March 17, 2020
March 17, 2020
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
TABLE OF CONTENTS
1.0
SCOPE
2.0
LINE ROUTES
3.0
2.1
Location
2.2
Paralleling and Crossing Transmission Lines
2.3
Paralleling and Crossing Major Highways
2.4
Vertical Clearances above Ground, Road Crossings and Paralleling, and Crossing of
Rail Road
GENERAL GUIDE LINES FOR METALLIC FACILITIES LOCATED IN PROXIMITY
OF TRANSMISSION LINES (INDUCED/CONDUCTIVE VOLTAGE
INTERFERENCES)
3.1
Inductive & Conductive Voltage Requirements
3.2
Paralleling Facility (Induced Voltage Case)
3.3
Crossing Facility (Conductive Voltage Case)
4.0
SPACING FROM MAIN OIL FACILITIES
5.0
CONDUCTOR SPACING AND CLEARANCE
5.1
Horizontal Clearance between Conductors on the same Support
5.2
Vertical Clearance between Line Conductors.
5.3
Clearance of Conductor from its own Support - Basic Clearance.
5.4
Clearance between Conductors carried on different Supports
5.5
Clearance of Conductors from other supporting Structures
5.6
Clearance of Conductors from other Installations
5.7
Mid-Span Clearance
5.8
Air Gap Requirements
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 2 OF 43
TRANSMISSION ENGINEERING STANDARD
6.0
7.0
TES-P-122.09, Rev. 02
RIGHT-OF-WAY WIDTH REQUIREMENTS
6.1
General
6.2
Conductor Clearance to edge of Right-of-Way
6.3
Right-of-Way Width Requirements for Single Transmission Line
6.4
Right-of-Way Width Requirements for Parallel Transmission Lines
6.5
Example Calculation of Right-Of-Way
6.6
Horizontal Clearances between Parallel Transmission Lines and Other Obstacles
BIBLIOGRAPHY
FIGURE TE-2209-0100-00 Clearance Requirement for Conductors of Same Circuit or Different
Circuit on the Same Support
FIGURE TE-2209-0200-01 Right-Of-Way (ROW) for Single Transmission Line
FIGURE TE-2209-0300-01 Right-Of-Way (ROW) for Two Parallel Transmission Lines (identical
insulator string configuration)
FIGURE TE-2209-0400-01 Right-Of-Way (ROW) for Two Parallel Transmission Lines (different
insulator string configuration)
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 3 OF 43
TRANSMISSION ENGINEERING STANDARD
1.0
TES-P-122.09, Rev. 02
SCOPE
The purpose of this standard is to highlight National Gird Saudi Arabia practices with respect
to the clearances required for various paralleling and crossing facilities and Right of Way
(ROW) requirements for the design of overhead transmission lines.
The designs of existing transmission lines may not in all cases meet the requirements set forth
in this standard, therefore; those are excluded from the scope of this standard. However, taps
from or extensions to these existing transmission lines are covered under the scope of this
standard.
2.0
LINE ROUTES
2.1
2.2
Location
2.1.1
Transmission lines shall be located as near as possible to roads for easy
accessibility during construction and later for inspection, maintenance and
operation. Obstacles such as high hills, wadis, water flooding areas, swampy
ground or poor soils etc. shall be avoided. Selection of routes shall also take
into account future planning, grade and conditions of the terrain to be
traversed.
2.1.2
Selection of final route for any transmission line shall be coordinated with
the concerned departments in National Grid Saudi Arabia.
2.1.3
Coastal or corrosive atmosphere areas shall be avoided wherever possible.
Whenever it is not possible to avoid such areas, suitable protective measures
shall be adopted in the design of transmission line components including
foundations to combat the corrosion.
Paralleling and Crossing Transmission Lines
2.2.1
Adequate clearance shall be provided between parallel and crossing
transmission lines. Clearances between adjacent conductors of two parallel
lines and clearances between crossing lines shall be established per
equations 09-1 to 09-20.
2.2.2
Transmission line crossings shall be avoided as far as possible, but when
these are unavoidable, they shall be arranged in such a way that the higher
voltage line or line of higher security and the most important line to the
transmission network crosses over the line of lower voltage or lower
security. Additionally, line crossings shall be configured such that a single
component failure will not cause outage more than one other line (beyond
the line with failed component). The transmission lines shall cross each other
at an angle as close to 90 degrees as possible.
Transmission line crossings shall be designed keeping in view the network
reliability and the ease in routine maintenance/inspection operations.
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 4 OF 43
TRANSMISSION ENGINEERING STANDARD
2.2.3
TES-P-122.09, Rev. 02
Unless other methods of transmission line crossings such as GIL (Gas
Insulated Line) or underground cables etc. are specified in the Scope of
Work/Technical Specifications, following shall be considered:
a.
Crossing Below the Existing Transmission Lines
Gantry structures (single layer or double layer as applicable) with
conductors in horizontal configuration shall be used for crossing below
the existing transmission lines. The crossing arrangement shall be
designed to provide full protection to the underneath transmission line
from lightning using shield wires or other means. If required, optical
fiber ground wire (OPGW) may be replaced with underground nonmetallic fiber optic cable in concrete encased duct bank.
i.
Transmission Line Crossing (two lines of same voltage)
The security/importance/priority of the existing transmission line
shall be decided by National Grid Saudi Arabia.
ii. Transmission Line Crossing (more than two lines of same voltage
or higher/lower voltage)
The transmission line shall cross below the existing lines of the
same or higher voltage but shall cross above the lower voltage line.
If required, modifications to existing transmission line structures
may be made to meet the clearance requirements.
For all cases where higher voltage transmission line shall cross
below the lower voltage transmission line, approval of National
Grid Saudi Arabia shall be mandatory.
b.
Crossing above the Existing Transmission Lines
Crossing above the existing 380kV transmission line shall only be
allowed if it does not jeopardize the safety, security and reliability of
the existing lines. This shall be decided by National Grid Saudi Arabia.
c.
Common Supporting Structure
Where practical and if approved by National Grid Saudi Arabia,
common supporting structure (structure acting as a common support to
each transmission line, forming an integral part at the point of crossing)
may be designed for crossing two transmission lines of the same or
different voltages.
2.2.4
TESP12209R02/MAT
The vertical clearance between any crossing lines carried on different
supporting structures shall not be less than those given in Table 09-9.
Date of Approval: March 17, 2020
PAGE 5 OF 43
TRANSMISSION ENGINEERING STANDARD
2.3
TES-P-122.09, Rev. 02
Paralleling and Crossing Major Highways
2.3.1
Paralleling Major Highways
Major highways are defined as any primary or secondary roads which are
normally accessible to traffic with no restriction. These highways are the
backbone of the road network providing fast, safe and efficient routes of
travel between major cities/towns, connecting two or more regions and serve
all international airports/seaports connections and military installations
within the Kingdom of Saudi Arabia. Traffic on these highways is of primary
importance. Minimum distance from transmission line center to the edge of
zone of major highways for restricted and unrestricted ROW are given in
Table 09-1. The edge of zone of major highway is defined as the fencing line
or a point at 5 meters distance from the toe of slope, whichever is farther.
Table 09-1: Distance between Transmission Line and Major Highways
Line Voltage,
kV
Minimum distance from transmission line center to the
edge of zone of major highways, meters
Un-Restricted ROW
Restricted ROW
(Notes 1 & 3)
(Notes 2 & 3)
69
110/115/132
230
380
Maximum Height of
Transmission Line
Structure Plus 5 meters
20
30
35
50 (Note 4)
Notes to Table 09-1:
1. Un-restricted ROW is that which imposes no or minimum restrictions on the land use.
2. Restricted ROW is the area where land use is limited because of congestion due to other
facilities and/or non-availability of land due to other reasons.
3. In certain cases the owner of highways (Ministry of Transport - MOT or others) may
require higher distances than those given in the above table. In all such cases, the
concerned authorities shall be consulted to determine the exact requirements. Their
approval shall be mandatory.
4. Minimum distance from the conductors shall be maintained as 40 meters.
2.3.2
Crossing Major Highways
Where transmission line routes cross major highways, the angle of
intersection shall be as close as possible to 90 degrees, but shall not be less
than 45 degrees in any case. The distance from the center of transmission
line structure to the edge of the zone of major highways shall be as per table
09-1
2.3.3
Paralleling and Crossing Roads Other Than Major Highways
When paralleling and crossing roads other than major highways, especially
roads in urban / rural areas, minimum distance from transmission line center
to the edge of road shall not be less than 20 meters for 69kV to 132kV, 25
meters for 230 kV and 40 meters for 380 kV transmission lines provided that
public safety & reliability of the lines are not affected.
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 6 OF 43
TRANSMISSION ENGINEERING STANDARD
2.3.4
TES-P-122.09, Rev. 02
Transmission Lines in the Medians of Roads
If required, the transmission lines may be located in the medians of the two
roads in the built-up areas subject to approval from owner of the roads and
National Grid Saudi Arabia. Existing right of way of the roads shall be
applicable in this case. Specified conductor clearances over road surface, to
buildings and other installations at the edge of right of way shall be
maintained and structures shall be protected with crash barriers.
2.3.5
Crash Barriers
All line structures where foundations are located within a distance of 30
meters from the edge of travelled portion of roads (paralleling or crossing
transmission line routes including major highways) shall be protected by
providing crash barriers around them without jeopardizing access to the line
for maintenance. These protective measures shall be considered individually
on a project basis for their effectiveness. The general design of the crash
barriers shall be as per Transmission Standard Drawing TB-800095.
2.4
Vertical Clearances above Ground, Road Crossings and Paralleling, and Crossing of
Rail Road
2.4.1
Vertical clearance is defined as the vertical distance between the highest
point on terrain (grade, road surface, railroad, rail etc.) and the lowest
conductor of the overhead lines. Calculation of actual line clearance shall be
based on conductor sag at maximum design temperature of transmission
line. Grading of existing natural ground level to meet the vertical clearance
requirements shall not be acceptable unless otherwise approved by National
Grid Saudi Arabia.
2.4.2
The minimum vertical clearances required for National Grid Saudi Arabia
transmission line designs for 380 kV and below over various types of roads
and terrain are given in Table 09-2 and shall be followed unless otherwise
specified in the approval letters of different approval agencies involved.
2.4.3
Roads to be crossed by National Grid Saudi Arabia transmission lines have
been categorized as “A” designated high clearance roads; and “B”, for other
roads not requiring high clearance.
2.4.4
There are some areas where certain road crossings shall require additional
clearance. The extra high clearance roads in the industrial areas such as
Jubail, Dammam, Yanbu, and Jazan etc. may require a vertical clearance in
the range of 18-28 meters above roads or highways. The concerned
authorities shall be contacted to coordinate the exact requirements.
2.4.5
The category of roads to be crossed by the transmission line shall be
determined during base design stage. In case of module-paths (40m vertical
clearance), the concerned authorities shall be contacted to coordinate the
exact requirements. The module-path is defined as the dedicated route for
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 7 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
transportation of very heavy equipment of extended height in the industrial
areas.
2.4.6
Highways and roads designated to be used for hauling heavy and oversized
loads are classified as Category ‘A’. All other roads, highways and
expressways are classified Category ‘B’.
2.4.7
On projects where the transmission line is determined to be extremely
important (such as 230 kV and 380 kV System) and power interruption
cannot be tolerated, then all roads to be crossed by this line shall be
considered as Category “A” roads, and the Project Scope of Work and
Technical Specifications for such a project shall explicitly state this
requirement.
2.4.8
The road clearances in this Standard for designated high clearance roads and
expressways and highways considerably exceed the minimum requirements
recommended by the NESC for vertical clearances above roadways.
2.4.9
The vertical clearances over the type of terrain not covered by Table 09-2,
such as canals, waterways, terrain in the vicinity of airports or any unusual
situation which might be developed, shall be resolved separately and
mutually agreed to by interested parties.
