Remote signaling and control of electric railway power networks

After a brief outline of the principles of a supervisory control system for substations and the problems involved, a detailed description is given of the control system installed on the Netherlands Railways, which on completion will control 65 substations and track sectioning switches from a central control room at Zwolle (N. Holland), involving the remote control of 700 items of apparatus together with 650 remote indications. Diagrams show the general layout of the 9-channel network and the scheme of operation for signalling and remote indication. Illustrations show the control desks at Zwolle and the equipment at the transmitting station and substations.