World War II United States Merchant Navy was the largest civilian

Navy A navy, naval force, military maritime fleet, war navy, or maritime force is the military branch, branch of a nation's armed forces principally designated for naval warfare, naval and amphibious warfare; namely, lake-borne, riverine, littoral z ...

in the world, which operated during

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

. With the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

fighting a

world war A world war is an international War, conflict that involves most or all of the world's major powers. Conventionally, the term is reserved for two major international conflicts that occurred during the first half of the 20th century, World War I ...

in all the

world ocean The ocean is the body of salt water that covers approximately 70.8% of Earth. The ocean is conventionally divided into large bodies of water, which are also referred to as ''oceans'' (the Pacific, Atlantic, Indian, Antarctic/Southern, and ...

s, the demand for

cargo In transportation, cargo refers to goods transported by land, water or air, while freight refers to its conveyance. In economics, freight refers to goods transported at a freight rate for commercial gain. The term cargo is also used in cas ...

and

fuel A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work (physics), work. The concept was originally applied solely to those materials capable of releasing chem ...

was very high. Cargo and fuel was needed around the world for the

United States Navy The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 millio ...

United States Army The United States Army (USA) is the primary Land warfare, land service branch of the United States Department of Defense. It is designated as the Army of the United States in the United States Constitution.Article II, section 2, clause 1 of th ...

United States Marine Corps The United States Marine Corps (USMC), also referred to as the United States Marines or simply the Marines, is the maritime land force service branch of the United States Department of Defense. It is responsible for conducting expeditionar ...

United States Army Air Forces The United States Army Air Forces (USAAF or AAF) was the major land-based aerial warfare service component of the United States Army and ''de facto'' aerial warfare service branch of the United States during and immediately after World War II ...

United States Coast Guard The United States Coast Guard (USCG) is the maritime security, search and rescue, and Admiralty law, law enforcement military branch, service branch of the armed forces of the United States. It is one of the country's eight Uniformed services ...

and the support of the allied nations of the United States. American steamship companies chartered ships from the

Maritime Commission The United States Maritime Commission was an independent executive agency of the U.S. federal government that was created by the Merchant Marine Act of 1936, which was passed by Congress on June 29, 1936, and was abolished on May 24, 1950. The c ...

and

War Shipping Administration The War Shipping Administration (WSA) was a World War II emergency war agency of the US government, tasked to purchase and operate the civilian shipping tonnage the United States needed for fighting the war. Both shipbuilding under the Maritime C ...

to meet the demand. Many

United States Merchant Marine The United States Merchant Marine is an organization composed of United States civilian sailor, mariners and U.S. civilian and federally owned merchant vessels. Both the civilian mariners and the merchant vessels are managed by a combination of ...

ships were newly built in the

Emergency Shipbuilding Program The Emergency Shipbuilding Program (late 1940 – September 1945) was a United States government effort to quickly build simple cargo ships to carry troops and materiel to allies and foreign theatres during World War II. Run by the U.S. Maritim ...

, other ships were older

World War I World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...

ships that were put back in service, or private ships acquired under Emergency war requisitions. The Merchant Navy operated in the

Pacific War The Pacific War, sometimes called the Asia–Pacific War or the Pacific Theatre, was the Theater (warfare), theatre of World War II fought between the Empire of Japan and the Allies of World War II, Allies in East Asia, East and Southeast As ...

and European war. Over 200 US Merchant ships took part in the

D-day The Normandy landings were the landing operations and associated airborne operations on 6 June 1944 of the Allied invasion of Normandy in Operation Overlord during the Second World War. Codenamed Operation Neptune and often referred to as ...

Normandy landings The Normandy landings were the landing operations and associated airborne operations on 6 June 1944 of the Allies of World War II, Allied invasion of Normandy in Operation Overlord during the Second World War. Codenamed Operation Neptune and ...

. To make a Normandy

breakwater Breakwater may refer to: * Breakwater (structure), a structure for protecting a beach or harbour Places * Breakwater, Victoria, a suburb of Geelong, Victoria, Australia * Breakwater Island, Antarctica * Breakwater Islands, Nunavut, Canada * ...

Harbor A harbor (American English), or harbour (Commonwealth English; see spelling differences), is a sheltered body of water where ships, boats, and barges can be moored. The term ''harbor'' is often used interchangeably with ''port'', which is ...

, called

Mulberry harbour The Mulberry harbours were two temporary portable harbours developed by the Admiralty (United Kingdom), British Admiralty and War Office during the Second World War to facilitate the rapid offloading of cargo onto beaches during the Allies of ...

