Re: Flat Wheels in Sydney

["Tibor Weitzen" <wtzn@ozemail.com.au>]

"chris 'fufas' grace" <chris@icos.net.nz> wrote in message
1999Jul2.172459.2690@transdataco.nz">news:1999Jul2.172459.2690@transdataco.nz...
>
>
>
> Matthew Geier wrote in message <7lha3b$f49$1@metro.ucc.usyd.edu.au>...
> >In article <keithm.78.377B3708@commslab.gov.au>,
> >Dave Malcolm <keithm@commslab.gov.au> wrote:
> >>
> >>Cast iron shoes work as well on minor flats.
> >>
> > Not on Tangaras. They have disk brakes :-). This is the reason they
appear
> >to have more flats....
> >
> I was wondering about this. Could the cause be fallen leaves as it is in
the
> UK? The other problem is that tread brakes 'condition' the wheel tyre
while
> disk brakes do not...

1. The UK "fallen leaves" are tales for non-railway public & reporters. Ask
National Rail people about millipedes in SA and how AN/NRC fight them with
air-brushes etc.
2. During tendering period for 4GT, I have performed a lot of brake
calculations that revealed, that disc brakes are extremely sensitive to
track conditions and there shall be most attention paid to relation between
braking effort and rail adhesion of the wheel during the WHOLE braking
period until the train stops. The low speed is most dangerous for skidding -
the driver's experience most crucial in this stage of stopping or slowing
down.
3. The composite brake shoe CAN NOT 'condition' the wheel. The cast iron can
do it in very limited amount.

Take care.