Misplaced Pages

#378621

111-511: Despite its failure to enter widespread service, the lessons learned were applied to the follow-on Aegis Combat System and the associated AN/SPY-1 passive electronically scanned array (PESA) radar. Prior to the development of SCANFAR, the Navy had been developing an advanced anti-aircraft weapon system combining an extremely advanced radar system, the AN/SPG-59 , with a new long-range missile known as

222-429: A helicopter hangar with one anti-submarine helicopter and one armed attack helicopter . The Aegis program has also projected reducing the cost of each Flight IIA ship by at least $ 30 million. Recent Aegis Combat System ships come with active electronically scanned array radars which use solid-state gallium nitride emitters. These include Canadian Surface Combatant (CSC) and Spanish F110-class frigates , which use

333-513: A plug and fight network of land, sea, and air-based sensors to help detect and track ballistic missile threats and select Patriot and THAAD surface-to-air launchers that are best positioned for a successful intercept. On 5 October 2011, U.S. Secretary of Defense Leon Panetta announced that the United States Navy will station four Aegis Ballistic Missile Defense System warships at Naval Station Rota , Spain, to strengthen its presence in

444-417: 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;

555-462: 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

666-403: 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"

777-472: A drastic decline in readiness, and left Aegis Combat Systems in low state of readiness. The Aegis system was involved in a disaster in which USS  Vincennes mistakenly shot down Iran Air Flight 655 in 1988 resulting in 290 civilian deaths. A formal military investigation by the United States Navy concluded that the Aegis system was completely operational and well maintained. The investigation found that if

888-591: A large number of targets can be engaged simultaneously. The computer -based command-and-decision (C&D) element is the core of the Aegis Combat System and came from the Naval Tactical Data System (NTDS) threat evaluation and weapons assignment (TEWA) function. This interface makes the ACS capable of simultaneous operation against almost all kinds of threats. In December 2019, Lockheed Martin released

999-410: 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

1110-407: 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

1221-703: 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

SECTION 10

#1732859183379

1332-642: 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

1443-438: A multi-year trilateral exercise plan in response to North Korea's continued ballistic missile launches. In 2010, it was reported that Aegis radar systems on board some individual warships were not being maintained properly. A Navy panel headed by retired Vice Adm. Phillip Balisle issued the "Balisle report," which asserted that over-emphasis on saving money, including cuts in crews and streamlined training and maintenance, led to

1554-641: A new era in surface warfare as the first Aegis ship outfitted with the Martin Marietta Mark-41 Vertical Launching System (VLS), allowing a wider missile selection, more firepower, and survivability. The improved AN/SPY-1B radar went to sea in USS ; Princeton , ushering in another advance in Aegis capabilities. USS  Chosin introduced the AN/UYK-43 / 44 computers, which provide increased processing capabilities. During 1980,

1665-532: A possible acronym of Advanced Electronic Guided Interceptor System although this definition was never used. The main manufacturer of the Aegis Combat System, Lockheed Martin, makes no mention of the name Aegis being an acronym, nor does the U.S. Navy . In 1970, then-Captain Wayne Meyer was named Manager Aegis Weapons System. Under his leadership the first systems were successfully deployed on various U.S. Navy vessels. The first Engineering Development Model (EDM-1)

1776-533: A promotional video heralding the 50th anniversary of the Aegis combat system. Aegis was initially developed by the Missile and Surface Radar Division of RCA , which was later acquired by General Electric . The division responsible for the Aegis systems became Government Electronic Systems. This, and other GE Aerospace businesses, were sold to Martin Marietta in 1992. This became part of Lockheed Martin in 1995. By

1887-561: 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);

1998-466: 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

2109-594: 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

2220-560: 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

2331-499: 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

SECTION 20

#1732859183379

2442-550: A simplified version of the SPG-59. The main radar would be used solely for surveillance, with target illumination being left to existing radar systems used with earlier missiles like the RIM-8 Talos or RIM-24 Tartar . During development it was found that attempting to use a single antenna for both search and tracking did not work effectively, so the system was modified to use two antennas, one for surveillance and another for tracking. Thus

2553-452: A target. The pencil beam could be manually operated. SCANFAR was eventually replaced by the AN/SPS-48E . Gary M. Farral RD2, USS Long Beach CG(N)-9 2 November 1966 to 28 December 1968 Aegis Combat System The Aegis Combat System is an American integrated naval weapons system, which uses computers and radars to track and guide weapons to destroy enemy targets. It was developed by

