"Calling ON" Signal
• It Simply means "to Call". This is a subsidiary signal.
• This signal is located below the STOP signals of HOME, STARTER or INTERMEDIATE STARTER.
...
more... • This signal is NOT located below the ADVANCED STARTER.
• It is identified by black letter "C" on a white board.
• This is used in case of emergency.
• CALLING ON Signal and Main Signal are never given together.
Main uses ---
• If the HOME or STARTER signal is out of order, then the train cant be moved forward. On seeing the calling on Signal as YELLOW, although the main signal is RED, the loco pilot can move forward the train at very low speed.
• If a train is occupied on platform, the main signal will be red, because of interlocking. If a locomotive has to be connected or a link train has to be connected in the same platform, the CALLING ON signal is given as main signal will not work at that time.
Pics attached for reference .
Source -
click here