Table 09-2: Vertical Clearances for Roads and Terrain Crossings
Transmission Line Voltage
(Line to Line) kV
69/110-132
230
380
(m)
(m)
(m)
Category
Type of Crossing
A.
Designated High Clearance Roads (Note 1)
14.0
18.0
18.0
B.
Expressways & Highways
12.0
15.0
15.0
12.0
15.0
15.0
7.5
8.0
10.0
15.5
18.0
18.0
1.4
2.0
3.0
9.5
9.5
13.5
40
40
40
4.0
5.0
6.0
5
5.7
7
C.
D.
City Streets, Alleys Driveways, Parking
Lots & Other Areas Traversed by Vehicles,
Paved or Unpaved
Open Terrain, Desert Areas, etc.
(Notes 2 & 3)
Railroad (non-electrified) (Note 4)
E
F.
G.
H.
I.
Railroads (electrified)
Top of contact wire/feeder of
electrified rail (Note 5)
Ground Facilities, Pipelines (Oil, Water,
Gas), Communication lines
Extra High Clearance (Module-Paths)
Top of Trees, Plants & Hedges etc. capable
of supporting a ladder or being climbed.
(Note 6)
Transmission Line Crossings with Gantry
Structures (Note 7)
Notes to Table 09-2:
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 8 OF 43
TRANSMISSION ENGINEERING STANDARD
1.
2.
3.
4.
5.
6.
7.
8.
9.
2.4.10
TES-P-122.09, Rev. 02
Roads categorized as “A” are those specifically designated by National Grid Saudi Arabia Asset
Maintenance Department as roads requiring vertical clearance in excess of clearances listed in Category
“B” and “C”. Vehicle traffic is expected to exceed 5.5 meter height and the transmission lines need not
normally be removed from service.
For transmission lines when located in open terrain within 15km and 5km from the boundary limits of
metropolitan cities and other cities/towns/villages respectively, the required clearances listed under
Category “D” shall be increased to that required under Category B or C.
When transmission lines are located in desert area affected by shifting sand dunes, the clearance listed
in Category “D” shall be increased by a minimum of two (2) meters in the spans indicating shifting
sand dunes.
Assumed height of the rail car (non-electrified) is 6 meters.
Additional margins of 1.0 m and 2.0 m (total 3.0 m) shall be added to account for design errors and
wind induced dynamic conductor movement/safety during maintenance operations respectively.
As a general practice, trees and plants etc. are not allowed within transmission line ROW. The
clearances mentioned above are under exceptional cases when these cannot be removed.
The clearances listed under category I shall only be applicable when clearances under category D are
not possible to achieve / maintain and shall only be considered if crossing area is properly fenced as
per Company Standard and no access is allowed to the general public .
The clearances shall be increased @ 3 % for each 300m in excess of 1,000m altitude above mean sea
level.
A margin of 0.6 m clearance specified in TES-P-122.07 to account for plotting profile errors etc. shall
be in addition to the values mentioned in Table 09-2 above.
Paralleling and Crossing Railroad Track
a.
Minimum distance from the center of transmission line to the edge of
the railroad track for restricted and unrestricted rights of way are given
in Table 09-3. The edge of railroad track is defined as the fencing line
or a point at 5 meters distance from the toe of slope, whichever is
farther.
b.
Where transmission line routes cross railroad tracks, the angle of
intersection shall be as close as possible to 90 degrees, but not less than
45 degrees in any case.
Whenever the required crossing angle is not satisfied, the Engineer
responsible for base design/detailed engineering shall perform an
induced voltage study and recommend possible steps to be taken to
reduce any adverse effects.
Table 09-3: Distance between transmission line and Railroad
Line Voltage, kV
69/110/115/132
230
380
Minimum distance from transmission line
center to the edge of railroad track, m
Unrestricted ROW
Restricted ROW
40
30
45
35
55
50 (Note 1)
Note 1: Minimum distance from the conductors shall be maintained as 40 meters.
c.
TESP12209R02/MAT
The minimum vertical clearances required for transmission lines over
the railroad tracks are given in Table 09-2.
Date of Approval: March 17, 2020
PAGE 9 OF 43
TRANSMISSION ENGINEERING STANDARD
3.0
TES-P-122.09, Rev. 02
General Guidelines for Metallic Facilities located in Proximity of Transmission Lines
(Induced/Conductive Voltage Interferences)
3.1
Inductive and Conductive Voltage Requirements.
The guidelines listed below shall be followed for all the requests of customer metallic
facilities, such as pipelines, railroad, communication cables, cathodic protection
systems, etc., (whether overhead, above-ground or under-ground) to cross and/or run
in close proximity to National Grid Saudi Arabia transmission lines. The following
guidelines shall be applied to all facilities in a single location in case more than one
facility is involved in the request.
3.1.1
3.1.2
National Grid Saudi Arabia approval for allowing other parties to construct
and install their projects in parallel to and/or crossing the transmission lines
shall be granted if the project proponent satisfies all the following
conditions:
a.
Accepts full liability and any consequential damages due to the
electrical interference (induced/conductive voltage) effects and
satisfies conditions given in Clause 3.3.1 and 3.3.2 below (for
crossing only).
b.
Performs at his expense induced/conductive voltage study and
proves to National Grid Saudi Arabia’s satisfaction that the resulting
touch voltages are within the limits specified in Clause 3.1.2 and
3.1.3 below and satisfies the conditions given in Clause 3.3.1 and
3.3.2 below (for crossing only).
c.
Satisfies the requirements specified in Clause 3.2 and 3.3.
The maximum touch voltage limit to insure safety to personnel during
steady-state conditions shall be as follows:
Conditions
Continuous Voltage
Continuous Current
3.1.3
Limits
12 V
10 mA
The maximum touch voltage limit to ensure safety to personnel during fault
conditions shall be according to the following ANSI/IEEE 80 equation:
Vtouch 
116  017
. 
t
Where:
 = Surface soil resistivity in ohms-meters
t = Fault duration in seconds. This shall be taken as 0.5 seconds or backup
clearing time whichever is higher.
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 10 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
Therefore, for 500 ohm-meter top soil resistivity and 0.5 second fault
clearing time, the safe touch voltage limit is 284 V.
3.1.4
3.2
If the proponent’s induced/conductive voltage study shows the need to
install mitigation to limit the touch voltage, National Grid Saudi Arabia shall
review the case to determine that the appropriate procedures are followed.
Paralleling Facility (Induced Voltage Case)
Following minimum horizontal spacing between the transmission line center and
above grade or below grade metallic facility shall be maintained.
Table 09-4: Spacing between Parallel Transmission Lines and Metallic Facility
Line Voltage, kV
Length of metallic
facility in parallel with
transmission line, km
Minimum horizontal
spacing, m
230 and below
less than 1.6
40
380
less than 1.6
50
69 - 380
more than 1.6
150
In case of spacing less than that given above, induced voltage study shall be performed to
verify the requirements of Clause 3.1.2 & 3.1.3 and case shall be referred to National Grid
Saudi Arabia for review / and approval.
3.3
Crossing Facility (Conductive Voltage Case)
3.3.1
The minimum vertical clearance between the transmission lines and ground
facilities shall be per Table 09-2.
3.3.2
When ground facilities cross transmission line access roads, the facility
crossing shall be designed to provide safe passage for vehicular traffic. For
unpaved crossing of above grade facility, refer TES-P-122.11.
3.3.3
When the facility routes cross overhead transmission line (and vice versa)
the preferred angle of intersection is 90 degrees and if not possible, the
crossing angle between 45 to 135 degrees shall be acceptable.
If angle is within the limits, no induced voltage study is required. However,
in cases where the angle requirement cannot be met, induced voltage study
shall be performed to verify the requirements of Clause 3.1.2 & 3.1.3. If the
induced voltages are within the allowable limits, no further action is required
other than to meet the minimum spacing requirements per Table 09-4 above.
In case, the induced voltages are not within the limits, appropriate mitigation
measures shall be adopted and submitted to National Grid Saudi Arabia for
review and acceptance.
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 11 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
3.3.4
The facility shall cross the transmission line at mid span between the
structures. If this is not possible, the minimum horizontal separation between
the facility and the center of transmission line structure shall not be less than
40 meters. In case the minimum distance cannot be maintained the request
shall be referred to National Grid Saudi Arabia for review and approval.
3.3.5
If the facility runs parallel to the transmission line after the intersection then
it shall also meet minimum distance requirements mentioned under clause
3.2 above. If the metallic facility is crossing below the grade and changing
its direction at a distance less than 150 meters from crossing, the facility
shall be grounded at the point where the direction is changing.
If the metallic facility is crossing above the grade, the facility shall be
grounded up to 100 meters along the length of the facility in both directions
from the crossing point. If the facility is changing its direction at a distance
greater than 100 meters but less than 150 meters from the crossing point,
additional grounding shall be provided at the point where the direction is
changing. The grounding of the metallic facility shall be to the satisfaction
of the concerned party.
4.0
SPACING FROM MAIN OIL FACILITIES
Following minimum horizontal spacing between center of 69kV to 380kV transmission lines
and edge of main oil facilities shall be provided for safe operation and maintenance of both.
Table 09-5: Spacing between Transmission Lines and Main Oil Facilities
Oil Facility
5.0
Spacing, m
Oil & Gas Wells and GOSPs
200
Oil Trunk / Burn Pits and Ground Flares
150
Elevated Flare Stacks, Oil-Water Separators and Skimming Ponds, Oil
Process Areas, Gasoline Stations, Chemical & Pressure Storage
Vessels, Booster & Shipping Pump area / LPG Rack, Low and High
Flash Stocks etc.
60
CONDUCTOR SPACING AND CLEARANCE
5.1
Horizontal Clearance between Conductors on the same Support
5.1.1
Horizontal Clearance - Fixed Support
Conductors attached to fixed supports shall have horizontal clearances from
each other not less than the larger value required by equations given below:
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 12 OF 43
TRANSMISSION ENGINEERING STANDARD
a.
Conductors of the Same Circuit
i.
ii.
b.
TES-P-122.09, Rev. 02
H = 300+10 (U-8.7)
. S
F = 7.6 (U) +8 212
(Eq.09-1)
(Eq.09-2)
Conductors of Different Circuits
i.
ii.
H = 715+10 (Uo-50)
. S
F = 7.6 (Uo) + 8 212
(Eq.09-3)
(Eq.09-4)
Where:
H = Basic horizontal clearance between conductors in mm.
F = horizontal clearance due to sag between conductors in mm.
U = maximum operating voltage phase to phase over 8.7 kV
Uo= Maximum operating voltage between line conductors of different
circuits which shall be the greater of the phasor difference
between the conductor involved, or the phase-to-ground voltage
of the higher voltage circuit. For circuits having the same phases
and nominal voltage, either circuit may be considered to be the
higher voltage circuit.
S = Final unloaded sag based on computed ruling span at every day
conductor temperature, no wind, in mm.
A margin of 0.6m shall be added to the calculated values to account for
design errors.
The clearances shall be increased @ 3 % for each 300m in excess of
1,000m altitude above mean sea level.
5.1.2
Horizontal Clearance - Suspension Insulators
Where suspension insulators are used and are not restrained from movement,
the clearance shall be increased so that one string of insulators may swing
transversely through a range of insulator swing up to its maximum design
swing angle without reducing the values given in equations 09-1 to 09-4 and
09-11 to 09-20. The maximum design swing angle shall be based on wind
pressure to be calculated corresponding to a wind speed of 140km/h
explained:
Wind speed of 170km/h as specified for the design of structures is a 3-second
gust wind associated with 50 years return period at 10 meter height above
ground in flat and open country terrain (Exposure Category “C” defined as
open terrain with scattered obstructions having heights generally less than
9.1m per ASCE Manual # 74 “Guidelines for Electrical Transmission Line
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 13 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
Structural Loading” third edition-2009). However, gust winds of short
duration (such as 3-second) will neither affect the swing angles nor the force
acting on the structures (CIGRE Technical Brochure 348-2008). Only
sustained winds (averaged over sufficiently long period of time such as 1minute) can affect the swing angle and produce offset of the conductor sag.
Based on gust wind speed of 170km/h, sustained wind corresponding to 1minute average time is estimated 140km/h with resulting wind pressure of
927 N/m2. This shall be used to determine swing angle and right of way
requirements.
a.
The insulator swing shall be calculated as follows:
For maximum angle of swing:
 2T Sin /2   HS x Pc 

