89-639: The Army Air Forces Antisubmarine Command was formed in the fall of 1942 to establish a single command to control antisubmarine warfare (ASW) activities of the Army Air Forces (AAF). It was formed from the resources of I Bomber Command , which had been carrying out the antisubmarine mission in the Atlantic and Caribbean since the Attack on Pearl Harbor due to the lack of long range Naval aviation in that area. The command's units conducted ASW along
178-578: A "coastal command", similar to RAF Coastal Command , operating "when necessary, under the proper Naval authority." That same month saw both a new high in sinkings by U-boats and a shift in their attacks from the Atlantic coast to the Caribbean Sea. In response, the AAF established the Gulf Task Force, with elements of Third Air Force augmenting I Bomber Command, at Miami , Florida to augment
267-417: A 35–40 lb (16–18 kg) cone-shaped steel drum on a 5 ft (1.5 m) shaft, intended to be thrown at a submarine. Firing Lyddite shells, or using trench mortars , was tried. Use of nets to ensnare U-boats was also examined, as was a destroyer, HMS Starfish , fitted with a spar torpedo . To attack at set depths, aircraft bombs were attached to lanyards which would trigger their charges;
356-625: A combination of sensor and weapon technologies, along with effective deployment strategies and sufficiently trained personnel. Typically, sophisticated sonar equipment is used for first detecting, then classifying, locating, and tracking a target submarine. Sensors are therefore a key element of ASW. Common weapons for attacking submarines include torpedoes and naval mines , which can both be launched from an array of air, surface, and underwater platforms. ASW capabilities are often considered of significant strategic importance, particularly following provocative instances of unrestricted submarine warfare and
445-462: A comparable WW2 submarine; in addition, they recharged their batteries using a snorkel and could complete a patrol without surfacing. This led to the introduction of longer-ranged forward-throwing weapons, such as Weapon Alpha , Limbo , RBU-6000 , and of improved homing torpedoes. Nuclear submarines , even faster still, and without the need to snorkel to recharge batteries, posed an even greater threat; in particular, shipborne helicopters (recalling
534-589: A day after the declaration of war by the United States the Army Air Forces (AAF) began patrols of both the East and West coasts. Defense plans drawn up before the war began assigned the Navy responsibility for operations beyond the coastline, with Army aircraft serving in a supporting role. Because naval aviation that could perform long range patrols was nearly non-existent along the Atlantic coast in early 1942,
623-403: A device intended for countermining , a "dropping mine". At Admiral John Jellicoe 's request, the standard Mark II mine was fitted with a hydrostatic pistol (developed in 1914 by Thomas Firth & Sons of Sheffield) preset for 45 ft (14 m) firing, to be launched from a stern platform. Weighing 1,150 lb (520 kg), and effective at 100 ft (30 m), the "cruiser mine"
712-410: A large role. The use of nuclear propulsion and streamlined hulls has resulted in submarines with high speed capability and increased maneuverability, as well as low "indiscretion rates" when a submarine is exposed on the surface. This has required changes both to the sensors and weapons used for ASW. Because nuclear submarines were noisy, there was an emphasis on passive sonar detection. The torpedo became
801-407: A large, modern submarine fleet, because all had fallen in the grip of Mahanian doctrine which held guerre de course could not win a war. At the beginning of the conflict, most navies had few ideas how to combat submarines beyond locating them with sonar and then dropping depth charges on them. Sonar proved much less effective than expected, and was no use at all against submarines operating on
890-703: A long tail boom (fixed-wing aircraft) or an aerodynamic housing carried on a deployable tow line (helicopters). Keeping the sensor away from the plane's engines and avionics helps eliminate interference from the carrying platform. At one time, reliance was placed on electronic warfare detection devices exploiting the submarine's need to perform radar sweeps and transmit responses to radio messages from home port. As frequency surveillance and direction finding became more sophisticated, these devices enjoyed some success. However, submariners soon learned not to rely on such transmitters in dangerous waters. Home bases can then use extremely low frequency radio signals, able to penetrate
979-656: A meeting with their American counterparts in June 1917. In October 1918, there was a meeting in Paris on "supersonics", a term used for echo-ranging, but the technique was still in research by the end of the war. The first recorded sinking of a submarine by depth charge was U-68 , sunk by Q-ship HMS Farnborough off County Kerry , Ireland 22 March 1916. By early 1917, the Royal Navy had also developed indicator loops which consisted of long lengths of cables lain on
