In message , John Rowland
writes

Are they running a special timetable prior to the closure in order to
get all the trains the same way around during the closure, or is there
no such thing as a 1973 stock being "the wrong way around"?

Up ^^ there, I said:

Terminal 4 station closes from Friday 7 January, although some trains
will run non stop via the loop for turning purposes on that day as
required.
--
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)