"Barry Salter" wrote in message
...
On Wed, 10 May 2006 12:13:02 +0100, Walter Briscoe
wrote:

I note Bakerloo services stopped this morning following radio failure.

What usage for radio is essential to run tube services?

Contact with the Line Controller in the main. If, for example, Oxford
Circus was closed due to a security alert, the Line Controller (or an
underling thereof) would need to inform all of the drivers (sorry, Train
Operators) so they don't stop there. Similarly, if they want to
terminate the train early for some reason, or hold it in a station to
even out gaps in the service, etc...

The main reason is that in deep level tubes the radio automatically sends an
alarm to the Line Controller in the event of the T/Op collapsing and
releasing the CTBC. It also opens a radio PA channel allowing the Line
Controller to speak over the trains PA (The idea being that s/he will ask if
there are any LU staff or medically qualified personnel on the train). If
you travel on the tube very late at night you will sometimes hear tests of
this functionality being carried out. This was one of the ways LUL was able
to get deep level OPO past HMRI...
--
Cheers, Steve.
Change from jealous to sad to reply.