How many liberty ships were sunk

A total of thirty-seven factories worked night and day on an assembly line in order to produce the Liberty Ships. Welded structure of the ship enable the continuous block manufacturing.

This manufacturing method of cargo ship was similar to that used in Japan during the same period. However, the scale involved in the Liberty Ship construction for the Pacific War was amazing. Between and , the thirty-seven shipyards produced 5, ships 2, were Liberty Ships which were equivalent to DWT 56 million.

Many damages and accidents of cargo vessel were occurred, and especially for Liberty Ships. The vast majority of these accidents were related to brittle fracture. By 1st of April , cases of damage had been reported for cargo vessels, of which were to Liberty Ships. Total numbers of damages were reported. These numbers vary by source. Parker's work states that the number of construction of cargo vessel was and that the number of damaged Liberty Ships was with being sunk or incurring serious damage.

It is important to keep in mind the discrepancies due to the difference of assortment and counting period. Occurrence and progress of brittle cracks may result in catastrophic failure if the condition is satisfied.

In January at the Oregon shipyard, the Liberty Ship "Schenectady" suddenly broke in two with a large sound when it was mooring at outfitting basin. In March at the outside New York port, "Manhattan", which was on sailing, was also broke in two.

A total of seven ships were broken like this. Sequence A committee for investigating these accidents of cargo vessels was established in The report completed three years thereafter on July 15th, , and the committee was dissolved. The investigation into the cause of the accidents was wide-ranging and systematic research on structure and welding. The interim report suggested the importance of modification of structural design that reduces stress concentrations, improvement of weld quality that eliminates initial defect, and reduction of residual stresses by welding.

However, the lack of steel toughness was not sufficiently recognized; insufficient attention was paid for the material. It was only considered that "rimmed steel" is preferred than "killed steel".

So-called "welding steel" which possesses superior fracture toughness and weld crack resistance was not used in the wartime. The production of the welding steel was started after the war. It was regulated to use for vessel's body later.

The final report concluded that the number of accidents due to welding structure was statistically small and it will have no problem by the countermeasures.

It is also stated that the construction of the large number of cargo vessels enable the transportation of military logistics which helped the victory. Overall the project, therefore, was thought success.

It called for building 50 ships a year. The replacement fleet was to consist of fast tankers and three types of fast cargo ships. While the basic hulls and power plants were standardized, much of the equipment for cargo handling and crew accommodations were varied to fit the needs of different shipowners and operators.

Shortly before the war in Europe started in , the original schedule was doubled to ships a year, and then doubled again in to ships a year. By that time, the 10 operating shipyards of had grown to The ships being built under this program were excellent vessels and comparatively fast.

In one of the new ships made a trans-Atlantic crossing averaging a speed of 17 knots. During that same year the commission completed its first all-welded vessel. This technique enabled shipbuilders to assemble vessels much more rapidly than by riveting.

Welding also reduced the weight of a ship by about tons. In , war broke out in Europe. By , the Nazis had swept through western and central Europe, leaving Britain alone. They sank ships in the first nine months of the war.

In September of , a representative of J. Thompson, a major British shipbuilder, came to the United States to order ships here. The company brought plans for a freighter based on a Thompson-designed prototype built in a 10,ton vessel driven by a 2,hp engine cruising at 11 knots. In New York, the British group met the chairman of the U.

Maritime Commission, Adm. This certainly would have been an excellent idea, except that no yards were available to build them. The solution was new yards built by a partnership between Todd Shipyards Inc. This appeared to be an ideal combination, since Todd was a well-established shipbuilding firm, and Kaiser was equally well-established in heavy construction. Although hull construction was soon proceeding well in these new yards, the high-powered engines needed to drive the new C-ships were complicated.

Adequate numbers of these engines simply were not going to be available quickly enough. By , it was obvious that these faster, more complicated vessels would have to wait. What was needed immediately was quantity rather than quality. Clearly, a new design would require time-consuming development and testing, taking time that neither the British nor we had. The triple-expansion steam engine was also based on a British design that dated to about No mention was ever made to those of us who sailed on them, or to those who built them, or to the public, that the ship was based on a British design.

