Any wheeled vehicle, usually self-propelled, used to transport heavy articles or materials. In mining, usually applied to dump and/or bottom-dump semitrailers used to transport mined waste and ore materials. The number of types of these haulage units varies widely from the small 2-st (1.8-t) standard dump truck to the unit with capacity 200 st (181 t) or greater. For larger stripping operations, where the haulage conditions are not too rugged, a diesel tractor pulling a bottom-dump semitrailer of capacity 40 to 3394 60 st (36 to 54 t) is most common. The newer trucks are equipped with power steering, power brakes, torque converters, and automatic transmissions.