On Sat, 16 Jul 2011 02:19:28 +0100, Clive
wrote:

In message ,
" writes
In my time on both the Northern and Central lines trains were frequently
moved around depots with the doors wide open, if only to get some fresh
air through them.
That's because the driver had turned on the bypass switch.
Neither the 38 or 62 stock that I worked on had any kind of interlock to
cut power if any door was open.

AFAIR the only interlock was (allegedly) with the guard's bell.