Roland Perry writes
ok then. so what would happen to the tube if london's power got cut? im
guessing theres no auxillary system in place....is there? i think i remember
something about them having their own fossil fuel power generators...

They used to have their own power generation, but take it from the
National Grid now.

Indeed they used to generate all their own power - the main power
station was at Lots Road in Chelsea. And as you say, they do take most
of their power from the National Grid now- but the Greenwich power
station has been kept as a back-up.

--
Dave