Ore dock

An ore dock is a large structure used for loading ore (typically from railway cars or ore jennies) onto ships which then carry the ore to steelworks or to transshipment points. Most known ore docks were constructed near iron mines on the upper Great Lakes and served the lower Great Lakes. Ore docks still in existence are typically about 60 feet (18 m) wide, 80 feet (24 m) high, and vary from 900 feet (270 m) to 2,400 feet (730 m) in length. They are commonly constructed from wood, steel, reinforced concrete, or combinations of these materials.

They are commonly used for loading bulk ore carriers with high mass, low value ore, such as iron ore, in raw or taconite form.

The typical construction of an ore dock is a long high structure, with a railway track or tracks along the top with a number of "pockets" into which ore is unloaded from cars, typically by gravity. Each pocket has a chute that can be lowered to discharge the ore into the hold of a ship berthed alongside. The use of pockets and chutes allows loading the dock asynchronously of its discharge into the freighter.

The docks storage bins or pockets typically are wider at the top than the bottom, and lead to movable steel chutes. These chutes project out over the water at a slight angle from the sides of the docks. The hinged chutes, which when lowered allow ore to drop into ships from the pockets, are located at twelve-foot intervals over the length of the dock.

This spacing is not coincidental, as the docks and the lakers they could load evolved together, and laker hatch spacing is typically 12, or 24-foot (7.3 m) on center.

Ore docks were a common sight in many Lake Superior ports of Minnesota, Wisconsin and especially Michigan. Rich iron ore deposits were first discovered in the Upper Peninsula in the 1840s and remain a significant source of wealth for the state. By the 1890s, Michigan was the largest supplier of iron ore in the United States. Railroads would haul ore from the mines to great ore docks on the Great Lakes in places such as Escanaba and Marquette, where it would be loaded on ore freighters and transported to the rest of the country.

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