1. SURVEY & TOWER SPOTTING
FOR TRANSMISSION LINES
BY
G. EMMANUEL MADHUKAR
APTRANSCO

2. TRANSMISSION LINES

3. TRANSMISSION LINES

4. TRANSMISSION LINES
• Extra High Voltage
– 110 kV, 132 kV, 220 kV, 400 kV
• Ultra High Voltage
– 765kV
• High Voltage Direct Current
– ±500kV

5. TRANSMISSION LINES
• Survey is the most important activitySurvey is the most important activity
• Best possible routeBest possible route
• Right of WayRight of Way
• Techno-Economical ProjectTechno-Economical Project
• Timely completion of the projectTimely completion of the project
• Increasing DemandIncreasing Demand

6. PRELIMINARY SURVEY AND WALK
OVER SURVEY
• Topographical map
• Bee line
• Identify possible routes
• Familiarize
• Indicate the feasibile routes

7. TOPO MAP

8. TOPO MAP
Sending end SSSending end SS
Receiving end SSReceiving end SS
AP 1AP 1
AP 2AP 2
AP 3AP 3
AP 4AP 4
Bee LineBee Line

9. PRELIMINARY SURVEY – SELECTION OF
ROUTE
• Shortest possible route
• Less number of deviations

10. DETAILED SURVEY – TOOLS
• Theodolite & Ranging rods
• Dummpy level & Measuring staff
• Measuring chain
• Megger

11. DETAILED SURVEY – Theodolite

12. DETAILED SURVEY
• 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

13. DETAILED SURVEY
• 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

14. 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

15. DETAILED SURVEY – CORRIDORS
• 132 kV Line 27 M
• 220 kV Line 35 M
• 400 kV Line 52 M

16. DETAILED SURVEY –LINE PROFILES
• Graphical representation
• Scale
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

17. DETAILED SURVEY –LINE PROFILES
• Indicate all Power Lines crossings: LT to 765 kV
• Indicate all P & T Lines crossings
• Indicate all Railway crossings
• Indicate all River crossings
• Indicate all Roads: Cart Tracks to National Highways
• Indicate all Villages

18. DETAILED SURVEY –LINE PROFILES
• Indicate all Agricultural wells
• Indicate all Field bunds & Earth bunds
• Indicate all Boulders
• Indicate all Ponds & Lakes
• Indicate type of Soil
• Indicate Crops & Trees

19. DETAILED SURVEY –LINE PROFILES

20. DETAILED SURVEY –LINE PROFILES

21. DETAILED SURVEY –LINE PROFILES

22. DETAILED SURVEY –LINE PROFILES

23. TOWER SPOTTING –SAG TEMPLATE

24. 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

25. 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 the two
centre points of adjacent spans

26. TOWER SPOTTING –SPAN LIMITATIONS
SPAN 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

27. TYPE OF TOWERS
ANGLE
(in degrees)
132
kV
220
kV
400
kV
0 to 2 P A DA
2 to 15
R
B DB
15 to 30 C DC
Above 30 S D DD

28. TYPE OF TOWERS
ANGLE
(in degrees)
132
kV
220
kV
400
kV
0 to 2 K X MA
2 to 30 L Y MC
Above
30
M Z MD

29. 132 kV TOWERS
Suspension
3900
3860
3860
14653
4200
Tension
7200
3900
4000
12583
7750

30. 220 kV TOWERS
Suspension
4865
5050
5050
19380
6295
Tension
7795
5050
5082
17048
10800

31. 400 kV TOWERS
Suspension
3000
8000
8000
25800
12000
Tension
6800
8000
8100
22000
15000

32. RIVER CROSSING TOWERS
JC
4729
5127
5268
6357
17670
AT/400 kV
6900
9000
9000
46570
25000

33. EHV TRANSMISSION LINES
CROSSING

34. CLEARANCES
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

35. CLEARANCES
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

36. TOWER SCHEDULES
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

37. CHECK SURVEY
• Marking of Tower Location
• Forward & Backward Line Points
• Pit Marking
• Excavation

38. MODERN TECHNIQUES
• Global Positioning System
• Total Station
• PLS CADD

39. GLOBAL POSITIONING SYSTEM
• Satellite dependent
• Latitude & Longitude coordinates of the
position
• Starting coordinates and ending coordinates
• Map Source Software
• Google Earth
• Topo sheet can be generated
• Bee Line & Routes can be marked

40. GLOBAL POSITIONING SYSTEM

41. TOTAL STATION
• Similar to Theodolite
• Not dependent on satellite
• Arbitrary Coordinates of the position
• Coordinates of the position obtained from GPS
• Alignment, Distance & Levels are recoded
simultaneously
• Horizontal & Vertical Angles can be recorded

42. TOTAL STATION
• Raw data
• Text
• Auto Plotter
• Auto CAD
• Line Profile can be generated

43. PLS CADD
• Data from Total Station
• Sag calculation data
• Tower Spotting
• 2-D Model can be generated
• 3-D Model can be generated

44. PLS CADD

45. PLS CADD

46. IMPORTANT POINTS- Survey
• Length of the line
• Levels in the corridors
• Crossings
• Markings in check survey

47. Thank You
&
God Bless You