 VS x Wc   Wi /2 
  Arc Tan 
(Eq.09-5)
For minimum angle of swing:
 2T Sin  / 2   HS x Pc  
  Arc Tan 

  VS x Wc   Wi / 2 
Where
(Eq.09-6)
 = angle with the vertical through which the insulator string swings
 = line angle in degrees
T = conductor tension at the temperature and wind loading for which
the clearance is specified, in Newton
HS = horizontal span, which is 1/2 the sum of adjacent spans, in meters
VS = vertical span, which is the distance between the low point of sag
in adjacent spans, in meters
Pc = wind load per unit length of conductor (conductor diameter times
wind pressure), in Newton/meter
Wc = weight per unit length of bare conductor, in Newton/meter
Wi = weight of insulator string divided by number of conductors per
phase, in Newton
b.
The horizontal swing of insulators can be obtained from the equation:
B = (Insulator assembly length) Sin 
Where:  is the maximum swing angle calculated per equation 09-5.
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 14 OF 43
TRANSMISSION ENGINEERING STANDARD
5.1.3
TES-P-122.09, Rev. 02
Horizontal Clearance for different Circuits where one or both Circuits
exceed 98kV Phase-to-Ground
a.
The clearances specified in equations 09-1 to 09-4 and equations 09-5
and 09-6 may be reduced for circuits with known switching surge
factors but shall not be less than the clearances derived from the
equation below:
1.667
 U (SSF) a 
Min. clearance (H) = 1000 L  L

