Spud wrote

Well, I was being a bit tongue in cheek. But I suspect if the line had been
run by the underground since its inception rather than BR until the 90s
then
probably a single line connection would have been built by now to transfer
stock instead of having the faff of craning them in and out when any heavy
overhauls are required.

Until the 1990s, when the site was required for building Waterloo
International, access to the W&C was via a hoist in Waterloo Yard. W&C stock
could be brought to the surface using the hoist, and AIUI worked under its
own power to Wimbledon Depot for overhaul. The W&C originally had its own
power station, and coal trucks used the hoist to provide power. In 1948 the
lift descended while some trucks were being shunted on to it, and 4 coal
trucks and a loco landed at the bottom of the shaft.

Peter