in
another way.
1.Tangent suspension tower and it is generally A - type
tower.
2.Angle tower or tension tower or sometime it is called
section tower. All B, C and D types of transmission
towers come under this category.
Electrical Transmission Tower types and design
Types of Transmission Tower
Apart from the above customized type of tower, the
tower is designed to meet special usages.
1.River crossing tower.
2.Railway/ Highway crossing tower.
3.Transposition tower.
These are called special type tower.
Types of Transmission Tower
Apart from the above customized type of tower, the
tower is designed to meet special usages.
1.River crossing tower.
2.Railway/ Highway crossing tower.
3.Transposition tower.
These are called special type tower.
Electrical Transmission Tower types and design
Classification of Transmission Tower
Based on numbers of circuits carried by a transmission
tower, it can be classified as:
1.Single circuit tower
2.Double circuit tower
3.Multi circuit tower.
Classification of Transmission Tower
Based on numbers of circuits carried by a transmission
tower, it can be classified as:
1.Single circuit tower
2.Double circuit tower
3.Multi circuit tower.
Transmission Tower Erection
Method of Tower Erection
There are four main methods of erection of steel
transmission towers which are described below:
1)Build-up method or Piecemeal method.
2)Section method.
3)Ground assembly method.
4)Helicopter method.
Method of Tower Erection
There are four main methods of erection of steel
transmission towers which are described below:
1)Build-up method or Piecemeal method.
2)Section method.
3)Ground assembly method.
4)Helicopter method.
Transmission Tower Erection
Build Up Method of Tower Erection
This method is most commonly used in India for the erection
of 66kV, 132kV, 220kV and 400kV transmission line towers.
This method consists of erecting the towers, member by
member. The tower members are kept on ground serially
according to erection sequence to avoid search or time loss.
The erection progresses from the bottom upwards. The four
main corner leg members of the first section of the tower
are first erected and bolted with the stub.
The members / sections are hoisted either manually or by
winch machines operated from the ground
Build Up Method of Tower Erection
This method is most commonly used in India for the erection
of 66kV, 132kV, 220kV and 400kV transmission line towers.
This method consists of erecting the towers, member by
member. The tower members are kept on ground serially
according to erection sequence to avoid search or time loss.
The erection progresses from the bottom upwards. The four
main corner leg members of the first section of the tower
are first erected and bolted with the stub.
The members / sections are hoisted either manually or by
winch machines operated from the ground
Transmission Tower Erection
Build Up Method of Tower Erection
Build Up Method of Tower Erection
Transmission Tower Erection
Section Method of Transmission
Tower Erection
In the section method, major sections of the tower
are assembled on the ground and the same are
erected as units. Units are erected with the help of
mobile cranes.
Section Method of Transmission
Tower Erection
In the section method, major sections of the tower
are assembled on the ground and the same are
erected as units. Units are erected with the help of
mobile cranes.
Transmission Tower Erection
Ground Assembly Method of Tower Erection
This method consists of assembling the tower on
ground, and erecting it as a complete unit. The
complete tower is assembled in a horizontal position
on even ground.
After the assembly is complete the tower is picked
up from the ground with the help of a crane and
carried to its location, and set on its foundation.
Ground Assembly Method of Tower Erection
This method consists of assembling the tower on
ground, and erecting it as a complete unit. The
complete tower is assembled in a horizontal position
on even ground.
After the assembly is complete the tower is picked
up from the ground with the help of a crane and
carried to its location, and set on its foundation.
Transmission Tower Erection
Helicopter Method
•In the helicopter method, the
transmission tower is erected in
section. Sometimes a completely
assembled tower is raised with
the help of helicopter.
•This method is mostly used
where access to the tower
location is limited.
1
Helicopter Method
•In the helicopter method, the
transmission tower is erected in
section. Sometimes a completely
assembled tower is raised with
the help of helicopter.
•This method is mostly used
where access to the tower
location is limited.
1
Transmission Tower Erection
Transmission Tower Erection
Transmission Tower Erection
Transmission Tower Foundation
Cross Arms assembled on ground for erection
Cross Arms assembled on ground for erection
Transmission Tower Foundation
Cross Arms Erected
Cross Arms Erected
Transmission Tower Erection
Tower erection - Finishing Works
All nuts shall be tightened with one to two threads shall be
projected outside the nuts.
Punching after nut tightening and tack welding shall be
done along with bolt and nut together to ensure that the
nuts are not loosened in course of time.
The joints shall be painted with zinc paint on all contact
surfaces during the course of erection to avoid rusting.
The finally erected tower shall be truly vertical after
erection. Tolerance limit for vertical shall be one in 360 of
the tower height.