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#17327719670841068-614: A pathfinder unit . By mid November, the 480th Group had been relieved and was on its way back to the US. Its two squadrons were inactivated in October and their personnel assigned elsewhere. The majority of the command's squadrons were redesignated as bombardment squadrons and transferred to Second Air Force, while the 25th and 26th Wings were disbanded. In August 1943, the command was redesignated I Bomber Command and reassigned to First Air Force . It continued to oversee antisubmarine units in
1157-575: A ram with which to sink submarines, and U-15 was thus sunk in August 1914. During June 1915, the Royal Navy began operational trials of the Type D depth charge, with a 300 lb (140 kg) charge of TNT ( amatol , as TNT supplies became critical) and a hydrostatic pistol, firing at either 40 or 80 ft (12 or 24 m), and believed to be effective at a distance of 140 ft (43 m);
1246-471: A result, in the latter half of 1943, US subs were suddenly sinking Japanese ships at a dramatically higher rate, scoring their share of key warship kills and accounting for almost half of the Japanese merchant fleet. Japan's naval command was caught off guard; Japan had neither the anti-submarine technology or doctrine, nor the production capability to withstand a tonnage war of attrition , nor did she develop
1335-598: A semi-autonomous oceangoing unmanned naval vessel. Today some nations have seabed listening devices capable of tracking submarines. It is possible to detect man-made marine noises across the southern Indian Ocean from South Africa to New Zealand. Some of the SOSUS arrays have been turned over to civilian use and are now used for marine research. Several countries developed anti-submarine missiles including United States , Russia , China , South Korea , Japan and India . Anti-submarine missiles give flexibility in terms of
1424-571: A ship by an underwater vehicle are generally believed to have been during the American Revolutionary War , using what would now be called a naval mine but what was then referred to as a torpedo. Even so, various attempts to produce submarines had been made prior to this. In 1866, British engineer Robert Whitehead invented the first effective self-propelled torpedo, the eponymous Whitehead torpedo ; French and German inventions followed soon thereafter. The first submarine with
1513-507: A similar idea was a 16 lb (7.3 kg) guncotton charge in a lanyarded can; two of these lashed together became known as the Depth Charge Type A. Problems with the lanyards tangling and failing to function led to the development of a chemical pellet trigger as the Type B. These were effective at a distance of around 20 ft (6.1 m). Perhaps the best early concept arose in a 1913 RN Torpedo School report, describing
1602-719: A torpedo was Nordenfelt I built in 1884–1885, though it had been proposed earlier. By the outbreak of the Russo-Japanese War , all the large navies except the Germans had acquired submarines. Nevertheless, by 1904, all powers still defined the submarine as an experimental vessel and did not put it into operational use. There were no means to detect submerged U-boats, and attacks on them were limited at first to efforts to damage their periscopes with hammers. The Royal Navy torpedo establishment, HMS Vernon , studied explosive grapnel sweeps; these sank four or five U-boats in
1691-617: Is an inactive United States Air Force unit. Its last assignment was with the Army Air Forces Antisubmarine Command , based in New York City , New York. It was the principal United States Army Air Forces Unit conducting anti-submarine warfare off the East Coast of the United States and Canada until it was disbanded on 15 October 1943. In 1985 the wing was reconstituted and redesignated
1780-542: The R1 was the first ASW submarine. 211 of the 360 U-boats were sunk during the war, from a variety of ASW methods: This period saw the development of active sonar ( ASDIC ) and its integration into a complete weapons system by the British, as well as the introduction of radar . During the period, there was a great advance due to the introduction of electronics for amplifying, processing, and displaying signals. In particular,
1869-579: The 25th Bombardment Group , a Sixth Air Force unit, that was also engaged in antisubmarine patrols. Finally, the 23d Antisubmarine Squadron deployed to Edinburgh Field , Trinidad to defend against this threat and to experiment with its 75mm cannon armed North American B-25 Mitchells . Disagreements between the AAF and the Navy over command of long range aviation units engaged in antisubmarine warfare and of whether those forces would best be employed (offensively or defensively) continued into 1943, and in June,
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#17327719670841958-553: The 479th Antisubmarine Group was formed at RAF St Eval . Squadrons from Newfoundland had moved to England to replace those moved to Morocco. The group conducted patrols over the Bay of Biscay , achieving its greatest success in the first two months it was active. Following this period, German U-boats adopted tactics that kept them submerged in the group's area of operations during daylight hours. The group continued its patrols, occasionally engaging Luftwaffe aircraft until October. It
