12M Swaged Tubular Pole Durable For Overhead Electric Lines 11KV Or 33KV
1. Scope
1.1 This Specification covers the design, fabrication, testing and supply of tubular steel
poles commonly used in overhead electric lines.
2. General
The steel pole shall be fabricated in several lengths and strengths as specified in
Table 1 contained herein.
2.1 The steel tubular poles must be manufactured by a company approved to quality
standard ISO 9001:2000. The ISO 9001 certification number, the name of the
authorized approving authority with the contact address and telephone and fax
numbers shall also be stated. The Bidder shall enclose a copy of the ISO 9001
certificate with the bid .
3. Description
3.1 The steel poles shall be of swagged design and shall consist of three (3) separate
lengths of steel tubing swagged at two joints to fabricate the poles. However, there
are some numbers of poles as mentioned in the price and delivery schedule which
shall be of folding type. The quantities of such folding poles shall be intimated at the
time of contract.
3.2 The steel tubing used in pole fabrication shall be of steel of any approved process
possessing a minimum tensile strength of 42 kg/sq. mm and a chemical
composition of not more than 0.06% sulphur and not more than 0.06%
phosphorous.
3.3 The tubing diameter and tubing wall thickness shown in Table 1 for each length of
pole are the minimum size to be used in fabricating each length of pole. It shall be
the responsibility of the Bidder to determine the adequacy of the component tubing
shown for the load to be sustained. However, in no case the tubing diameter and
wall thickness for any component tube be less than the value shown in Table 1.
3.4 Tubular poles shall be made of welded tubes, swagged and joined together. The
upper edge of each joint shall be chamfered at an angle of about 45-degree. The
steel poles shall be composed of three sections of diminishing diameters and
minimum diameter thickness and lengths of pole shall be as shown in Table 1.
3.5 All tubes forming parts of the above supports shall be made from hot insulated
seamless or continuously welded steel in accordance with BS 6323 or equivalent
applicable Standards.
Chapter 2. Technical Specification for 11kv lines 2-2
GSEEP/W/ICB-03 2073/74-03
3.6 The entire section of the poles shall be galvanized with minimum coating of weight
not less than 460-gm/-sq. m internally and externally.
3.7 Each pole shall be provided with a steel top plate 3-mm minimum thickness
welded to the end of the section. The top plate shall not project beyond the
perimeter of the top section. Each pole shall also be provided with a welded base
plate welded to the bottom of the pole.
3.8 The pole shall, be drilled in accordance with the drilling patterns as defined in the
Figure. All the holes shall be of 18 mm dia. However, the manufacturer must get
approval of the drilling pattern before manufacturing the poles. Each pole shall be
marked with the appropriate length as shown in Figure.
3.9 The folding type of poles shall be fabricated in such a way that the section pieces
can be carried to the site and fitted on the site itself. The pole section on top shall
have a flange and the section under it shall overlap to a length of 25 cm as shown
in the diagram. The poles shall be drilled in such a way that the section in top
could be securely fixed the section under it by two bolts of 5/8" x 7" at 90 degree
each other. Two such joints form a complete pole of three sections as shown in Fig
2 and 3.
3.10 The size of the base plate shall be as per governing standard.
4 Tolerance
4.1 The following tolerances shall be maintained:
a) Tolerance of diameter: Not Applicable
b) Tolerance on weight: Not Applicable
c) Tolerance on thickness: Not Applicable
e) Straightness: The finished poles shall not be out of straightness
by more than 1/600 of the height.
5. Tests
5.1. The following test (s) shall be performed for the pole furnished. All testing shall be
fully documented and certified test reports shall be provided to NEA.
a Tensile test and chemical analysis for sulphur and phosphorous
b. Deflection test
c. Permanent set test
d. Drop test
Chapter 2. Technical Specification for 11kv lines 2-3
GSEEP/W/ICB-03 2073/74-03
5.2 Number of poles selected for conducting tensile test and chemical analysis for
sulphur and phosphorous shall be as given below:
Lot Size No. of poles
Up to 500 1
501 to 1000 2
1001 to 2000 3
2001 to 3000 4
3001 and above 5
5.3 Number of poles selected or conducting deflection test, permanent set test and drop
test shall be as given below:
Lot Size No. of poles
Up to 500 5
501 to 1000 8
1001 to 2000 13
2001 to 3000 18
3001 and above 20
The deflection test, permanent set test and drop test shall be conducted in
succession on each of the poles selected.
IS Designation Overall Length |
410SP- 52 11 m |
410 SP-43 10 m |
410 SP-31 9 m |
410 SP-13 8 m |
||||||
Planting depth. m | 1.8 | 1.8 | 1.5 | 1.5 | ||||||
Sections: | ||||||||||
Length, m Top (h1) |
2.7 | 2.4 | 2 | 1.75 | ||||||
Middle (h2) | 2.7 | 2.4 | 2 | 1.75 | ||||||
Bottom (h3) | 5.6 | 5.2 | 5 | 4.50 | ||||||
Outside Diameter, mm Top (h1) |
114.3 | 114.3 | 114.3 | 88.9 | ||||||
Middle (h2) | 139.7 | 139.7 | 139.7 | 114.3 | ||||||
Bottom (h3) | 165.1 | 165.1 | 165.1 | 139.7 | ||||||
Thickness, mm | ||||||||||
Top (h1) 3.65 3.65 | ||||||||||
3.65 | 3.25 | |||||||||
Middle (h2) | 4.5 | 4.5 | 4.5 | 3.65 | ||||||
Bottom (h3) | 4.5 | 4.5 | 4.5 | 4.5 | ||||||
Approximate weight, kg | 175 | 160 | 147 | 101 | ||||||
Crippling load, kgf | 307 | 348 | 367 | 301 | ||||||
Application of load from top of pole, m |
0.6 | 0.6 | 0.3 | 0.3 |