wrote in message
On Thu, 13 Aug 2009 13:38:28 +0100
"Colin McKenzie" wrote:
If other posts to this thread are right, 4cm extra width adds about
0.6 sqm floor space. Crush-loaded, that must be about 3 extra people
per carriage. That's useful capacity.

Well it would be if people could be broken up into pieces and slotted
into the carraige in odd little bits of free space. But anyway who's
been in a tube when its packed and your back is against the door
knows that an extra inch behind you is going to make bugger all
difference to the amount of people who can squeeze on.

I think the internal size will be more than 40mm wider, due to thinner
carriage walls, but of course that's nothing to do with tunnel size.