, 33 merchant ships were sunk 1,000 yards from shore. Some of the ''ghosts'' merchant ships used were damaged and others were deemed too old.

Crew

The ships were operated by volunteer civilian crews, that were employed and trained by private shipping and passenger companies. Most ships had

armament A weapon, arm, or armament is any implement or device that is used to deter, threaten, inflict physical damage, harm, or kill. Weapons are used to increase the efficacy and efficiency of activities such as hunting, crime (e.g., murder), law e ...

for self defense, most ships had deck guns manned by

United States Navy Armed Guard The United States Navy Armed Guard was a force of United States Navy gunners and related personnel established during World War II to protect U.S. merchant shipping from enemy attack.World War II U.S. Navy Armed Guard and World War II U.S. Merc ...

from the US Navy Troops. The 144,857 strong Navy Armed Guards also operated the

radio Radio is the technology of communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connec ...

, semaphore-signal flags, and the

signal lamp Signal lamp training during World War II A signal lamp (sometimes called an Aldis lamp or a Morse lamp) is a visual signaling device for optical communication by flashes of a lamp, typically using Morse code. The idea of flashing dots and dashes ...

. Navy Armed Guard were also training in

first aid First aid is the first and immediate assistance given to any person with a medical emergency, with care provided to preserve life, prevent the condition from worsening, or to promote recovery until medical services arrive. First aid is gener ...

. United States Navy Armed Guard operated on 6,200 ships by the end of the war. Cross training with the ship's crew to cover roles was often completed. In 1943 the

United States Merchant Marine Academy The United States Merchant Marine Academy (USMMA or Kings Point) is a United States service academies, United States service academy in Kings Point, New York. It trains its midshipman, midshipmen (as students at the academy are called) to serv ...

was founded to train Merchant Marine officers.

Losses

Merchant Navy at its peak had over 215,000 men operating the Merchant Navy

ship A ship is a large watercraft, vessel that travels the world's oceans and other Waterway, navigable waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research and fishing. Ships are generally disti ...

s. The losses by the end of the war was 8,651 crew deaths. Merchant Marine were killed at a

per capita ''Per capita'' is a Latin phrase literally meaning "by heads" or "for each head", and idiomatically used to mean "per person". Social statistics The term is used in a wide variety of social science, social sciences and statistical research conte ...

rate much higher than those of the combined

United States Armed Forces The United States Armed Forces are the Military, military forces of the United States. U.S. United States Code, federal law names six armed forces: the United States Army, Army, United States Marine Corps, Marine Corps, United States Navy, Na ...

. Merchant Navy crews were killed at a rate of 1 in 26 (US Navy rate was 1 in 114). The greatest loss was in the

Battle of the Atlantic The Battle of the Atlantic, the longest continuous military campaign in World War II, ran from 1939 to the defeat of Nazi Germany in 1945, covering a major part of the naval history of World War II. At its core was the Allies of World War II, ...

due to

U-boat U-boats are Submarine#Military, naval submarines operated by Germany, including during the World War I, First and Second World Wars. The term is an Anglicization#Loanwords, anglicized form of the German word , a shortening of (), though the G ...

torpedo A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, such ...

deck gun A deck gun is a type of naval artillery mounted on the deck of a submarine. Most submarine deck guns were open, with or without a shield; however, a few larger submarines placed these guns in a turret. The main deck gun was a dual-purpose w ...

attacks. During the war 3.1 million tons of US

merchant ship A merchant ship, merchant vessel, trading vessel, or merchantman is a watercraft that transports cargo or carries passengers for hire. This is in contrast to pleasure craft, which are used for personal recreation, and naval ships, which are ...

s were sunk in 733 ships. Merchant ships were lost due to

submarine A submarine (often shortened to sub) is a watercraft capable of independent operation underwater. (It differs from a submersible, which has more limited underwater capability.) The term "submarine" is also sometimes used historically or infor ...

destroyer In naval terminology, a destroyer is a fast, maneuverable, long-endurance warship intended to escort larger vessels in a fleet, convoy, or carrier battle group and defend them against a wide range of general threats. They were conceived i ...

naval mine A naval mine is a self-contained explosive weapon placed in water to damage or destroy surface ships or submarines. Similar to anti-personnel mine, anti-personnel and other land mines, and unlike purpose launched naval depth charges, they are ...

s, armed raiders, gun boats,

aircraft An aircraft ( aircraft) is a vehicle that is able to flight, fly by gaining support from the Atmosphere of Earth, air. It counters the force of gravity by using either Buoyancy, static lift or the Lift (force), dynamic lift of an airfoil, or, i ...

