"Brian Watson" wrote:

This got me thinking literally, "are there any depots or
strategically-placed triangular junctions at which a train could be turned
right round?"

LU trains are not, as far as I know, biased to be driven from one end or the
other, but I could see circumstances such as the Circle Line where it could
be an advantage to turn a train to even out wear on the wheels.

I don't know whether some variant of it still runs, but there used to
be a train in the inner rail Circle service which stood for a while at
Edgware Road after the evening peak then renumbered into the
Hammersmith & City sequence, continued inner rail to Tower Hill and
then ran via Aldgate East. I did not know how physical sets were
allocated to train numbers so don't know if there was a pattern to
ensure sets were turned or if they were chosen on a "need" basis by
depot staff.

Cheers,
John