Patent GB-803114-A (GB)
Title: Improvements in or relating to centralised control systems for railways
IPC: B61L19/14
Filed: 1956-09-24
Abstract: 803,114. Railway centralized control systems. GENERAL RAILWAY SIGNAL CO. Sept. 24, 1956 [Sept. 26, 1955], No. 29119/56. Class 105. In a centralized control system a railway track layout is divided into separate control areas and a plurality of master control devices, sufficient to take care of all the track points and signals in any one of such control areas at a given time, are mounted on a master panel within convenient reach of the operator; and the appropriate master control devices are rendered effective to govern the interlocked group of points and signals of any one control area which the operator may select by the operation of selecting means, which operation causes a visual display both on the master panel and on the track diagram for identifying the interlocked group then under control of the master panel and the relationship, by physical arrangement or visual correlation of like symbols, between the usable master control devices and corresponding signalling functions at the particular field location. The operator selectively governs control areas in accordance with indications of train presence shown on the track diagram. The invention is described as applied to a route-control system of the N-X (entrance-exit) type and to a system using individual points and signal levers, utilizing in both cases a suitable form of code communication system for transmitting over line wires the necessary controls for points and signal operation and the appropriate indications of points positions, signal indications, track section occupancy and the like, from the field to the control office. There may be a plurality of master panels at a control office to be used by the same or different operators, the panels having their associated code setting and change relays interconnected in a chain circuit so that station codes and control codes from the respective master panels may be distributed to the various field stations one at a time. The panels are interlocked to avoid two panels being allocated to the same control area, since conflicting controls from the two different panels might result. In the system using individual points- and signal-levers applied to a single line for traffic in both directions and with passing sidings, the operator at the control office is able to allocate his master panel to a given siding, position master points- and signal-levers for the train movement desired, and actuate the start button for either or both ends of each siding, as occasion may require, whereupon new control codes are transmitted to the field station or stations at the end or ends of the siding one at a time utilizing, for example, a code communication system of the station selecting time-code type. The siding selector is locked as by an electromagnetic lock, if and so long as the master panel is being used for the controlling functions and a " free " indicator directly on the master panel clearly shows when it is in use. The master panel should have points- and signal-levers sufficient to take care of the points and signals at any one of the siding ends or control areas subject to master panel control. Should the operator wish to operate a points alone without clearing a signal, e.g. to test the operation of a switch machine, or free a points of snow or ice, viewing key-switches are provided on the master panel for siding ends to permit the operator to obtain indications of points position when such a viewing switch is operated alone. When the master panel is used to transmit controls to the field station at a given siding end a visual record of such action is displayed at the corresponding location on the track diagram in the form of a distinctive flashing illumination in one of the points-position indicators. The points and signals respond in due time to the control codes and indications of a completed operation are received to change the flashing indication to a steady lighting and to provide a signal clear green light in the signal symbol on the track diagram. As shown in the track diagram, Fig. 1, for an N-X system in which traffic can move thereover in both directions, a suitable group identifying symbol I, II lights up when that group with which the symbol is associated is subject to control by the master panel and the different control areas or interlocked groups have their boundaries distinctively identified by colour, boundary lines, &c. The master control panel, Fig. 2, carries a plurality of entrance and exit buttons disposed in pairs 1-NB-L-1-XB-L, &c., the number of pairs chosen being to afford entrance and exit control for the largest number of signal locations in any one of the interlocked groups. Each entrance button such as 1-NB-L is of the self-restoring type so as to close one set of contacts 12, Fig. 5, when turned in the direction of the arrow associated therewith on the panel, for entrance designation, and another set of contacts 13, Fig. 5, when pulled out for restoration purposes. Each exit button such as 1-XB-L is a spring return push-button operating a single contact 14, Fig. 5, and is preferably provided with an arrow to indicate the direction of traffic that can be established by its actuation. Display openings 15 adjacent each pair of buttons for a changeable illuminated letter A &c. or other symbol carried on belts suitably driven together from a groupselecting means, correlates that pair of buttons with the particular signal location A &c. on the track diagram of the interlocked group then under the control of the master panel. The buttons on the master panel occupy preferably the same geographical relationships as the signal locations on the track diagram. Each interlocked group or control area is selected as required by a rotatable knob 17 on the master panel, with an indexing mark to co-operate with symbols such as the numerals I, II pertaining to the respective interlocked groups, and operates the shaft of a rotary selector switch SS, Fig. 5, and the group identifying indicator 16 on the track diagram. The switch SS controls the energization of group selector relays GS relating to the respective interlocked groups. Two relays I-GS-1 and I-GS-2 operated in multiple for each interlocked group, on account of the number of controlling contacts required, are shown in Fig. 5. The invention is described as applied to an N-X system which provides sectional rear release route locking in connection with time-release approach or stick locking and track-detector locking, one or more of the interlocked groups being controlled from and supervised by the central office by the synchrostep code communication system in which the necessary controls for switch and signal operation and the appropriate indications of switch positions, signal indications, track section occupancy and the like from the field to the control office, are transmitted over a limited number of line wires as disclosed in the Specifications 767,604 and 717,142 and in particular there is described the manner in which the terminals of the transmitters and receivers for such message circuits at the different locations are connected to controlling contacts or code responsive relays so as to bring about the transmission and reception of the desired controls or indications. For a train movement over route A to D in the interlocked Group I designated Smithville, the presence of the train is indicated by lighting of the approach indicator 38, Fig. 1, and the selector knob 17, Fig. 2, is set in position I to tie-up the master control panel with the Smithville control area. Contacts 19 of switch SS, Fig. 5, energize in multiple the group selector relays I-GS-1+2. At f.c. 39 I-GS-1 (front contact 39 of relay I-GS-1) the group indicator I on the track diagram is lighted to indicate that the selector knob has been operated to or is in the proper position required. Energization of the group selector relays closes at contacts such as 41, 43 connections to buses such as 40, 42 connected with the contacts 12, 13, of the pairs of N-X buttons such as 1-NB-L and 1-XB-L to the appropriate corresponding entrance and exit relays such as A-NR, A-XR, for the respective signal locations. Similarly the bus 45 for the contact of exit button 2-XB-R now designated as relating to signal location D, is connected through f.c. 46 I-GS-2 and b.c. 47 D-NR (back contact 47 of relay D-NR) to the exit relay D-XR. Thus the particular entrance and exit relays A-NR and D-XR belonging to the initiation and completion circuit network of that particular interlocked Group I are operatively connected to the appropriate pairs of master control buttons then usuable for route control of this interlocked group. The entrance button 1-NB-L is identified by the letter A opposite to it and by its position. The relay A-NR is held operated over its front contact 48 and contact 49 of a magnetic-stick occupancy indication relay 2-TK of the track section and at f.c. 50 A-NR, Fig. 6, a red lamp R is illuminated on the track diagram over contact 51 of the magstick indication relay A-GK for the signal A verifying that the correct master button has been operated. At f.c. 34 A-NR the code instruction circuit is energized to light up indicators such as 52 at the ends of available routes originating at signal A, i.e. in the present case at signal D. The red light at symbol A and the light 52 on the track diagram indicate the route to be taken. If the entrance relay A-NR is unwanted, as when the points are to be tested or operated to clear them of snow, the button 1-NBL is pulled to close the pull-out contact 13 and close over contacts 43, 44 a circuit through the lower knock-down winding of relay A-NR which opposes the energized upper winding and releases this relay. The master-exit button 2-XB-R identified by the letter D alongside is pressed to establish the route A-D and energizes over b.c. 55 2-XB-R, wire 45, f.c. 46 I-GS-2, the exit relay