attacks,

kamikaze , officially , were a part of the Japanese Special Attack Units of military aviators who flew suicide attacks for the Empire of Japan against Allied naval vessels in the closing stages of the Pacific campaign of World War II, intending to d ...

attacks, grounding and ocean storms. Convoy system with

escort carrier The escort carrier or escort aircraft carrier (U.S. hull classification symbol CVE), also called a "jeep carrier" or "baby flattop" in the United States Navy (USN) or "Woolworth Carrier" by the Royal Navy, was a small and slower type of aircraf ...

submarine chaser A submarine chaser or subchaser is a type of small naval vessel that is specifically intended for anti-submarine warfare. They encompass designs that are now largely obsolete, but which played an important role in the wars of the first half of th ...

s, planes and other support, reduced losses by 1944. Merchant Navy ship sunk or captured by

Imperial Japan The Empire of Japan, also known as the Japanese Empire or Imperial Japan, was the Japanese nation state that existed from the Meiji Restoration on January 3, 1868, until the Constitution of Japan took effect on May 3, 1947. From Japan–Kor ...

caused 609 crewmen to be captured as

prisoners of war A prisoner of war (POW) is a person held captive by a belligerent power during or immediately after an armed conflict. The earliest recorded usage of the phrase "prisoner of war" dates back to 1610. Belligerents hold prisoners of war for a ...

, many died in prison.

Ships

Liberty ship of World War II The Emergency Shipbuilding Program built many types of ships to support the war. The most numerous ships were the 2,710 cargo

Liberty ship Liberty ships were a ship class, class of cargo ship built in the United States during World War II under the Emergency Shipbuilding Program. Although British in concept, the design was adopted by the United States for its simple, low-cost cons ...

s. Liberty ships were built between 1941 and 1945, with a new module assembly process so that about three ships were built every two days.

Victory ship The Victory ship was a class of cargo ship produced in large numbers by American shipyards during World War II. They were a more modern design compared to the earlier Liberty ship, were slightly larger and had more powerful steam turbine engin ...

s were a faster replacement ship for the Merchant Navy. Between 1944 and 1946, 531 Victory ships were built, with some to the US Navy and 414 to the Merchant Navy. The Merchant Navy also operated: other cargo ships like: Type N3, Type C1, Type C2, Type C3, and the largest Type C4. Merchant Navy operated tanker ships like: T1 tanker,

T2 tanker The T2 tanker, or T2, was a class of oil tanker constructed and produced in large numbers in the United States during World War II. Only the T3 tankers were larger "navy oilers" of the period. Some 533 T2s were built between 1940 and the end of 1 ...

and the largest T3 Tankers for

fuel oil Fuel oil is any of various fractions obtained from the distillation of petroleum (crude oil). Such oils include distillates (the lighter fractions) and residues (the heavier fractions). Fuel oils include heavy fuel oil (bunker fuel), marine f ...

aviation gasoline Avgas (aviation gasoline, also known as aviation spirit in the UK) is an aviation fuel used in aircraft with spark-ignited internal combustion engines. ''Avgas'' is distinguished from conventional gasoline (petrol) used in motor vehicles, wh ...

, and

Diesel fuel Diesel fuel, also called diesel oil, heavy oil (historically) or simply diesel, is any liquid fuel specifically designed for use in a diesel engine, a type of internal combustion engine in which fuel ignition takes place without a spark as a re ...

. Merchant Navy operated special ships like: Type L6, called ''Lakers'', Type P1 small Passenger ships, Type P2 Passenger, Type R, refrigerated cargo ships, Type B Barges and Type V Tugboats. The Merchant Navy operated

Troopship A troopship (also troop ship or troop transport or trooper) is a ship used to carry soldiers, either in peacetime or wartime. Troopships were often drafted from commercial shipping fleets, and were unable to land troops directly on shore, typic ...

s, both passenger ships and cargo ships converted to troopships. For World War II 97 Victory ships temporarily were converted to troopship. By the end of the war over 11,000 ships were under the control of the War Shipping Administration. Many World War 2 surplus merchant ships were removed from the

National Defense Reserve Fleet The National Defense Reserve Fleet (NDRF) consists of Ship, ships of the United States, mostly Merchant ship, merchant vessels, that have been Reserve fleet, mothballed but can be activated within 20 to 120 days to provide shipping during nationa ...

and put into action to support the

Korean War The Korean War (25 June 1950 – 27 July 1953) was an armed conflict on the Korean Peninsula fought between North Korea (Democratic People's Republic of Korea; DPRK) and South Korea (Republic of Korea; ROK) and their allies. North Korea was s ...

and

Vietnam War The Vietnam War (1 November 1955 – 30 April 1975) was an armed conflict in Vietnam, Laos, and Cambodia fought between North Vietnam (Democratic Republic of Vietnam) and South Vietnam (Republic of Vietnam) and their allies. North Vietnam w ...