However, the adaptation of this design to mass production was entirely an American accomplishment. Probably the most important change was the method of assembly. At the time this program started, riveting was still the standard method for building ships. Many of the cracks were nucleated at an edge where a weld was positioned next to a hatch; the edge of the crack and the weld itself both acted as crack concentrators. Also contributing to failures was heavy overloading of the ships, which increased the stress on the hull.

Engineers applied several reinforcements to the ship hulls to arrest crack propagation and initiation problems. A total of 2, Liberty ships were built, with an expected lifespan of just five years. A little more than 2, made it through the war, and of these entered the US cargo fleet.

Many others entered Greek and Italian fleets. Many of these ships were destroyed by leftover mines, which had been forgotten or inadequately cleared.

Look at the chart in the above photograph. What statistical information does this chart present? By how much has the amount of cargo carried grown between and ? How does this photograph of the shipyard help you in answering Question 2? Photo 1 shows both Victory ships and Liberty ships under construction. Can you find the Liberty ship in Photo 1? What clues did you use to determine the difference between the Victory ships and Liberty ships? Maritime Commission Washington, D.

News Foto Release No. Not done with mirrors: Victory ships almost as far as the eye can reach line up at a West Coast shipyard for final outfitting before joining our vast merchant fleet. On Maritime Day, May 22, we shall have nearly of these crack cargo type in service, and more will be delivered before the year is out.

Maritime Administration Questions for Photo 2 1. This photo and caption was sent to local newspapers by the Maritime Commission to announce the upcoming Maritime Day. What do you think Maritime Day was about? Would Maritime Day be something worth celebrating? What artistic elements did the photographer include in this Photo 2? On the docks in front of the ships are lengths of chain. How might the chain be used on these ships?

Photo 3 shows a convoy of ships in the North Atlantic. Some of the ships in the convoy are Liberty ships. In , The United States established the forward military base in Argentia, Newfoundland to support convoy escorts and patrol aircraft. The photograph was taken from an airplane assigned to the USS Albemarle AV-5 , a seaplane tender a ship built to house and support seaplanes , in October At the time the photo was made, the Albemarle was based at Argentia.

Many cargo ships were sunk by the U-Boats. Some of the many innovations that came out of World War II to locate submarines include radar, sonar, and high frequency direction finding. Because ships traveling alone were almost certain targets for submarines, the U. The Navy and Coast Guard escorted the convoys with destroyers. Unlike modern submarines, which can stay submerged for months at a time, the submarines in World War II spent most of their time on the surface and submerged only when attacking ships or evading detection.

In areas that were close to land, airplanes were used to scout for submarines. Many of these scouting planes also carried bombs so they could attack detected enemy submarines. Questions for Photo 3 1.

Using an atlas, locate Newfoundland, Canada. Look at Map 2. Why did it make sense to base convoy escorts and patrol aircraft, such as the seaplanes from the USS Albemarle, in Newfoundland? Why would grouping ships together in convoys help protect ships from submarines?

Photo 3 shows part of the wing of the patrol aircraft. In what ways did the patrol aircraft help protect ships carrying supplies? This stamp was issued by the U. The stamp depicts a Liberty ship unloading cargo. Questions for Illustration 1 1.

Look up the word "commemorate" in the dictionary. What does it mean? What is a "merchant marine"? Why do you think it was important to honor the Merchant Marine with a postage stamp? The words "Peace and War" are placed at the top of the stamp.

Why do you think these words were put on the stamp? Why is the word "peace" placed first? Questions for Photo 4 1. The ship was launched September 27, Considering the year it was built, what might be one reason why this Liberty ship doesn't have any weapons?

Note the faint white markings on the bow of the ship. Those are numbers. What do you think the numbers are for? Based on your answer, can you determine if this ship is loaded or unloaded? How did you come to your conclusion? The ship has three masts. What could they be used for? If needed, compare Photo 4 with Illustration 1. They were built in great numbers to counter the threat from submarines and to ensure that the flow of men and material was unhindered.

