Clive Feather:
IIRC, there's a class of mainline train that has a *fake* push button on
it ...
There's a good reason for this - the door in question is operated by
breaking a light beam. If your body doesn't break the beam, reaching out
to the button will.

Neil Williams:
That'd be all the Adtranz kit - when it's working - Electrostars, Turbostars
and the likes.

Well, which is supposed to break the beam -- your body or your extended
hand? Where are the lamp and sensor placed in relation to the door?

Are these the doors for walking from one car to the next?
--
Mark Brader "Things are getting too standard around here.
Toronto Time to innovate!"
-- Ian Darwin and David Keldsen