In message m, Martin
Underwood writes
"Clive D. W. Feather" wrote in message
...
In article ,
MetroGnome writes
Is it because the crossing has to be closed to road traffic before the
train
arrives, and while it dwells in the platform? I've seen this before on
heavy rail (eg for London-bound trains at Higham's Park) - presumably
because the crossing is within the signal overlap of the station starting
signal, and therefore a train cannot be let into the platform until the
crossing is clear of road traffic in case the train overshoots.

No: an open level crossing is not counted as an obstruction in the
overlap (unless, of course, there's a problem such as a broken-down
car), so trains can be signalled up to a red signal right at the
crossing.

Really? I thought that it was standard practice to close a level crossing if
it was just beyond the end of a platform in case the train overshot and
strayed onto the crossing. Certainly that's what's done with London-bound
trains at Sunningdale and Reading-bound trains at Egham.

Or are you saying that it *is* done, but that it's for safety rather than
purely signalling reasons?

It has the advantage that the signal at the end of the platform can be
cleared, so the preceding signal shows green or double-yellow and the
train can enter the station at a reasonable speed rather than having to
slow down to a crawl after the single yellow (as is required by
'professional driving' policies).
--
Spyke
Address is valid, but messages are treated as junk. The opinions I express do
not necessarily reflect those of the educational institution from which I post.