On 25 Oct 2004 22:15:20 GMT, (Soniakostas) wrote:

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.

Within a "train" of underground carriages you will typically get two
units attached to each other. On some lines each unit has 4 cars - e.g.
the Victoria and Metropolitan Lines have 8 car trains while on others
you get a mix of 4 cars and 3 cars to give a 7 car train (Piccadilly
Line or Circle / Hammersmith and City)

Depending on the configuration of the train some carriages have motors
(what you term an engine) and others don't have any - called trailer
cars. A bit like an articulated lorry where the front bit has the
engine and the back bit - the trailer - carries whatever is being
transported from a to be.

Now I might get shot down in flames from one of our resident drivers or
engineers here but one way to tell which is which is to look at a train
on the opposite track and see which wheels have the "shoe" attached to
pick up the electric power. If a carriage has shoes then it is a motor
car, if there are no shoes then it is a trailer car. The best lines to
see this on are the sub surface lines like the Met or District lines
because there are two tracks side by side.

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)

This is partly to do with platform lengths because some lines can only
take 6 or 7 car trains and not 8 cars. On some Circle and Hammersmith
and City trains the end passenger car actually has a very small driving
console behind a panel so the train can be driven in the depot from this
position to join up to another four car train.

The other reason is that we have to be able to take trains apart to
allow them to be maintained or repaired if something breaks down on
them. If you had two seven car trains and in train number one the 3 car
unit had to fixed you'd have the four car bit spare. For train number
two the 4 car unit needs to be fixed then the 3 car section is spare. We
can then join the two spare sections together to get a working 7 car
train.

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 ?

Lots of people have already provided answers to this but you right in
that the trains were developed to test some different engineering bits
but also to test different interior designs with the public.

Hope that info is useful.
--
Paul C


Admits to working for London Underground!