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[email protected] · December 19th 15, 09:26 PM posted to uk.transport.london,cam.transport

In article , (Roland Perry)
wrote:

In message , at 19:47:17 on Sat, 19
Dec 2015, Tim Ward remarked:

So it's like this:

Ely ------------------------------------ Peterborough
\
Ely ---------a-------------------------- Peterborough
\
*
\
b------c--------------- Kings Lynn
\ \
\ -------------- Kings Lynn
\
d------------------ Norwich
\
----------------- Norwich

As is fairly obvious, places like "*" are a monster bottleneck.

That looks a bit cheap and nasty, even to a non-trainspotter. Whose
clever idea was that design then?

British Rail (the nationalised outfit which people still insist could
have done no wrong) in the 70's/80's simplifying lots of junctions to
have fewer moving parts, on the grounds that rail transport was in
managed decline.

At the time there was probably only 1tph in either the Kings Lynn or
Norwich directions.

It was later than that, as part of the Cambridge-King's Lynn electrification
which was completed in the early 90s. Single lead junctions saved a lot of
money so were a frequent value engineering element. Indeed there are still
junction arrangements using them which save money compared to conventional
double junctions but don't have the bottlenecks. Shepreth Branch Junction is
an example with no conflicting moves using only 4 simple points:

------------
Foxton \
-------- \
\ \
---------a--b--c---
Shelford \ Cambridge
--------------d----

The stretch between points a and b is both the Up Shepreth Branch and Down
West Anglia line.

When Ely North Junction was rationalised there was no direct
Cambridge-Norwich service (introduced in 2002) and the idea of half-hourly
trains to and from King's Lynn was in the land of the fairies. There was no
Ipswich-Peterborough service either.

People forget how much rail traffic has grown since privatisation.

--
Colin Rosenstiel