500k

Where:
b
(Eq.09-7)
UL-L = Maximum alternating current crest operating voltage between
different circuits. If the voltages are of the same phasor and
magnitude, one conductor shall be considered grounded.
SSF = Maximum switching surge factor expressed in per unit peak
operating voltage between different circuit. (SSF value shall be
obtained from Transmission Asset Planning Department).
a = 1.15, the allowance for three standard deviations
b = 1.03, the allowance for nonstandard atmospheric conditions.
k = 1.4, the configuration factor for a conductor-to-conductor gap
The clearance shall be increased @ 3 % for each 300m in excess of
450m above mean sea level.
b.
5.1.4
5.2
The clearance derived from above equation shall not be less than the
basic clearance given in equations 09-1 to 09-4.
The method on how to determine the horizontal clearance between
conductors of the same or different circuits on the same support is shown in
Figure TE-2209-0100-00.
Vertical Clearance between Line Conductors
All conductors located at different levels on the same supporting structure of the same
or different circuits for the same sag, shall have vertical clearances not less than
required by the equations given below:
5.2.1
For Phases of the same Circuit
a.
Vs = 830+10 (U-50)
(Eq.09-8)
Where:
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 15 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
Vs = Basic vertical clearance phase-to-phase, in mm
U = Maximum operating voltage phase-to-phase, over 50 kV
b.
Minimum vertical clearances calculated based on the above equation
are tabulated below:
Table 09-6: Vertical Clearances between Line Conductors for same
Circuit on the same Structure
Line Voltage, kV
Vertical Clearance between Phases of the
same Circuit on the same Structure, m
69
1.10
110/115
1.60
132
1.80
230
2.90
380
4.60
Notes to Table 09-6:
1.
A margin of 0.15m shall be added to account for design errors.
2.
The clearances at the supporting structures shall be increased to compensate
the reduction in span clearances caused by jumping of conductors in the
longer spans.
3.
The clearances shall be increased @ 3 % for each 300m in excess of 1,000m
altitude above mean sea level.
5.2.2
For different Circuits on the same Structure of different/Same Nominal
Voltage
a.
Vc = 830+10[(U01+U02)-50]
(Eq.09-9)
Where:
Vc = Basic vertical clearance between circuits in mm
U01 = Maximum phase-to-ground voltage of circuit at upper level, over
50 kV
U02 = Maximum phase to ground voltage of circuit at lower level, over
50 kV
When the circuits have the same nominal voltage, either circuit may be
considered to be the higher voltage circuit.
b.
TESP12209R02/MAT
Minimum vertical clearances were calculated based on the above
equation and tabulated below:
Date of Approval: March 17, 2020
PAGE 16 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
Table 09-7: Vertical Clearance between different Circuits on the same
Structure for different Voltages
Nominal Circuit
Voltages, kV
Vertical Clearance between different
circuits on the same structure, m
69/69
1.20
110/110
1.75
115/115
1.80
132/132
2.0
230/230
3.25
380/380
5.15
Notes to Table 09-7:
1.
A margin of 0.15m shall be added to account for design errors.
2.
The clearances at the supporting structure shall be so adjusted that the clearances at
any point in the span shall not be less than the values given in the table when
measured with upper conductor at final unloaded sag at the maximum temperature
for which the conductor is designed to operate and the lower conductor at final
unloaded sag under the same ambient conditions and without electrical loading.
3.
The clearances shall be increased @ 3 % for each 300m in excess of 1,000m altitude
above mean sea level.
5.2.3
Clearances for different Circuits where one or both exceed 98kV Phase to
Ground
The clearances specified in equations 09-8 and 09-9 may be reduced for
circuits with known switching surge factors, but shall not be less than the
clearances required by the equation below:
  U (SSF)  UL a 
Min. Clearance (V) = 1000 H

500k


Where:
1.667
 bc (Eq.09-10)
UH = Higher voltage circuit maximum crest operating voltage to ground
UL = Lower voltage circuit maximum crest operating voltage to ground
SSF = Higher voltage circuit maximum switching surge factor expressed in
per-unit peak voltage to ground. (SSF value shall be obtained from
Transmission Asset Planning Department).
a = 1.15, the allowance for three standard deviations
b = 1.03, the allowance for nonstandard atmospheric conditions.
c = 1.2, the margin safety
k = 1.4, the configuration factor for conductor-to-conductor gap
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 17 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
The clearance shall be increased @ 3 % for each 300m in excess of 450m
above mean sea level.
5.3
Clearance of Conductor from its own Support - Basic Clearance
5.3.1
Clearance in any direction from a line conductor to the surface of its own
support structure shall not be less than that calculated by the following
equation:
Clearance ‘T’ = 330mm+5mm (U-50)
(Eq.09-11)
Where, U = Maximum operating voltage phase-to-phase, over 50kV
Minimum clearances of conductor to its own supporting structure were
calculated based on the above equation and tabulated below:
Table 09-8: Clearance of Conductor to its own Support
Line Voltage, kV
Clearance of Conductor from
its own Support Arm and Structure, m
No Wind
Maximum Wind
69
0.69
0.45
110/115
1.30
0.60
132
1.50
0.65
230
2.10
0.85
380
3.50
1.30
Notes to Table 09-8:
1.
For clearances under no wind condition, a margin of 0.15m shall be added to account
for design errors.
2.
The clearances under maximum wind shall be maintained when the insulator strings
and conductors swing transversely up to maximum design swing angle.
3.
The clearances under no wind condition shall be increased @ 3 % for each 300m in
excess of 1,000m altitude above mean sea level.
5.3.2
Clearances of Conductor from its own Support-Alternate Clearances for
Voltages exceeding 98kV Phase to Ground
The clearances specified in Eq.09-11 may be reduced for circuits with
known switching surge factor but shall not be less than the clearances
derived from the equation shown below:
1.667
 U (SSF) a 
Min. Clearance (T) = 1000 L-G

