Abstract: A self-unloading load hauling box for use on a towed carriage or carried by a powered mobile vehicle wherein the box is a rigid unit having a bottom wall with a floor plate and side walls and front end wall projecting up from the rigid bottom wall. An endless belt is looped around the bottom wall and runs on a driven roller at the rear end and an idler roller at the front end of the box. The endless belt is driven through an arc of selected length at spaced apart intervals to unload contents from the box. The jerky action from intermittently driving the belt has a tendency to cause a vibration, loosening the content in the box and thus results in a relatively even discharge during unloading. Between the upper run of the endless belt and the upper surface of the floor is a friction reducing pad which also absorbs shock loads tending to reduce damage to the belt and/or floor when loading heavy chunk material.