Patent GB-821044-A (GB)
Title: Improvements relating to railway section block signalling systems
IPC: B61L13/00
Filed: 1955-09-05
Abstract: 821,044. Railway section block signalling systems. SOC. TECHNIQUE POUR L'INDUSTRIE NOUVELLE S.A., STIN. Sept. 5, 1955 [Sept. 3, 1954], No. 25374/55. Class 105. In a train-operated signalling system for a both-way traffic single-track railway divided into block sections 0-1, 1-2, &c., Fig. 2; each of which has transmitting and receiving block apparatus EB0-RB1, EB1-EB2, &c. at the ends and includes a passing siding 1, 2, &c., in order to give priority to certain classes of trains such as espress trains, in the automatic signalling equipment so that only trains without priority have to stop at a siding and wait for a train with priority to pass, which can proceed non-stop through the stations 1, 2 by the through route, block signalling apparatus is provided in each block section for automatically demanding the direction of the train through the section and automatically clearing the section when the train has passed out of the section and a transmitting device T1 is provided in each block section for transmitting a train priority signal distinct from the normal block signal, from the entrance section end to be received at the other or exit section end by a receiver R2, and the transmitting and receiving devices are so connected with the block signalling apparatus that the received priority signal demands the direction of the train in the succeeding block section and, if the block conditions of that section are fulfilled, causes that succeeding section to be reserved for the train, the transmitting device T1 of each section after the first section 0-1 being automatically operated as by track circuit apparatus on the entry of the train into the section, the transmitting device T0 of the first section being under the control of a switch P whereby on operation, manually or otherwise, the train priority signal is passed along the track via the receiving and transmitting devices R1, T1 ahead of the train so that the train has reserved for it automatically the section at least one in advance of the section it occupies, whereas a train of no-priority for which the switch P is not operated has only the section which it occupies reserved by the normal block signalling apparatus. The priority signal may be transmitted along the same leads L01, L12, &c. of the block signalling apparatus, the priority signal then differing in some characteristic way, e.g. A.C. or D.C. impulses when the normal block signal is D.C. and may be transmitted between two block control signals or with the block control signals by varying the repetition frequency of these latter. The priority signal transmitting and receiving devices may be at least, in part, formed by components of the 'block signalling apparatus and the receiving device, e.g. R1 of one section, e.g. 0-1, may be at least partially combined with the transmitting device T1 of the succeeding section, e.g. 1-2. These devices may each comprise at least one relay which in its normal at rest condition or in its operative condition may be energized or released and may consist of a mechanical or magnetic interlocking relay.