The SS Iosco was a notable Great Lakes freighter constructed in 1891 by the West Bay City Shipbuilding Company (F.W. Wheeler Shipyards) in West Bay City, Michigan. Named after Iosco County, Michigan, she was one of the largest wooden ships ever built, measuring an overall length of 312 feet (95 meters). Her hull, constructed from white oak, was reinforced with steel arches, a steel keelson, steel cross bracing, and steel plates to support her enormous size and structural integrity. The hull length between perpendiculars was 291 feet (89 meters), with a beam of 41 feet (12 meters) and a cargo hold depth of 20 feet (6.1 meters). Driven by a powerful three-cylinder triple expansion steam engine built by the Frontier Engine Works Company of Detroit, the Iosco could generate approximately 1,000 horsepower. Her engine featured cylinders measuring 20, 32.5, and 55 inches in diameter, with a 42-inch stroke, and was powered by two coal-burning Scotch marine boilers constructed by Wickes Brothers of Saginaw, Michigan. These boilers stood 12 feet high and 11.75 feet wide, operating at a steam pressure of 167 pounds per square inch. The Iosco's service record ended tragically in September 1905 when she foundered on Lake Superior. While towing the schooner barge Olive Jeanette, both vessels encountered a storm, which led to their sinking near the Huron Islands. The wreckage of the Olive Jeanette was discovered in over 300 feet of water about eight miles off the islands in the 1990s. The Iosco's wreck, however, has not yet been found. Reports from the time indicate that the lighthouse keeper on Huron Island witnessed the sinking of a large schooner, presumed to be the Olive Jeanette, and wreckage consistent with the Iosco was found nearby. The incident resulted in the loss of all crew members aboard both vessels—nineteen on the Iosco and seven on the Olive Jeanette—highlighting the perilous nature of Great Lakes shipping during that era. The sinking marked a significant event in maritime history on the Great Lakes, illustrating the dangers faced by wooden freighters navigating storm-prone waters.

This description has been generated using GPT-4.1-NANO based on the Vessel's wikidata information and then modified by ShipIndex.org staff.