Conductor economics for EHV transmission

THE USE of bundle conductors for power transmission was first proposed by P. H. Thomas in 1909. The electrical characteristics of bundle conductors were then recognized to be superior in many respects to the characteristics of comparable single conductors. However, it was also known at that time that bundle conductors had higher initial costs and a more complex mechanical structure than single conductors. Therefore, no significant applications of this new concept were made in the next 40 years, although in 1931 C. A. Boddie proposed a 500-kv line with four conductors in a bundle. As a result of extensive investigations made in the last 10 years of the electrical and mechanical characteristics of bundle conductors, many transmission lines have been and are being built all over the world utilizing this type of construction.