The following activities will help students discover more about Liberty and Victory ships and the role their community and its residents played during World War II. Activity 1: Pay Tribute to Local History Have students design a postage stamp depicting an important event that happened in your community. Encourage students to be creative with designs and color. Students should share their "stamps" in class and hold a class discussion on why they chose to commemorate that particular event.

Activity 2: Serving the War Effort By using simple designs, perfecting mass-production techniques and building the necessary shipyards, the U.

However, there were not enough workers for all the new shipyards. Many men who could have built ships were serving in the armed forces. As a result of this labor shortage, many factories and shipyards hired women, minorities, and men unable to go to war to work on the assembly lines and in the shipyards to manufacture the products needed to prosecute the war. The women were given the nickname "Rosie the Riveter" after a worker in a popular song.

Ask students to locate persons in the community or their families who worked in the farms, factories and shipyards during World War II. Students may find that local organizations that serve veterans and senior citizens are a good resource for locating these individuals in their communities.

Organize a class project to participate in the Veterans History Project of the Library of Congress by interviewing these persons and donating the interviews to the Library of Congress. The project website offers sample interview questions for civilians who worked in support of the United States during the war. A free "Field Kit" is also available with tips for interviewing. Activity 3: Carrying the Supplies The Liberty ships and Victory ships carried many different types of important supplies in support of the war including food, fuel, vehicles, ammunition, and spare parts.

Ask students to locate farms or factories in your community that supplied the war effort. Have them research how they supported the war. The local historical society or library's local history section is a good place for students to start their research.

Students may need to look at old phone books, city directories, or newspapers to determine which businesses were active in their community during the war and whether they were involved in war production.

Students should share the information they have discovered in the form of papers, project boards, computer slideshows, skits, or oral presentations.

Liberty Ships and Victory Ships, America's Lifeline in War will help students in understanding how the United States mobilized a massive construction effort to build a large merchant fleet to serve in war and peace. Of the thousands of ships built during World War II, only a small number remain. Those interested in learning more will find that the Internet offers a variety of materials about the people, vessels, and organizations associated with this great accomplishment.

The park opened in and is still in development. The park preserves and interprets the history of the men and women who worked at the factories and shipyards in and around Richmond, California in support of World War II.

Visit their website , for more information on the merchant marine, including an Education page. The site also contains links to the Maritime Museum, which includes artifacts and historic pictures. Naval Historical Foundation A non-profit organization dedicated to preserving and promoting the Navy's proud heritage. The Foundation supports the activities of the Naval Historical Center. Their website has information on primary sources including oral histories, memoirs and personal paper collections.

Maritime Service Veterans Veterans of the merchant marine and U. Naval Armed Guard operate this extensive website. This is a comprehensive site about the history and traditions of the merchant marine. American Rosie the Riveter Association This is a national organization made up of the women who worked in the factories and shipyards during World War II. The website includes a newsletter and links to related sites.

Historic Naval Ship Visitors Guide This website , maintained by the Historic Naval Ships Association, is a worldwide listing of historic ships that are open to the public, including ships' histories and contact information. The website includes a history of this U-Boat, a virtual tour and a transcript of the show that includes a detailed account of the Battle of the Atlantic during the early years of World War II, when the submarine threat to shipping was at its height. The website also has a Teacher Resources page.

Explore This Park. Where it fits into the curriculum Topics: This lesson can be used in U. Theme III: People, Places and Environments Standard A - The student elaborates mental maps of locales, regions, and the world that demonstrate understanding of relative location, direction, size, and shape.

Theme V: Individuals, Groups, and Institutions Standard A - The student demonstrates an understanding of concepts such as role, status, and social class in describing the interactions of individuals and social groups.

Theme VI: Power, Authority and Governance Standard C - The student analyzes and explains ideas and governmental mechanisms to meet wants and needs of citizens, regulate territory, manage conflict, and establish order and security.

Theme VII: Production, Distribution and Consumption Standard A - The student gives and explain examples of ways that economic systems structure choices about how goods and services are to be produced and distributed. Objectives for students 1 To outline the reasons behind the massive merchant-ship building program the United States undertook in the years before its entry in World War II.