2664-706: 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

2775-527: Is 26,800 lb (12,200 kg) for the self-defense version, 29,800 lb (13,500 kg) for the tactical version, and 32,000 lb (15,000 kg) for the strike version, thus incorporating anti-submarine warfare (ASW) systems and Tomahawk Land Attack Cruise Missiles (TLAM). Shipboard torpedo and naval gunnery systems are also integrated. AWS, the heart of Aegis, comprises the AN/SPY-1 Radar, MK 99 Fire Control System, Weapon Control System (WCS),

2886-544: Is 30 times more sensitive and thus can handle 30 times more targets comparing to the SPY-1D radar, providing increased air and missile defense capabilities. Flight IIA ships will also be upgraded to SPY-6 in the future, giving them Aegis BMD capabilities. Aegis Ashore is a land-based version of Aegis BMD which includes the AN/SPY-1 radar and command systems, and Mk 41 VLS equipped SM-3 and SM-6 missiles. Test installation exists at

2997-560: Is controlled by an advanced, automatic detect-and-track, multi-function three-dimensional passive electronically scanned array radar , the AN/SPY-1. Known as "the Shield of the Fleet", the SPY high-powered (6 megawatt ) radar is able to perform search, tracking, and missile guidance functions simultaneously with a track capacity of well over 100 targets at more than 100 nautical miles (190 km). However,

3108-560: Is not intended to replace the SM-2 series of missiles. The SM-6 Block IB includes a larger 21-inch rocket motor that sits on top of the 21-inch booster. To enable Ballistic Missile Defense capabilities, signal processing for the SPY-1 radar was upgraded using commercial off-the-shelf components and open architecture standards. The Multi-Mission Signal Processor (MMSP) provides Anti-Air Warfare (AAW) and Ballistic Missile Defense (BMD) capability for

3219-454: 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

3330-654: The Arleigh Burke -class destroyer was designed using an improved sea-keeping hull form, reduced infrared and radar cross-sections, and upgrades to the Aegis Combat System. The first ship of the class, USS  Arleigh Burke , was commissioned during 1991. Flight II of the Arleigh Burke class, introduced in 1992, incorporated improvements to the SPY-1 radar, and to the Standard missile, active electronic countermeasures, and communications. Flight IIA, introduced in 2000, added

3441-534: 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,

SCANFAR - Misplaced Pages Continue

3552-535: The AN/SPY-7 radar from Lockheed-Martin, and Constellation -class frigates which use AN/SPY-6 radar from Raytheon . AN/SPY-6 radar will also be installed in Flight III and Flight IIA Arleigh Burke -class destroyers, giving them Ballistic Missile Defense capability currently deployed on Flight I and Flight II ships. The Aegis Ballistic Missile Defense System (BMD) program by the U.S. Missile Defense Agency enables

3663-488: 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

3774-672: The East China Sea southwest of the Japanese home islands. On 22 February 2023, five warships from the United States, Japan, and South Korea held a multilateral ballistic missile defense exercise in the Sea of Japan in response to the launch of a North Korean Hwasong-15 ballistic missile on 18 February 2023, landing in Japan's exclusive economic zone (EEZ) in the Sea of Japan, in an area 125 miles west of

3885-529: The NATO missile defense system . The word " Aegis " is a reference that dates back to Greek mythology, with connotations of a protective shield, as the Aegis was the buckler (shield) of Zeus, worn by Athena. The Aegis Combat System (ACS) implements advanced command and control (command and decision, or C&D, in Aegis parlance). It is composed of the Aegis Weapon System (AWS), the fast-reaction component of

3996-851: The Pacific Missile Range Facility in Hawaii . A site in Deveselu , Romania is operational since 2016, and a site near Redzikowo , Poland will become operational in 2022. Japan intended to deploy two systems with an AN/SPY-7 AESA radar by 2021, but cancelled these plans in 2020. Possible deployments of Aegis Ashore include U.S. naval base at Guam . U.S. Army Integrated Air and Missile Defense Battle Command System (IBCS) program aims to integrate Aegis BMD and its AN/SPY-1 and AN/SPY-6 radars with MIM-104 Patriot ( AN/MPQ-65 A and GhostEye), NASAMS (GhostEye MR), AN/TPY-2 ( THAAD and GMD ), and F-35 Lightning II ( AN/APG-81 ) radars to form

