Liberty ship
The Liberty ships were cargo ships built as part of a WWII era program to increase the number of U.S. flag vessels. Liberty ships were slow, but economical to build; more than 2,700 of them were built by major shipyards and by emergency shipyards that had been set up to fill the need for cargo shipping.
The project was managed by Henry J. Kaiser.
The first Liberty ship was the SS Patrick Henry, launched September 7, 1941. Early on, each ship took about 230 days to build, but the average eventually dropped to 42 days. The record was set by the SS Robert E. Peary, which was launched 4 days and 15 1/2 hours after the keel was laid, although this was a publicity stunt and was not repeated. The ships were made assembly-line style, from premade sections. In 1943, three new Liberty ships were being completed every day. They were all named after famous Americans.
Many Liberty ships survived the war, and made up a large percentage of the postwar cargo fleet. The term "Liberty-size cargo" for 10,000 tons may still be heard in the shipping business.
The success of the immense effort to build Liberty ships, the sheer number of ships built, and the fact that some of the ships survived far longer than they had been designed to, have combined to make Liberty ships a subject of much specialized study.
Late in the war, the building of Liberty ships was replaced by that of Victory ships and other more substantial types of cargo ships.
The two surviving Liberty ships are the SS John W. Brown and the Jeremiah O'Brien, both museum ships. The John W. Brown, based in Baltimore, still puts out to sea regularly.
Another notable Liberty ship was the SS Stephen Hopkins, which sank a German commerce raider in a ship-to-ship gun battle in 1942. She was the first American ship to sink a German surface combatant.
The SS Richard Montgomery is also notable, though in a less positive way; the wreck of the ship lies off the coast of Kent with over 3,000 tons of explosives still on board, enough to match a small nuclear detonation should they ever go off.
The accomodation, bridge and main engine of these vessels were located in the middle of the shift. A tunnel connected the main engine shaft to the aft part of the shift connected with the propeller.
Following the Second World War the Liberty ships became the vessels with which the Greek shipping business was resureccted.
See also