While this is not a marine application, an alternative method is to just have a big enough drum that you just lay a single row of cable, in this case, a mine lift hoist at the Quincy Mine in Hancock, in Michigan's Upper Peninsula. It was installed in 1918, and was used to lift mine cars from, at the time, the deepest mine shaft in the world. The drum, which is spiral grooved, had a capacity of nearly 11,000 feet of cable. The mine shaft, Quincy #2, had an angled (55˚ from vertical) shaft length of 9,260 feet (vertical depth of 6,200 feet) and the hoist could lift 10 tons of copper ore at nearly 36 mph. The hoist was built on what at the time was also the largest single block of reinforced concrete in the world, 3,200 cubic yards. The mine continued to operate until 1945, when the dramatic drop in the price of copper after the end of WWII, no longer allowed the mine to operate at a profit.
October 2010 (Sony DSC-H2)
This is the Quincy Mine Hoist House where the hoisting machinery was installed:
October 2010 (Sony DSC-H2)
And this shows that Quincy #2 Shaft House. Note that the steam plant had been demolished years ago:
October 2010 (Sony DSC-H2)
And here is the Quincy #2 Shaft House. Note that slope of the large section of the roof shows the angle at which the shaft went into the ground. The reason for angle is that the shafts were cut to follow the geological angle of the strata, shafts than ran out horizontally from this single angled shaft. There were dozens of similar mines in the area, and they all followed that same angle. Note that Quincy #2 is the best preserved example of copper mines in the area, which was originally opened for operation in 1868.
October 2010 (Sony DSC-H2)
This shows a typical piece of 'float copper', often found in the area. The copper taken from these mines was pure ore. There was no actual 'smelting' process, only the mechanical separating of the rock from the pure copper, which was then melted and poured in ingots for shipment.
October 2010 (Sony DSC-H2)
John R. Baker, P.E. (ret)
EX-'Product Evangelist'
Irvine, CA
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