Patent GB-582980-A (GB)
Title: Improvements relating to railway traffic controlling apparatus
IPC: B61L23/22
Filed: 1942-11-27
Abstract: 582,980. Railway signalling systems. TOMLINSON, A. V. (Union Switch & Signal Co.). Nov. 27, 1942, No. 16872. [Class 105] The selection of traffic direction along a single-line stretch between passing sidings is effected by means of traffic direction control relays at the ends of the stretch, of which the traffic direction control relay at the exit end is energized through a centralized traffic control system by the central office, and the arrangement is such that on the office sending a further transmission for the eventual clearance of a signal at the entrance end this effects the de-energization of a control relay at the entrance end whereby the steady track-circuit current existingly applied at the entrance end for an established traffic direction is changed to a coded track circuit current applied at the exit end. Level crossing signals and electric points-locking are properly controlled. In the figures the letters W and L denote West or Left-bound and E and R East or Right-bound. Fig. 1a shows the control and indication arrangements at the central office and Figs. 1b, 1d in line a stretch of single line between two passing sidings. The last traffic direction set up was West-bound so that lever 8, Fig. 1a is in the L (left) position, West-bound traffic direction relay 8WFSR is energized, and East-bound traffic direction relay 8EFSR de-energized. Accordingly steady rail current is supplied at the West-bound entrance end G from a source IS over front contacts 29, 30 of a relay 10L.TCTM which is energized from a source B over back contacts 23 of a relay 7R.WSR (for points-lock control), 24 of a signal control relay 10L.HSR, 25 of opposing traffic-direction relay 8EFSR, 26 of a signal stick relay 10L.SR, and front contacts 27 of a repeater relay 9TM for short entrance-section track relay 9TR, 28 of a relay 10L.KM (signal at stop). This steady current is relayed Westward through the stretch and at exit end D energizes track relay 6R.TR. A front contact 32 of this relay energizes repeater relay 6R.TM and this in turn energizes relay 6R.TFSA. It will be noted that relay 6R.TCTM is not energized since back contacts 36 of relay 8W.FSR and 34 of relay 6R.TFSA are open. To clear the entrance signal for a Westbound move an office code is transmitted to pick up relay 10L.HSR. This opens its back contact 24 so that relay 10L.TCTM drops so removing the steady current from the rails at G whereby the track relay 6R.TR at D drops to cause the dropping of relays 6R.TM, 6R.TFSA so that a back contact 34 of the latter now causes a code-current of 75 interruptions per minute to be applied to the rails at the West-bound exit end D by the energization of relay 6R.TCTM with 75 interruption current over back contacts 35, 34 of relays 6L.AHR, 6R.TFSA, front contact 36 of West-bound traffic direction relay 8W.FSR, back contact 37 of relay 6R.SR, and front contact 38 of repeater relay 5TM for shortsection track relay 5TR. This coded rail current operates track relay 10L.TR at Westbound entrance end and its repeater relay 10L.TM whereby relays 10L.TFSA, 10L.TBSA are energized to operate the de-coding relay 10L.CDR whereby the entrance signal 10LA (or 10LB) is cleared in known manner. When the train enters the short entrance section the track relay 9TR drops to pick up signal stick relay 10L.SR over back contact 48 and front contact 49 of signal relay 10L.AHR and when the train enters the single-line stretch track relay 10L.TR remains down to de-energize the decoding relay 10L.CDR so that the signal stick relay 10L.SR continues energized by its stick circuit from source B over back contacts 50 of decoding relay 10L.CDR, 51 of a relay 10L.CHAR, 49 of signal relay 10L.AHR and stick contact 52. When the West-bound train has passed the exit end D and vacated the short section of track relay 5TR 75-code current will be applied to relay 6R.TCTM and consequently also to the rails at location D whereby track relay 10L.TR at location G will be code-operated to energize decoding relay 10L.CDR which will open its back contact 50 to de-energize signal stick relay 10L.SR so that relay 10L.TCTM becomes energized from source B over a circuit as traced above and places steady current on the rails at location G. This steady current during the first 11 off " period of the 75 code which is being applied at location D energizes track relay 6R.TR and in turn relays 6R.TM and 6R.TFSA, the latter opening its back contact 34 to open the circuit to relay 6R.TCTM which thereupon ceases to apply code to the rails. An office indication that the stretch is set for West-bound traffic is effected by track indication relay 8WTK which is energized by a message code sent from the field station 234 at location D by the presence of energy on terminal 90 over back contacts 76, 77 of relays 6R.DR and 6R.CDR (decoding relays for track current) and front. contacts 78, 79 of relays 6R.TFSA (steady rail current detector) and 8W.FSR (West-bound traffic direction relay). An indication lamp 8WFKE is lit over contact 120 of stick relay 8 WFK picked up over a front contact 182 of the relay 8W.TK and normal contact of a polar stick relay 8L.PR set by a traffic direction lever at the office. This lamp denotes West-bound traffic direction set up. To set up for East-bound traffic the office lever 8 is moved to the R position (dotted) whereby a polar stick relay 8L.PR is energized over front contact 108 of West-bound track indication relay 8W.TK (West-bound still set up) and "Start" relays 234ST, 236ST are energized to transmit code from the office ; the code transmitted by 236ST in conjunction with energy applied to terminal 104 over reverse contact 110 of polar relay 8L.PR and front contact 186 of a relay 236S causes the Eastbound traffic direction relay 8EFSR to be energized while in a similar manner the removal of energy from terminal 102 by the open normal contact 110 of polar relay 8LPR causes traffic direction relay 8WFSR to be deenergized. With East-bound traffic direction relay 8EFSR energized 75 interruption code current is for the moment applied to relay 10L.TCTM whereby this current is applied to the rails at the new exit end G but as soon as the opposing traffic direction relay 8WFSR drops steady current is applied at the new entrance end D so that on the first off " period at G the track relay 10LTR is energized which in turn energizes relays 10LTM and 10LTFSA the latter then opening its back contact 56 to cut off the 75 code supply to relay 10LTCTM. It should be noted that reversal to East-bound can only be effected if front contact 108 of indication relay 8WTK is closed ; this requires the decoding relays 6RCDR, 6RDR to be de-energized closing their back contacts 76, 77 and the rail current in West-bound exit section 6RT to be steady to cause relay 6RTFSA to close its front contact 78 so that energy is applied to terminal 90 to cause the operation of relay 8WTK. The arrangement where an intermediate signal is provided at location E is shown in Fig. 1c and this figure should be regarded as inserted between Figs. 1b and 1d. Assuming that West-bound traffic is set up the steady rail current applied to track section 10LT at entrance end G is relayed at location F by a front contact 58 of track relay 7AETR energizing a relay 7AWCTM to apply steady current to track section 7RT. This in turn is relayed at the intermediate signal location E by track relay 7ETR and relay 7ETFSA a front contact 60 of the latter energizing a relay 7WCTM over back contacts 61, 62, 63 of a directional stick relay 7ES, of a decoding relay 7HR, and of a directional stick relay 7WS. If now to clear the West-bound signal 10LA an office code is transmitted to energize the relay 10LHSR steady current will be removed from the rails causing 75-code rail current to be applied at West-bound exit end D. This 75-code operates track relay 7WTR and relays 7WTFSA, 7TM 7BSA, at the intermediate signal location E. This results in the energization of decoding relay 7HR whereby a West-bound directional stick relay 7WS is picked up over front contact 70 of relay 7HR, back contact 71 of relay 7ETFSA and front contact 72 of relay 7WTFSA. Also relay 7ECTM is energized over back contact 60 of relay 7ETFSA, 180 interruption contact 67, front contact 68 of decoding relay 7HR, and back contact 69 of Eastbound directional stick relay 7ES to apply 180 code current to section 7RT. This is relayed as before to section 10LT to operate decoding relay 10LCDR whereby the signal 10LA will be cleared. After the train has entered the stretch and passed the intermediate signal 7W the Westbound directional stick relay is maintained by its stick circuit over back contact 73 of relay 7WTFSA (now dropped) and in this condition of affairs the relay 7ECTM is energized with 75-code current over back contact 60 of relay 7ETFSA, 75-code contact 75, front contact 76 of directional stick relay 7WS, back contact 68 of decoding relay 7HR, and back contact 69 of directional stick relay 7ES. Thus 75 code current is applied to section 7RT and relayed to section 10LT where it causes the energization of de-coding relay 10LCDR which opens its back contact 50 in the stick circuit of the signal stick relay 10LSR whereby steady current is again applied to the rails at the location G. At the intermediate signal location E this steady current energizes relays 7ETR, 7ETFSA during an " off " period of the coded rail current in section 6RT whereby relay 7WCTM is energized to apply steady current to section 6RT it being noted that Westbound directional stick relay 7WS was dropped by the opening of back contact 73 of relay 7WTFSA as soon as coded rail current was applied to exit end of section 6RT on departure of the train. For the unlocking of points at an intermediate signal location the arrangement shown in Figs. 3a and 3a (continued) is employed and this should be regarded as inserted between Figs. 1b and 1d. With a train on the ma