Re: Locks fitted on NSW country trains

[David Johnson <trainman@ozemail.com.au>]

Barry Campbell wrote:

> David Johnson wrote in message <3A16ACDD.722F2EA7@ozemail.com.au>...
> >Eben Levy wrote:
> >
> >> Locking equipment was started to be installed from a couple of years ago,
> it
> >> all started when a young boy apperently "FELL" out of a syd-mlb XPT,
> there
> >> aqre thories he was pushed and all.... I know DJ did testing on the doors
> to
> >> see how much force you needed to open whilst in motion and it was
> apperantly
> >> to much for a kid of his age..... Dave? any more info you can provide?
> >
> >Turning the handle wasn't a problem, the air pressure difference would be
> the
> >deciding factor, which increases with train speed.
> >
> I assume this means that the air pressure outside is less (Bernoulli
> effect?) so that the door tends to be kept closed by pressure of the air
> conditioning.

Basically, yes.  The trains are slightly pressurised by the Air Conditioner
Fans.  As the train moves, air passes by the outside of the door causing a low
pressure outside the door and a high pressure inside.

--
David Johnson
trainman@ozemail.com.au
http://www.ozemail.com.au/~trainman/
------------------------------------
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