It was in the mid 1990s. I remember as a child the "It's fruitless if it's not orange" posters reminding people to wait for the orange light before opening the doors. It is controlled by the guard from a panel by each door - it isn't fully automatic.

The secondary door locking is a separate bolt at the top of the door - you can see a box on the door itself that it goes into. It was fitted to serve 2 purposes - to prevent people opening the doors when the train was moving, not in a station or whatever, but also to prevent the incidents of coach body distortion possibly causing doors to come open, which wasn't well understood but appeared to have caused a few deaths of people who fell from trains who may have been standing by or leaning on the door.

There has been talk over the years of sealing the windows and adding internal handles, including prototypes, but nothing ever seems to come of it. Chiltern Railways are prototyping a new design of automatic door, which if found to be reliable and not too expensive may prove to be the solution.

Meanwhile, I could never understand why the UK passed by the standard European UIC self-closing folding door. This always seemed a very clever design to me. The experimental XP64 coaches had that type of door but without the automatic locking and closing - the key features! "Not invented here" syndrome, perhaps?

Neil