Anti-Submarine Warfare

he ability to detect, track and destroy submarines is returning as a primary mission for modern naval forces in the Asia-Pacific region. Many nations are currently reinforcing their submarine fleets for the first time in many decades;

19th Mar 2012


 Anti-Submarine Warfare


 ASW capabilities in the Asian region


Byline: Claire Apthorp / London


The ability to detect, track and destroy submarines is returning as a primary mission for modern naval forces in the Asia-Pacific region. Many nations are currently reinforcing their submarine fleets for the first time in many decades; but all eyes are on China as its growing military might increasingly threatens long-term security. China’s focus on developing advanced submarine technology has many of its neighbours – and their allies – readdressing their own ability to face submarine aggression, by developing their own anti-submarine warfare (ASW) capabilities.
The waters of the Asian region are some of the most heavily trafficked sea-lanes in the world. The ability to pass through these areas, particularly around Indonesia, Malaysia, Vietnam, China, Singapore and the Philippines, is vital not only for trade within Asia, but for world trade as a whole. The South China Sea and the Strait of Malacca are amongst the most heavily trafficked waters in the world, the latter linking the Pacific Ocean to the Indian Ocean, and as a result, sees vast amounts of trade pass through a narrow corridor. As China’s military build up and the ‘string of pearls’ strategy brings more of the region’s vital points under potential Chinese control, a serious threat to free movement through these waters becomes a more realistic prospect.
China’s strategy to potentially control shipping lanes involves a number of features. Being heavily reliant on the flow of oil from the Middle East, the country has a significant interest in gaining a higher level of control over sea-lanes during times of tension.
By way of a set of strategic placements of bases stretching from China’s territorial waters to the Middle East, these developments will see China’s influence in the region increase, and US interests – and regional security - threatened. Included in China’s plans for naval expansion are surface frigates, destroyers and amphibious ships with greater Blue Water capabilities than those already in operation, submarines, and a range of long-range weapons, including cruise missiles; as well as its own ASW capabilities.


Growing unease
The People’s Liberation Army Navy (PLAN) is expected to commission a number of new submarines this year. Attack submarines will indeed form a central aspect of China’s ability to conduct deep water operations. Since the 1990s the PLAN has acquired a range of imported submarines, including 12 Russian Kilo-class. China is also developing a number of indigenous vessels, including the Jin class (Type 094) nuclear-powered ballistic missile submarine; the Shang class (Type 093) new nuclear powered attack submarine; the Yuan class (Type 041 or Type 039) non-nuclear powered attack submarine; and the Song class (Type 039 or Type 039G) non-nuclear powered attack submarine.
Although few details are known of the technology onboard the vessels, they are believed to include significant Russian hardware. The US Department of Defence (DOD) also believes that a number of new versions of the Type 093, the Type 095, will enter service in around 2015, and in 2010 China was reported to have launched a successor to the Yuan class. In terms of armament, the PLAN’s fleet is armed with a range of weapons including a number of different anti-surface cruise missiles, wire-guided and wake-homing torpedoes, as well as mines. When the Jin-class boats come into service they are expected to be armed with nuclear-armed submarine launched ballistic missiles, which the US DOD estimates to have a range of between 7,200 and 7,400 km.
Despite its own expansion of submarine technologies, China’s ability to detect enemy submarines in its own waters remains limited. US submarines pose the greatest threat to the PLAN’s growing naval fleet, and with US submarine technology arguably the most advanced in the world, China’s ability to prevent penetration into its coastal waters or international waters they want to control, is lacking. As part of its own ASW capabilities, China is understood to be investing in forward-looking technologies including the use of unmanned underwater vessels (UUVs), something US Special Forces have been pursuing for some time.
The US Navy’s Ohio-class guided-missile submarines have been equipped with robotic min-subs and different types of UUVs. The Sea Stalker underwater robot is designed to detect radio communications and collect data on areas outside the reach of the host boat; while for above-water operations the Scan Eagle UAV and Buster UAV carries sensors to carry out covert operations to expand the reach of the host boat’s onboard battle management systems.
With similar intentions, the PLAN has revealed plans to develop hunting patterns for UAVs that use genetic algorithms and work with dropped sonar buoys to track submarines as part of a wider underwater weaponry and chemical defence programme. Towards the end of 2011, it was also revealed that the Chinese People’s Liberation Army (PLA) has developed or acquired a new maritime patrol plane designed to track and destroy submarines, designated Y-8F-600. Understood to be a derivative of the An-12 cargo plane, the aircraft was originally sighted in Airborne Early Warning (AEW) configuration with rotodome or AESA radar. The latest weapons carrier version has been modified to carry a weapon bay, surface-search radar, EO/IR sensor turret and an anomaly detector boom. The associated sensor and processing technology required to turn an aircraft such as the Y-8F-600 into an integral part of a wider ASW capability are as yet to be revealed by the PLAN – or perhaps even developed – but the aircraft shows the government’s intent to develop these technologies.