500k

Where:
TESP12209R02/MAT
Date of Approval: March 17, 2020
b
(Eq.09-12)
PAGE 18 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
UL-G = Maximum alternating current crest operating voltage to ground
SSF = Maximum switching surge factor expressed in per-unit peak voltage
to ground
a = 1.15, the allowance for three standard deviations with fixed insulator
supports
a = 1.05, the allowance for one standard deviation with free swinging
insulators
b = 1.03, the allowance for nonstandard atmospheric conditions
k = 1.2, the configuration factor for conductor-to-tower window
The clearance shall be increased @ 3 % for each 300m in excess of 450m
above mean sea level.
5.3.3
5.4
When suspension insulators are used and are not restrained for movement,
the clearance shall be increased so that the insulator strings may swing up to
maximum design angle without reducing the values as tabulated in Table 098. The maximum insulator swing angle shall be determined as outlined in
equation 09-5.
Clearance between Conductors carried on different Supports
5.4.1
Horizontal Clearance between Conductors
a.
Basic Clearance
The horizontal clearance between adjacent conductors carried out on
different supporting structures shall not be less than required by the
equation below:
Clearance = 1500mm+10mm [(U01+U02)-22]
(Eq.09-13)
Where:
U01 = Maximum Phase-to-Ground Voltage in kV of Line #1
U02 = Maximum Phase-to-Ground Voltage in kV of Line #2
The clearance shall be maintained when one insulator string swings up
to its extreme position while the string of adjacent conductors remains
at rest.
A margin of 0.6m shall be added to the calculated values to account
for design errors.
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 19 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
The clearance shall be increased @ 3 % for each 300m in excess of
1,000m above mean sea level.
b.
Alternate Clearances for Voltages exceeding 98kV Phase-to-Ground
The clearances specified in equation 09-13 may be reduced for circuits
with known switching surge factor but shall not be less than the
clearances derived from the equation 09-7.
5.4.2
Vertical Clearance between Conductors
a.
Basic Clearance
The vertical clearance between any crossing or adjacent conductors
carried on different supporting structures of the same or different
nominal voltages shall not be less than that shown in Table 09-9 or as
required by the following equation, whichever is larger.
Clearance = 600mm+10 [(U01-22)+(U02-22)]
(Eq.09-14)
Where:
U01 = Maximum phase-to-ground voltage of Line at upper level, over
22 kV
U02 = Maximum phase-to-ground voltage of Line at lower level, over
22 kV
Table 09-9: Minimum Vertical Clearance between Conductors where the
Conductors of one Line cross over the Conductors of another
Lower Level Conductor
Upper Level Conductor
Transmission Voltages (Line to Line)
Type of Crossing
69kV
(m)
110kV
(m)
115kV
(m)
132kV
(m)
230kV
(m)
380kV
(m)
69kV Transmission Lines
1.10
-
1.40
-
2.10
3.10
110kV Transmission Lines
115kV Transmission Lines
132kV Transmission Lines
230kV Transmission Lines
380kV Transmission Lines
Distribution Lines (34.5kV
and below) / Electrified
Railroads contact wires
Overhead Ground Wire/
OPGW/Guys/Span Wires
Communication Lines
1.40
2.10
3.10
1.60
3.30
1.70
2.40
3.40
1.90
3.50
2.40
3.20
4.10
3.30
3.40
3.50
4.10
5.10
0.90
1.20
1.30
1.40
2.05
3.02
1.40
1.70
1.70
1.80
2.50
3.40
2.0
2.20
2.30
2.50
3.10
4.10
Notes to Table 09-9:
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 20 OF 43
TRANSMISSION ENGINEERING STANDARD
1.
2.
3.
b.
TES-P-122.09, Rev. 02
Additional margins of 1.0 m and 2.0 m (total 3.0 m) shall be added to account for design errors
and wind induced dynamic conductor movement/safety during maintenance operations
respectively. The above mentioned margin of 2.0 m may be reduced to 1.0 m if the cross-over
is quite away from the mid-points of the spans thereby limiting the conductor movement.
The clearances shall be maintained under the conditions, when upper level conductors are at
the final unloaded sag at maximum design temperature of conductor and lower level conductors
are at the initial sag at the minimum design temperature of conductor or at final unloaded sag
under the same ambient condition without electrical loading whichever results in larger
difference.
The clearances shall be increased @ 3 % for each 300m in excess of 1,000m altitude above
mean sea level.
Alternate Clearances for Voltages exceeding 98 kV Phase-To-Ground
The clearances specified in equation. 09-14 may be reduced where the
higher voltage circuit has a known switching surge factor but shall not
be less than the clearances derived from the equation 09-10.
5.5
Clearance of Conductors from other supporting Structures
Conductors of one line passing near a lighting support, traffic signal support, or a
supporting structure of a second line, without being attached thereto, shall have
clearance from any part of the structure not less than calculated by the equation below:
5.5.1
Horizontal Clearance
a.
Clearance “G” = 1500mm+10mm (U0-50)
(Eq.09-15)
Where U0 is the maximum operating voltage phase-to-ground, in
excess of 50kV.
Minimum horizontal clearance of a line conductor to a rigid supporting
structure, other than its own, based on the above equation was
calculated and tabulated in Table 09-10.
Table 09-10: Horizontal Clearance of Conductor from other
Supporting Structure
Nominal Voltage (kV)
Minimum Horizontal Clearance of Conductor from
other Supporting Structure, m
69
110/115
1.50
1.75
132
1.85
230
2.50
380
3.50
Note: A margin of 0.6m shall be added to account for design errors and the clearances shall be
increased @ 3 % for each 300m in excess of 1,000m altitude above mean sea level.
b.
TESP12209R02/MAT
These clearances have to be increased by the distance resulting from
horizontal swing of the conductor and insulator assembly due to wind.
Date of Approval: March 17, 2020
PAGE 21 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
i.
The maximum insulator swing angle can be determined by
equation 09-5.
ii.
The maximum design swing angle shall be based on a 927 N/m2
wind on the conductor, final sag at every day temperature. The
conductor swing shall be calculated as follows:
 = Arc Tan (Pc/Wc)
(Eq.09-16)
Where: Pc and Wc are defined in equation 09-6.
The horizontal swing of conductors due to wind can be
obtained from the equation:
C = Sc x sin 
(Eq.09-17)
Where: Sc is the conductor sag, which shall be final sag based
on computed ruling span at every day temperature, with 927
N/m2 wind.
5.5.2
Vertical Clearance
Min. Clearance = 1700 mm + 10 mm (U0-50)
(Eq.09-18)
Where: U0 = Maximum operating Voltage Phase-to-Ground, in excess of
50kV.
Minimum vertical clearance of a line conductor to a rigid supporting
structure, other than its own, was calculated based on the above equation and
given in Table 09-11.
Table 09-11: Vertical Clearance of Conductor from other Supporting
Structure
Nominal Voltage, kV
Minimum Vertical Clearance of Conductor from other
Supporting Structure, m
69
110/115
1.70
1.95
132
2.05
230
2.70
380
3.70
Note: A margin of 1.0m shall be added to account for design errors and the clearances shall be
increased @ 3 % for each 300m in excess of 1,000m altitude above mean sea level.
5.5.3
Alternate Clearance for Voltages exceeding 98kV to Ground
The clearances specified in equations 09-15 and 09-18 may be reduced for
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 22 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
circuits with known switching surge factors but shall not be less than the
values derived from the following equations.
a.
Min. horizontal clearance in mm
 U SSFa 
 1500  1000 L G

500k


1.667
b.
 bc
(Eq.09-19)
 bc
(Eq.09-20)
Min. vertical clearance
 U SSFa 
 1800  1000 L G

