An Approach to Develop a Compact Transmission Line Tower with Special 8-Legged Configuration

Abstract

For transmission of electricity from power generation plant to substations, many types of structures are being used. The main function of these structures is to support the power conductors and earth-wire. 4-legged steel lattice tower is one of these structures, which is widely used for this purpose. The main drawback of a 4-legged lattice tower is its larger base width, which occupy very large area. Nowadays, in many countries, adequate land is not available to consider such large land occupying towers. In these situations, using monopoles became common practice. But the monopoles are much costlier than the 4-legged lattice towers. To avoid the use of monopoles and to reduce the base width at the same time, in the present work, an approach has been adopted to use a special lattice type structure with eight legs. A 220 kV multi-circuit suspension tower with 0°–2° deviation has been considered for present study. The detail explanations, like, tower geometry, load calculations, analysis and design of the proposed structure has been covered in the paper. It has been observed that land requirement can be considerably minimized by use of the proposed 8-legged tower. The cost of the 8-legged tower is slightly more than a 4-legged tower but much lesser than that of monopoles as the total weight of steel required is very less as compared to monopole. The results obtained from the study of the proposed tower have been compared with 4-legged tower and monopole. This paper discusses the feasibility of using the transmission line tower with 8-legs. The paper also discusses a comparative study of cost, right of way, height and base width of 4-legged tower, monopole and proposed 8-legged tower.