Engineering Wonders of the World
Volume III

258 ENGINEERING WONDERS OF THE WORLD. TWO HULETT AUTOMATIC ORE UNLOADERS AT WORK. The walking beam of the nearer one has been run back from the ship, and the mast has been raised. The unloader in the background is seen in the act of clipping its mast into the ship’s hold. number of voyages while the Lakes are open to navigation.. A consequence of quick un- loading is naturally cheaper freight rates, owing to the great saving of labour as well as of time effected by the marvellous unloading and stacking machines employed. One of the most remarkable devices used for the rapid disembarkation of iron ore is the Hulett un- loader. This machine consists primarily of two parallel girders mounted upon a structure wide enough to span four lines of railway. The girders are at right angles to the quay. The whole structure is supported by wheels, and can be moved along the quay into the position required for unloading the boat. Travelling upon the parallel girders is a trolley carrying a long rocking beam pivoted at the centre. From the end of this beam hangs a two-jawed automatic bucket, which is arranged to be lowered on to the ore with its two halves apart or open. As soon as the closing mechanism is put into operation, the jaws move together, biting into the pile of ore. Not a small bite, however, as it is noth- ing extraordinary for one of these buckets to bring up ten tons of ore. The action of the machine when unloading a boat is briefly as follows : The trolley with the walking-beam travels forward along the girders out over the boat, until the mast carrying the bucket at its lower end is above one of the hatches. The mast then descends until the bucket rests upon the iron ore, when the bucket is closed and the mast raised. The trolley then moves back ; the bucket comes over a large bin built into the superstructure, opens its jaws, and discharges the ore. This cycle of operations is repeated until the boat has been emptied. From the bin the ore is dumped through