Regional response
China’s move toward more advanced submarine technology has been an important factor in the increase of ASW capabilities amongst its regional neighbours. Singapore has a current requirement for fixed wing ASW aircraft that will most likely replace the Armed Force’s Fokker 50 maritime patrol assets. Singapore has some of the most advanced ASW capabilities in the Asian region, and with the Royal Singapore Navy (RSN) already fielding a balanced fleet of missile gunboats, missile corvettes, patrol vessels, anti-submarine patrol vessels, mine counter measure vessels, and landing ships tank. In 1997 the RSN commissioned the first anti-submarine patrol vessels (APVs), designed to detect surface and underwater threats, equipped with a 76mm OTO Melara Gun, a Mistral surface-to-air missile system, hull-mounted sonar and torpedoes, and advanced command and control, navigation and communication systems.
The RSN already plays a central role in a number of key multi-lateral forums, including the Five Power Defence Arrangements (FPDA), which sees forces from Australia, Malaysia, New Zealand, Singapore and the UK working together for capacity building to enhance their level of inter-operability, especially in dealing with new emerging security threats, including threats to maritime security. Interoperability is key to building a secure ASW network within the Asia-Pacific region. Many – if not the majority – of nations in the region do not possess the naval technology to provide a comprehensive ASW capability, and as a result, inter-service operations are vital to achieving effectiveness in this area.
In adding to the aerial layer of their ASW capabilities, Singapore will continue to play a central role in these operations. To fulfil the current requirement the government is understood to be considering Boeing’s P-8A Poseidon, Alenia’s ATR 42MP, and a Bombardier Q400 offering from IAI and Elta Systems. Singapore already operates the Sikorsky S-70B from its Formidable class multi-role stealth frigates, which are amongst the most advanced combat surface vessels in the region, and are fitted with the Eurotorp lightweight A244 Torpedo System to counter submarine threats.
With built-in ASW capabilities, the S-70B Seahawk was acquired by the RSN in January 2005, when a contract was signed with Sikorsky for six aircraft. The acquisition marked a significant milestone in the RSN’s force development, and enhanced its ability to undertake a wide spectrum of missions and carry out its mission of defending Singapore and its vital sea lines of communications more effectively. The S-70B model is a blend of field proven technology and state-of-the-art airframe, avionics and mission equipment making it one of the world’s most capable helicopters. The system is integrated with a Rockwell Collins flight management system including an advanced navigation and communication suite. The weapons management system has a flexible open architecture capable of integrating indigenous weapons and mission equipment.


