"MIG" wrote

I don't think they Central Line has any normal trips all round the
loop, but the presence of a large depot could result in it going in
from one end and then back into service from the other. They managed
to avoid this with the 1962 stock and then seemed to abandon the
principle some time in the 1980s, so they started facing in all
directions towards the end of their life. And it presumably matters
less with 1992 stock.

For many years the Hainault to Woodford line only had a shuttle service,
with short formations which, AIUI, were normally kept to this service. It
was converted to ATO as a trial for the Victoria Line - did use of ATO stop
after the experimental phase, or did it continue?

Peter