wrote in message
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On Wed, 29 Jun 2016 13:42:32 +0100, "D A Stocks"
wrote:

"Recliner" wrote in message
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I took a ride on the Greenford-Paddington shuttle yesterday, in the
light of its imminent truncation to West Ealing, and noticed some
newish four-rail track between Drayton Green and West Ealing
junctions. All four rails were firmly clipped to the concrete
sleepers. I've not noticed it before -- does anyone know why it's
used?

https://www.flickr.com/photos/reclin...7667614586524/

More pictures in
https://www.flickr.com/photos/reclin...57667614586524


You tend to see track like that on high viaducts, or anywhere else that a
derailed train would have an uncomfortable landing if it left the railway
altogether.

e.g. around 29:06 on this video dating from 2005

https://www.youtube.com/watch?v=Jl9wBpvu86U

You can see the same location, side by side in 1953 and 1983 at around
2:42
he
https://www.youtube.com/watch?v=E6Ll96VNuSc

I've seen that before but does it really work? Has there ever been a
derailment on such stretch of track?


Here is a case where a freight train pretty much demolished the viaduct it
was travelling on. No guard rails - there are many miles of track on similar
viaducts in urban areas:
http://www.railwaysarchive.co.uk/doc...Bexley1997.pdf

--
DAS