Tower erection - Finishing Works
All nuts shall be tightened with one to two threads shall be
projected outside the nuts.
Punching after nut tightening and tack welding shall be
done along with bolt and nut together to ensure that the
nuts are not loosened in course of time.
The joints shall be painted with zinc paint on all contact
surfaces during the course of erection to avoid rusting.
The finally erected tower shall be truly vertical after
erection. Tolerance limit for vertical shall be one in 360 of
the tower height.
103/30
Stringing
Stringing
Transmission of Power
Stringing
Stringing overhead conductors in transmission is a very
specialized type of construction requiring years of
experience, as well as equipment and tools that have
been designed, tried, and proven to do the work.
Stringing
Stringing overhead conductors in transmission is a very
specialized type of construction requiring years of
experience, as well as equipment and tools that have
been designed, tried, and proven to do the work.
Transmission of Power
Medhods of installing
There are four methods that can be used to
install overhead transmission conductors:
Slack stringing
Semi-tension stringing
Full-tension stringing
Helicopter stringing
Medhods of installing
There are four methods that can be used to
install overhead transmission conductors:
Slack stringing
Semi-tension stringing
Full-tension stringing
Helicopter stringing
Transmission of Power
Slack stringing
This type is normally limited to lower voltage lines and
smaller conductors.
The conductors are normally placed on “Reels” or “Jack
Stand” and it is unreeled from the drum and dragged
along the ground by vehicle or pulling device.
This method is typically used during construction of
new lines where Right Of Way is readily accessible.
Slack stringing
This type is normally limited to lower voltage lines and
smaller conductors.
The conductors are normally placed on “Reels” or “Jack
Stand” and it is unreeled from the drum and dragged
along the ground by vehicle or pulling device.
This method is typically used during construction of
new lines where Right Of Way is readily accessible.
Transmission of Power
Semi Tension method of stringing
Semi tension methods are merely an upgrading of slack
stringing, but do not necessarily keep the conductor
completely clear of the ground, or the lines used to pull
Semi Tension method of stringing
Semi tension methods are merely an upgrading of slack
stringing, but do not necessarily keep the conductor
completely clear of the ground, or the lines used to pull
Transmission of Power
Full Tension method of stringing
This is a method of installing the conductors in which
sufficient pulling capabilities on one end and tension
capabilities on the other, keep the wires clear of any
obstacles during the movement of the conductor from
the reel to its final sag position.
This ensures that these current-carrying cables are
“clipped” into the support clamps in the best possible
condition, which is the ultimate goal of the work itself.
Full Tension method of stringing
This is a method of installing the conductors in which
sufficient pulling capabilities on one end and tension
capabilities on the other, keep the wires clear of any
obstacles during the movement of the conductor from
the reel to its final sag position.
This ensures that these current-carrying cables are
“clipped” into the support clamps in the best possible
condition, which is the ultimate goal of the work itself.
Transmission of Power
Stringing with helicopters
This is much more expensive per hour of work, but can be much
less expensive when extremely arduous terrain exists along the
right-of-way and when proper pre-planning is utilized.
Although pulling conductors themselves with a helicopter can be
done, it is limited and normally not practical.
Maximum efficiency can be achieved when structures are set and
pilot lines are pulled with the helicopter, and then the conductor
stringing is done in a conventional manner.
Stringing with helicopters
This is much more expensive per hour of work, but can be much
less expensive when extremely arduous terrain exists along the
right-of-way and when proper pre-planning is utilized.
Although pulling conductors themselves with a helicopter can be
done, it is limited and normally not practical.
Maximum efficiency can be achieved when structures are set and
pilot lines are pulled with the helicopter, and then the conductor
stringing is done in a conventional manner.
Transmission Line
Component of Transmission Line
Component of Transmission Line
Transmission Line
Components of Transmission Line
Components of Transmission Line
Common Tools Required for Stringing
Common Tools Required for Stringing
Common Tools Required for Stringing
Common Tools Required for Stringing
Material Handling - Conductors
Handling, Loading /Unloading ,Transport & Storage
Handling, Loading /Unloading ,Transport & Storage
Material Handling - Conductors
Handling, Loading /Unloading ,Transport & Storage
1.Handling and transporting of the conductor and accessories shall
be carried out in such a manner as to minimize the possibility of
damages from abrasion through rough handling or dirt and grit.
2.The drums should always be transported in vertical position with
the cable ends fixed to prevent cable from slackening.
3.The drum should not be stored on its side under any
circumstances whatsoever.
4.The ends of the cable should be sealed to prevent water
penetration.
5.Loading and unloading are performed so that the drum remains
in vertical position and the sides of the drum are not damaged.
