dump car[′dəmp ‚kär]
an open railroad car with a rectangular-shaped body and a pneumatic unloading device. A dump car is tilted to one side or the other when freight is unloaded, and the side is opened or raised at the same time. Dump cars are used mainly for hauling ore and loose building materials on the ground of large enterprises. Dump cars have a capacity of 40 to 80 tons.