In message , Tom
Anderson writes
Would it be sensible to electrically connect all four rails, with a set
of crocodile clips or something, when working on the track in
situations like this? Then, if there was a mistake which fed voltage to
one or more rails, it would short out, and circuit breakers located
wherever the feed-in was happening would break and cut it off. It would
be something you could do at the site which would absolutely guarantee
that there was no dangerous voltage there. The problem might be the
effect it had on other parts of the system, though.
Don't tube trains still carry Short Circuiting Devices (SCDs) anymore?
It used to be that when traction current had been discharged a driver
would clip the device over the outside (live) rail, look away incase of
arcing, then smartly smack the other end down onto the centre negative
rail. It would then be left there in situ for safety until it was
required to restore traction current.
--
Clive