2047-626: The 480th Antisubmarine Group was formed at Craw Field , French Morocco to conduct patrols north and west of Morocco along the Atlantic approaches to the Strait of Gibraltar . The group was formed with the 1st and 2d Antisubmarine Squadrons , which had moved to Morocco from England. In July 1943, German submarines concentrated off the coast of Portugal to intercept convoys bound for the Mediterranean Sea. The group damaged and sank several subs, protecting supply lines for Operation Husky ,
2136-602: The 525th Combat Crew Training Group , but has never been active with that designation. The 25th Antisubmarine Wing was activated in November 1942 to combat German U-boats in the coastal waters of the United States. The wing 's tactical area of responsibility ranged from Labrador south along the Atlantic Coast to the Georgia/Florida border and seaward to approximately 100 miles from coastline. The wing
2225-493: The Admiralty . To attack submerged boats, a number of anti-submarine weapons were derived, including the sweep with a contact-fused explosive. Bombs were dropped by aircraft and depth charge attacks were made by ships. Prior to the introduction of dedicated depth charge throwers, charges were manually rolled off the stern of a ship. The Q-ship , a warship disguised as a merchantman, was used to attack surfaced U-boats, while
2314-488: The Civil Air Patrol , but flew the only long range aircraft. Activity in this region was at such a low level that for three months, from December 1942 to February 1943, not a single enemy U-boat was sighted. An exception was in the waters near Trinidad , where German subs were attacking merchant shipping. From December 1942, air echelons from various squadrons deployed to Trinidad, where they joined elements of
2403-544: The Gulf Sea Frontier . The command situation had only worsened, with two air forces, two navy sea frontiers, and two army defense commands, with differing areas of responsibility, all involved in aerial ASW with ad hoc command relations and separate administrative and operational command arrangements. Later in the month, the War Department requested General Arnold to reorganize I Bomber Command to fulfill
2492-660: The Second World War , the Allies developed a huge range of new technologies, weapons and tactics to counter the submarine danger. These included: Italian and German submarines operated in the Mediterranean on the Axis side while French and British submarines operated on the side of the Allies. The German Navy sent 62 U-boats to the Mediterranean; all were lost in combat or scuttled. German subs first had to pass through
2581-589: The Whiskey and Zulu classes. Britain also tested hydrogen peroxide fuels in Meteorite , Excalibur , and Explorer , with less success. To deal with these more capable submarines new ASW weapons were essential. This new generation of diesel electric submarine, like the Type XXI before it, had no deck gun and a streamlined hull tower for greater underwater speed, as well as more storage battery capacity than
2670-511: The Wolfpack achieved initial success, but became increasingly costly as more capable ASW aircraft were introduced. Technologies such as the Naxos radar detector gained only a temporary reprieve until detection apparatus advanced yet again. Intelligence efforts, such as Ultra , had also played a major role in curtailing the submarine threat and guiding ASW efforts towards greater success. During
2759-530: The blimps of World War I) have emerged as essential anti-submarine platforms. A number of torpedo carrying missiles such as ASROC and Ikara were developed, combining ahead-throwing capability (or longer-range delivery) with torpedo homing. Since the introduction of submarines capable of carrying ballistic missiles , great efforts have been made to counter the threat they pose; here, maritime patrol aircraft (as in World War II) and helicopters have had
Army Air Forces Antisubmarine Command - Misplaced Pages Continue
2848-491: The postwar era, ASW continued to advance, as the arrival of nuclear submarines had rendered some traditional techniques less effective. The superpowers of the era constructed sizable submarine fleets, many of which were armed with nuclear weapons ; in response to the heightened threat posed by such vessels, various nations chose to expand their ASW capabilities. Helicopters , capable of operating from almost any warship and equipped with ASW apparatus, became commonplace during
2937-428: The "life and death" urgency in the Atlantic. However, US Vice Admiral Charles A. Lockwood pressured the ordnance department to replace the faulty torpedoes; famously when they initially ignored his complaints, he ran his own tests to prove the torpedoes' unreliability. He also cleaned out the "deadwood", replacing many cautious or unproductive submarine skippers with younger (somewhat) and more aggressive commanders. As