4107-542: The RIM-161 Standard Missile 3 (SM-3) mid-course interceptors and the RIM-156 Standard Missile 2 Extended Range Block IV (SM-2ER Block IV) terminal-phase interceptors. The SM-2ER Block IV can engage the ballistic missiles within the atmosphere (i.e. endoatmospheric intercept) in the terminal phase of a missile's trajectory with a blast fragmentation warhead. The Standard Missile 3 is a development of

4218-455: The RIM-50 Typhon . The radar was an active electronically scanned array that acted both as a long-range surveillance system as well as the target illumination and guidance system for the missiles. The system proved to be beyond the state of the art, in particular it required a large number of individual broadcast elements that proved to be unreliable and expensive. SCANFAR was to some extent

4329-637: 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

4440-574: 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

4551-502: 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

SCANFAR - Misplaced Pages Continue

4662-524: 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

4773-406: The commanding officer had relied on the complete tactical data displayed by the Aegis system, the engagement might never have occurred. Additionally, psychological effects of the crew subconsciously manipulating the data to accord with a predefined scenario greatly contributed to the false identification. The investigation found that the Aegis Combat System did not contribute to the incident and that

4884-491: 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

4995-471: The "air picture" it provided was good, with over-the-horizon capabilities. In 1967, during a shipyard overhaul period, the Long Beach radar system was converted from electronic tubes to solid state electronic boards. Converting to solid state for radar and radio equipment lightened the superstructure by 20 tons. AN/SPS-33 was an S band radar with a pencil beam function that could focus a single radar beam on

5106-479: 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

5217-466: 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

5328-526: 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

5439-585: The AN/SPY-1 Radar is mounted lower than the AN/SPS-49 radar system and so has a reduced radar horizon . The Aegis system communicates with the Standard missiles through a radio frequency (RF) uplink using the AN/SPY-1 radar for mid-course update missile guidance during engagements, but still requires the AN/SPG-62 fire-control radar for terminal guidance. This means that with proper scheduling of intercepts,

5550-633: The Aegis Anti-Aircraft Warfare (AAW) capability, along with the Phalanx Close In Weapon System (CIWS) , and the Mark 41 Vertical Launch System . Mk 41 VLS is available in different versions that vary in size and weight. There are three lengths: 209 in (5.3 m) for the self-defense version, 266 in (6.8 m) for the tactical version, and 303 in (7.7 m) for the strike version. The empty weight for an 8-cell module

5661-552: The Aegis system to act in a sea-based ballistic missile defense function, to counter short- and medium-range ballistic missiles of the variety typically employed by a number of potential opponent states. The program is part of the United States national missile defense strategy and NATO European missile defense system . BMD capabilities allow vessels equipped with Mk 41 Vertical Launching System (VLS) to intercept ballistic missiles in post-boost phase and prior to reentry, using

SECTION 50

#1732859183379

5772-616: The Aegis-equipped naval forces of the Japanese Maritime Self Defense Force (MSDF). The two ASEV warship would be exclusively tasked for dedicated ballistic missile defense (BDM) missions (BMD等) and operate off the Korean peninsula in the Sea of Japan , allowing the other Aegis guided-missile destroyers to meet other contingencies (侵攻阻止) while operating independently to maintain the sea lines of communication (SLOC) open in

5883-652: 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

5994-573: The Carter Administration due to its increased cost compared to the non-nuclear DDG 47. With the cancellation of the CGN 42, the DDG 47 Aegis destroyer was redesignated as CG 47, a guided missile cruiser. The first cruiser of this class was USS  Ticonderoga , which used two twin-armed Mark-26 missile launchers, fore and aft. The commissioning of the sixth ship of the class, USS  Bunker Hill opened

6105-660: The Command and Decision Suite, and Standard Missile family of weapons; these include the basic RIM-66 Standard , the RIM-156 Standard ER extended range missile, and the newer RIM-161 Standard Missile 3 designed to counter ballistic missile threats. A further SM-2 based weapon, the RIM-174 Standard ERAM (Standard Missile 6) was deployed in 2013. Individual ships may not carry all variants. Weapons loads are adjusted to suit assigned mission profile. The Aegis Combat System

