GB698816A - Improvements in and relating to remote control and/or indication systems - Google Patents

Abstract

698,816. Electric selective signalling systems. SIEMENS & GENERAL ELECTRIC RAILWAY SIGNAL CO., Ltd., FIELD, R. W. G., and MOTT, J. E. Jan. 24, 1952 [Jan. 24, 1951], No. 1851/51. Class 40 (i). [Also in Group XXXVII] In a system of the kind described in Specification 691,032 for the centralized selective remote control of railway traffic equipment at plural outstations having series connected line relays responsive to coded impulse trains from the control station, wherein the operation of the remote equipment is monitored by the repetition back of coded impulse trains from the appropriate outstation to the control station, an interruption of the series line circuit for a time in excess of any interruption normal in the code transmission operates relay means to short circuit the line at each outstation in turn until either a closed line circuit is established between one or more outstations and the control station, or until shortcircuits have been established at all outstations. Fig. 2 shows a traffic control system for a section of single track railway comprising a control station and outstations A to E each controlling the local traffic and signal equipment through series line relays LA, LB responsive to coded impuise signals peculiar to each station, and returning coded signals to the control station for each operation, as described in Specification 691,032. Normally when no signals are passing the looped line wires 1, 2 carry a steady central battery current to hold relays LA, LB operated, which in turn operate slow-release relays SR at e.g. station A, C and E having release times of e.g. 60, 40, 30 seconds. Interruption of the line loop e.g. between stations C and E releases relay SR in E after 30 seconds and operates a stick relay to shortcircuit the lines after station E through resistance R3 whose value is equal to that of the remaining line circuit, and transmits a characteristic code indicating operation back to the control station. Since the line is still interrupted relay LA of C is inoperative, and after 10 seconds the associated slow-acting relay and stick relay operate to shortcircuit the line between C and D through R2 and transmit a coded indication signal to the control station. The line is now looped and normal operation takes place up to station C. The control station may now, by transmitting a characteristic control code for each stick relay, release each energized stick relay in turn, to test for fault clearance. Persistence of the fault re-operates the slow-release relay of the relevant outstation, which indicates at the control station as before. The fault sectionalizing equipment may be provided at each and every outstation and the slow release relays may be of the kind described in Specification 621,636, [Group XL(c)]. Each outstation has a manual sectionalizing switch MS.