3026-470: The "range recorder" was a major step that provided a memory of target position. Because the propellers of many submarines were extremely loud in the water (though it doesn't seem so from the surface), range recorders were able to gauge the distance from the U-boat by sound. This would allow mines or bombs around that area to be detonated. New materials for sound projectors were developed. Both the Royal Navy and
3115-526: The 1960s. Increasingly capable fixed-wing maritime patrol aircraft were also widely used, capable of covering vast areas of ocean. The Magnetic Anomaly Detector (MAD), diesel exhaust sniffers , sonobuoys and other electronic warfare technologies also became a staple of ASW efforts. Dedicated attack submarines , purpose-built to track down and destroy other submarines, became a key component as well. Torpedo carrying missiles, such as ASROC and Ikara , were another area of advancement. The first attacks on
3204-485: The AAF agreed that "The Army is prepared to withdraw Army Air Forces from anti-submarine operations at such time as the Navy is ready to take over those duties completely." In July, plans were made for 77 of the command's Consolidated B-24 Liberators equipped for antisubmarine warfare to be exchanged for an equal number of B-24s assigned to the Navy. Navy squadrons relieved the 479th Group in October, and its personnel and planes were transferred to Eighth Air Force to form
3293-611: The Allied merchant convoys and strategic shipping lanes to any degree that German U-boats did. One major advantage the Allies had was the breaking of the Japanese "Purple" code by the US, so allowing friendly ships to be diverted from Japanese submarines and allowing Allied submarines to intercept Japanese forces. In 1942 and early 1943, US submarines posed little threat to Japanese ships, whether warships or merchant ships. They were initially hampered by poor torpedoes, which often failed to detonate on impact, ran too deep, or even ran wild. As
3382-477: The Army's Eastern Defense Command to undertake offshore patrols with all available aircraft. The first patrols were performed by elements of I Bomber Command , which would be the primary AAF command involved in antisubmarine warfare (ASW) in early 1942, with assistance from I Air Support Command . However, although I Bomber Command was primarily involved in conducting ASW, it was doing so on an emergency basis, and
3471-466: The Army's desire for a single mobile force. The command drew its personnel and equipment from I Bomber Command, which was simultaneously inactivated. In November 1942, the command's units were organized into two wings, reflecting the Navy desire that forces in a sea frontier be unified under a single command. The 25th Antisubmarine Wing , Located in New York City, was responsible for patrols off
3560-711: The Atlantic Coast, while the 26th Antisubmarine Wing in Miami , Florida conducted operations in the Caribbean and the Gulf of Mexico. By late 1942, German strategy had shifted to one of defending against planned Allied offensives in Europe and North Africa by striking at their lines of communication, rather than striking merchant shipping wherever it was most vulnerable. As a result, the Kriegsmarine concentrated its U-boats in
3649-507: The Atlantic and Gulf coasts of the United States, in the Caribbean Sea and in Europe, where it used bases in England and French Morocco. Its operations were marked by disagreements between the AAF and the Navy concerning the conduct of air ASW. In the fall of 1943, the ASW mission was transferred to the Navy and the command became a bomber training unit until it was inactivated in 1946. Within
Army Air Forces Antisubmarine Command - Misplaced Pages Continue
3738-470: The First World War. A similar approach featured a string of 70 lb (32 kg) charges on a floating cable, fired electrically; an unimpressed Admiral Edward Evans considered any U-boat sunk by it deserved to be. Another primitive technique of attacking submarines was the dropping of 18.5 lb (8.4 kg) hand-thrown guncotton bombs. The Lance Bomb was developed, also; this featured
3827-512: The Navy developed and introduced the Kyushu Q1W anti-submarine bomber into service in 1945. The Japanese depth charge attacks by its surface forces initially proved fairly unsuccessful against U.S. fleet submarines. Unless caught in shallow water, a U.S. submarine commander could normally escape destruction, sometimes using temperature gradients ( thermoclines ). Additionally, IJN doctrine emphasized fleet action, not convoy protection, so
3916-811: The Pacific, mainly against coastal shipping. In the immediate postwar period, the innovations of the late war U-boats were quickly adopted by the major navies. Both the United Kingdom and The United States studied the German Type XXI and used the information to modify WW2 fleet boats, the US with the GUPPY program and the UK with the Overseas Patrol Submarines Project. The Soviets launched new submarines patterned on Type XXIs,
