In article ,
none "" wrote:
On 27/07/11 14:04, d wrote:
On Wed, 27 Jul 2011 04:36:48 -0700 (PDT)
wrote:
No, the Central Rises as it enters stations, then descends leaving
them. It was built this way in order to aid acceleration and
braking. The stations, in effect, are at the top of "underground
hills"

Why isn't this done any more - eg jubilee, victoria lines? It seems to be a
simple way to save energy.

Unfortunately the modern way is to get 'new blood' which means that
previous good practice, lessons learnt, or even basic skills are forgotten.

I think you'll find that these principles are adhered to, even on
new built lines, where it is possible.

Trouble is, these days there are more underground obstructions -
not least other underground railways - and this means that in order
to get from A to B, you have to thread your way past foundations
for tall buildings, and other underground railways.

This makes it harder to achieve the "underground hill" effect -
although I note that if the diagram on
http://www.crossrail.co.uk/route/stations/ is correct, almost all
Crossrail stations will be on a hump.

Cheers,

--
Mike Bristow