"Richard J." wrote in message
m...
wrote on 08 April 2009 19:40:50 ...
"Paul Scott" wrote in message
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wrote in message
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"Paul Scott" wrote in message
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Yes - as discussed here in the past, the District renewals towards
Upminster appear to use identical rail and sleepers to recent NR track
renewals - the same 'mainline' firms are involved albeit in a
Metronet led consortium.
Eventually the whole SSR is supposed to get the same treatment...

What will the sleepers be made of?

Concrete - obviously the fittings for the fourth rail are additional,
but the same rail securing, with pandrol clips, as on the big railway...

I'm no concrete expert but, AIUI, water gets into concrete. This causes
the sleeper to crack and disintegrate.

Really? Perhaps you should inform railway companies throughout the world
about that, given that concrete is by far the most common material for new
sleepers. Don't you ever look at the track?
--
Concrete does allow for higher speeds.