4005-640: The Type D*, with a 120 lb (54 kg) charge, was offered for smaller ships. In July 1915, the British Admiralty set up the Board of Invention and Research (BIR) to evaluate suggestions from the public as well as carrying out their own investigations. Some 14,000 suggestions were received about combating submarines. In December 1916, the RN set up its own Anti-Submarine Division (ASD), from which came
4094-409: The U.S. Navy fitted their destroyers with active sonars. In 1928, a small escort ship was designed and plans made to arm trawlers and to mass-produce ASDIC sets. Several other technologies were developed; depth sounders that allowed measurement by moving ships were a new innovation, along with a greater appreciation of the properties of the ocean that affected sound propagation. The bathythermograph
4183-433: The US submarine menace was slight in the beginning, Japanese commanders became complacent and as a result did not invest heavily into ASW measures or upgrade their convoy protection to any degree to what the Allies in the Atlantic did. Often encouraged by the Japanese not placing a high priority on the Allied submarine threat, US skippers were relatively complacent and docile compared to their German counterparts, who understood
4272-413: The United States through October 1943 and overseas through December. It began to train bomber crews in early 1944, when Replacement Training Units were reassigned to the command from Second Air Force ( heavy bombers ) and Third Air Force (medium and light bombers ). However, the AAF was finding that standard military units, based on relatively inflexible tables of organization, were not well adapted to
4361-487: The best ships and crews went elsewhere. Moreover, during the first part of the war, the Japanese tended to set their depth charges too shallow, unaware U.S. submarines could dive below 150 feet (45m). Unfortunately, this deficiency was revealed in a June 1943 press conference held by U.S. Congressman Andrew J. May , and soon enemy depth charges were set to explode as deep as 250 feet (76m). Vice Admiral Charles A. Lockwood , COMSUBPAC , later estimated May's revelation cost
4450-701: The burden for aerial antisubmarine patrols fell on the AAF, which had available aircraft, but whose crews had not been trained for the mission. German Navy submarines began operating in American coastal waters. By March 1942 fifty-three ships had been sunk in the North Atlantic Naval Coastal Frontier . As a result, the Commander of the North Atlantic Naval Coastal Frontier requested
4539-530: The early part of the Pacific War, Japanese subs scored several tactical victories, three successful torpedo strikes on the US fleet carriers Yorktown (CV-5), USS Saratoga and USS Wasp (CV-7), The Saratoga survived the attack and was repaired, while the Yorktown and Wasp were both abandoned and scuttled as a result of the attack. The USS North Carolina (BB-55) received a single torpedo in
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#17327719670844628-399: The end of World War II . While dipping hydrophones appeared before war's end, the trials were abandoned. Seaplanes and airships were also used to patrol for submarines. A number of successful attacks were made, but the main value of air patrols was in driving the U-boat to submerge, rendering it virtually blind and immobile. However, the most effective anti-submarine measure was
4717-440: The endurance of small submarines. Previously the emphasis had been largely on deep water operation but this has now switched to littoral operation where ASW is generally more difficult. There are a large number of technologies used in modern anti-submarine warfare: In modern times forward looking infrared (FLIR) detectors have been used to track the large plumes of heat that fast nuclear-powered submarines leave while rising to
4806-522: The fact a submarine of the day was often on the surface for a range of reasons, such as charging batteries or crossing long distances. The first approach to protect warships was chainlink nets strung from the sides of battleships , as defense against torpedoes . Nets were also deployed across the mouth of a harbour or naval base to stop submarines entering or to stop torpedoes of the Whitehead type fired against ships. British warships were fitted with
4895-455: The helicopter has been used solely for sensing and rocket delivered torpedoes used as the weapon. Surface ships continue to be an important ASW platform because of their endurance, now having towed array sonars. Submarines are the main ASW platform because of their ability to change depth and their quietness, which aids detection. In early 2010 DARPA began funding the ACTUV programme to develop
4984-405: The highly defended Straits of Gibraltar , where nine were sunk, and a similar number damaged so severely they had to limp back to base. The Mediterranean is calmer than the Atlantic, which made escape for U-boats more difficult and was ringed with Allied air bases. Similar ASW methods were used as in the Atlantic but an additional menace was the use by Italians of midget submarines. Operating under
