The belt was covered with a steel casing to prevent the wind blowing away zinc oxide powder. It was extensible, and retracted after a load was delivered to the ship's hold.[1] The main conveyor belt featured an innovative movable alignment system, designed to reduce the risk of the belt escaping the driving wheels under the pressure of the falling ore. The main belt dumped the ore on the slightly lower extensible conveyor belt, which could be protruded for 15 metres (49 ft) and channeled the ore powder into a vertical shaft going to the hold of a moored ship.