500k


Where:
1.667
UL-G = The maximum crest operating voltage to ground
SSF = Maximum switching surge factor expressed in per-unit peak
voltage to ground (SSF value shall be obtained from
Transmission Asset Planning Department).
a = 1.15, the allowance for three standard deviations
b = 1.03, the allowance for nonstandard atmospheric conditions
c = Margin of safety, 1.2 for Vertical clearances and 1.0 for horizontal
clearances
k = 1.15, the configuration factor for Conductor-to-Plane gap
The clearances shall be increased @ 3 % for each 300m in excess of 450m
above mean sea level.
5.6
Clearances of Conductors from other Installations
The horizontal and vertical clearances of line conductors from other structures such
as tall buildings, signs, chimneys, TV masts, lighting poles, monuments in the roundabout etc., shall be established as required, taking into consideration all local
conditions and the latest government and owner regulations.
5.6.1
Basic Clearance
Minimum clearances of wires, conductors and cables passing by, but not
attached to building and other installations, shall not be less than those given
in the following table. The horizontal clearance mentioned in the table shall
be maintained when the conductor swings up to the design swing angle.
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 23 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
Table 09-12: Minimum Clearance of Conductors Adjacent to but not attached to
Buildings and other Installations except Bridges (see notes 5, 6 and 7)
Communication
Cables and
Grounded Guys
Clearance of
Conductors Voltage, kV
69
110- 132
230
380
Buildings (Horizontal Clearance) m
To wall and projections (Note 3)
1.40
2.55
2.95
3.6
4.55
To unguarded windows (Note 4)
1.40
2.55
2.95
3.6
4.55
To balconies and areas accessible to
pedestrians (Note 1)
1.40
2.55
2.95
3.6
4.55
Buildings (Vertical Clearance) m
Above or below roof or projection not
accessible to pedestrians (Note 1)
0.90
4.05
4.50
5.10
6.10
Above or below balconies and roofs
accessible to pedestrians (Note 1)
3.20
4.35
4.80
5.40
6.35
Above roofs accessible to vehicles but
not subject to truck traffic
3.20
4.35
4.80
5.40
6.35
4.70
5.85
6.30
6.90
7.85
Above roofs accessible to truck traffic
(Note 2)
Signs, Chimneys, radio and television antennas, lighting poles, monuments in the round-about
tanks and other installations not classified as buildings m
Horizontal
0.90
2.55
2.95
3.6
4.55
Vertical above or below
0.90
2.70
3.10
3.70
4.70
Notes to Table 09-12:
1.
A roof, balcony or area is considered accessible to pedestrians if the means of access is through a
doorway, ramp, stairway or permanently mounted ladder.
2.
For the purpose of this rule, trucks are defined as any vehicle exceeding 2.45 m in height.
3.
This clearance may be reduced to 75 mm for the grounded portions of guys.
4.
Windows not designed to open may have the clearances permitted for walls and projections.
5.
A margin of 1.0 m shall be added to account for design errors.
6.
The clearances shall be increased @ 3 % for each 300 m in excess of 1,000 m altitude above mean
sea level.
7.
As a general practice, buildings and other installations are not permitted within the transmission line
ROW. The clearances mentioned here are under exceptional cases when these cannot be removed.
Under such cases it shall be ensured that no part of the buildings is exposed to electric fields in excess
of 5kV/m (IEEE Standard C95.6) including outer walls, balconies and roofs.
5.6.2
Alternate Clearance for Voltages exceeding 98kV to Ground
The clearance specified in Table 09-12 may be reduced for circuit with
known switching surge factors but shall not be less than the values derived
from equations 09-19 and 09-20.
5.7
Mid-Span Clearance
The separation between the overhead ground wire and the top conductor is a function
TESP12209R02/MAT
Date of Approval: March 17, 2020
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TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
of the actual structure footing resistance, wind speed, the number of insulators in the
insulator string, type of insulator, the span length and the acceptable number of
outages per 100 km per year.
5.7.1
The clearance at mid-span between the overhead ground wires and the
conductors shall be greater than that at the structure and shall be well
coordinated so that the flashover occurs at the structure.
5.7.2
Line voltages have little relationship on the required mid-span clearances.
The mid-span clearances for National Grid Saudi Arabia 69kV through 380
kV transmission lines shall not be less than those tabulated below. The
clearances shall be maintained at every day temperature, final sag with no
wind for the design ruling span of the transmission lines. The values for
intermediate ruling spans may be interpolated.
Table 09-13: Mid-Span Clearance between Conductors and OGW/OPGW
Span, m
Mid-Span Clearance
(between conductors and OGW/OPGW), m
91 - 213
3.5
244
4.5
305
6.0
350
6.8
366
7.0
400
7.8
427
8.5
450
9.1
Note: Applicable for all altitude levels.
5.7.3
5.8
For spans longer than those in the above table, the final sag of the overhead
ground wire with no wind at every day temperature shall not be more than
the conductor sag.
Air Gap Requirements
5.8.1
Shielded Lines
To maintain adequate clearances the air gap distance between any conductor
and structure shall be correlated to the insulation levels considering each of
the three types of voltage stresses (lightning impulse, switching surge and
power frequency) under the condition at which each is likely to govern and
given in the following table.
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 25 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
Table 09-14: Air Gap Requirement for Shielded Lines
Line Voltage, (kV)
Air Gap, (m)
69
0.69
110/115
1.30
132
1.50
230
2.1
380
2.60
Note: The clearances shall be increased @ 3 % for each 300m in excess of
1,000m altitude above mean sea level.
5.8.2
Unshielded Lines
For unshielded lines the following criteria shall be used to specify clearances
of conductor to structure. Further the minimum conductor to structure and
conductor to conductor clearances shall not be less than Eq. 09-1 to Eq. 0920 or by the correlated air gap clearances to insulation levels, the larger value
shall be used, for various situations. Basic clearances shall be based on the
maximum system voltage under emergency conditions.
6.0
a.
For the “no wind” or normal position of the insulator, the conductor
clearance to structure shall be the air gap equivalent of the insulator
string impulse flashover value plus ten (10) percent.
b.
For the 430 N/m2 wind position, the conductor clearance to structure
shall be the air gap equivalent of the insulator string impulse flashover
value.
c.
For 927 N/m2 wind position, the conductor clearance to structure shall
be the air gap equivalent of 60Hz wet flashover value of the insulator
string. The air gap clearance plus the distance allowed for the swing of
insulator by the maximum wind of 927 N/m2 will determine the
clearance from conductor to structure in the normal position.
RIGHT-OF-WAY WIDTH REQUIREMENTS
Transmission line Right-of-Way is a strip of land that is used to construct, operate, maintain
and repair transmission line facilities. The line is normally centered in the right-of-way.
6.1
General
6.1.1
TESP12209R02/MAT
Right-of-way requirements for 69 kV, 110kV, 115 kV, 132kV, 230 kV and
380 kV transmission lines are discussed in this part. All right-of-way shall
be secured before design and construction.
Date of Approval: March 17, 2020
PAGE 26 OF 43
TRANSMISSION ENGINEERING STANDARD
6.1.2
6.2
TES-P-122.09, Rev. 02
Right-of-way for 69kV to 380kV transmission lines shall be as shown in
Tables 09-16 to 09-18, or shall be calculated using the equations 09-21 &
09-22. The larger value from these equations shall be used.
Conductor Clearance to edge of Right-of-Way
6.2.1
Minimum horizontal separation between conductors on the same support
shall be calculated by equations 09-1 to 09-4. The large value from these
equations shall be used. This value shall be increased by the distance to the
end of the longest insulator support on each line structure.
6.2.2
Minimum horizontal clearances from conductors to edge of right-of-way
shall be based on values in Tables 09-16 to 09-18 or in accordance with the
following equations. The larger value shall be used. Transmission voltages
shall be based on maximum operating voltage under emergency conditions:
a.
Basic Clearance
= 2300 mm + 10 mm (U0-22)
(Eq.09-21)
Where:
U0 = Maximum operating voltage phase-to-ground over 22 kV.
6.3
Right-of-Way Width Requirements for Single Transmission Line
6.3.1
Figure TE-2209-0200-01 shows the procedures to be followed to establish
the right-of-way for various types of transmission line structures.
6.3.2
Explanation of symbols used in Figure TE-2209-0200-01 and steps to be
taken to establish right-of-way requirements in restricted areas are given
below:
A = Distance from centerline of structure to insulator attachment in mm.
1 = Angle of maximum swing for suspension insulator string. It is preferred
to use the 1 as 45 swing.
If 45 swing is used, it will include most conditions for structures currently
being used with the insulator string at maximum blowout or structure design
limitations.
If the minimum right-of-way is required to be obtained for a special area
control then the actual conditions or 1 may be calculated for the worst
conditions of the line under consideration.
B = Offset due to insulator swing for suspension insulators equal to length
of insulator string plus hardware length times Sin 1
TESP12209R02/MAT
Date of Approval: March 17, 2020
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TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
2 = Angle of maximum swing for conductors is determined by multiplying
the conductor diameter in meters by the wind pressure in N/m2 on
conductor and dividing by the conductor unit weight in Newton per
meter.
Tan 2 
Conductor Dia x Wind Pressure
Unit Weight
(Eq.09-22)
C = Offset due to conductor sag x Sin 2. Conductor sag shall be the final
sag based on computed ruling span at every day temperature with 927
N/m2 wind
D = Horizontal clearance from conductor to edge of right-of-way at
maximum swing calculated for conditions established for structure to
be used (see Clause 6.2.2)
E = Total distance each side, from centerline to edge of right-of-way.
6.4
Right-of-Way Width Requirements for Parallel Transmission Lines
6.4.1
Figures TE-2209-0300-01 and TE-2209-0400-01 show the procedures to be
followed in order to establish the minimum right-of-way for typical
configurations of parallel transmission lines.
6.4.2
Steps A through E, as in clause 6.3.2, shall be followed and the angles 1
and 2 shall be determined for each of the two lines that are being paralleled.
Then determine the dimensions required for Items F and G. The larger of
these two shall determine the distance between the parallel transmission
lines.
a.
Separation between lines as dictated by minimum clearance between
conductors carried on different Supports
The horizontal clearance between conductor of one line to conductor
of another line shall meet the following conditions: (a) both conductors
displaced by a 927 N/m2 wind at every day temperature, final sag; (b)
if insulators are free to swing, one shall be assumed to be displaced by
a 927 N/m2 wind while the other shall be assumed to be unaffected by
the wind (see Figure TE-2209-0300-01).
F = Clearance between conductors of parallel transmission lines as
determined by equation 09-3 and 09-4 for phases of different
circuits.
b.
TESP12209R02/MAT
Separation between lines as dictated by minimum clearance of
conductors from one line to the supporting structure of another
Date of Approval: March 17, 2020
PAGE 28 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
The horizontal clearance of a conductor of one line to the supporting
structure of another when the conductor and insulator are displaced by
a 927 N/m2 wind at every day temperature final sag.
G = Clearance of conductor from other supporting structures, as
determined by the equation 09-15.
6.4.3
6.5
The separation between lines will depend upon the spans and sags of the
lines as well as how the structures of one line line-up with structures of
another. In order to avoid the unreasonable task of determining the
separation of the structures span-by-span, a standard separation value shall
be used based on a worst case analysis. Thus if structures of one line do not
always line-up with the other, the separation required by clause 6.4.2.b
above shall be based on assumption that the structure of one line is located
next to the point of the line that has the most sag.
Example Calculation of Right-of-Way
6.5.1
Information needed to determine the right-of-way requirements for structure
types of any transmission lines are tabulated on Table 09-15.
6.5.2
Typical calculations for a 380kV double circuit steel tower with VSuspension insulator string (46 X 2 units of aero form type cap & pin disc
insulators), and ACSR/AW Condor” conductor with 400 meters ruling span
are:
a.
Dimension ‘A’
A ≃ 7.60 m derived from the drawing for “Latticed Steel Vertical
Configuration 380kV Double Circuit Suspension (Tangent) Type
Tower S1N. Dimension ‘A’ depends on tower structure design
and configuration.
b.
Dimension ‘B’
Assume 1 = 45° for I-Strings
1 = 0° for V-Strings (no deflection)
Length of Insulator String (including hardware) = 7.5 m
B = Length of Insulator String x Sin 1
= 7.5 m x sin 0 = 0 m (for V-String case)
c.
Dimension ‘C’
Angle of maximum swing for conductors:
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 29 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
 27.72 mm / 1000 x 927 
2 = Arc Tan 
  60.86 ° say 610
14.32 N/m