6216-463: 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

6327-461: The Japanese home islands . On 16 November 2022, the guided-missile destroyer Maya fired an SM-3 Block IIA missile, successfully intercepting the target outside the atmosphere in the first launch of the missile from a Japanese warship. On 18 November 2022, the Haguro likewise fired an SM-3 Block IB missile with a successful hit outside the atmosphere ( pictured ). Both test firings were conducted at

6438-555: The Mediterranean Sea and bolster the ballistic missile defense (BMD) of NATO as part of the European Phased Adaptive Approach (EPAA) missile defense program. On 16 February 2012, it was reported that the Arleigh Burke -class destroyers Donald Cook and Ross would be relocated to Rota during Fiscal Year 2014, followed by Porter and Carney in fiscal year 2015. On 9 May 2013, Commander Destroyer Squadron 60

6549-747: The Missile and Surface Radar Division of RCA , and it is now produced by Lockheed Martin . Initially used by the United States Navy , Aegis is now used also by the Japan Maritime Self-Defense Force , Spanish Navy , Royal Norwegian Navy , Republic of Korea Navy , and Royal Australian Navy , and is planned for use by the Royal Canadian Navy . As of 2022, a total of 110 Aegis-equipped ships have been deployed, and 71 more are planned (see operators ). Aegis BMD (Ballistic Missile Defense) capabilities are being developed as part of

6660-506: 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

6771-771: 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,

SECTION 60

#1732859183379

6882-519: The SM2-ER Block IV, capable of exo-atmospheric intercept (i.e. above the atmosphere) during the midcourse phase; its kinetic warhead (KW) is designed to destroy a ballistic missile's warhead by colliding with it. RIM-174 Standard ERAM (Standard Missile 6) extended range active missile is a further development of the SM-2ER Block IV, which adds a booster and an active radar homing seeker. SM-6 can be used for either air defense or ballistic missile defense, providing extended range and increased firepower; it

6993-421: 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

7104-473: The U.S. Pacific Missile Range Facility on Kauai Island , Hawaii, in cooperation with the U.S. Navy and U.S. Missile Defense Agency . This was the first time the two ships conducted SM-3 firings in the same time period, and the tests validated the ballistic missile defense capabilities of Japan's newest Maya -class destroyers . On 23 December 2022, the Japanese Ministry of Defense's 2023 budget and program guidance illustrated examples of operation (運用の一例) for

7215-409: 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

7326-433: 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

7437-487: 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

7548-412: The captain asked for a status of the original target identifier TN4474, the Aegis system had recycled that identifier to a different target which was descending, indicating possible attack posture. An article by David Pogue in Scientific American rated it as one of the five "worst digital user-interface debacles of all time." Anti-submarine warfare Anti-submarine warfare ( ASW , or in

7659-451: The earlier plan of Aegis Ashore installations, commissioning one by the end of fiscal year 2027, and the other by the end of FY2028. The budget for design and other related expenses are to be submitted in the form of "item requests", without specific amounts, and the initial procurement of the lead items are expected to clear legislation by FY2023. Construction is to begin in the following year of FY2024. At 20,000 tons each, both vessels will be

7770-414: 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

7881-399: 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

7992-440: 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

8103-517: 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

8214-449: The first 28 ships (DDGs 51–78) of the U.S. Navy's Arleigh Burke -class destroyers. This capability is also incorporated in USS  John Finn  (DDG-113) and following new construction, as well as Aegis Ashore. MMSP modifies transmitters of the SPY-1D radar to enable dual-beam operation for reduced frame times and better reaction time, and provides stability for all waveforms , allowing

8325-469: The gas turbine powered Spruance class . When the CSGN was cancelled, the Navy proposed a modified Virginia -class design (CGN 42) with a new superstructure designed for the Aegis Combat System and with a displacement of 12,100 tons. As compared to the CSGN, this design was not as survivable and had reduced command and control facilities for an embarked flag officer. Ultimately this design was also cancelled during

8436-497: 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

8547-405: 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

8658-637: 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

8769-555: 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

8880-457: 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

8991-473: The island of Ōshima , which lies 30 miles (48 km) west of the main island of Hokkaido . Two additional ICBMs were subsequently launched on 20 February 2023, with both landing in the Sea of Japan off the east coast of the Korean Peninsula . On 19 December 2023, United States, Japan, and South Korea announced the activation of a real-time North Korea missile warning system as well as jointly established

