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The Hulett was a design of automatic ore unloader that once saw wide usage along the Great Lakes of North America. They were unsuited to tidewater ports because they could not adjust for rising and falling tides, and few were so used. ==History== The Hulett was invented by George Hulett of 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 in Conneaut, Ohio. It was successful, and many more were built along the Great Lakes, especially the southern shore of Lake Erie to unload boats full of taconite from the iron mines near Lake Superior. Substantial improvements were later made on the design by Samuel T. Wellman. It is these second-generation Huletts which continue to stand to this day. The Hulett machine revolutionised iron ore shipment on the Great Lakes. Previous methods of unloading lake freighters, involving hoists and buckets and much hand labor, cost approximately 18¢/ton. Unloading with Huletts cost only 5¢/ton. Unloading only took 5–10 hours, as opposed to days for previous methods. Lake boats changed to accommodate the Hulett unloader, and became much larger, 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 lake's Huletts were used until about 1992, when self-unloading boats were standard on the American side of the lake. All have since been scrapped. In 1999, only six remained, the group of four at Whiskey Island in Cleveland, Ohio the oldest. Another set was used unloading barges of coal in South Chicago until 2002 and were demolished in the Spring of 2010. In spite of the Cleveland machines being on the National Register of Historic Places and designated as a Historic Mechanical Engineering Landmark, they were demolished in 2000 by the Cleveland Port Authority to enable development of the underlying land. The Port Authority disassembled and retained two Huletts, to enable their reconstruction at another site, but the reconstruction has not yet happened. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Hulett」の詳細全文を読む スポンサード リンク
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