A crane truck is used for the most part to lift heavy cargo and transport the load horizontally to another location. Because the loads are specific, crane trucks built by OJ Watson are customized to move the specific load required. A self-propelled loading-unloading machine is mounted on the truck body. The rotating cantilevered boom is generally equipped with a hoist rope, wire ropes or chains, and sheaves that lift and lower materials. At OJ Watson, we call them a shop on wheels.