Post war

At the end of the war, the US Merchant Navy was given the task of helping bring Troops and for some their

war bride War brides are women who married military personnel from other countries in times of war or during military occupations, a practice that occurred in great frequency during World War I and World War II. Allies of World War II, Allied servicemen ...

s home, called

Operation Magic Carpet Operation Magic Carpet was the post–World War II operation by the U.S. War Shipping Administration (WSA) to repatriate over eight million American military personnel from the European (ETO), Pacific, and Asian theaters. Hundreds of Libert ...

. Some traveled on Navy ships, but many of the 3,500,000 men and women came home on Merchant Navy ships, call troopships. Some of the US Merchant Navy continued in post-war relief efforts and general cargo shipping to help nations around the world recover from the devastating war. The Seagoing cowboys did United Nations Relief and Rehabilitation work from 1945 to 1947. Seagoing cowboys use cargo ships with added cages and horse stalls to take

livestock Livestock are the Domestication, domesticated animals that are raised in an Agriculture, agricultural setting to provide labour and produce diversified products for consumption such as meat, Egg as food, eggs, milk, fur, leather, and wool. The t ...

to war-torn nations. Many merchant ships were placed in the

Reserve Fleet A reserve fleet is a collection of naval vessels of all types that are fully equipped for service but are not currently needed; they are partially or fully Ship decommissioning, decommissioned. A reserve fleet is informally said to be "in mothba ...

after the war, some were sold, many scrapped and a few became

museum ship A museum ship, also called a memorial ship, is a ship that has been preserved and converted into a museum open to the public for educational or memorial purposes. Some are also used for training and recruitment purposes, mostly for the small numb ...

Legacy

* American Merchant Marine Veterans Memorial in San Pedro, California. *World War II Merchant Marine Memorial Coyote Point Park in

San Mateo County, California San Mateo County ( ), officially the County of San Mateo, is a county (United States), county located in the U.S. state of California. As of the 2020 United States census, the population was 764,442. Redwood City, California, Redwood City is th ...

*American Merchant Mariners Memorial in

Battery Park The Battery, formerly known as Battery Park, is a public park located at the southern tip of Manhattan#Manhattan Island, Manhattan Island in New York City facing New York Harbor. The park is bounded by Battery Place on the north, with Bowling ...

New York Harbor New York Harbor is a bay that covers all of the Upper Bay. It is at the mouth of the Hudson River near the East River tidal estuary on the East Coast of the United States. New York Harbor is generally synonymous with Upper New York Bay, ...

Navy – Merchant Marine Memorial The Navy and Marine Memorial, is a monument honoring sailors of the United States Navy, Coast Guard, the United States Merchant Marine, the NOAA Commissioned Officer Corps and others who died at sea during World War I and other times. It is l ...

in Washington, D.C. *''

Action in the North Atlantic ''Action in the North Atlantic'' is a 1943 American war film from Warner Bros. Pictures. It was produced by Jerry Wald, directed by Lloyd Bacon, and adapted by John Howard Lawson from a story by Guy Gilpatric. The film stars Humphrey Bogart and R ...

'' 1943 movie with

Humphrey Bogart Humphrey DeForest Bogart ( ; December 25, 1899 – January 14, 1957), nicknamed Bogie, was an American actor. His performances in classic Hollywood cinema made him an American cultural icon. In 1999, the American Film Institute selected Bogart ...

. *''The Rebels of PT-218'', (''The Rebels of World War II'') a 2021 movie about the a Liberty ship that became a war ship. *''The Men Who Sailed the Liberty Ships'' Film of Veterans of the American merchant marine in World War II tell their story. *''Forgotten Victory'' SS Lane Victory 2021 Documentary *
Onboard a Liberty Ship, 1940s US Navy, WWII
' US Navy color film
SS ''Hannibal Victory''
1945 Documentary film. * List of United States Merchant Navy Film and TV shows *

Rosie the Riveter World War II Home Front National Historical Park Rosie the Riveter World War II Home Front National Historical Park is a United States national historical park located in Richmond, California, near San Francisco. The park preserves and interprets the legacy of the United States home front d ...