Handling, Loading /Unloading ,Transport & Storage
1.Handling and transporting of the conductor and accessories shall
be carried out in such a manner as to minimize the possibility of
damages from abrasion through rough handling or dirt and grit.
2.The drums should always be transported in vertical position with
the cable ends fixed to prevent cable from slackening.
3.The drum should not be stored on its side under any
circumstances whatsoever.
4.The ends of the cable should be sealed to prevent water
penetration.
5.Loading and unloading are performed so that the drum remains
in vertical position and the sides of the drum are not damaged.
Material Handling - Conductors
Avoid storage like this
Avoid storage like this
Transmission of Power
Stringing Procedure
The stringing procedure is broadly divided into the
following steps:
Paying out & stringing of Conductor.
Paying out & stringing of Earthwire.
Final sagging of Earthwire and conductor.
Clipping & Fixing accessories.
Stringing Procedure
The stringing procedure is broadly divided into the
following steps:
Paying out & stringing of Conductor.
Paying out & stringing of Earthwire.
Final sagging of Earthwire and conductor.
Clipping & Fixing accessories.
Transmission of Power
Steps of Stringing
Proper Guying
Insulator Hoisting.
Paying out of pilot wire & Conductor.
Rough sagging of conductor.
Final sagging of conductor.
Clipping & Spacering.
Finishing activities.
Jumpering.
Final Checking.
Steps of Stringing
Proper Guying
Insulator Hoisting.
Paying out of pilot wire & Conductor.
Rough sagging of conductor.
Final sagging of conductor.
Clipping & Spacering.
Finishing activities.
Jumpering.
Final Checking.
Guying
Before commencing of stringing, the angle towers where the
stringing is to be started must be provided with guy supports.
Before commencing of stringing, the angle towers where the
stringing is to be started must be provided with guy supports.
Guying
Precautions which should be taken at the time of guying?
The guys used generally are 20 mm steel wire rope. The guys are
attached to the tower at the tip of the cross arm , to the strain
plates with suitable D-shackles.
The guys are anchored in the ground at an angle of 45 deg. or
less from the horizontal, attached to dead end anchors .
The guy wire is attached to the dead end anchor wire with the
help of turn buckles of 10 tons capacity.
Excessive tightening of guy should be avoided. It is advisable to
tighten the guy progressively at the time of rough sagging of the
conductor.
Precautions which should be taken at the time of guying?
The guys used generally are 20 mm steel wire rope. The guys are
attached to the tower at the tip of the cross arm , to the strain
plates with suitable D-shackles.
The guys are anchored in the ground at an angle of 45 deg. or
less from the horizontal, attached to dead end anchors .
The guy wire is attached to the dead end anchor wire with the
help of turn buckles of 10 tons capacity.
Excessive tightening of guy should be avoided. It is advisable to
tighten the guy progressively at the time of rough sagging of the
conductor.
Guying – Anchoring on ground
Insulator Hoisting
Insulator Hoisting
Single / Double suspension insulator strings are used on
suspension towers and single /double tension insulator strings are
used on angle and dead end towers. This is generally indicated in
the tower schedule.
Double suspension insulator strings are used lines on Suspension
towers of Railway, River and Power Line Crossings only.
Single / Double suspension insulator strings are used on
suspension towers and single /double tension insulator strings are
used on angle and dead end towers. This is generally indicated in
the tower schedule.
Double suspension insulator strings are used lines on Suspension
towers of Railway, River and Power Line Crossings only.
Suspension Type Insulators
Consist of a number of porcelain discs
connected in series by metal links in
the form of a string.
Consist of a number of porcelain discs
connected in series by metal links in
the form of a string.
Suspension Type Insulators
The conductor is suspended at the
bottom end of this string while the
other end of the string is secured
to the cross-arm of the tower.
These insulators have a number of
interconnected porcelain discs,
with each unit designed to support
a particular voltage.
Together, a system of these discs is
capable of effectively supporting
high voltages.
The conductor is suspended at the
bottom end of this string while the
other end of the string is secured
to the cross-arm of the tower.
These insulators have a number of
interconnected porcelain discs,
with each unit designed to support
a particular voltage.
Together, a system of these discs is
capable of effectively supporting
high voltages.
Strain Type Insulators
When there is a dead end of the
line or there is corner or sharp
curve, the line is subjected to
greater tension. To relieve the line
of excessive tension, strain
insulators are used.
However, for the high voltage
transmission lines, strain insulator
consists of an assembly of
suspension insulators as shown.
When there is a dead end of the
line or there is corner or sharp
curve, the line is subjected to
greater tension. To relieve the line
of excessive tension, strain
insulators are used.
