ABSTRACT Transmission line towers constitute about 28 to 42 percent of the cost of the transmission line. The increasing demand for electrical energy can be met more economically by developing different light weight configurations of transmission line towers. The present work describes the analysis and design of three legged self-supporting 400 kV double circuit steel transmission line towers models with an angle and tube sections. In this study constant loading parameters including wind forces as per IS: 802 (1995) are taken into account in both models. The efforts have been made to do 3D analysis of tower considering all the members of the space truss as primary members. STAAD. Pro program has been used to analysis and design the members of 400 kV double circuit tower have deviation angle 2 degree. The maximum sag and tension calculations of conductor and ground wire as per IS: 5613 (Part 3/ Sec 1) 1989. The comparative study is presented here with respective to axial forces, deflections, maximum sectional properties, critical loading conditions between both models of towers. The study shows that tower with tube sections are efficient and have better forceweight ratio including 20.6% saving in weight of steel with tubes against steel with angles in three legged transmission line tower
