Liberty ship

From SpottingWorld, the Hub for the SpottingWorld network...
SS John W. Brown is one of only two surviving operational Liberty ships.
SS John W. Brown, one of two surviving operational Liberty ships
Class overview
Name:Liberty ship
Builders:18 shipyards in the USA
General characteristics
Class and type: Cargo ship
Displacement: 14,245 long tons (14,474 t)[1]
Length: 135 m (441 ft 6 in)
Beam: 17.3 m (56 ft 10.75 in)
Draft: 8.5 m (27 ft 9.25 in)
Propulsion: Two oil-fired boilers,
triple-expansion steam engine,
single screw, 2,500 horsepower (1,864 kW)
Speed: 11 to 11.5 knots (20 to 21 km/h)
Range: 23,000 miles (37,000 km)
Capacity: 10,856 metric tons (10,685 long tons) deadweight (DWT)[1]
Complement: 41 men
Armament: Stern-mounted 4-in (102 mm) deck gun for use against surfaced submarines, variety of anti-aircraft guns

Liberty ships were cargo ships built in the United States during World War II. Though British in conception, they were adapted by the U.S. as they were cheap and quick to build, and came to symbolize U.S. wartime industrial output. Based on vessels ordered by Britain to replace ships torpedoed by German U-boats, they were purchased for the U.S. fleet and for lend-lease provision to Britain. Eighteen American shipyards built 2,751 Libertys between 1941 and 1945, easily the largest number of ships produced to a single design.

The production of these vessels mirrored, on a much larger scale, the manufacture of the Hog Islander ship and similar standardized types during World War I. 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 the original design life of five years, make them the subject of much study.

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 turbine construction, 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 obsolete but reliable design. Britain specified coal fired plants because it had plenty of coal mines but no 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, Ocean Vanguard, was launched on 16 August 1941.

The design was modified by the United States Maritime Commission to conform to American construction practices and to make it even quicker and cheaper to build. The U.S. 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 featured 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.

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 but substitutes welding for riveting. Riveted ships took several months to construct. The work force was newly trained—no one 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 because of their looks. 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 Franklin D. 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.

Early on, each ship took about 230 days to build (Patrick Henry took 244 days), but the average eventually dropped to 42 days. The record was set by Robert E. Peary, which was launched 4 days and 15½ hours after the keel was laid, although this publicity stunt was not repeated—and 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 new Liberty ships were being completed every day. They were mainly 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 were named for 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.[2]

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[vague] 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 Template:Convert/tonTNT 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 re-christened SS Grandcamp, which caused the Texas City Disaster on April 16, 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, creating the first seagoing helicopter-equipped ships, and provided medical evacuation of combat casualties in both the Philippines and Okinawa.[3]

The last 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.[4]


Early Liberty ships suffered hull and deck cracks, and a few were lost to such structural defects. During World War II, there were nearly 1,500 instances of significant brittle fractures. Twelve ships, including three of the 2,710 Liberties built, broke in half without warning, including the SS John P. Gaines,[5][6] which sank on 24 November 1943 with the loss of 10 lives. Suspicion fell on the shipyards which had often used inexperienced workers and new welding techniques to produce large numbers of ships in great haste. Constance Tipper of Cambridge University demonstrated that the fractures were not initiated by welding, but instead by the grade of steel used which suffered from embrittlement.[7] She discovered that the ships in the North Atlantic were exposed to temperatures that could fall below a critical point when the mechanism of failure changed from ductile to brittle, and thus the hull could fracture relatively easily. The predominantly welded (as opposed to riveted) hull construction then allowed cracks to run for large distances unimpeded. One common type of crack nucleated at the square corner of a hatch which coincided with a welded seam, both the corner and the weld acting as stress concentrators. Furthermore, the ships were frequently grossly overloaded and some of the problems occurred during or after severe storms at sea that would have placed any ship at risk. Various reinforcements were applied to the Liberty ships to arrest the crack problems, and the successor design, the Victory ship, was stronger and less stiff to better deal with fatigue.

Several designs of mass-produced petroleum tankers were also produced, the most numerous being the T2 tanker series, with about 490 built between 1942 and the end of 1945.

After the war

More than 2,400 Liberty ships survived the war. Of these, 835 made up the postwar cargo fleet. Greek entrepreneurs bought 526 ships and Italian ones bought 98. Shipping magnates like John Theodoracopoulos,[8] Aristotle Onassis,[9] Stavros Niarchos,[9] Stavros George Livanos, the Goulandris brothers,[9] and families named Andreadis, Tsavliris, Achille Lauro, and Bottiglieri were known to have started their fleets by buying Liberty ships.

The term "Liberty-size cargo" for 10,000 long tons (10,000 t) may still be heard in the shipping business.

