"Paul Terry" wrote in message
...

When plans for closing Lot's Road were drawn up it was stated that there
would be three bulk supply points on the National Grid for London
Underground, any two of which could keep the system running if there was
a failure - so I guess at least two supply points must have failed.

So, triple redundancy (almost) like you have on airliners.

Three separate feeders into each supply point would be ideal, or two with a
standby generator and a UPS as an alternative.
--
Terry Harper, Web Co-ordinator, The Omnibus Society
http://www.omnibussoc.org
E-mail:
URL: http://www.terry.harper.btinternet.co.uk/