Солтүстік Американың Ұлы көлдеріндегі кен тиелгіш құрылғысы

Ore unloader used in the Great Lakes of North America

The Hulett was an ore unloader that was widely used on the Great Lakes of North America. It was unsuited to tidewater ports because it could not adjust for rising and falling tides, although one was used in New York City.

The Hulett was invented by George Hulett of Conneaut, Ohio, in the late 19th century; he received a patent for his invention in 1898. The first working machine was built the following year at Conneaut Harbor. doubling in length and quadrupling in capacity. By 1913, 54 Hulett machines were in service. Two were built at Lake Superior (unloading coal) and five at Gary, Indiana, but the vast majority were along the shores of Lake Erie. The additional unloading capacity they brought helped permit a greater than doubling of the ore traffic in the 1900–1912 period. A total of approximately 75 Huletts were built. One was installed in New York City to unload garbage. The Port Authority disassembled and retained two Huletts, to enable their reconstruction at another site, but the reconstruction has not yet happened. but they chose another contractor later in the month, which expects to salvage the arms and buckets.

The electrically powered Hulett unloader rode on two parallel tracks along the docks, one near the edge and one further back, ordinarily with four railroad tracks in between. Steel towers, riding on wheeled trucks, supported girders that spanned the railroad tracks. Along these girders ran a carriage which could move toward or away from the dock face. This in turn carried a large walking beam which could be raised or lowered; at the dock end of this was a vertical column with a large scoop bucket on the end. A parallel beam was mounted halfway down this column to keep the column vertical as it was raised or lowered. The machine's operator, stationed in the vertical beam above the bucket for maximum cargo visibility, could spin the beam at any angle. The scoop bucket was lowered into the ship's hold, closed to capture a quantity (10 tons approx.) of ore, raised, and moved back toward the dock. The workmen who operated the Hulett uploaders were known as Ore Hogs. To reduce the required motion of the carriage, a moving receiving hopper ran between the main girders. It was moved to the front for the main bucket to discharge its load, and then moved back to dump it into a waiting railroad car, or out onto a cantilever frame at the back to dump the load onto a stockpile. The Hulett could move along the dock to align with the holds on an ore boat. When the hold was almost empty, the Hulett could not finish the job itself. Workmen entered the hold and shoveled the remaining ore into the Hulett's bucket. In a later development, a wheeled excavator was chained to the Hulett's bucket and lowered into the hold to fill the Hulett.