wrote in message

On Mon, 9 Jan 2012 11:53:53 -0000
"Recliner" wrote:
"Roland Perry" wrote in message

In message , at 19:45:42 on
Sat, 7 Jan 2012, Eric remarked:
Or, better still, this pictu

http://www.metro-pole.net/actu/IMG/j...4287_p1200.jpg

That's a much better picture.

If those are indeed two separate twin-axle bogies, they're very
close to the ends of the carriages, which means there won't be much
relative movement between them (compared to normal carriages with
much more overhang). This makes it much easier to fit open gangways.

First it was because tube trains are too narrow, then it was because
they're not articulated, now you're grasping at this straw. Just
admit you were wrong.

If the bogies are very near the car ends, then the effect is close to
articulation. But with the circular profile of Tube tunnels, I'm certain
that reasonable sized open gangways are not feasible without true
articulation. If you look at the relative movement of Tube car ends, you
can see just how difficult it would be -- look at how much smaller the
gangway is compared to the outer body in S stock and 378s in order to
accommodate all the movement.

So, sorry Boltar, you won't be seeing open gangways in LU Tube stock in
the absence of articulation.