Patent GB-795201-A (GB)
Title: Improvements in or relating to centralized railway traffic control systems
IPC: B61L27/02
Filed: 1955-07-04
Abstract: 795,201. Centralized railway traffic control systems. SIEMENS & HALSKE AKT.-GES. July 4, 1955 [July 2, 1954], No. 19333/55. Class 105. In a centralized railway traffic control system orders are transmitted from the central office to the trains by radio and train position indications initiated by any train through control means automatically such as magnetic, inductive, optical or electronic or by the train crew at certain positions in the section are transmitted by radio to the central office and are applied at the central office to control or prepare circuits necessary for producing block section interlockings between section control equipment locations such as block signal cabins, halts and stations. Block interlocking apparatus and signal cabin interlocking apparatus are located at the central office instead of at individual cabins and switching stations and installations such as track circuits and axle counters are dispensed with. Remote control over land lines is only used to cancel the central office blockings produced by radio transmitted indications when the local operating staff of the stations co-operate in train-end indication following upon clearance of a block section or station track section or when reliable clearance indications of such sections can be produced locally by automatic insulated track installations or automatic block installations. The indications transmitted by radio or land line are stored in central office latch relays which provide the preconditions for transmitting or blocking movement orders to the train and preclude conflicting movements of trains electrically upon a movement order is passed to a train. Release of the " occupancy " relays, which are picked up by the train position indications, route setting relays and route locking relays, from a picked-up condition into the unoperated condition is effected under the control of train-end indications transmitted by radio or land-line after the train has completely passed through the previously occupied section. Assume a route is set for a train to leave the station section H3, Fig. 1, to travel to the station section W2, the route being R17.3 block 17/20 and R19.2. The route is set by entrance-exit keys to close contacts K17.3 and K19, Fig. 2a, which shows the interlocking circuitry between route setting latch relays S, the circuit under consideration being for the pick-up winding a of route-setting relay S17.3 which sets the points suitably for a train to travel from the station road R17.3 into the block section 17/20. The circuit of this relay includes back contacts of other route-setting relays. S15.3.1, S18.2.1, S18.3.1, &c., of conflicting routes, of the direction determining relay D20.1 which operates when the train travel is in the direction from station W to station H, and of the train occupancy relay 017/20.1 to ensure that the block section 17/20 is clear, and of the route locking relay L17/18 for the station arrival roads R18.2, R18.3, and departure roads R17.1 of station H. This relay contact L17/18.1 prevents operation of all other route-setting circuits for the rightend of station H once the set route has been locked. This route-locking latch relay L17/18, Fig. 2a, is picked up over its winding a when the route-locking indication relay MF (not shown) is picked up to close its front contact MF17/18 by the train-accepting local signal cabin at station W. The direction determining latch relay D17 for the train movement from station H to station W is picked up over front contact S17.3.3 of route relay S17.3 and front contact L17/18.2 of the route locking relay L17/18. At back contact D17.1 the circuits of route-setting relays S18.2, S18.3 for arrival routes 18.2 and 18.3 at station H are opened. At front contact L17/18.3, Fig. 4, storage of the movement orders for transmission to the train by radio from the control office is effected, but before this occurs proving is carried out to ensure that the occupancy relay of the advance section, viz. 017/20, Fig. 3, is in the released condition. If conditions are correct, the order setting relay C17/18.3, Fig. 4, is picked up over front contacts S17.3.5, O17/20.5, back contacts T17/18.2.1 and Q2 and prepares at front contact C17/18.2.2 the circuit for the pick-up winding a of the order transmitter latch relay T17/18.2 until the occupancy relay OH3 of the station road H3 in the rear has been picked up by the train position indicator relay front contact MP15, Fig. 3, prior to entering the road H3, over a front contact S15.3.3 of the route setting relay S15.3 (not shown), for route R15.3. At front contact OH3.5, Fig. 4, the latch relay T17/18.2 is picked up over front contacts L17/18.3 and S17.3.6 and the movement order is transmitted by radio to the train. At back contact T17/18.2.1 the pick-up circuit of the order-setting relay C17/18.2 is interrupted but a hold circuit is provided at front contact T17/18.2.2 until an acknowledgement signal of the movement order is received as a radio signal at the central office to operate an acknowledgement relay Q (not shown) which at its back contact Q2 interrupts the pick-up and holding circuits of the order setting relay C17/18.2 and on dropping away this relay, at back contacts C17/18.2.3 prepares the circuit of release winding b of relay T17/18.2 and in this state, the transmitter relay cannot repeat an identical order transmission and it is only after the occupancy relay 017/20 of the subsequent track section 17/20 to which the movement order applied has been actuated as the train proceeds and passes the device P17, Fig. 1, for initiating train position signals for transmission by radio to the central office and on receipt of the signals at the central office to operate a train position indication relay front contact MP 17 to pick up relay 017/20 to signify that the block section 17/20 is occupied, that the circuit of the release winding b of relay T17/18.2 is completed at front contact 017/20.6. At back contact 017/20.6 a second point in the order setting relay pick-up circuit is opened. When the block section 17/20. has been indicated " clear " by the operation of a train end indication relay MZ19/20 (not shown), of which a contact MZ19/20.2, Fig. 3, releases the occupancy relay 017/20, another order can be transmitted. At front contact MZ19/20.1, Fig. 2b, the release winding of relay D17 is energized. As the train completely leaves the station H a train-end indication relay MZ17/18 (not shown) is energized and at its front contact MZ17/18.2, Fig. 3, energizes the release winding of occupancy relay OH3 and at front contact MZ17/18.1, Fig. 2b, energizes the release winding b of the route-setting relay S17.3. The ordersetting relay C17/18.2 and its associated transmitter relay T17/18.2 are used for the departure routes R17.3 and R17.1, Fig. 1, and for the arrival routes R 18.3 for a speed-restricted movement while the other order setting relay C18.1 and transmitter relay T18.1 are used for the arrival route R18.2 only, for full speed ahead.