Page 170 - IRSEM_Main Book

7.1.18 Subsidiary Signals - Calling-on Signal

(a) Function: A Calling-on signal when taken 'OFF' calls on the Loco Pilot of
a train to draw ahead with caution, after the train has been brought to a
stop even though the Stop Signal above it is at 'ON’. Such 'OFF' position
indicates to the Loco-pilot that he should be prepared to stop short of any
obstruction.

(b) Aspects: A Colour Light Calling-on signal has no independent aspect in
the ‘ON’ position and shall display no light in the ‘ON’ position and a
miniature yellow light in the 'OFF' position.

(c) The colour light Calling-on signal shall be provided with a marker
consisting of a white enamelled disc with letter 'C' in black.

(d) Placement of Calling-on Signal: Calling-on signal shall be placed below
a Stop Signal governing the approach of a train. Under approved special
instructions, a Calling-on Signal may be provided below any other Stop
Signal except the last Stop Signal.

(e) Working of Calling-on Signal

(i) Calling-on Signal shall neither be capable of being worked at the same
time as the Stop signal above nor shunt signal below it (if any).

(ii) Calling-on signal shall lock and detect all the points in the route
including isolation points (if any), which the Main signal above it detects
excluding those in overlap.

(iii) Calling-on signal requires all the level crossing gates in the route to be
closed and locked against road traffic.

(iv) At stations where Station Master controls the reception and dispatch of
trains, such control shall be extended to Calling-on Signals also.

(v) It is required to provide track circuits at a *suitable distance and a time
delay circuit to ensure that the Calling-on Signal is taken 'OFF' only
after the train has been brought to a stop.

*Note:
(i) For reception signals, 5 rail length (65 meters) Calling-on track circuit and 60
seconds time delay shall be provided.
(ii) For dispatch signals, no time delay is required for taking off Calling-on Signal.
However provision for ensuring that the train has stopped shall be covered in
Station Working Rules (SWR) and to be ensured by operating staff.

(vi) Provision for manual replacement of Calling-on Signal shall be included
in concerned Station working Rules(SWR).

Chapter 7: Essentials of Signalling Page 139 of 535