5073-653: The introduction of submarine-launched ballistic missiles , which greatly increased the lethality of submarines. At the beginning of the twentieth century, ASW techniques and submarines themselves were primitive. During the First World War , submarines deployed by Imperial Germany proved themselves to be a capable threat to shipping, being capable of striking targets even out in the North Atlantic Ocean. Accordingly, multiple nations embarked on research into devising more capable ASW methods, resulting in
5162-570: The introduction of escorted convoys , which reduced the loss of ships entering the German war zone around the British Isles from 25% to less than 1%. The historian Paul E. Fontenoy summarised the situation as: "[t]he convoy system defeated the German submarine campaign ." A major contributing factor was the interception of German submarine radio signals and breaking of their code by Room 40 of
5251-457: The introduction of practical depth charges and advances in sonar technology; the adoption of the convoy system also proved to be a decisive tactic. After a lull in progress during the interwar period, the Second World War would see submarine warfare and ASW alike advance rapidly, particularly during the critical Battle of the Atlantic , during which Axis submarines sought to prevent Britain from effectively importing supplies. Techniques such as
5340-415: The invasion of Sicily. Portions of the 480th deployed to Sicily to provide coverage for Operation Avalanche , the landings on mainland Italy. In November 1943, the 480th Group returned to the United States. In January 1944, it moved to Clovis Army Air Field , and was reassigned to form cadres for heavy bombardment units being activated by Second Air Force. Following the activation of the 480th Group,
5429-511: The largest and longest range vessels of their type and were armed with the Type 95 torpedo . However, they ended up having little impact, especially in the latter half of the war. Instead of commerce raiding like their U-boat counterparts, they followed the Mahanian doctrine, serving in offensive roles against warships, which were fast, maneuverable and well-defended compared to merchant ships. In
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#17327719670845518-541: The launch platform. India developed supersonic long range anti-submarine missile called SMART . The missile helps to deliver torpedo 643 km away. In World War I , eight submarines were sunk by friendly fire and in World War II nearly twenty were sunk this way. Still, IFF has not been regarded a high concern before the 1990s by the US military as not many other countries possess submarines . 25th Antisubmarine Wing The 25th Antisubmarine Wing
5607-409: The main weapon (though nuclear depth charges were developed). The mine continued to be an important ASW weapon. In some areas of the ocean, where land forms natural barriers, long strings of sonobuoys, deployed from surface ships or dropped from aircraft, can monitor maritime passages for extended periods. Bottom mounted hydrophones can also be used, with land based processing. A system like this SOSUS
5696-478: The navy as many as ten submarines and 800 crewmen. Much later in the war, active and passive sonobuoys were developed for aircraft use, together with MAD devices. Toward the end of the war, the Allies developed better forward-throwing weapons, such as Mousetrap and Squid , in the face of new, much better German submarines, such as the Type XVII and Type XXI . British and Dutch submarines also operated in
5785-543: The northern and eastern Atlantic. To meet this challenge, the command moved two squadrons to England in November, where they operated with RAF Coastal Command. The two units were attached to the 1st Antisubmarine Group (Provisional), which became the 2037th Antisubmarine Wing (Provisional). The decision to deploy the squadrons was made quickly and preparations for their reception and the maintenance of their aircraft were almost nonexistent. Lack of hangar space at RAF St Eval forced them to perform major maintenance outside during
5874-476: The ocean's surface, to reach submarines wherever they might be. The military submarine is still a threat, so ASW remains a key to obtaining sea control. Neutralizing the SSBN has been a key driver and this still remains. However, non-nuclear-powered submarines have become increasingly important. Though the diesel-electric submarine continues to dominate in numbers, several alternative technologies now exist to enhance
5963-464: The organizations needed (unlike the Allies in the Atlantic). Japanese antisubmarine forces consisted mainly of their destroyers, with sonar and depth charges. However, Japanese destroyer design, tactics, training, and doctrine emphasized surface nightfighting and torpedo delivery (necessary for fleet operations) over anti-submarine duties. By the time Japan finally developed a destroyer escort , which
6052-419: The requirements of ASW air operations, either in support of, or in lieu of, naval forces to protect Allied shipping. Disagreements between the Army and the Navy over command relationships delayed activation of the command until October 1942. The activation of the single Army Air Forces Antisubmarine Command at New York City to control all Army Air Forces units conducting antisubmarine warfare reflected
