Liberty Ship - History and Service

History and Service

In 1936, the American Merchant Marine Act was passed to subsidize the annual construction of 50 commercial merchant vessels to be used in wartime by the United States Navy as naval auxiliaries. The number was doubled in 1939 and again in 1940 to 200 ships a year. Ship types included a tanker and three types of merchant vessel, all to be powered by steam turbines. Limited industrial capacity, especially for reduction gears, meant that relatively few of these ships were built.

In 1940, the British government ordered 60 tramp steamships from American yards to replace war losses and boost the merchant fleet. These Ocean-class ships were simple but fairly large (for the time) with a single 2,500 hp (1,860 kW) reciprocating steam engine of obsolescent but reliable design. Britain specified coal-fired plants because it had plenty of coal mines but no significant indigenous oil fields. The predecessor designs, including the Northeast Coast, Open Shelter Deck Steamer, were based on a simple ship originally produced in Sunderland by J.L. Thompson & Sons (see Silver Line) from 1879, and widely manufactured up to the SS Dorrington Court, which was built in 1938. The order specified an 18-inch (0.5 m) increase in draft to boost displacement by 800 long tons (810 t) to 10,100 long tons (10,300 t). The accommodation, bridge and main engine of these vessels were located amidships, with a long tunnel to connect the main engine shaft to its aft extension to the propeller. The first Ocean-class ship, SS Ocean Vanguard, was launched on 16 August 1941.

The design was modified by the United States Maritime Commission to conform more, but not entirely, to American construction practices, but more important, to make it even quicker and cheaper to build. The US version was designated 'EC2-S-C1': 'EC' for Emergency Cargo, '2' for a ship between 400 and 450 feet (120 and 140 m) long (Load Waterline Length), 'S' for steam engines, and 'C1' for design C1. The new design replaced much riveting, which accounted for one-third of the labor costs, with welding, and had oil-fired boilers. The order was given to a conglomerate of West Coast engineering and construction companies known as the Six Companies, headed by Henry J. Kaiser, and was also adopted as the Merchant Marine Act design. Liberty ships were designed to carry 10,000 tons of cargo, usually one type per ship, but, during wartime, generally carried loads far exceeding this.

On 27 March 1941, the number of lend-lease ships was increased to 200 by the Defense Aid Supplemental Appropriations Act, and increased again in April to 306, of which 117 would be Liberty ships.

The ships were constructed of sections that were welded together. This is similar to the technique used by Palmer's at Jarrow, North-East England, but substitutes welding for riveting. Riveted ships took several months to construct. The work force was newly trained – no one had previously built welded ships. As America entered the war, the shipbuilding yards employed women, to replace men who were enlisting in the armed forces.

The ships initially had a poor public image due to their appearance. In a speech announcing the emergency shipbuilding program, President Franklin D. Roosevelt had referred to the ship as "a dreadful looking object", and Time magazine called it an "Ugly Duckling". To try to assuage public opinion, 27 September 1941 was dubbed Liberty Fleet Day, as the first 14 "Emergency" vessels were launched that day. The first of these was SS Patrick Henry, launched by President Roosevelt. In remarks at the launch ceremony, FDR cited Patrick Henry's 1775 speech that finished "Give me liberty or give me death". Roosevelt said that this new class of ships would bring liberty to Europe, which gave rise to the name Liberty ship.

The first ships required about 230 days to build (Patrick Henry took 244 days), but the average eventually dropped to 42 days. The record was set by SS Robert E. Peary, which was launched 4 days and 15½ hours after the keel was laid, although this publicity stunt was not repeated: in fact much fitting-out and other work remained to be done after the Peary was launched. The ships were made assembly-line style, from prefabricated sections. In 1943, three Liberty ships were completed daily. They were usually named after famous Americans, starting with the signatories of the Declaration of Independence.

Any group which raised war bonds worth $2 million could propose a name. Most bore the names of deceased people. The only living namesake was Francis J. O'Gara, the purser of the SS Jean Nicolet, who was thought to have been killed in a submarine attack, but, in fact, survived the war in a Japanese prisoner of war camp. Other exceptions to the naming rule were the SS Stage Door Canteen, named for the USO club in New York, and the SS U.S.O., named after the organization itself.

Another notable Liberty ship was SS Stephen Hopkins, which sank the German commerce raider Stier in a ship-to-ship gun battle in 1942 and became the first American ship to sink a German surface combatant.

SS Richard Montgomery is also notable, though in a less positive way: the wreck of the ship lies off the coast of Kent with 1,500 tons of explosives still on board, enough to match a small nuclear weapon should they ever go off. One Liberty ship that did explode was the SS E. A. Bryan which detonated with the energy of 2,000 tons of TNT (8,400 GJ) in July 1944 as it was being loaded, killing 320 sailors and civilians in what was called the Port Chicago disaster. Another infamous Liberty ship that exploded was the rechristened SS Grandcamp, which caused the Texas City Disaster on 16 April 1947, killing at least 581 people.

Six Liberty ships were converted at Point Clear, Alabama, by the United States Army Air Forces into floating aircraft repair depots, operated by the Army Transport Service, starting in April 1944. The secret project, dubbed "Project Ivory Soap", provided mobile depot support for B-29 Superfortress and P-51 Mustangs based on Guam, Iwo Jima, and Okinawa beginning in December 1944. The six ARU(F)s (Aircraft Repair Unit, Floating), however, were also fitted with landing platforms to accommodate four R-4 helicopters, where they provided medical evacuation of combat casualties in both the Philippines and Okinawa.

The last new-build Liberty ship constructed was the SS Albert M. Boe, launched on 26 September 1945 and delivered on 30 October 1945. She was named after the chief engineer of a United States Army freighter who had stayed below decks to shut down his engines after a 13 April 1945 explosion, an act that won him a posthumous Merchant Marine Distinguished Service Medal. In 1950, a "new" liberty ship was constructed by Industriale Maritime SpA, Genoa, Italy by using the bow section of Bert Williams and the stern section of Nathaniel Bacon, both of which had been wrecked. The new ship was named SS Boccadasse, and served until scrapped in 1962.