On passenger coaches, the main reservoir pipe is also used to supply air to operate doors and air suspension.
In 1938 these became part of the 'H Stock', retaining their hand operated doors.
Maybe they just operate doors differently than we do.
Aligning the track precisely during installation guarantees smoothly operating doors.
Prior to this modification, it had been necessary to station a conductor in every car of a train to operate doors.
As mentioned above, each car as delivered required its own conductor to operate doors.
They had 4 single power operated doors on each side and were of spot-welded construction.
Comeng trains have power operated doors that must be pulled open by hand but are closed by the driver.
These cars were the first new tube cars to be built with air operated doors.
Following conversion to air operated doors, the trains became collectively known as Q Stock.