On Wed, 14 Nov 2007, BH Williams wrote:

"Peter Masson" wrote in message
...

"Lüko Willms" wrote

Why and how would the Class 92 locomotives have to be "configured for
HS1"? They do support TVM and KVB, don't they?

I think they only have it configured for the Channel Tunnel, which uses
different speed bands from HS1 or LGV. ISTR that when one freight train
was allowed to use the CTRL it had to do so under special regulations
as it was effectively unsignalled.

The TVM configurations are specific to route and stock, as they include
the braking curves for given items of stock under given conditions.
[...] the options are either to give the driver a 'FREP' ( a numbered
message which has to be read out by the signaller and repeated back by
the driver) for each signal or to class the entire route as a work-site
and authorise the driver to proceed at 'marche-a-vue' (a speed at which
the train may be stopped short of any obstruction, with a normal maximum
of 40 kph, IIRC) as far as a given 'repere' or other stopping point.

This is one of the things that absolutely baffles me about the automated
signalling systems that are being deployed now - why is it the signalling
system that makes decisions about how fast a train should go, and not the
train? The signals should just keep track of each train, set of points,
buffer stop and other thing to avoid running into, and tell the trains
where they are (and tell them about any specific speed restrictions, too).
Computers on the trains can then use their knowledge of the train's
performance to calculate an appropriate speed. Situations like the above
are not exactly unprecedented, and the signalling system should have been
designed to deal with them.

tom

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