On 17 Aug, 16:24, Graeme wrote:
In message
* * * * * wrote:

On Tue, 17 Aug 2010 07:16:21 -0700 (PDT)
Andy wrote:
It's not daft to build a train to fit the more modern infrastructure
on the Victoria line, the 2009 stock would never be able to run on any

The reason AFAIK that the victoria line tunnels were built larger was to
reduce *air resistence and make the trains more efficient. Presumably at
least part of those savings have now been lost due to the bigger trains..

[snip]

The Victoria Line booklet[1] published by LT in 1969 states that it was
discovered that opening out the tunnels to 12'6" (from 12') did indeed reduce
the air drag to a degree comparable to that of open-air operation. *However
it is emphatic that that was not a design criterium. *Minimum tunnel diameter
is actually 12'2" so there will be little losss of efficency in practice.

[1] The Story of the Victoria Line by John R Day. P28

--
Graeme Wall

This address not read, substitute trains for rail
Transport Miscellany at www.greywall.demon.co.uk/rail
Photo galleries at http://graeme-wall.fotopic.net/

Let's cut to the chase. The 2009 stock is a monumentally crap design
that we are going to be stuck with for another 40 years. I could cry.

Desiros can be built without six inch thick walls and chunky
obstructions everywhere (apart from the armrests). Even the worst LU
stock till now has seats that one can sit in. The design of the 2009
stock is either idiotic or malicious. Words fail me.