6141-695: The same attack with the USS Wasp, causing it to miss critical naval actions of the Guadalcanal campaign. Once the US was able to ramp up construction of destroyers and destroyer escorts , as well as bringing over highly effective anti-submarine techniques learned from the British from experiences in the Battle of the Atlantic , they would take a significant toll on Japanese submarines, which tended to be slower and could not dive as deep as their German counterparts. Japanese submarines, in particular, never menaced
6230-428: The same clear-water conditions in the Mediterranean – such that British submarines were painted dark blue on their upper surfaces to make them less visible from the air when submerged at periscope depth – the Royal Navy, mostly operating from Malta , lost 41 submarines to the opposing German and Italian forces, including HMS Upholder and HMS Perseus . Japanese submarines pioneered many innovations, being some of
6319-514: The seabed to detect the magnetic field of submarines as they passed overhead. At this stage, they were used in conjunction with controlled mines which could be detonated from a shore station once a 'swing' had been detected on the indicator loop galvanometer . Indicator loops used with controlled mining were known as 'guard loops'. By July 1917, depth charges had developed to the extent that settings of between 50–200 ft (15–61 m) were possible. This design would remain mainly unchanged through
6408-589: The ships actually monitoring the enemy submarine. Submerged submarines are generally blind to the actions of a patrolling aircraft until it uses active sonar or fires a weapon, and the aircraft's speed allows it to maintain a fast search pattern around the suspected contact. Increasingly anti-submarine submarines, called attack submarines or hunter-killers, became capable of destroying, particularly, ballistic missile submarines. Initially these were very quiet diesel-electric propelled vessels but they are more likely to be nuclear-powered these days. The development of these
6497-408: The successive generations of Allied airborne radar. The first generation of Allied airborne radar used a 1.7 meter wavelength and had a limited range. By the second half of 1942 the " Metox " radar detector was used by U-boats to give some warning from airborne attack. During 1943, the Allies began to deploy aircraft equipped with new cavity magnetron-based 10-centimeter wavelength radar (ASV III), which
6586-499: The surface, as U-boats routinely did at night. The Royal Navy had continued to develop indicator loops between the wars but this was a passive form of harbour defense that depended on detecting the magnetic field of submarines by the use of long lengths of cable lain on the floor of the harbour. Indicator loop technology was quickly developed further and deployed by the US Navy in 1942. By then, there were dozens of loop stations around
6675-624: The surface. FLIR devices are also used to see periscopes or snorkels at night whenever a submariner might be incautious enough to probe the surface. Satellites have been used to image the sea surface using optical and radar techniques. Fixed-wing aircraft, such as the P-3 Orion & Tu-142 provide both a sensor and weapons platform similar to some helicopters like the Sikorsky SH-60 Seahawk , with sonobuoys and/or dipping sonars as well as aerial torpedoes . In other cases
6764-497: The term "Asdic", but relations with the BIR were poor. After 1917, most ASW work was carried out by the ASD. In the U.S., a Naval Consulting Board was set up in 1915 to evaluate ideas. After American entry into the war in 1917, they encouraged work on submarine detection. The U.S. National Research Council , a civilian organization, brought in British and French experts on underwater sound to
6853-545: The training mission. Accordingly, in April 1944, a more functional system was adopted in which each base was organized into a separate numbered Army Air Force Base Unit, that could be adjusted to the proper size for that base's mission. Using this organization, it continued to train bomber organizations and personnel (at a reduced level after the end of the war) until inactivated in March 1946. The command remained inactive until it
6942-499: The winter. A deployed squadron was responsible for the first confirmed sinking of an enemy sub by one of the command's aircraft. Although they did not initially sink a large number of U-boats, their harassing tactics required German subs to adopt evasive tactics and reduced the number and effectiveness of attacks on convoys crossing the Atlantic. In February 1943, The squadrons participated in Operation Gondola, whose goal
7031-513: The world. Sonar was far more effective and loop technology for ASW purposes was discontinued shortly after the conflict's end. The use and improvement of radar technology was one of the most important elements in the fight against submarines. Locating submarines was the first step in being able to defend against and destroy them. Throughout the war, Allied radar technology was much better than their German counterparts. German U-boats struggled to have proper radar detection capabilities and keep up with
