george matthews wrote:I am sure that running with open doors in Britain would be a serious offence
I'm sure it would be nowadays. But I travelled to school every day from 1966-1972 on the suburban EMUs on the Liverpool Street line. There were two types of EMU in use. The inner suburban ones had air-operated sliding doors controlled by the guard. However the outer suburban ones were non-corridor compartment stock with slamming doors and no central locking. We used to take great delight in opening them at speed. Depending on which direction the hinges were, you either had to put all your weight on it to open it against the air pressure, or else it was torn out of your hands and slammed back against the side of the train. Very dangerous, but fun for young grammar school boys. I'm not sure when those trains were withdrawn, but it can't have been that long before the Granville disaster.
Also, BR Mk 1 and Mk 2 coaches (and maybe later marks?) didn't have centrally-locked doors. You have to open the window and lean out to open the door using the exterior handle, and this could be done while the train was moving at speed. HSTs were only retrofitted with centrally-locked doorsin the last few years, if I recall correctly.
In South Africa you still regularly see suburban EMUs running with the sliding doors open and people hanging out of the doors.