The U.S. Merchant Marine in WWII: The World's Largest Cargo Fleet
Eddy, E. Gordon, Sea Classics
Creating the merchant ships that enabled the United States to fight a two-ocean war was an achievement of unprecedented accomplishment.
As the 60th Anniversary of America's entry into World War II fast approaches, SEA CLASSICS salutes America's Merchant Marine as the delivery force that kept open the supply lines to our wartime Allies.
THE WARTIME FLEET
The unprecedented growth of the United States merchant fleet was the primary reason for the WSA's ability to meet the tonnage demands of the war. Upon America's entry, the fleet, augmented by foreign vessels acquired by negotiation, requisition, and seizure in American ports, totaled about 900 dry-cargo vessels of 6,700,000 dead-weight tons and some 440 tankers of 5,150,000 dead-- weight tons.
By the end of the war with Japan the WSA-controlled fleet numbered 4,221 with a dead-weight tonnage of 44,940,000. The curve had risen rapidly. At the end of 1942, there were 1,639 ships in WSA operation; in 1943, 2,847; 1944, 3,744.
The greater percentage of the merchant fleet in September 1945 was obtained from construction. The remaining tonnage was acquired by bareboat and time charter agreements with their owners and intergovernmental negotiation.
The WSA fleet consisted of approximately 20 major merchant, military, and emergency type dry-cargo vessels and ten major type tankers.
The race between ship construction and sinkings by the enemy was won by the Allied convoy system and naval superiority in combating the submarine menace, and an unprecedented shipbuilding technique. WSA losses, including marine casualties during 1942, were equivalent to 39 percent of new ship construction in that year. This was reduced to eleven percent in 1943, less than eight percent in 1944, and four percent in 1945. In 1944, 32 vessels of 85,400 tons were expended in military operations during the long anticipated invasion of France.
About 75 percent of the vessels under WSA control consisted of Liberty type ships, a relatively slow vessel of eleven knots speed and 10,800 dead-weight tons. Victory ship construction began in 1944, when turbines became more readily available for merchant fleet building. The Victory was an emergency type vessel of about the same tonnage as the Liberty, but more modern in its propulsion machinery which gives it speeds ranging from 15 to 17 knots. It supplanted the Liberty building program in 1945.
The remainder of the fleet included the "C" types which vary from the small coastal vessels of 5,000 dead-weight tons to the C4 freighters of 13,500 dead-weight tons. In addition, there were special types built prior to 1939 made up primarily of freighters, combination passenger and cargo ships, reefers (refrigerator ships for perishable cargoes), and bulk carriers. Many of the auxiliary vessels serving the Army and Navy as aircraft carriers, troopships, cargo vessels, and modified tank carriers may be recognized as modifications and conversions of major design types that are the backbone of the merchant fleet.
The tanker fleet is made up principally of the "T" or standard type tanker varying in size from 15,900 to 23,000 dead-weight tons and the emergency type tanker converted from modified Liberty ship hulls. Privately-built tankers and miscellaneous types built prior to 1939 comprise the remainder of the tanker fleet.
In 1942, the primary need was to expand the size of the fleet in number and tonnage. Concentration on Liberty ship production kept the bulk of the fleet at a low-speed level, but the construction of Victory and "C" type ships in increasing ratio brought the present WSA dry-cargo fleet to a point where about 24 percent is capable of 14.5 knots or better, while 74 percent is capable of from ten to 14.4 knots. Only two percent of the tonnage is slower than ten knots.
HOW THE FLEET WAS OBTAINED & OPERATED
To say that the United States was better off in shipping at the start of World War II than it had been as it entered World War I would be in fact only partially correct. …