On Tue, 4 Jan 2011 23:15:25 -0800 (PST)
1506 wrote:
On Jan 5, 12:49=A0am, Clive wrote:
In message , The Iron Jelloid
writesI'm thinking of what happen=
s if we get another savage cold spell in
Jan/Feb, as we did last year. =A0The 3rd rail heating system is only jus=
t
being developed / tested, will take a while to deploy network wide.

LT used heating the rails back in the 60s, they just passed mains juice
down through one rail and back through the other, leaving the resistance
to do the heating for them.
They also employed snow cars which would run at night in open sections
with a very hard brush (imagine 2" nails as each bristle) and a grease
to sit on the rail making icing near impossible.

This would seem to be a solution. although I liked the idea, up
thread, of self warming rails (and overhead). Would the lack of a
fourth rail be a problem?

The 3rd rail problem is easy to solve - use the system in use in the states
on the new york subway and probably many places elsewhere. Still use top
contact but just cover it over so theres a grove left and use a tongue
instead of a shoe that pokes out of the train and contacts the top of the
rail. That way trains would be coverted first allowing both types to run
on the same lines and once all have been coverted then you cover over the
3rd rail. Why anyone is wittering on about side or bottom contact beats me.

Fairly easy to see he

http://www.nycsubway.org/perl/show?77382

B2003