"Paul Weaver" wrote in message
oups.com...
Steve Dulieu wrote:
It also opens a radio PA channel allowing the Line Controller to speak
over the trains PA

Can the line controller stop the train too?


OK, how it works on the Picc (I'm not familiar with other stock, but I
imagine it's the same) is like this;
T/Op keels over and drops the CTBC.[1]
Train comes to a grinding halt due to the emergency brake application that's
just been made.
Train sits there for 60 seconds.
If the T/Op doesn't depress the CTBC within that 60 seconds, a REALLY loud
alarm sounds in the cab for a further 30 seconds.
If the CTBC has not been depressed within that 30 seconds the train sends a
CTBC alarm via the train radio to the Line Controller at Earls Court, this
causes a dedicated display on his desk to show the train number and
activates the facility to speak over the trains PA if required. It also
illuminates the "Calling On" light at the rear of the train.
Line Controller attempts to contact T/Op on incident train, if he can't,
then he instigates a step-through procedure using the train behind whilst at
the same time using the PA facility to attempt to get assistance to the
casualty T/Op.

[1] CTBC = Combined Traction Brake Controller - Deadmans Handle to those
that don't speak railway
HTH
--
Cheers, Steve.
Change from jealous to sad to reply.