Centaur wrote:
"Richard J." wrote in message
...
Isn't it possible to detect
that the train has stopped and that it's in the correct
position in a small fraction of a second?

No its not, believe it or not. There had been a real
problem about a year ago following a software update on the
trains in copnnection with making ATO braking smoother
which now seems to have been rectified by lots of tweaking.
They way they explained it, to the simple minded (like me),
was that when the train berthed on the PAC a series of
event checks are made, up to 10 different things, including
what train it actually is, where its going, load weighing,
oh and many more I can't even begin to think of, but one of
them is Doors Opening.

What was happening, was, that on some headwall stops at the
PAC, the doors opening 'event' simply got missed and the
whole process had to return again to the beginning. It
depended a great deal on where the train was. If it was at
a station where there was a route diverge ahead then the
event took longer, sometimes many seconds. I think I
counted up to 10seconds on one occasion at East Acton
westbound but in general when this happened it was
definitely several seconds. It was a real pain because the
driver didn't know whether to operate the override switch
or not as the doors wouldn't open and passengers had to
wait thinking what the heck was wrong.

Thankfully new software seems to have rectified this
problem today but it took many months. However it does
serve to show how your point about, "Isn't it possible to
detect that the train has stopped and that it's in the
correct position in a small fraction of a second?" isn't
all its cracked up to be.10 years on and the 1992 stock
have been an absolute nightmare apart from the Chancery
Lane incident.

Surely you can't find anything else to ask?
DaveR

When are they bringing back real trains, such as 1923 Stock?