Liberty Ships

Copyright 2004 Project Liberty Ship

Specifications:

The Liberty Ships (officially Maritime Commission standard EC2-S-C1 emergency cargo ships) were one of the great production triumphs of the Allies in the Second World War.  These ships were built as fast and as cheaply as possible, with a "programmed obsolescence" of just five years, with the first ship (the Patrick Henry) being launched in September 1941.  The idea was that they could be produced faster than the U-Boats in the Atlantic could sink them.  One shipyard set a record of laying down and launching a Liberty Ship in just 24 hours.  This was not typical, of course, but many yards were routinely launching Liberty Ships a month after laying them down.

The design was based on British Ocean-class cargo ships ordered from American yards in 1940, modified to burn oil rather than coal. The hull form was modified for easier construction and the crew's quarters were placed in a single amidships deck house resembling those of Maritime Commission standard types. The use of an old but reliable triple-expansion reciprocating engine design helped ensure that the machinery could be manned by inexperienced crews while avoiding a competition with warship construction for more modern geared turbine machinery.

The name "Liberty Ship" was a propaganda invention that took some time to work up. In his 3 January 1941 announcement of the emergency shipbuilding program, Roosevelt referred to the design as a "dreadful looking object", and Time described the ships as "Ugly Ducklings." By May 1941 the Maritime Commission saw the need for a more positive label, and asked that the ships be consistently referred to as "Emergency Ships." It was suggested at the same time that those operating under the American flag be called the "Liberty Fleet." However, in the wake of the widely publicized launching of Patrick Henry, the term "Liberty Ship" came into widespread use.

A total of 2708 Liberty Ships were constructed during the war.  This represents a total deadweight tonnage of nearly 30,000,000 tons. Production ramped up from just 2 ships in December 1941 to a peak of 128 ships in November 1943, then ramped back down less than ten ships a month in late 1945.

These ships were not without their disadvantages.  They had definite structural weaknesses, and their all-welded construction was sometimes unreliable.  A few ships broke apart in the heavy seas of the North Atlantic where cold temperatures made the welds brittle.  Nevertheless, and in spite of their "emergency" nature, many Liberty ships were still plying the waves thirty years later.

The production schedule below is total production. The number actually allocated to the Pacific is less easily ascertained, but theoretically should have been roughly 30% of the total except in the first and final months of the Pacific War.

Production schedule

References

Lane (1951)

Project Liberty Ship (accessed 1 January 2007)

The Pacific War Online Encyclopedia © 2007, 2009 by Kent G. Budge.  Index

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