In message , Clive
writes

Overall, it could easily take 15 to 20 minutes to get a train reversed
to the previous station.
All this surprises me, I thought reversing in tube was banned under any
circumstances.

Oh no, but you do have to be in possession of a 'Wrong Direction Move
Form' duly signed by an Operating Official, cut out various bits of
safety equipment (and of course be in the 'right' cab) before you can do
the move.
--
Steve Fitzgerald has now left the building.
You will find him in London's Docklands, E16, UK
(please use the reply to address for email)