Hi i have a few qurstions to ask regarding to the underground trains that
always made me wonder.

1) Firstly when a train goes does the first car pull and the last one push ?
otherwise how just one car can pull so many other cards same size as itself ?
In the rasilway trains one carriage is pulling and the last is pushing i was
wondering if the same happens to the underground trains.

2) I noticed sometimes in a train with many carriages they put in a middle an
engine car but they have it as a passenger car not doing anything, howcome they
didnt put a normal passenger car and they put an engine car in the middle as
well ? (usually circle line or metropolitan)

3) Going back to the past i would like to ask what was the purpose exactly of
the so called "prototype trains" back in 1986 like the green one here
http://world.nycsubway.org/perl/show?23602 and here
http://world.nycsubway.org/perl/show?23618

Did these trains ever carried passengers or they just used them to test the
engineering of the forthcoming trains ? if thats what they were used for
howcome they were completely furnished inside with seats maps and everything ?

Lastly were these prototype trains in service long andf how many were created
if anyone knows

thanks a lot guys and gals !

-a true underground fan from uxbridge !