LIBERTY SHIPS

Liberty ships were American-made, mass-produced merchant vessels that were used by the Allies to carry freight, troops, and fuel during World War II (1939–1945). A few were converted to other uses, including tank transports, hospitals, and repair shops. A Liberty ship was a modified version of a merchant ship of simple design that was conceived in Great Britain. The original plan called for the vessels to be riveted, but riveting was a time-consuming process. By September 1940, Britain was under siege by German naval and air forces and lacked sufficient time or capital to build such ships for itself. So when production of the merchantmen was turned over to the United States, industrialist Henry J. Kaiser (1882–1967) sped up production by welding the vessels and applying revolutionary prefabrication techniques. Kaiser started with an initial keel-to-deliver time of over 200 hundred days. Within a year, however, Liberty Ships were being launched just 24 days after the laying of the keel. They traveled at a top speed of 11 knots, and came in different sizes and weights, with the largest being almost 450 feet long and over 10,000 tons.

Approximately 250 Liberty Ships were sent to Great Britain and the Soviet Union under the Lend-Lease program, while another 200 were used by American forces. Liberty ships take their name from "Liberty Fleet Day," a day in September 1941 when the first one was launched. Because of the high rate of production, a number of Liberty Ships were defective. But others endured repeated pounding by German surface ships and submarines. One ship even sunk a German auxiliary cruiser with its single four-inch gun.

See also: Lend-Lease Act, World War II