Some Liberty ships were lost after the war to naval mines that were inadequately cleared. The Pierre Gibault was scrapped after hitting a mine in a previously cleared area off the Greek island of Kythira in June 1945,[10] and the same month saw the Colin P. Kelly Jnr take mortal damage from a mine hit off the Belgian port of Ostend.[11] In August, 1945 the William J. Palmer was carrying horses from New York to Trieste when it rolled over and sank 15 minutes after hitting a mine a few miles from destination. All crew members and six horses were saved.[12] The Nathaniel Bacon hit a minefield off Civitavecchia, Italy in December 1945, caught fire, was beached, and broke in two; the larger section was welded onto another Liberty half hull to make a new ship 30 feet longer, named Boccadasse.[13] As late as December 1947, the Robert Dale Owen, renamed Kalliopi and sailing under the Greek flag, broke in three and sank in the northern Adriatic Sea after hitting a mine.[14] Other Liberties lost to post-war mines include the John Woolman, Calvin Coolidge, Cyrus Adler, and Lord Delaware.[15]

In the 1960s three Liberty ships were reactivated and converted to technical research ships with the hull type AGTR and used to gather electronic intelligence and for radar picket duties by the United States Navy. SS Samuel R. Ailken became the USS Oxford (AGTR-1), SS Robert W. Hart became the USS Georgetown (AGTR-2), and SS J. Howland Gardner became the USS Jamestown (AGTR-3). All of these ships were decommissioned and stricken from the Naval Vessel Register in 1969 and 1970.

File:SS Hellas Liberty (restored).jpg
SS Hellas Liberty (ex SS Arthur M. Huddell) in June 2010

Only two operational Liberty ships, the SS John W. Brown and the Jeremiah O'Brien, remain. The John Brown has had a long career as a school ship and many internal modifications, while the Jeremiah O'Brien remains largely in its original condition. Both are museum ships that still put out to sea regularly. In 1994, the O'Brien steamed from San Francisco to England and France for the 50th anniversary of D-Day, the only large ship from the original Overlord fleet to participate in the anniversary. In 2008, the Arthur M. Huddell was transferred to Greece and was converted to a floating museum dedicated to the history of the Greek merchant marine [16]; however, while missing major components were restored, this ship is no longer operational.

Liberty ships continue to serve in a "less than whole" function many decades after their launching. In Portland, Oregon the hulls of the Richard Henry Dana and Jane Addams serve as the basis of floating docks.[17] The SS Albert M. Boe survives as the Star of Kodiak, a landlocked cannery in Kodiak Harbor at 57°47′12″N 152°24′18″W / 57.78667°N 152.405°W / 57.78667; -152.405.

Fifty-eight Liberty ships were lengthened by 70 feet (21 m) starting in 1958.[18] The bridges of most of these were also enclosed in the mid-1960s in accordance with a design by naval architect Ion Livas. This gave the ships an additional 640 long tons (650 t) of carrying capacity at a small additional cost.[19][citation needed]

U.S. shipyards

Liberty ships were built at seventeen shipyards located along the Atlantic, Pacific and Gulf coasts:[20]

Fictional appearances

A Liberty ship was featured in the Quantum Leap episode 'Ghost Ship'.

A Liberty ship, converted to a hospital ship, is the eponymous subject and setting of Alistair MacLean's mystery thriller San Andreas (1984) The prologue to this novel, also by MacLean, is an interesting essay on Liberty ships and the conditions, character and behavior of the British Merchant Marine owners that used them, and sailors that sailed them.

A Liberty ship is featured in the Humphrey Bogart 1943 film Action in the North Atlantic. Its deck gun is described as being 5" rather than 4", probably for wartime propaganda reasons. Called the Sea Witch in the film, it was described as having been launched from a shipyard in Kearny, New Jersey.[citation needed]

In Clive Cussler's book Deep Six, the prologue details a Liberty ship that disappears in the 1960s and becomes a recurring ghost ship in The Flying Dutchman vein. It is later found by Dirk Pitt, leading to further adventures.

Most of the engine room scenes of the 1997 film Titanic were shot aboard the museum Liberty Ship SS Jeremiah O'Brien in San Francisco Bay. Scott Sigler's book Nocturnal also has several scenes that take place on the Jeremiah O'Brien.

The wreck of the SS Richard Montgomery is central to the plot of Stephen Barlay's 1977 novel Blockbuster, in which an extortionist threatens to blow it up, thereby causing serious flooding in central London, if his demands are not met.

See also


  1. 1.0 1.1 Davies, 2004, page 23.
  2. Reading 1: Liberty Ships National Park Service Cultural Resources.
  3. The Hoverfly in CBI, Carl Warren Weidenburner
  5. Wreck of the SS John P Gaines
  6. Fracture - some maritime examples. Mechanical Engineering Department, University of Western Australia.
  7. Constance Tipper (researcher into Liberty ship fracture)
  8. The Shipping World and Shipbuilding & Marine Engineering News, 1952, p. 148.
  9. 9.0 9.1 9.2 Elphick, Peter. Liberty, p. 401.
  10. Elphick, Liberty, p. 309.
  11. Elphick, Liberty, p. 166.
  12. Elphick, Liberty, p. 271.
  13. Elphick, Liberty, p. 108.
  14. Elphick, Liberty, p. 402.
  15. Elphick, Liberty, p. 325.
  16. The Hellas Liberty Project
  17. Did You Know: Liberty Ships Still Afloat in Portland
  18. Modern Ship History
  19. The History of Modern Shipping
  20. "WWII Construction Records, Private-Sector Shipyards that Built Ships for the U.S. Maritime Commission". Colton Company. Retrieved 2007-12-01. 


External links

Wikimedia Commons has media related to:
[[Commons: Category:Liberty ships

| Liberty ships


cs:Liberty (loď) da:Liberty-skib de:Liberty-Frachter el:Λίμπερτυ fr:Liberty ship it:Liberty (navi trasporto) nl:Liberty (scheepstype) ja:リバティ船 no:Libertyskip pl:Statki transportowe typu Liberty ru:Либерти (судно) fi:Liberty-alus sv:Libertyfartyg zh:自由轮