guided weapons

guided weapons. For the purposes of this entry, a ‘guided weapon’ is an unmanned weapons system the path of which can be steered during its travel, either automatically or remotely, to increase the chances of it striking the target.

The first guided weapon to see action during the Second World War was the US-built ‘Mark 24 Mine’, a deliberately misleading codename applied to an air-dropped torpedo fitted with an acoustic homing head and designed for attacking submerged submarines. It was first used on 12 May 1943, when a Liberator of No. 86 Squadron RAF dropped one into the swirl left by U-456 as it dived in the North Atlantic. The weapon followed the U-boat for about two minutes, then detonated against it causing severe damage. The following day the boat was finished off by Allied warships. Between then and the end of the war the ‘Mark 24 Mine’ destroyed about a dozen enemy submarines.

The German Navy developed its own acoustic homing torpedo, for use by U-boats against Allied convoy escorts. Codenamed the ZAUNKÖNIG (wren)—the British called it the GNAT—it first saw action on 20 September 1943 when it caused serious damage to the Royal Navy frigate Lagan. After a brief initial spell of success, Allied warships were equipped with the ‘foxer’ device, a towed noisemaker, which lured homing torpedoes safely away from them. Thereafter ZAUNKöNIG became ineffective and its use was discontinued.

Also during 1943, the Luftwaffe introduced two separate types of air-dropped radio command guided weapon for use against enemy ships: the Henschel Hs293 glider bomb, and the Fritz-X guided bomb. The Hs293 resembled a small aircraft with a wing span of 3.1 m. (10 ft. 3½ in.) and carried a 500 kg. (1,100 lb.) warhead in the nose. After release from the carrying aircraft (usually a Dornier 217 or Heinkel 177), a rocket motor accelerated the weapon to maximum speed of about 600 km/h (375 mph) then cut out. The missile coasted on, steered to the target by an observer in the nose of the aircraft operating a joystick controller linked to a radio transmitter. The Hs293 became the first airborne guided missile to sink an enemy ship, after one struck the Royal Navy sloop Egret off northern Spain on 27 August 1943 and caused her magazine to explode.

The Fritz-X was a free-fall bomb weighing 1,400 kg. (3,100 lb.), fitted with fixed cruciform wings midway along the body and movable control surfaces at the tail. Its radio guidance system was similar to that used by the Hs293. Released from high altitude, the bomb achieved a velocity sufficient to penetrate the deck armour of a battleship. First used during a Luftwaffe attack on Italian warships on their way to surrender to the Allies on 9 September 1943, two of them hit the battleship Roma and she blew up with heavy loss of life. The specifications of these bombs became known to the Allies through MAGIC intelligence.

The US Army Air Forces developed a weapon similar to the Fritz-X, codenamed the AZON, a 454 kg. (1,000 lb.) bomb fitted with radio guidance equipment. The weapon was first used in action in February 1944, and it scored hits on locks in the River Danube and the Avisio viaduct in northern Italy. Later it was used with considerable success against bridge targets in the Burma campaign.

Another US guided weapon that saw operational use was APHRODITE, a war-weary B17 or B24 bomber fitted with 11,340 kg. (25,000 lb.) high explosive charges and equipment to transmit television pictures of the target. Radio-guided on to targets by ‘mother’ aircraft, the explosive bombers were used against targets in Europe. The twin-engined TDR assault drone, used by the US Navy in the Pacific war, operated on a similar principle. Near the end of the war the US Navy's Bat anti-ship missile entered service. This unpowered glider weapon was fitted with a 454 kg. (1,000 lb.) warhead, and carried to within range of enemy ships by a PB4Y-2 Privateer aircraft. The radar of the parent aircraft was used to illuminate the target, and the missile homed on the source of the reflected signals using its semi-active radar homing head.

Finally, and to illustrate the breadth of the ‘guided weapon’ genre, there was the German Goliath weapon that can best be described as a self-propelled remote-controlled demolition charge. First used against the Anzio beachhead in February 1944, the tracked vehicle resembled a miniature First World War tank 1.75 m. (5 ft. 9 in.) long. It weighed 285 kg. (628 lb.) and carried an 80 kg. (176 lb.) high explosive charge. Electrical steering signals from the control unit were passed via wires unreeled by the weapon as it headed for the target. The Goliath was powered by a Zundapp petrol engine and had a maximum speed of 20 km/h (12 mph). See also explosive motor boats.

Alfred Price

Bibliography

Gunston, B. , Rockets and Missiles (London, 1979).
Price, A. , Aircraft versus Submarine (London, 1973).