Page 6 - March 2023 Track N Times

FEATURE STORY

Mountain Grades Continued

You can see from the table below if you were to take a piece of Loram equipment and release the brakes at the
top of the mountain and start your decent without brakes applied, you could be going 20 to 30 mph within a mi-
nute. Here is where it goes sideways, by the time brakes are applied, and the lag time for the brakes to set up to
become effective, you have already picked up more speed and it takes more brake pressure to slow, which in turn
puts more pressure on the brake shoes to the wheels that generates heat. The more pressure that is applied to
the braking forces puts heat into the wheels, and you start to lose the coefficient properties of your brake shoes
and that constitutes the loss of braking compacity. The longer this goes on eventually the brake shoes become
too hot and they lose all braking properties and are no longer effective and melt off, now putting the brake head
into the wheels.

Accel Rate 1.0 1.0 2.0 2.0

Grade % (ft./sec^2) Distance(ft) Speed(mph) Distance(ft) Speed(mph)

1.0 .031 566 12.9 2264 25.7

1.5 0.48 856 19.5 3424 38.9

2.0 0.64 1146 26.0 4583 52.1

2.5 0.80 1436 32.6 5742 65.3

Thermo Cracks

Thermo cracks can start to develop when heat generated by brake friction to the wheels is excessive for long peri-
ods of time.

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VOLUME 4 : ISSUE 2