"Recliner" wrote in
:

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.

If cars have shared bogies, or bogies very near the ends, the centre throw
will be greater than with the current placement of the bogies. Given the
tight fit of tube trains in their tunnels I would imagine that that would
give a clearance problem on curves - unless you go for substantially
shorter (and more) cars, like the Space Train.

On the Waterloo and City they solved a similar problem by grinding part of
the flanges off the tunnel lining segments, but as I recall the Victoria
Line has concrete linings without flanges.

I had a look this morning at the width/height issue, and 3 average height
people can stand side-by-side in the vestibule area facing along the car.
So I think a wide gangway would probably allow two people to pass, provided
the gangway was about as high as the internal car body.

Peter CS