"Paul Scott" wrote in message
news snip
I reckon there could be some debate about the door setup, I don't see
how two sets of double doors in the centre of each carriage provides
25% more doors than a 1/3 - 2/3 set up, unless of course the
carriages are somewhat shorter than 20m...

Yes, as with any articulated train, the carriages will be much shorter
than the equivalent non-articulated version. Think of two sets of double
doors between *each* pair of bogies, rather than alternate pairs of
bogies.