GK/Rt0044 - Provision & use of facilities

[khalid]

Signaller will give calling on signal route:
a. Main signal is not showing off aspect because of signal in advance is blank.
b. Main signal all off aspect are (Lamp) failure.
c. Main signal route indicator is failure.
d.Overlap point is failure to operate.
e. Signal control track circuit is / are failure.
In this condition signaller will give Calling on Signal route.

Note that in the UK, "calling-on" means different to India.
It is a Position Light aspect which permits a passenger train to enter a section of line KNOWN ALREADY TO BE OCCUPIED by another passenger train. Obviously this is not widely used; we of course generally signal the railway on ABSOLUTE (i.e. only 1 train oper section of line at any one time) rather than PERMISSIVE (more than one train) principles. However in UK it is nothing to do with failures; permissive moves are used when operationally needed in normal circumstances.

I think Mr.NJK has incompletely presented the case for the calling-on signal on the Indian Railways.While it is true that it can be used under conditions of failure outlined by him,its major purpose is also to permit the reception of a train into an occupied line such as while attaching an engine to a train already standing in the platform.Another important purpose is to enable the clearance of the calling-on when sufficient overlap is not available due to a conflicting movement(rather than a points failure)in the overlap portion.
It should also be noted that routinely,reception of a train into an occupied line is actively discouraged unless it is an emergency.
Drivers are instructed to ensure that when they get the calling-on they must not exceed a speed of 15 KMPH and may proceed even more slowly if visibility is poor or while negotiating curved tracks.

Khalid.