Chief of Naval Operations
THE UNITED STATES entered World War I in 1917 with a total of 24 diesel powered submarines. U.S. Navy submarines patrolled the waters off the U.S. East Coast and deployed overseas to the Azores and Ireland. The American submarines primary missions were to escort Allied shipping and counter the German U-boat threat. Though there were no confirmed sinkings of U-boats by American submarines the number of German attacks repulsed by near misses showed the submarine to be an effective anti-submarine weapon. However, it was Germanys use of the U-boat in World War I that demonstrated the vital role the submarine would play in the next global conflict.
After the war, the U.S. Navy slowly built up its submarine force. Submarine construction contracts with commercial shipyards were cut back, forcing the Lake Torpedo Boat Company to go out of business in 1922. The Portsmouth Naval Shipyard in New Hampshire became one of the largest submarine builders in the U.S. and between 1924 and 1929 the Portsmouth yard designed and built five 381-foot V-class submarines. Between 1932 and 1941, Portsmouth built an additional 22 submarines in the 1500-ton category. It was during this period that the first all-welded submarine, USS Pike (SS-173), was completed. The welded hull allowed Pike to submerge to much greater depths than her predecessors and at the same time provided greater protection against depth-charge attacks.
|Sonar is a system for detecting submarine sound in the water. It was
first developed by the British for use against U-boats in World War I. Radar uses radio
waves to detect objects on and above the land and sea surface. Radar was developed in the
1930s to detect aircraft. Both sonar and radar technology matured during World War
II, and both were used by the Allies to combat German U-boats. Sonar and radar were also
added to Allied submarines to warn of aircraft attack and counterattack from surface
vessels. Since World War II sonar has been the most important of the submarines
senses. Hydrophones are the submarines ears, and they listen for sounds from other
ships and the echoes of sound waves transmitted from the submarine itself.
During World War II German submarine losses increased sharply as radar-equipped Allied aircraft attacked U-boats running on the surface recharging their batteries. To charge the batteries that powered the electric motors for submerged operations, all submarines had to surface to run their air-breathing diesel engines. To counter the Allied radar threat the Germans perfected a Dutch device known as the snorkel. Using a snorkel a submarine could run its diesel engines and recharge its batteries while operating just below the surface. Air for the diesel engines was drawn into the submarine through the snorkel that was extended to the surface. To some extent the snorkel reduced vulnerability to detection and attack, but it protruded above the surface and could be detected by radar. The Germans introduced the snorkel too late in the war to make a difference.
Although the U. S. Navy still had a relatively small number of submarines when World War II broke out, this fact did little to dampen the spirits of American submariners. On January 7th, 1942, one month after the attack on Pearl Harbor, the USS Pollack (SS-179) sank a Japanese freighter off Tokyo Bay. It would be the first of many sinkings by U.S. submarines. When the figures were finally tabulated, it was found that American submarines sank five and one-half million tons of Japanese shipping, over half of the entire Japanese merchant fleet. U. S. subs accounted for about 60 per cent (over 1300 ships) of all Japanese merchant and warship tonnage sunk, yet the submarine strength at that time comprised less than two per cent of the entire U. S. Fleet.
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