Re: Flat Wheels in Sydney

[David McLoughlin <davemcl@REMOVEiprolink.co.nz>]

Rob McKiernan wrote:
 
> I caught a suburban train from Newtown to the City recently and while
> waiting for the train to arrive I noticed that just about every second
> suburban that went past had a flat wheel and some trains more. 
> Can somebody out there tell me why this is so?. Is it bad driving or some
> other mechanical explanation?.  I have travelled a bit on overseas systems (Rome, Paris, London,
> Washington etc) and it seems to be a uniquely Sydney problem.

I have often experience flat wheels on trams (though increasingly less
so with the widespread use of computerised braking and automatic
sanding) but certainly I can support your contention that it is not
something one notices much on trains. In fact I do not recall any major
case of flat wheels on a train, especially on the modern, quiet trains
one gets these days where a flat wheel would stand out.

Trams are more prone to them because they have to stop suddenly in
street traffic, which can cause a flat especially with older trams like
Melbourne's Ws, though I have been on Zs with terrible flats. Trains
being on private track can slow down at leisure... the only stops likely
to cause a flat would be if the driver had to slam on the brakes to try
to avoid hitting a pedestrian on the tracks or a car swerving around
level crossing gates.

Maybe Sydney trains face more of these kind of emergency stops than
elsewhere.

David McLoughlin
Auckland New Zealand