Thunderbug wrote:
What is the motor-type noise that comes from under trains on the Met line?
It's obviously something that spins around but it doesn't seem to be related
to propelling the train?


If it was this morning it was probably the wheels locking up or
spinning, I couldn't get the Chesham Shuttle faster than 25mph on its
way up there, and was braking for the next station when I did!