Scales. There are two types of scales available for weighing cars,
static and weight-in-motion. See AAR Scale Handbook.
Static Scale. One car at a time is rolled onto the scale, stopped,
and weighed. The scale usually is a beam balance type, but can be a load cell
Weigh-in-Motion Scale. This scale weighs cars coupled together
while being pulled over the scale by a locomotive at slow speed. The scale is
a load cell type.
Selection. If a scale is necessary, a static scale would probably
meet Navy needs. Weigh-in-motion scales are sophisticated devices used where
large numbers of cars are to be weighed each day.
Scales shall be located to minimize switching.
Alignment. A minimum of 100 feet of tangent tracks shall be
provided on scale approaches. Gradients should be less than 0.05 percent over
a static scale. Weigh-in-motion scales tracks should be level or slightly
upgrade allowing the train to be stretched during weighing.
Dead Rails. Where a by-pass track cannot be built around the
scale, use dead rails to gauntlet equipment not to be weighed over the scale.