In 1916, the then Assistant Secretary of the Navy, Franklin D. Roosevelt ordered the US Navy to design a small anti-submarine vessel that could be built quickly in small civilian boatyards, as if war came, larger shipyards would be busy building larger warships. Consideration was given to adopting an wooden Motor Launch built in large numbers by ELCO for the British Royal Navy, but the General Board of the United States Navy thought that these boats were too small to be effective seaboats. The task of designing the new type was given to an experienced designer of small boats, Albert Loring Swasey. He drew up a design for a wooden boat, emphasizing seaworthiness over speed. At first it was intended to use two engines, but a shortage of these engines resulted in the design being changed to use three gasoline engines. Armament was initially planned to be two guns, but the aft gun was usually replaced by a depth charge thrower to attack submerged submarines, with two Colt machine guns completing the armament. Many boats were fitted with hydrophones for detecting underwater noises, with either a K-tube fish-type device of range or SC and MB tubes of range. An initial order of 345 SC boats placed in 1917 was planned to be delivered by the end of 1917, with further orders for the French Navy pushing the total ordered up to 448.
Operational history
Deliveries started in July 1917, with deliveries continuing into 1919, with 441 boats built, and the remaining seven boats canceled. One hundred were sold to France, and a further 121 US Navy SC boats were deployed to Europe to operate off Britain and France and in the Mediterranean, where they supported the Otranto Barrage with the remaining US Navy boats operating off the East Coast of the United States. The US Navy lost six SC boats during World War I; lost in collision with the tanker Fred M. Weller on 1 October 1918, in a fire on 22 December 1917, was lost in collision on 5 June 1918, in a collision on 4 August 1918, by friendly fire from the trawler Felix Taussig on 27 August 1918 and by fire on 19 February 1918. France lost three SC-boats. Following the end of the war, four boats were transferred to Cuba, while 14 boats were transferred to the United States Coast Guard in 1919–1920. Eight of the French SC boats remained in service at the outbreak of World War II. By December 1941, only 11 boats remained in US Navy service, with two continuing in use until at least April 1945. Two boats were sold to the Bulgarian Navy and saw action in World War II, sinking one Soviet submarine.
