Manitowoc Shipbuilding Company, located in Manitowoc, Wisconsin, was a major shipbuilder for the Great Lakes. It was founded in 1902, and made mainly steel ferries and ore haulers. During World War II, it built submarines, tank landing craft (LCTs), and self-propelled fuel barges called "YOs". Employment peaked during the military years at 7000. The shipyard closed in 1968, when Manitowoc Company bought Bay Shipbuilding Company and moved their shipbuilding operation to Sturgeon Bay.