Remote control of electrified railways

A brief outline is given of the evolution of remote control systems utilizing telephone switching equipment to the supervisory control of traction sub-stations, and references are made to early installations in the Paris area. The chief features of the installation (1947) on the Nicircmes-Seacutete section (40 miles, 5 sub-stations) of the French National Rlys are described and the control board (at Nicircmes) is illustrated. A detailed description is given of the recent installation of the synchronous-selection system on the Paris-Dijon-Lyons trunk line, on which 52 substations (equipped with Hg-arc rectifiers) serving 205 route miles are controlled from 3 stations (Paris, Dijon, Lyons). Illustrations show the control rooms at Paris and Lyons, relays and other items of equipment, and the operation of the system is described at length with the aid of block diagrams of supervisory and controlled stations. Mention is made of the reliability of the system and equipment, and possible future developments are discussed.