In message , at 23:21:06 on Mon, 8 Aug
2011, D A Stocks remarked:
I understand one of the prerequisites for the introduction of
regenerative braking on the Central Line was a requirement to replace
older motors in escalators at stations. They share their supply with
the traction and needed to be able to handle the greater variations in
supply voltage.

That's quite interesting. I've been at a couple of National Rail
stations (one SWT, one FCC) where the power had failed to the station
itself, but remained in place for the trains. Neither had escalators.
--
Roland Perry