"Roland Perry" wrote

As you say, it can happen on some "grandfather rights" rural routes. I
was on a 5-car train a week ago that stopped at two stations with only
room for 3-cars. The way they organised it was for the guard to make
several announcements and walk through the train, and then *only* open
the door at the very front of the train by the driver's cab.

In slam door days there were three options:
1 - Guard goes through train and moves passengers who wish to alight at a
short platform, so that they are in a coach which will be adjacent to the
platform.
2 - Front of train stops at platform, then train draws up to get next
portion by the platform. I've been on a train which drew up twice to let one
passenger alight at Duncraig.
3 - Passengers climb down to track level. I've done this at Culrain, and at
Corrour, when the Saturday evening train used to have a 6 coach seats and
sleeper portion for London, plus a 6 coach portion for Glasgow. I alighted
somewhere in the vicinity of the loop points.

Peter