Liberty ship

The Liberty ship was a class of cargo ship built in the United States during World War II. Though British in conception, the design was adapted by the United States for its simple, low-cost construction. Mass-produced on an unprecedented scale, the now iconic Liberty ship came to symbolize U.S. wartime industrial output.

The class was developed to meet British orders for transports to replace those torpedoed by German U-boats. The vessels were purchased both for the U.S. fleet and lend-lease deliveries of war materiel to Britain and the Soviet Union. Eighteen American shipyards built 2,710 Liberty ships between 1941 and 1945, easily the largest number of ships produced to a single design.

Their production mirrored on a much larger scale the manufacture of the Hog Islander and similar standardized ship types during World War I. The immensity of the effort, the sheer number of ships built, the vaunted role of women workers in their construction, and the survival of some far longer than their original five-year design life, all make them the subject of much continued interest.