On 25 Feb, 12:41, "Peter Masson" wrote:
"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.

Yes, mostly single units of two 1960 stock motors with two standard
stock trailers, then later one 1938 stock trailer. But at any given
time there would also be one 1967 stock unit shared with the Victoria
Line, which always seemed to be one of the later batch (xx62 to xx79 I
think) for the Brixton Extension. I wonder if there were minor detail
differences that stopped them using the others on the Central?

But even with the shuttle pattern, there were several journeys from/to
Grange Hill via Woodford at either end of each rush hour, which were
full length 1962 stock. These didn't use ATO, so there was dual
signalling. The large depot is between Hainault and Grange hill
stations and trains entered and left service in both directions for
the rush hours. They would be facing in opposite directions.

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?

The thing I am not sure of the timing of is the demise of the 1962
stock and the beginning of the current service pattern.

It could be that ATO was abandoned for the whole loop to be taken over
by 1962 stock for a while, and then reintroduced (presumably a very
different kind of control) for the 1992 stock.

But it certainly used ATO until it ceased running as a shuttle.