However, for the high voltage
transmission lines, strain insulator
consists of an assembly of
suspension insulators as shown.
Strain Type Insulators
Strain type insulators are
horizontally suspended suspension
insulators.
When the tension in lines is
exceedingly high, at long river
spans, power line, railway & road
crossings, two or more strings are
used in parallel.
Strain insulators are typically used
for high voltage transmissions.
Strain type insulators are
horizontally suspended suspension
insulators.
When the tension in lines is
exceedingly high, at long river
spans, power line, railway & road
crossings, two or more strings are
used in parallel.
Strain insulators are typically used
for high voltage transmissions.
Silicon Rubber Composite Insulators
Composite insulators with silicone
rubber sheds offer advantages over
traditional ceramics:
Improved safety for personnel
and equipment.
superior pollution performance
due to hydrophobic surface
condition.
Excellent seismic performance.
Low weight & Flexible design
Short delivery times
Composite insulators with silicone
rubber sheds offer advantages over
traditional ceramics:
Improved safety for personnel
and equipment.
superior pollution performance
due to hydrophobic surface
condition.
Excellent seismic performance.
Low weight & Flexible design
Short delivery times
Insulator fitted with Roller and Pulley
for conductor Payout
for conductor Payout
Insulator Prepared for Hoisting
Insulator Hoisting
Insulator Hoisting
Payout
The paying out of conductor is done generally between two
tension towers. In between two tension towers, there could
be either zero or one or more suspension towers.
A pilot wire is used to pull the conductor. The pilot wire is
initially laid through the centre wheel of the roller.
The pilot wire can be laid and joined with pilot wire
connectors or it can be pulled from one side of the section.
Scaffolding shall be provided for P&T and road crossing before
paying out of the pilot wire.
The paying out of conductor is done generally between two
tension towers. In between two tension towers, there could
be either zero or one or more suspension towers.
A pilot wire is used to pull the conductor. The pilot wire is
initially laid through the centre wheel of the roller.
The pilot wire can be laid and joined with pilot wire
connectors or it can be pulled from one side of the section.
Scaffolding shall be provided for P&T and road crossing before
paying out of the pilot wire.
Stringing Procedure
Drum Scheduling - Basics
1.For effective utilization of the conductor and to prevent Wastage
of the conductor.
2.Details of Tower schedule, Receipt of drum details, Standard
length of each drum.
3.Knowledge of Usage of cut lengths for Jumpers and Short Spans.
4.All the joints or splices shall be made at least 30 metres away
from the tower structures.
5.No joints or splices shall be made in spans crossing over main
roads, railways and small river tension spans.
6.Not more than one joint per sub conductor per span shall be
allowed.
Drum Scheduling - Basics
1.For effective utilization of the conductor and to prevent Wastage
of the conductor.
2.Details of Tower schedule, Receipt of drum details, Standard
length of each drum.
3.Knowledge of Usage of cut lengths for Jumpers and Short Spans.
4.All the joints or splices shall be made at least 30 metres away
from the tower structures.
5.No joints or splices shall be made in spans crossing over main
roads, railways and small river tension spans.
6.Not more than one joint per sub conductor per span shall be
allowed.
Transmission Line
Tower Schedule
Tower Schedule
Transmission Line
Sample Drum Scheduling
Sample Drum Scheduling
Paying out Earthwire
Earthwire drum on turn table& unreeling in
progress for payout.
Earthwire drum on turn table& unreeling in
progress for payout.
Payout of Earthwire
Final tensioning of Earthwire
Precautions before conductor Payout
Precautions before conductor Payout
Conductor Payout through Suspension Towers
Conductor Passing through rough terrains
Conductor Payout for each Phase
Conductor Rough Sag in progress
Conductor tensioning using come along Clam p and
four sheave pulleys
four sheave pulleys
Conductor Stringing Completed
Transmission Line Work Completion
Tags
Categories
GeneralDownload
Download Slideshow Get the original presentation fileQuick Actions
Statistics
- Views 92,749
- Slides 151
- Favorites 253
- Age 4007 days
Related Slideshows
22
Pray For The Peace Of Jerusalem and You Will Prosper
RodolfoMoralesMarcuc
33 views
26
Don_t_Waste_Your_Life_God.....powerpoint
chalobrido8
36 views
31
VILLASUR_FACTORS_TO_CONSIDER_IN_PLATING_SALAD_10-13.pdf
JaiJai148317
33 views
14
Fertility awareness methods for women in the society
Isaiah47
30 views
35
Chapter 5 Arithmetic Functions Computer Organisation and Architecture
RitikSharma297999
29 views
5
syakira bhasa inggris (1) (1).pptx.......
ourcommunity56
30 views