A utility pole is mainly a column or post which is used to support overhead power lines and various other public utilities like electrical cable, fiber optic cable, and related equipment such as transformers and street lights. Electrical wires and cables are routed overhead on utility poles as an inexpensive way to keep them insulated from the ground and out of the way of people and vehicles. Utility poles can be made of wood, metal, concrete, or composites like fiberglass. They are used for two different types of power lines: sub-transmission lines, which carry higher voltage power between substations, and distribution lines, which distribute lower voltage power to customers.
For carriage of overhead lines, wooden poles, concrete poles and steel poles and rail ropes are used. Which poles are to be used, depending on the importance of load, location, and place, the cost-effectiveness of such construction, including maintenance cost, and keeping its profit element in mind. In a low voltage line for all phases, natural and the earth we use a single-pole line. There are different types of poles used in the electrical system. We deliver two types of electrical pole – Previously, wooden poles were used for 400 volts and 230 volts L.T. line and 11 KV H.T line in a massive way. On some occasions for 33 KV lines, we used wooden poles. The cost-effectiveness of a wooden pole is much less in comparison to other electric pole and the expenditure incurred for its foundation is also comparatively much less. With proper maintenance and treatment of the wood, the wooden pole lasts for a long period. In wooden electric pole most commonly Shaal, Masua, Tik, Chir, Debdaru woods are also used for the purpose as per their availability. Presently to save and protect forests, to maintain ecological balance, the use of wooden pole is almost stopped. It is highly important to make sure that the wood used for the electric pole must be free from defects. Straight wood is much preferable for the purpose. Two short length poles can also be joint together is required.
The load-bearing capacity much more in steel poles in comparison to that of a wooden pole. With proper maintenance, these poles last for a long period of time. But these poles are much more expensive. These poles are used for 400/230 volt low and medium current system. These poles are preferred to be used in 11 KV H.T. line. In some cases, these poles are used in high voltage like 33 KV system.