Antisubmarine Warfare Systems

Antisubmarine Warfare Systems are designed to defeat the warmaking use of enemy submarines. This is done through the destruction of submarine bases or construction facilities, and most commonly by seeking out and destroying hostile submarines themselves.

There are two operational approaches to antisubmarine warfare. The most direct is to detect, classify, locate, track, and attack hostile submarines. The more indirect is to deny hostile submarines access to their targets.

Actual antisubmarine warfare occurred mainly during the two world wars, although planning and practice operations have been a major part of U.S. naval operations in the Cold War. Antisubmarine warfare in World War I was conducted particularly by the British and American navies against German U‐boats. The British use of barriers of mines in the English Channel in 1917–18 was relatively ineffective in destroying German submarines, but it apparently forced them to take the more distant North Sea route to the Atlantic. Nor did the Royal Navy's shelling of U‐boat bases on the Belgian coast do much damage. Much more effective was the combination in 1917–18 of the replacement of individual merchant ship sailings with the protected convoy system, plus the use of aerial and surface surveillance and then the destruction of submarines by British and American destroyers, frigates, and small sub‐chasers dropping depth charges. The majority of the 159 German U‐boats destroyed in enemy action were sunk by surface ships. By the summer of 1917, the British and Americans had greatly limited the effectiveness of the German submarine campaign.

During World War II, British and American efforts against German submarines were more sophisticated and much more extensive. Allied bombers raided U‐boat bases, particularly on the French and Norwegian coasts, but failed to penetrate the concrete‐roofed submarine shelters. However, after extensive German operations in the Atlantic in 1940–42, the Allies became increasingly effective in locating and destroying German submarines in the Atlantic, largely curtailing the U‐boat menace by the end of the war. In part this was due to the protected convoy system, but in large part it resulted from the Allied decryption of the German submarine fleet's cipher (through ULTRA) and the interception and location of U‐boat radio traffic through high‐frequency direction‐finding equipment. Particularly effective was the Allied campaign to locate and destroy the “Milk Cows”—fuel replenishment submarines for the German underwater “wolf packs.” The development of radar and improvement of sonar detection also aided the blimps and airplanes, frigates, and destroyers as they sought out enemy submarines and attacked them with depth charges. More than half of the 728 German U‐boats destroyed in action were sunk by aircraft. In the Pacific, the U.S. Navy sank 124 Japanese submarines (most of them by surface ships), while ineffective Japanese action resulted in the sinking of only 44 U.S. submarines. The Japanese proved unable to prevent American undersea vessels from imposing against Japan the most effective submarine blockade in history.

During the Cold War, the increased stealth provided by the development of nuclear‐powered and quiet‐running submarines posed major challenges. This became even more important when submarine‐launched ballistic missiles made the undersea boats a major factor in nuclear warfare. The U.S. Navy and other NATO forces prepared major plans and weapons systems to detect and destroy Soviet submarines. Systems were stationed at particular strategic positions to track or deter Soviet submarines, for example, outside their bases or in the entrance to the North Atlantic between Iceland and Greenland.

Modern antisubmarine warfare is conducted by three major naval platforms: hunter‐killer submarines; surface ships such as frigates and destroyers; and maritime patrol aircraft. Hunter‐killer submarines use hull‐mounted sonar as well as towed arrays to detect enemy submarines (by permitting listening at some distance from the noise of the ship itself); their principal weapons to destroy other submarines are heavy‐homing torpedoes. Modern frigates also have hull‐mounted sonar and passive towed arrays, as well as depth charges to destroy submarines. However, the frigates also employ helicopters, which can use dipping sonar and dropped sonobuoys (radio‐equipped buoys) for detection, and which can attack the submarines with lightweight honing torpedoes. Aircraft use sonobuoys and magnetic anomaly detectors for locating submarines and lightweight torpedoes for destroying them. Against submarine, as well as aircraft or missile, attack, modern U.S. naval carrier task forces rely particularly on protection in depth, with an outer ring of detection and destruction systems provided on, above, and under the sea.
[See also Submarines; Submarine Warfare.]

Bibliography

R. M. Grant , U‐boats Destroyed: The Effect of Anti‐Submarine Warfare, 1914–1918, 1964.
J. R. Hill , Anti‐Submarine Warfare, 1984.
D. Daniel , Anti‐Submarine Warfare and Superpower Stability, 1986.
W. J. R. Gardner , Anti‐Submarine Warfare, 1996.
Jane's Underwater Warfare Systems, 1995–1996, 1996.

William D. Smith