Противолодочная борьба: история и современные методы

Branch of naval 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 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 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 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 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 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 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 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 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 the First World War. A similar approach featured a string of 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 hand thrown guncotton bombs. The Lance Bomb was developed, also; this featured a cone shaped steel drum on a 5 feet (2 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, , fitted with a spar torpedo. To attack at set depths, aircraft bombs were attached to lanyards which would trigger their charges; a similar idea was a 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 feet (6 m). Perhaps the best early concept arose in a 1913 RN Torpedo School report, describing 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 feet (14 m) firing, to be launched from a stern platform. Weighing , and effective at 100 feet (30 m), the "cruiser mine" was also a potential hazard to the dropping ship.

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, 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 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 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.

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 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 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 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 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), Saratoga and 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 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 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 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 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 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 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 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 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 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 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 the Pacific, mainly against coastal shipping.

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 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 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. India introduced supersonic missiles to deliver torpedo at long ranges called SMART or Supersonic missile assisted torpedo system. This new technology helps to deliver the torpedo 1000 km away and gives flexibility in terms of the launch platform.