Liberty ships

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).