On Jan 9, 3:38*am, "Steve Dulieu"
wrote:
"John B" wrote in message

...
On Jan 6, 1:52 pm, wrote:

1) the depot is at Cockfosters. Not sure what time this incident took
place, but if the train died in a place where it blocked or

MId to late afternoon.

Right boys n' girls, this is what happened...

(I have simplified this a bit but it's still gonna' be long)

At about 14:53 a train departed CK platform 4, as it got out of the platform
it became rear-tripped, coming to a halt with the rear of the train about 2
metres out of the platform.

The T/Op went through his checks and identified the problem. He then set
about getting the train moving.

Sadly this is when it went all man-boobs up.

The train had come to a stand on the one bit of track leaving CK where it
was completely off juice (gapped in LU jargon) AND where the train will not
roll - in either direction.

Thanks for the comprehensive explanation (which I won't repeat).

The bit I don't understand is how a whole train can be gapped. Could
you clarify how that can occur (and why it isn't avoided for that
matter)? How many shoes need to be in contact for movement to be
possible, compressors to work etc?