Systems of Working
Systems of Working: GR 7.01
(1) All trains working between stations shall be worked on one of the following systems, namely –
(a) The Absolute Block System,
(b) The Automatic Block System,
(c) The Following Trains System,
(d) The Pilot Guard System,
(e) The Train Staff and Ticket System, or
(f) The One Train Only System.
(a) The absolute block system,
(b) The automatic block system, or
(c) The one train only system.
Essentials of the Absolute Block System: GR 8.01
Where trains are worked on the Absolute Block System
(a) no train shall be allowed to leave a block station unless Line Clear has been received from the block station in advance, and
(b) on double lines such Line Clear shall not be given unless the line is clear, not only up to the first stop signal at the block station at which such Line Clear is given, but also for an adequate distance beyond it;
(c) on single lines such Line Clear shall not be given unless the line is clear of trains running in the same direction, not only up to the first stop signal at the block station at which such Line Clear is given, but also for an adequate distance beyond it, and is clear of trains running in the direction towards the block station to which such Line Clear is given.
(d) Unless otherwise directed by approved special instructions, the adequate distance referred to in clauses (b) & (c) of sub-rule (1) shall not be less than –
(a) 400 meters in case of two-aspect lower quadrant signaling or two-aspect colour light signaling, and
(b) 180 meters in case of multiple-aspect or modified lower quadrant signaling.
Essentials of the Lock and Block System: SR 8.01 – 1
(a) It shall not be possible to take ‘‘Off’’ last stop signal to permit a train to leave a block station until ‘Line Clear’ has been received from the block station in advance.
(b) The entry of a train into the block section shall cause the last stop signal to be automatically replaced at ‘On’.
(c) Line Clear shall not be given by the block station in advance until the preceding train has passed over the section clearing track circuit or it’s equivalent and until stop signal / signals in rear of the train has / have been replaced to ‘On’ position.
Essentials of the Automatic Block System on double line: GR 9.01
(1) Where trains on a double line are worked on the Automatic Block System –
(a) the line shall be provided with continuous track circuiting or axle counters,
(b) the line between two adjacent block stations may, when required, be divided into a series of automatic block signalling sections each of which is the portion of the running line between two consecutive stop signals, and the entry into each of which is governed by a stop signal, and
(c) the track circuits or axle counters shall so control the stop signal governing the entry into an automatic block signalling section that –
(i) the signal shall not assume an ‘‘Off’’ aspect unless the line is clear not only up to the next stop signal in advance but also for an adequate distance beyond it, and
(ii) the signal is automatically placed to ‘On’ as soon as it is passed by the train.
(2) Unless otherwise directed by approved special instructions, the adequate distance referred to in sub-clause (i) of clause I of sub-rule (1) shall not be less than 120 meters.
Essentials of the One Train Only System: GR 13.02
Where trains are worked on the one train only system, only one train shall be on the section on which this system is in force, at one and the same time.
Procedure in case of accident or disablement on the one train only system: GR 13.04
(1) (a) If the train becomes disabled and requires assistance or if an accident occurs which renders it impossible for the train to proceed, the train shall be protected in accordance with the provisions of Rule 6.03 in the direction from which assistance, if necessary, is being obtained.
(b) The Guard of the train shall convey advice of the circumstances under which the train has become disabled and is not able to proceed, to the SM of the station from which assistance can best be obtained, and if it is necessary for such Guard to proceed to such station, shall instruct the Loco Pilot in writing to keep the train stationary until his return, and obtain his written acknowledgement.
(2) (a) Such SM, if he is not the SM of the base station, shall communicate this information to the SM of the base station. On receipt of such information, the SM of the base station may allow another engine to enter the line.
(b)The engine so sent shall either be accompanied by the Guard of the disabled train, who shall explain to the Loco Pilot where and under what circumstances he disabled train is situated, or the Loco Pilot of the engine so sent shall be given a written authority, containing such instructions as to where and under what circumstances the disabled train is situated and such other particulars as may be necessary to enter the line unaccompanied by the Guard of the disabled train.
(3) The Guard of the disabled train shall be responsible for the safe and proper working of the line until the disabled train has been moved and any other engine sent to the assistance of the disabled train has been returned to the base station.
(4) If there is no Guard of a disabled train, the Assistant Loco Pilot or Loco Pilot shall perform the duties imposed by this rule on the Guard, provided that the engine is not left unmanned in terms of Rule 4.20.
SR 13.04 – 1 If it is necessary for the Guard to remain with his train, he will send the advice to the nearest station through the Assistant Loco Pilot stating the nature and cause of the breakdown and at once protect the train in accordance with GR 6.03 in the direction from which relief is expected. If assistance has been asked for, he shall not allow the engine or any portion of his train to be moved until such time assistance arrives.