Railway electrification: design of overhead equipment

The paper discusses the problems facing the designers of overhead equipment for the electrification of railways. The principal factors are treated in the following order: basic considerations, copper section and catenary system, span length and sag in the catenary, structures and foundations, layout, general design, track equipment fittings, switching, bonding of rails, feeder cables, lightning protection. In each case reference is made to present British practice, and occasional reference is made throughout the paper to Australian, Brazilian, Indian, Polish, and South African railways, with which both the authors have been intimately connected.