On Sun, 4 Nov 2007, Richard J. wrote:

Tom Anderson wrote:
On Thu, 1 Nov 2007, Mr Thant wrote:

On 1 Nov, 20:48, Mizter T wrote:
Wonder if any of the Central line drivers might like to try doing
this?!

I read a story online somewhere (can't find it now) about a
Victoria Line driver getting out of his train when stuck at a red
signal, but without deactivating the ATO. As soon as the signal
cleared, the train restarted itself, narrowly missing him.

So Vic trains under ATO don't need a hand on a dead man's handle?
This i did not know. That seems like a funny decision.

No it's not. If you had a dead man's handle on the Vic and the driver
had a heart attack, the train would stop in the tunnel with nobody on
board able to radio for assistance or talk to the passengers. Without a
dead man's handle, the ATO would drive the train *safely* to the next
station where the driver and passengers could more easily and quickly be
attended to. Which would you prefer?

In that hypothetical situation, no dead man's handle. In the hazardous
situation that actually happened, a dead man's handle. You can make
hypothetical arguments either way - and probably find real-life cases too.
However, the fact that trains with dead man's handles have operated in
London for over a century without, as far as i know, the kind of situation
you describe having led to any casualties indicates to me that it's a
generally quite safe way of operating a train.

It would be interesting to know how many times dangerous situations have
been avoided through the use of the dead man's handle - driver sees an
obstruction and the line and releases it, sort of thing. With ATO, the
driver can presumably stop the train by some positive action, so he
wouldn't be powerless in that kind of situation; however, if he had become
incapacitated, he would be unable to take that action. An extreme case, i
know, and one rendered particularly unlikely by the entirely underground
nature of the Victoria line!

tom

--
First man to add a mixer get a shoeing! -- The Laird