In 1857, Captain George Judson, frustrated by the slow transfer of iron ore from trams on the dock to schooners at the harbor, helped inspire the first iron ore pocket dock. At the time, 20-30 men using shovels and wheelbarrows needed three to six days to move ore, creating bottlenecks as schooners waited for cargo. Judson suggested wooden chutes so boats would not have to wait while ore was loaded from piles on the dock, and innovators of the Lake Superior Iron Company developed the first pocket ore dock. These taller docks used pockets to store and dispense ore, and with 27 pockets, several boats could be loaded at once, reducing loading time from days to hours. The large concrete dock that still stands was built in 1931 for the Duluth, South Shore and Atlantic Railroad, later the Soo Line. Its first load, 10,103 tons of iron ore from the Ford Motor Company's Blueberry Mine west of Ishpeming, was loaded in 92 minutes. As fewer mining companies used the dock, it became economically obsolete and closed in 1971. A working pocket dock remains at Marquette's Presque Isle Harbor, north of here, where ore freighters can be seen loading iron ore pellets.