"MIG" wrote in message
...
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.


It's not that bad. It is still hot and rancid which is the issue that needs
addressing and they need to sort the teething problems. The number of
failures of 67 stock that I have encountered currently stands at zero!
Granted there was the set with the dodgy door recently but it still moved.

John