Notable ships

*'s crew were the first American casualties of the war on 8 AM on December 7, 1941. * SS Jean Nicolet, torpedoed by a Japanese submarine I-8 on July 2, 1944, off

Ceylon Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka, also known historically as Ceylon, is an island country in South Asia. It lies in the Indian Ocean, southwest of the Bay of Bengal, separated from the Indian subcontinent, ...

. Crew saved and then most killed by Japanese. *, , , , , , survived the war and scrapping to become

s. *, , , , each an

ammunition ship An ammunition ship is an auxiliary ship specially configured to carry ammunition, usually for naval ships and aircraft. An ammunition ship's cargo handling systems, designed with extreme safety in mind, include ammunition hoists with airlocks bet ...

, were attacked and sank with an explosion after kamikaze attack in 1945. *Ships of Convoy PQ 17, 24 merchant ships sunk and 153 merchant mariners killed in 1942. * had a

munitions Ammunition, also known as ammo, is the material fired, scattered, dropped, or detonated from any weapon or weapon system. The term includes both expendable weapons (e.g., bombs, missiles, grenades, land mines), and the component parts of ...

explosion An explosion is a rapid expansion in volume of a given amount of matter associated with an extreme outward release of energy, usually with the generation of high temperatures and release of high-pressure gases. Explosions may also be generated ...

on July 17, 1944, at

Port Chicago, California Port Chicago was a town on the southern banks of Suisun Bay, in Contra Costa County, California, Contra Costa County, California. It was located east-northeast of Martinez, California, Martinez, at an elevation of 13 feet (4 metres, m). It is bes ...

. * was built in 4 days, 15 hours and 29 minutes, a record. *, the last Liberty ship built, is now the headquarters of Trident Seafoods in

Kodiak, Alaska Kodiak (Alutiiq language, Alutiiq: ) is the main city and one of seven communities on Kodiak Island in Kodiak Island Borough, Alaska, Kodiak Island Borough, Alaska. All commercial transportation between the island's communities and the outside ...

. * SS ''Ohio'' was attacked in a Malta convoy and was still able to deliver needed fuel in

Operation Pedestal Operation Pedestal (, Battle of mid-August), known in Malta as (), was a British operation to carry supplies to the island of Malta in August 1942, during the Second World War. British ships, submarines and aircraft from Malta attacked Axis p ...

Malta Malta, officially the Republic of Malta, is an island country in Southern Europe located in the Mediterranean Sea, between Sicily and North Africa. It consists of an archipelago south of Italy, east of Tunisia, and north of Libya. The two ...

(called the ''saviour of the beleaguered island''). * sank the German commerce raider ''Stier'' in a ship-to-ship gun battle in 1942.Sawyer, L. A. and Mitchell, W. H. ''The Liberty Ships: The History of the "Emergency" Type Cargo Ships Constructed in the United States During the Second World War,'' Second Edition, pp. 13, 141-2, Lloyd's of London Press Ltd., London, England, 1985. . * and SS Winthrop Victory were present in

Tokyo Bay is a bay located in the southern Kantō region of Japan spanning the coasts of Tokyo, Kanagawa Prefecture, and Chiba Prefecture, on the southern coast of the island of Honshu. Tokyo Bay is connected to the Pacific Ocean by the Uraga Channel. Th ...

Victory over Japan Day Victory over Japan Day (also known as V-J Day, Victory in the Pacific Day, or V-P Day) is the day on which Surrender of Japan, Imperial Japan surrendered in World War II, in effect bringing the war End of World War II in Asia, to an end. The ...

on September 2, 1945. * became a war ship in the

Battle of Anzio The Battle of Anzio was a battle of the Italian Campaign (World War II), Italian Campaign of World War II that commenced January 22, 1944. The battle began with the Allies of World War II, Allied amphibious landing known as Operation Shingle, an ...

, an eight-day battle the ship shot down five German planes.

Ship operators

At its peak, about 130 companies served as ship operators for the War Shipping Administration.ibiblio.org, War Shipping Administration
/ref> American steamship companies operating merchant ships in World War II:

Tanker operators

Type T2-SE-A1 tanker Hat Creek underway at sea on 16 August 1943

American steamship companies operating merchant tanker ships in World War II:

External links

youtube How A Cargo Ship Helped Win WW2: The Liberty Ship StoryAmerican Merchant Marine at War

*

References

{{WWII US ships Liberty ships Victory ships Maritime history of the United States