Sag for 400m ruling span ≃ 13m at 25°C, final with 927 N/m2 wind
Offset due to conductor swing:
C = 13 m x sin 610 = 11.37 say 11.40m
Offset due to conductor swing for bundled conductor:
Cl  11.40 m +
d.
0.45
x Cos 61  11.50 m
2
Dimension ‘D’
Horizontal clearance to edge of right-of-way
 418

D  2300mm  10mm 
 22 
 3

D
e.
= 2,300 mm + 2,193 mm = 4,493 mm, say 4.50m
Dimension ‘E’
Distance each side of centerline to edge of right-of-way
E = A+ B+ C+ D = 7.60 + 0 + 11.50+ 4.5 = 23.60, say 24 m
Therefore, total width of right-of-way required shall be:
2 x E = 2 x 24 m = 48 m, say 50 m
To keep margin for variation in sag and cross arm structure
configuration etc., 50m width is standardized for 380kV.
6.5.3
Typical calculation for two parallel 380kV steel tower lines (Figure TE2209-0300-01
Tower configurations are the same as in clause 6.5.2. The separation
between two parallel 380kV steel tower lines shall be calculated by the two
equations shown below and greater value shall be considered:
Items A, B, C, D, and E to be calculated as in clause 6.5.2
a.
TESP12209R02/MAT
Horizontal Clearance between different phases of different circuits
according to conductor sag per equation 09-3 & 09-4
Date of Approval: March 17, 2020
PAGE 30 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
U 
U
F  7.6mm  1  2   8 2.12S
3
 3
Where:
U1 = U2 = 380kV x 1.1 = 418kV
S = Sag at 25C, final with 927 N/m2 wind
F = 7.6mm 242  242  8 2.1213,000
= 3,678 + 1,328 =5,006 mm, say 5.0 m
b.
Horizontal Clearance of conductor of one line to the supporting
structure of another (Eq.09-15)
U

