Staff System

(electric staff system), a method of communications between neighboring stations on single-track railroad sectors. Authorization to occupy the run is represented by a metal staff which the locomotive engineer receives from the duty man at the dispatching station and returns to the duty man at the destination station. Electrically interconnected staff devices are installed at each of the stations which limit the run. The total number of staffs in the two devices relating to a particular run is an even number, usually between 20 and 30 (the staff can be taken out of the device only if the two devices have an even number of staffs). When he receives the staff, the duty man at the destination station turns the handle of the inductor, which sends an electric current to the device at the dispatching station and authorizes the train to use the run. The staff system ensures traffic safety because it makes it impossible to send two trains into the same run simultaneously. Lines with intensive traffic use an automatic block system.