Re: Emergency Braking Was: Re: Beresfield Accident Findings

["Jeff Schmidt" <jschmidt@tpgi.com.au>]

>124 vehicles on the Coalies.?
>Australian National had to use the compressor wagon
>mainly because of leakage and long build up times after
>applications, the compressor's in the Loco's were
>working flat out keeping up.
>
>Hammersley Iron run 200 wagon trains, the heaviest in
>the World with all head end power (26,000 tonnes +)with
>no brake wagon.!  BUT they run with higher brake pipe
>pressures amongst other things.


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.

Jeff