G = 1500mm  10 1  50 
 3

= 1500 + 10(242 - 50)
= 1500 + 1920 = 3,420 mm, say 3.5m
F = 5m is larger than G, therefore, it is to be considered
Total right-of-way width shall be: E + A + B + C + F + A3 + E
= 23.60+7.60+0+11.50+5.0+13.70+ 23.60= 85 m
Table 09-15: Sample Data for Right-Of-Way Calculation
Sr. No.
Circuit No. 1 & 2
1
Maximum Line Voltage
2
Type of Structure
3
Drawing for Tower Type S1N
4
Distance, tower center to V-String center, m
5
Number of Insulators in V-String
6
Insulator String length (including hardware), m
7
Conductor
8
Stranding
54/7
9
Weight per unit, kg/m
1.461
10
Diameter, mm
27.72
11
Ruling span, m
12
TESP12209R02/MAT
Description
380kV
Lattice Steel (vertical configuration)
ET-905431
7.60
46 X 2
7.5
ACSR/AW Condor
400
2
Sag at 25 with 927 N/m wind, m
Date of Approval: March 17, 2020
13.0 (approximate)
PAGE 31 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
Table 09-16: Single Transmission Lines Right-of-Way Width Requirements
Line Voltage, (kV)
380
230
110/115/132
69
Structure
Lattice Steel Towers, D/C
(Vertical, V-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, S/C
(Horizontal, V-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Delta, I-String)
Steel Monopole, D/C
(Vertical, I-String))
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Delta, I-String)
Steel Monopole, D/C
(Vertical, I-String))
Lattice Steel Towers, D/C
(Vertical, I-String)
Steel Monopole, D/C
(Vertical, I-String))
Conductor
ACSR/AW
Condor
Ruling
Span, m
Normal ROW
Width, m
400
50
400
50*
400
56
350
44
350
57
200
32
350
34
350
42
200
25
300
28
200
20
Notes to Table 09-16:
i.
ROW marked with * applicable in the Inland Area for existing transmission lines where creepage distance is 31mm/kV
ii.
ROW values indicated in the above table are based on some specific structures and their cross-arm configurations and
may increase/decrease with respect to distance between center of structure and center of insulator string.
iii.
For transmission lines located in the median of the roads, existing ROW of the roads shall be applicable. Specified
conductor clearances over road surface, to buildings and other installations at the edge of right of way shall be
maintained and structures shall be protected with crash barriers.
iv.
ROW calculations are based on ACSR/AW Condor conductor. For other conductors the values shall be established
based on the actual span length and the conductor data.
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 32 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
Table 09-17: Parallel Transmission Lines Right-of-Way Width Requirements
Line Voltage, (kV)
380
380
380
380
380/230
380/230
380/230
380/230
380/132
380/115
380/115
380/69
Structure
Conductor
Lattice Steel Towers, D/C
(Vertical, V-String)
Lattice Steel Towers, D/C
(Vertical, V-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, S/C
(Horizontal, V-String)
Lattice Steel Towers, S/C
(Horizontal, V-String)
Lattice Steel Towers, D/C
(Vertical, V-String)
Lattice Steel Towers, S/C
(Horizontal, V-String)
Lattice Steel Towers, D/C
(Vertical, V-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, V-String)
Lattice Steel Towers, D/C
(Delta, I-String)
Lattice Steel Towers, D/C
(Vertical, V-String)
Steel Monopole, D/C
(Vertical, I-String)
Lattice Steel Towers, S/C
(Horizontal, V-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, V-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, V-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, V-String)
Lattice Steel Towers, D/C
(Delta, I-String)
Lattice Steel Towers, D/C
(Vertical, V-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Ruling
Span, m
Line Center
to Center, m
Normal ROW
Width, m
400
37
85
400
39
96*
400
45
100
400
40
92
30
75
36
88
28
68
34
84
26
66
28
70
30
74
26
63
400
350
400
ACSR/AW
Condor
350
400
200
400
350
400
350
400
350
400
350
400
300
* Applicable in the Inland Area for existing transmission lines where creepage distance is 31mm/kV.
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 33 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
Table 09-17: Parallel Transmission Lines Right-of-Way Width Requirements (Continued)
Line Voltage, (kV)
380/69
380/69
380/69
230
230
230
230
230
230
230/132
230/115
230/115
230/115
TESP12209R02/MAT
Structure
Conductor
Lattice Steel Towers, D/C
(Vertical, V-String)
Steel Monopole, D/C
(Vertical, I-String)
Lattice Steel Towers, S/C
(Horizontal, V-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, S/C
(Horizontal, V-String)
Steel Monopole, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Delta, I-String)
Lattice Steel Towers, D/C
(Delta, I-String)
Steel Monopole, D/C
(Vertical, I-String)
Steel Monopole, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Delta, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Steel Monopole, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Delta, I-String)
Steel Monopole, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Steel Monopole, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Delta, I-String)
Lattice Steel Towers, D/C
(Delta, I-String)
Lattice Steel Towers, D/C
(Delta, I-String)
Steel Monopole, D/C
(Vertical, I-String)
Ruling
Span, m
Line Center
to Center, m
Normal ROW
Width, m
25
58
30
71
30
67
350
28
72
350
41
98
350
21
53
350
34
85
27
65
34
78
25
64
25
60
35
84
32
73
400
200
400
300
400
200
ACSR/AW
Condor
Date of Approval: March 17, 2020
350
200
350
200
350
350
350
200
350
350
200
PAGE 34 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
Table 09-17: Parallel Transmission Lines Right-of-Way Width Requirements (Continued)
Line Voltage, (kV)
230/115
230/115
230/115
230/115
230/69
230/69
230/69
230/69
230/69
Structure
Conductor
Steel Monopole, D/C
(Vertical, I-String)
Steel Monopole, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Delta, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Steel Monopole, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Steel Monopole, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Delta, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Delta, I-String)
Steel Monopole, D/C
(Vertical, I-String)
Steel Monopole, D/C
(Vertical, I-String)
Steel Monopole, D/C
(Vertical, I-String)
Ruling
Span, m
Line Center
to Center, m
Normal ROW
Width, m
200
19
48
350
26
67
350
33
80
20
55
24
60
24
56
31
73
30
69
18
44
200
350
ACSR/AW
Condor
350
300
350
200
350
300
350
200
200
Note: Wherever ROW is restricted and not possible to maintain and accommodate above clearances and/or structure pads/access
road per TES-P-122.11, National Grid Saudi Arabia shall review the case to determine appropriate clearances and ROW.
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 35 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
Table 09-17: Parallel Transmission Lines Right-of-Way Width Requirements (Continued)
Line Voltage, (kV)
132
115
115
115
132/69
115/69
115/69
115/69
115/69
115/69
69
69
69
TESP12209R02/MAT
Structure
Conductor
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Delta, I-String)
Lattice Steel Towers, D/C
(Delta, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Delta, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Steel Monopole, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Delta, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Delta, I-String)
Steel Monopole, D/C
(Vertical, I-String)
Steel Monopole, D/C
(Vertical, I-String)
Steel Monopole, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Steel Monopole, D/C
(Vertical, I-String)
Steel Monopole, D/C
(Vertical, I-String)
Lattice Steel Towers, D/C
(Vertical, I-String)
Steel Monopole, D/C
(Vertical, I-String)
Ruling
Span, m
Line Center
to Center, m
Normal ROW
Width, m
350
20
54
350
27
69
350
23
60
350
25
64
19
50
21
53
20
49
23
57
23
53
200
14
37
300
16
43
200
12
31
15
39
350
300
350
300
ACSR/AW
Condor
Date of Approval: March 17, 2020
350
200
350
300
350
200
300
200
PAGE 36 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
Table 09-18: Wood Poles Transmission Lines Right-of-Way Width Requirements
Line Voltage,
(kV)
Ruling
Span, m
Maximum
Span, m
Normal ROW
Width, m
260-275
320
30
80-100
110-120
15
Wood Monopole,
H-Frame, S/C
260-275
320
25
Wood Monopole, S/C & D/C
80-120
140
15
H-Frame Wood, S/C
260-275
320
H-Frame Wood, S/C
260-275
320
H-Frame Wood, S/C
260-275
320
Wood Pole, S/C
80-100
110-120
Wood Pole, S/C
80-100
110-120
Wood Pole, S/C
80-100
110-120
H-Frame Wood, S/C
260-275
320
H-Frame Wood, S/C
260-275
320
260-275
320
Wood Pole, S/C
80-100
110-120
Wood Pole, S/C
80-100
110-120
Wood Pole, S/C
80-100
110-120
H-Frame Wood, S/C
260-275
320
H-Frame Wood, S/C
260-275
320
H-Frame Wood, S/C
260-275
320
Wood Pole, S/C
80-100
110-120
Wood Pole, S/C
80-100
110-120
Wood Pole, S/C
80-100
110-120
Structure
Conductor
Single Transmission Lines Right of Way Width Requirements
115
Wood Monopole,
H-Frame, S/C
Wood Monopole, S/C & D/C
69
ACSR/AW
Parallel Transmission Lines Right of Way Width Requirements
115
60
115
38
115
23
115/69
45
H-Frame Wood, S/C
ACSR/AW
115/69
37
115/69
21
69
42
69
23
69
20
Note: Wherever ROW is restricted and not possible to maintain and accommodate above clearances and/or structure pads/access road
per TES-P-122.11, National Grid Saudi Arabia shall review the case to determine appropriate clearances and ROW.
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 37 OF 43
TRANSMISSION ENGINEERING STANDARD
6.6
TES-P-122.09, Rev. 02
Horizontal Distance between other Parallel Transmission Lines and other Obstacles
The minimum horizontal distance between the route center line and other parallel
transmission lines, telecommunication lines or other obstacles such as buildings, trees
etc. shall not be less than that given in Table 09-19.
Table 09-19: Horizontal Distance between other Parallel Transmission
Lines and other Obstacles
Distance (in meters) of selected line route to objects for:
Transmission Line/
Obstacles etc.
380kV
230kV
132/115/110kV
Below
110kV
380kV
50
40
40
40
230kV
40
40
40
40
132/115/110kV
40
40
40
25
Below 110kV
40
40
40
20
Telecommunication Lines
40
40
25
20
Buildings, Trees etc.
Renewable Energy
Source:
Wind Farms
35
25
25
20
3 times the rotor diameter of wind turbine
Solar Farms (Note 2)
100
Notes to Table 09-19:
1.
The distances mentioned in the above table shall generally be applicable when the transmission line
route is passing through un-restricted areas. However, in restricted areas when it is not possible to
maintain these distances, lesser values per Table 09-17 may be applied.
2.
National Grid Saudi Arabia shall review the case to determine the appropriate spacing.
7.0
BIBLIOGRAPHY
7.1
Design Manual for High Voltage Transmission Lines, REA Bulletin 1724E-200,
U.S. Department of Agriculture, 2015 Edition
7.2
Transmission Line Design Manual, U.S. Department of the Interior, by Holland
H. Farr
7.3
National Electrical Safety Code, American National Standard Institute, 2017
Edition
7.4
IEC 61936-1, Power Installations Exceeding 1 kV A.C.-Part 1: Common Rules
7.5
Electrical Transmission and Distribution Reference Book, Central Station
Engineers (Westinghouse Electric Corporation), 1964
7.6
Estimating Lightning Performance of Transmission Lines, IEEE Transactions
Volume 83, 1964, J.M. Clayton & F.S. Young
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 38 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
7.7
Shielding of Transmission Lines, IEEE Paper No. 63-640, J.M. Clayton, F.S.
Young and A.R. Hileman
7.8
Elements of Power System Analysis, William D. Stevens, Jr.
7.9
NACE (National Association of Corrosion Engineers) International Standard
SP0177 - 2014 “Standard Practice: Mitigation of Alternating Current and
Lightning Effects on Metallic Structures and Corrosion Control Systems”
7.10
CSA (Canadian Standards Association) Standard C22.3 No. 6-13 “Principals
and practices of electrical coordination between pipelines and electric supply
lines”
7.11
Saudi ARAMCO Engineering Standard SAES-B-064, 2017 Onshore and
Nearshore Pipeline Safety
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 39 OF 43
TRANSMISSION ENGINEERING STANDARD
TESP12209R02/MAT
Date of Approval: March 17, 2020
TES-P-122.09, Rev. 02
PAGE 40 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
FIGURE TE-2209-0200-01
RIGHT OF WAY FOR SINGLE TRANSMISSION LINE
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 41 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
FIGURE TE-2209-0300-01
RIGHT OF WAY FOR TWO PARALLEL TRANSMISSION LINES
(INDENTICAL INSULATOR STRING CONFIGURATION)
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 42 OF 43
TRANSMISSION ENGINEERING STANDARD
TES-P-122.09, Rev. 02
FIGURE TE-2209-0400-01
RIGHT OF WAY FOR TWO PARALLEL TRANSMISSION LINES
(DIFFERENT INSULATOR STRING CONFIGURATION)
TESP12209R02/MAT
Date of Approval: March 17, 2020
PAGE 43 OF 43