Regional cooperation
India has worked closely with Singapore for many years on ASW capabilities. The two nations have a long history of joint ASW exercises for the mutual benefit of both nations, and continued cooperation between the RSN and the Indian Navy (IN).
In 2010 the IN’s first Anti-Submarine Warfare Corvette (ASWC), Kamorta, was launched, the first of a fleet of P-28 Corvette indigenously built for ASW capabilities with stealth characteristics gained by a low underwater radiated noise signature. Built by Garden Reach Shipbuilders and Engineers (GRSE), the four vessels are expected to be delivered by 2015. The first vessel will be commissioned in 2012, ship, Kadmatt, in 2013, and the third and fourth in 2014 and 2015.
The vessels will contain in excess of 80 percent Indian-designed content, including the weapon and sensor suites. They will have a displacement of around 2,500 tonnes, a length of 110 metres, and nearly 3,500 nautical mile endurance. Each vessel will carry a helicopter and be equipped with advanced electronic warfare systems and stealth mounted guns, and will be able to detect and destroy enemy submarines from a distance. Specific armament is understood to include the Oto Melara 76mm Super Raid gun in stealth mount, a Klub-N missile system, the Larsen and Toubro derivative of the RBU-6000 anti-submarine rocket launcher, and the Larson and Tubro built torpedo launcher. The onboard sensor is the DRDO-produced Central Acquisition Radar (CAR), which is capable of tracking 150 targets at ranges of 200 km. France’s DCNS will provide a raft-mounted Propulsion Power Transmission Systems (PPTS) package for the vessels.
The IN has also recently taken re-delivery of its Tu-142ME aircraft following a Russian upgrade programme that saw Beriev repaired and upgraded the maritime patrol aircraft that will extend the fleet’s service life by sixteen years. Originally equipped with the Korshun-K search-and-track ASW system which included magnetometer MMS-106 Ladoga and hydrology reconnaissance equipment, the upgrade included modernisation of jet-prop engines and installation of new onboard equipment. The eight aircraft are also understood to have been fitted with the air-launched Brahmos missile.
A major aspect of India’s ongoing programme to upgrade its ASW capabilities is with new helicopters for the naval air arm of the IN. This role is currently carried out by a range of Kamov and Sea King rotorcraft, the latter of which are due to be replaced by a modern alternative under a programme which will seek 60 new aircraft. A number of companies, including AgustaWestland (with the NH90 based solution), Sirkosky (with the S-70B Seahawk and MH-60R via US Foreign Military Sale), and a HAL and Eurocopter consortium (with the EC725), submitted responses to a 2005 request for proposal (RFP) for the programme, which has since stalled. In 2011 a new RFI was issued to source new-build Naval Multi Role Helicopters (NMRH), with advanced ASW, ASuW, SAR, ELINT and Special Operation / Commando operation capabilities.


Maritime safety
With one of the largest exclusive economic zones (EEZ) in the world, Japan is also redoubling its efforts to field advanced ASW capabilities. Japan utilises the maritime patrol aircraft fleet of the Japan Maritime Self-Defence Force (JMSDF) in an ASW role, and is currently developing the Kawasaki XP-1 to replace its fleet of Lockheed Martin P-3C Orions. Powered by four Ishikawajima-Harima Heavy Industries F7-10 turbofan engines, length of 38.0 metres, wingspan of 35.4 metres and height of 12.1 metres, the first prototype was handed over the Japanese defence ministry in 2008, and subsequently entered a long-term evaluation and test programme.
Built and manufactured domestically, Kawasaki called the XP-1 a completely new aircraft type. Airframe, engines and patrol systems have been developed indigenously with the latest technologies, and the aircraft is designed to carry out prolonged, extensive patrols in Japan’s EEZ. The aircraft has a greater range and useful load that the P-3C, and although the test programme has experienced difficulties during 2011, with rips and tears developing during ground testing, the programme remains so far on track.
The Japan Maritime Self-Defence Force (JMSDF) is also updating its ASW capabilities. In 2009 it took delivery of the first of two Hyuga class helicopter destroyers to replace its Haruna class helicopter destroyers. The vessels will primarily carry out ASW missions, in addition to peacekeeping operations, in concert with the The SH-60K anti-submarine helicopter, which has been developed from the SH-60 series by Mitsubishi Heavy Industries to operate from destroyer ships in an ASW role.
South of the equator, Australia is about to plug a gap in Anti-Submarine Warfare capabilities with the acquisition of 24 MH-60R ‘Romeo’ helicopters from the US. These have been acquired ahead of schedule because of the cancellation of the contract for 11 Super Seasprites in 2008. This left an alarming gap in ASW capabilities, which is now in the process of being plugged. The ‘Romeos’ will start arriving in 2014. In the medium term, Australia’s ageing fleet of AP-3C maritime patrol aircraft will be replaced by 8 P8-As and an as yet unspecified fleet of large UAVs for broad area surveillance.


 

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