7120-529: Was also a potential hazard to the dropping ship. During the First World War , submarines were a major threat. They operated in the Baltic, North Sea, Black Sea and Mediterranean as well as the North Atlantic. Previously, they had been limited to relatively calm and protected waters. The vessels used to combat them were a range of small, fast surface ships using guns and good luck. They mainly relied on
7209-530: Was deployed by the US in the GIUK gap and other strategically important places. Airborne ASW forces developed better bombs and depth charges , while for ships and submarines a range of towed sonar devices were developed to overcome the problem of ship-mounting. Helicopters can fly courses offset from the ships and transmit sonar information to their combat information centres . They can also drop sonobuoys and launch homing torpedoes to positions many miles away from
7298-484: Was disbanded in England in November. Despite the deployment of command units to Newfoundland, England and Morocco, the majority of the command remained in the United States conducting patrols and covering convoys in an area where the threat of submarine attack had substantially diminished. The Navy insisted that forces be retained in this area because of the ability of the German submarine force to rapidly shift its forces. The command's wings were assisted by Navy units and
7387-623: Was disbanded on 8 October 1948. [REDACTED] This article incorporates public domain material from the Air Force Historical Research Agency Antisubmarine warfare Anti-submarine warfare ( ASW , or in the older form A/S ) is a branch of underwater warfare that uses surface warships , aircraft , submarines , or other platforms, to find, track, and deter, damage, or destroy enemy submarines. Such operations are typically carried out to protect friendly shipping and coastal facilities from submarine attacks and to overcome blockades . Successful ASW operations typically involved
7476-674: Was invented in 1937, which became a common fixture amongst ASW ships within only a few years. There were relatively few major advances in weapons during the period; however, the performance of torpedoes continued to improve. During the Second World War , the submarine menace revived, threatening the survival of island nations like Britain and Japan which were particularly vulnerable because of their dependence on imports of food, oil, and other vital war materials. Despite this vulnerability, little had been done to prepare sufficient anti-submarine forces or develop suitable new weapons. Other navies were similarly unprepared, even though every major navy had
7565-515: Was more economical and better suited to convoy protection, it was too late; coupled to incompetent doctrine and organization, it could have had little effect in any case. Late in the war, the Japanese Army and Navy used Magnetic Anomaly Detector (MAD) gear in aircraft to locate shallow submerged submarines. The Japanese Army also developed two small aircraft carriers and Ka-1 autogyro aircraft for use in an antisubmarine warfare role, while
7654-605: Was strongly influenced by the duel between HMS Venturer and U-864 . A significant detection aid that has continued in service is the Magnetic Anomaly Detector (MAD), a passive device. First used during the Second World War, MAD uses the Earth's magnetosphere as a standard, detecting anomalies caused by large metallic vessels, such as submarines. Modern MAD arrays are usually contained in
7743-454: Was subject to withdrawal from these duties to perform its primary bombardment function. It soon became apparent that if the AAF were to continue with the ASW mission, its units would have to be organized under a specially trained and equipped command. In May 1942, General Arnold , Commanding General of the AAF, proposed to Admiral King , the Chief of Naval Operations , that the AAF establish
7832-543: Was to attack every U-boat traversing the Bay of Biscay at least once. The Navy believed that more antisubmarine forces were required to protect convoys in the North Atlantic, where attacks were becoming more concentrated. In March, the 19th Antisubmarine Squadron relocated to CFB Gander in Newfoundland , soon joined by two other squadrons. Eventually the command formed two groups in England and Morocco. In June 1943,
7921-600: Was undetectable by "Metox", in sufficient numbers to yield good results. Eventually the "Naxos" radar detector was fielded that could detect 10-cm wavelength radar, but it had a very short range and only gave a U-boat limited time to dive. Between 1943 and 1945, radar equipped aircraft would account for the bulk of Allied kills against U-boats. Allied anti-submarine tactics developed to defend convoys (the Royal Navy 's preferred method), aggressively hunt down U-boats (the U.S. Navy approach), and to divert vulnerable or valuable ships away from known U-boat concentrations. During
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