Re: Emergency Braking Was: Re: Beresfield Accident Findings

[telljb@ozemail.com.au (Tell)]

"Jeff Schmidt" <jschmidt@tpgi.com.au> wrote:
>Actually a higher brake pipe pressure increases leakage. For very long
>trains such as those in the States and iron ore trains in the Pilbra region
>the maximum brake pipe gradient is 15 psi (The difference between the loco
>and last wagon BP pressures). Don’t quote me on this but the reason why they
>can run such long iron ore trains is because the ambient temperature allows
>a higher brake pipe pressure to reach the last wagon. The colder it gets,
>the shorter the train.


There is one very important thing I overlooked with the
Hammersley trains, the ore wagons are in pairs joined
by a solid draw bar and each pair share a common brake
set up, thereby effectively reducing the brake system
by half.  Mount Newman of course use mid train helpers
on their 240 wagon trains which smartens up brake
response considerably.

----Tell
Alice Springs NT