table38
Established Member
You may be right. It looks like it might have been later Mk2s that had sealed droplights and internal handles, which were eventually changed for openable droplights and removal of the internal handles. By the time the Mk3s came around, they were designed from day one without the internal handles.
Earlier Mk 3's did indeed have internal door handles when they first rolled off the production line in 1974. However, due to a few incidences of doors being opened whilst trains were on the move, they were quickly plated over.
I'm not sure about the MK.3s, but Mk.2Ds had internal door handles, because people leaving the droplights open potentially screwed up the aircon so they had fixed droplights and internal door handles which (according to Michael Harris's book) had to be pulled towards you first, then turned.
But they were too easy to open and there was a fatality in 1971, so they enclosed the internal door handles with a "shield".
Later that year it was decided to remove the internal door handles completely and release the droplights, which were fitted with a spring to close them after use.