In message , at 12:09:45 on
Sun, 3 Aug 2008, Paul Scott remarked:
As I've mentioned before, TOCs such as SWT use SDO by whole unit, sometimes
only releasing the doors in 4 coaches of 12; or using single door only in
444s at 4 platform stations such as Beaulieu Rd, or Shawford.

Do those trains have a corridor connection between each set of 4
carriages?

One of the major design flaws in the networkers on the Cambridge line is
that they don't.

The 5-car train I mentioned earlier was made of three units (2+2+1) and
not only was there a corridor all the way through, the connecting doors
were open so you could see all the way through the train!
--
Roland Perry