Metro Rail Continuous Automatic Train Control System
Continuous Automatic Train Control System –(1) The Continuous Automatic Train Control system of working shall be adopted on the Metro Railway for movement of trains between stations and between depot and the main line.
(2) The Continuous Automatic Train Control system works on the principle of target speed and target distance with Cab Signaling by means of continuous transmission between track side and train through suitable approved means, ensuring safe movement of all trains under all operating conditions by continuously generating a safe operating envelope defined by the limit of movement authority and the maximum safe speed.
(3) The limit of movement authority shall be the farthest point to which the train may safely proceed taking into account margins for error in speed and distance measurement, calculating braking distances and the equipment reaction times.
(4) The maximum safe speed shall be maximum speed at which the train is permitted to travel without intervention by the train control and signaling system and it shall be continuously calculated in such a manner that permanent speed restrictions, the speed limits for the type of train and temporary speed restrictions shall not be exceeded and the train shall always stop without passing the limit of movement authority.
(5) The Continuous Automatic Train Control system will provide the following modes of train operation, namely:
(a) Automatic Mode, where provided.
(b) Automatic Reversal Mode (if provided).
(c) Coded Manual Mode
(d) Restricted Manual Mode.
(e) Cut Out Mode. and
(f) Run On Sight Mode, where provided
Automatic Mode –(1) In the Automatic Mode, the train shall operate without intervention by the Train Operator except closing of train doors and starting from a station stop and it shall operate under the supervision and control of Automatic Train Protection functions.
(2) In Automatic Mode, the train control and the signaling system shall–
(a) accelerate and decelerate the train by applying traction power, coasting and applying and releasing brakes.
(b) automatically control speed, acceleration, and stop the train at stations.
(c) provide all indications necessary to operate the train.
(d) determine continuously the maximum safe speed and limit of movement authority.
(e) prevent movement of the train in excess of the maximum safe speed and limit of movement authority
(f) open train doors on the correct side when the train is docked if permitted by the Automatic Train Protection door release and the platform screen doors, where provided, open automatically on the correct side;
(g) prevent the train from starting if train doors, or the platform screen doors where provided, are not detected closed;
(h) train re-starting from a signal stop shall be automatic; and
(i) train starting or re-starting from a station stop shall be initiated by the Train Operator.
Automatic Reversal Mode –(1) This mode, where provided, is used to reverse the running direction of a train automatically in areas of the section specifically defined in the special instructions which are possible only at specified track circuits of a station when train is at standstill.
(2) The transition from Automatic Mode or Coded Manual mode to Automatic Reversal mode is initiated automatically upon receiving the request for reversal operation from Automatic Train Supervision and has to be acknowledged by the Train Operator by pressing the Automatic Reversal button at standstill.
(3) The on-board Automatic Train Protection unit of leading cab activates the unit at trailing end on arrival at a station if a reversal operation is requested by Train Operator.
(4) The train borne Automatic Train Protection unit shall return from Automatic Reversal mode to Coded Manual mode once the reversal operation has been carried out successfully and the Train Operator has unlocked the new leading cab for further running.
Coded Manual Mode – (1) In Coded Manual Mode the train shall be driven by the Train Operator, obeying Cab Signals.
(2) In Coded Manual Mode, the train control and signaling system shall-
(a) provide cab signals and all other indications necessary to operate the train including current speed;
(b) determine continuously the target speed and limit of movement authority;
(c) prevent train operation in excess of the target speed or limit of movement authority;
(d) provide audible and visual warning if the train speed exceeds the target speed or the maximum safe speed;
(e) enable train doors when the train is docked, enabling only the doors on the platform side of the train; and
(f) prevent the train from starting if train doors, or the platform screen doors where provided, are not detected closed.