Liberty ships, mass-produced merchantmen which were constructed in the USA, many by the West Coast Kaiser shipyards. They were described as ships that were ‘built by the mile and chopped off by the yard’.

In September 1940 the British ordered 60 ships from the USA which were based on a British plan for a ship of simple design. To speed up the production of this order these vessels were welded, not riveted, and the original plans were considerably modified by the Americans to take this into account. In January 1941 the USA launched its own emergency construction programme of 200 ships based on the modified British design. These 7,126-ton, 11-knot, ships were dubbed ‘The Liberty Fleet’ and 27 September 1941, the day the first one, Patrick Henry, was launched, was called ‘Liberty Fleet Day’, a name which stuck.

Liberty ships came in several lengths and though most were designed to carry freight (see Figure ), troops, or fuel, others were modified for a variety of uses, from hospital ships to floating repair shops and Army Tank Transports (‘zipper ships’). American Liberty ships were mostly named after notable US citizens and a total of 2,710 were constructed. One was launched 4 days and 15½ hours after her keel was laid.

Under the Lend-Lease programme about 200 went to the UK and 50, which were never returned, to the USSR. Many were sunk in the convoys which sustained both countries. The British ships were given the prefix ‘Sam’, not as an indication of their origin but because it was the initials of their type of construction (Superstructure Aft of Midships).

The speed with which Liberty ships were produced, often by inexperienced workers, resulted in a high percentage of defects and the loss of a number of vessels—one in 30 suffered major fractures. However, some absorbed severe punishment both from the sea and from Axis attack, and one, Stephen Hopkins, sank a German auxiliary cruiser with her single 4 in. (10 cm.) gun.

Bibliography

Sawyer, L., and and Mitchell, W. , The Liberty Ships (Newton Abbot, 1970).

Liberty ships, mass-produced, prefabricated merchant vessels with all-welded hulls produced in quantity by American shipyards during the Second World War (1939–45). Their deadweight tonnage was 10,500 and they were fitted with triple expansion steam engines which gave them an overall speed of 11 knots. The original design was produced by the English Sunderland Company, Newcastle upon Tyne, as long ago as 1879. The British ships were given the prefix ‘Sam’, not as an indication of their origin but because it was the initials of their type of construction (Superstructure Aft of Midships). They were adopted by the Americans because they incorporated simplicity of design and operation, rapidity of construction, large cargo-carrying capacity, and were remarkably resistant to war damage. One even managed to sink a German armed merchantman with its 4-in. (10-cm) gun. Altogether 2,710 were built. Elphick, P. , Liberty: The Ships that Won the War (2002).
Sawyer, L., and and Mitchell, W. , The Liberty Ships (1970).

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