It's not a piece of string, it's quite a substantial piece of rope, which
adds to the resetting difficulty. The trains were originally part of a super
line upgrade so the tripcock reset cord was installed as a temporary measure
until ATP/ATO was introduced.
The cord itself goes through several tight bends from the loop that the
driver pulls in the offside cabinet down to the trip itself. The bends and
cord thickness have been a problem since we first tested train set 1 on the
test track at Washwood Heath.

Whilst conducting the conversion training for the drivers we used to tell
them to stick their J Door Key through the loop to get better leverage and
failing that, get out of the cab and attempt a reset pulling where the cord
is visible (about 6 inches from the trip).


"Neillw001" wrote in message
oups.com...
Excuse my ignorance, but why in the 21st Century are saftey-critical
devices on one of the most heavily-used urban metro systems in the
World reliant on a bit of string?

Neill