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[email protected] · February 17th 11, 11:27 AM posted to uk.transport.london

On Wed, 16 Feb 2011 19:41:23 +0000
"Clive D. W. Feather" wrote:
In message , d
wrote:
Some years ago there was a very good post on uk.railway explaining some
of this. For example, third rail running rails need to be isolated from
earth to keep stray voltages away from underground pipes, but 25kV AC

I didn't know that about 3rd rail, I assumed the rails were grounded. Doesn't
that mean that theres a potential risk of electrocution just from the running
rails?

Yes, if they're not correctly controlled by the distribution system.

I used to commute on the same train as an electrification safety expert.
He once explained to me that, with the original wiring plans for HS1, a
broken cable on the Northern Line could resulting in someone standing on
the platforms at Ashford International getting electrocuted.

Don't see how that could happen. Besides ,even if you had a continous 3rd
rail all the way from say mordon to ashford the voltage drop over that
distance would be significant, probably to the point where at ashford it
wouldn't be dangerous.

B2003