Shipyards
The goods which kept England in the war before the United States entered it, the troops America sent to Europe to fight it, their equipment, food, clothing, ammunition, soap, the reams upon reams of paper all armies generate, and quite literally even the kitchen sinks were sent by ship. In the Pacific a vast Navy was created to defeat the Japanese and troops were conveyed, from island to island driving the Japanese back. They too traveled by ship. The Germans and the Japanese did all they could to sink American ships, often successfully. American shipyards built the ships, repaired those that were damaged, and replace those that were sunk. It was a Herculean task.
The US Maritime Commission ran the Emergency Shipbuilding Program beginning in late 1940, originally intended to replace ships lost to German U-boats. Over the course of the war the Emergency Program built over 6,000 ships to transport cargo, liquids, and personnel. Before the ships could be built the yards to build them had to be constructed, and shipyards of all types were created along the coasts, in the Great Lakes, and on American rivers.
At the same time the military demanded landing craft of multiple types to land troops and equipment on fortified beaches in the Pacific, North Africa, Sicily, Italy and eventually France. Factories were built at inland locations in the United States and various locales of the British Empire for the construction of hordes of landing craft, while simultaneously the US Navy developed a crash program to train the officers and crews to man them. Special purpose full size ships were envisioned, designed, built, and placed in operation in a matter of months, and improvements to the designs based on lessons learned in combat were continuous.
The US Navy expanded dramatically as the war went on, with American shipyards working around the clock producing what became the largest fleet in the history of the world. The United States Navy increased by over 1,200 ships over the course of the war. Twenty one fleet aircraft carriers and seventy smaller escort aircraft carriers were delivered to the Navy by American shipyards during the months between December 1941 and May 1945. In addition to these, more than 200 destroyers and 30 cruisers were added to the fleet, and American shipyards produced ships for the British, Canadian, and Australian fleets at the same time.
The US shipbuilding industry evolved over the course of the war to adopt assembly line principles and practices to the construction of ships. Prefabricated parts arrived at the yards via rail or barge, and ships were assembled on the ways. Simplified design and shared resources allowed the industry to produce ships at the rate of more than three per day. By the end of the war the American Merchant Marine, like the United States Navy, was the largest in the world, and at least 18 new American shipyards had been built to produce and maintain America’s fleets.