In article , d ()
wrote:

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
happens if we get another savage cold spell in Jan/Feb, as we did
last year. The 3rd rail heating system is only just 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

Would it be worth the expenditure? Winters are a *lot* more severe in NYC.

--
Colin Rosenstiel