Whistle or horn codes consists of long and short blasts on the engine whistle. Here is a list of whistle codes. Notation: We use the following symbols to denote different kinds of whistles. Note that many of these are now no longer in use. The long whistle to indicate a train about to leave a station, and the short whistles to indicate light loco movements are the most common ones still in general use.
'o' : denotes a short blast on the horn.
'--' : denotes a comparatively long blast on the horn....
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'-----' : denotes a longer blast on the horn.
'----------' : denotes a very long blast on the horn
Code [ o ] - Before Starting:
Indication to driver of the assisting engine that driver of leading engine is ready to start.
Acknowledgement by the driver of the assisting engine.
Engine ready to leave yard
Engine ready to go to loco yard
Light loco or shunter about to move
Code [ o ] - On the run:
Assistance of other engine not required
Acknowledgement by driver of the assisting engine
Code [ -- ]
Normal departure from station on receipt of clear signal. This is usually followed by another long blast about 10-20 seconds after the first one, after the guard's all-right signal is received.
Beginning of shunting operation (if shunted rake has passengers in it)
Code [ o o ]
Call for guard's signal
Signals not exchanged by guard
Signals not exchanged by station staff
Code [ -- o ]
Guard to release brakes
Before starting engine from a mid section/station
Main Line clear
Code [ o o o ]
Guard to apply brakes
Train out of control, guard to assist
Code [ o o -- ]
Sudden loss of brake pressure or vacuum (perhaps by alarm chain being pulled)
Code [ o o o o ]
Train cannot proceed on account of accident, failure or other cause
Protect train in rear
Code [ -- -- o o ]
Call for guard to come to engine
Code [ o -- o ]
Token not received
Token missed
With wrong au thority to proceed
Passing stop signal at 'on' on proper authority
Code [ ----- ] - Before Starting
Vacuum recreated on ghat section, remove sprags
Passing automatic 'stop' signal at 'On'
Code [ ----- ] - On the run
Acknowledgement of guards signal
Code [ ---------- ]
Approaching level crossing or tunnel area
Recall staff protecting train in rear
Material train ready to leave
Running through a station
Approaching a stop signal at 'on'
Detained at stop signal
Crossing stop signal at 'on' after waiting the stipulated time.
Code [ -- o -- o ]
Alarm chain pulled
Insufficient vacuum in engine
Guard applies vacuum brakes.
Code [ -- -- ]
Raise Pantograph (electric loco only)
Code [ -- o -- ]
Lower Pantograph (electric loco only)
Code [ o o o o o o o o o ] (Frequently)
Apprehension of danger
Danger signal to driver of an approaching train whose path is obstructed
Moving in wrong direction on a double line.
Also used by EMU motormen to warn passengers on a crowded platform of the approach of a fast train which will not stop at that station
by__IRFCA