Scale test car

These include: Cars are weighed to ensure they are within the axle load limits of the railroad.

Cars are weighed to determine (by subtracting the car's unloaded, or tare weight from the total weight) the amount of cargo loaded.

This is used to bill the railroad's customers for the carriage of bulk commodities, so it is essential that the track scales be accurate.

Scale test cars needed special handling so they would not suffer damage, which might alter their weight.

They were reweighed periodically on accurate scales at the railroad's shops.