9102-514: The largest surface combatant warships operated by the JMSDF, and according to Popular Mechanics , they will "arguably [be] the largest deployable surface warships in the world.". On 6 October 2022, five warships from the United States, Japan, and South Korea held a multilateral ballistic missile defense exercise in the Sea of Japan ( pictured ) as part of the military response to ongoing North Korean intermediate-range ballistic missile tests over

9213-502: 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

9324-438: The late 1950s, the U.S. Navy replaced guns with guided missiles on its ships. These were sufficient weapons but by the late 1960s, the U.S. Navy recognized that reaction time, firepower, and operational availability in all environments did not match the anti-ship missile threat. The new threat of Soviet anti-ship missiles exposed a weakness in contemporary naval radar. The requirements of both tracking and targeting these missiles

9435-409: 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

9546-473: 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

9657-472: 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

9768-561: 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

9879-459: 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

9990-601: The radar system to detect, track, and support engagements of a broader range of threats. MMSP improves performance in littoral , ducted clutter , electronic attack (EA), and chaff environments and provides greater commonality in computer programs and equipment. As of April 2022, the U.S. and Japan are the only countries to purchase or deploy the Aegis BMD on their military ships. Flight III of Arleigh Burke -class destroyers starting with USS  Jack H. Lucas are equipped with AN/SPY-6 AESA radar from Raytheon , which

10101-680: 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

10212-428: 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

10323-514: 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

10434-589: 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

10545-408: 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

10656-494: 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

10767-609: 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

10878-467: The system ended up using three radar antennas, and was, therefore, similar to earlier systems. An automatic tracking computer was added to the system in 1967. Also, in 1967, USS Long Beach detected and destroyed two North Vietnamese MiGs, utilizing the SCANFAR and Talos missile systems. In service, the system proved to be temperamental, due largely to the huge number of vacuum tubes it used. Despite this,

10989-468: The system's recorded target data contributed to the investigation of the incident. The discrepancies between the Aegis data report and what the ship's personnel reported to the commanding officer are as follows: Other analyses found that ineffective user interface design caused poor integration with the crisis management human processes it was intended to facilitate. The Aegis System software shuffles target tracking numbers as it gathers additional data. When

11100-491: 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

11211-513: 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

11322-518: 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

11433-526: 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

11544-582: Was formally designated to perform type-command administrative oversight for the four BMD-capable destroyers based at Rota, Spain. The Japanese Maritime Self Defense Force (JMSDF) currently operates four Kongō , two Atago , and two Maya -class guided-missile destroyers as part of its "Aegis Afloat" program ( See table below ). Additionally, on 31 August 2022, The Japan Ministry of Defense announced that JMSDF will operate two " Aegis system equipped ships " (イージス・システム搭載艦 in Japanese) ( pictured to replace

11655-437: Was installed in a test ship, USS  Norton Sound , in 1973. During this time frame, the Navy envisioned installing the Aegis Combat System on both a nuclear-powered " strike cruiser " (or CSGN) and a conventionally-powered destroyer (originally designated DDG 47). The CSGN was to be a new, 17,200 ton cruiser design based on the earlier California and Virginia -class cruisers. The Aegis destroyer design would be based on

11766-674: 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

11877-625: Was limited by the number of radars on each ship, which was typically 2–4. In 1958 the navy started the Typhon Combat System , a prophetic program culminating in the futuristic but unreliable AN/SPG-59 phased array radar, which was never made viable and was cancelled in 1963 to be replaced by the Advanced Surface Missile System (ASMS). As a result, the U.S. Navy decided to develop a program to defend ships from anti-ship missile threats. An Advanced Surface Missile System (ASMS)

11988-508: 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

12099-596: Was promulgated and an engineering development program was initiated in 1964 to meet the requirements. ASMS was renamed "Aegis" in December 1969 after the aegis , the shield of the Greek god Zeus . The name was suggested by Captain L. J. Stecher, a former Tartar Weapon System manager, after an internal U.S. Navy contest to name the ASMS program was initiated. Captain Stecher also submitted

12210-582: 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

12321-600: 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

#378621