Submarine Warfare and Upgrades

The submarine is far superior, in terms of influencing a maritime situation, than any battleship for it combines firepower with covert flexible operation, opening the way to a wide variety of other roles, especially in the modern world. Maritime domination was the submarine’s original role focusing upon denying waters to hostile warships; indeed the first modern submarine attack in 1912 was by the Greek submarine Delfin against a Turkish ironclad. A century later this remains a relevant role as demonstrated in 1982 when the sinking of an ancient cruiser by a submarine saw the Argentinean navy confined to harbour for most of theSouth Atlantic campaign. The presence of submarines remains a major inhibitor to enemy surface strike or amphibious groups and therefore a deterrent to precipitous action.

The submarine then rapidly expanded into interdicting maritime lines of communication and destroying mercantile fleets. The impact of German attacks upon the British Empire in two world wars, and the way US submarines strangled the Japanese Empire in the Second World War are well known. Indeed the latter helped to shape Asian history by weakening Japanese control on the mainland and the offshore islands and archipelagos. Asian economies are increasingly dependent upon maritime trade over great distances both for importing raw materials and for exporting manufactured goods. The threat from pirates off the Horn of Africa as well as ‘choke points’ such as the Straits of Malacca demonstrates their vulnerability.

Submarine attack, or the threat of submarine attack, can wreak havoc on maritime trade; indeed the Japanese Maritime Self Defence Force is shaped to securing the island kingdom’s sea lanes, although most modern navies appear to be in denial and prefer to focus more upon the original role of Fleet attack.

Compared with wartime boats, submarines have high underwater speeds, and through hull shaping, ‘rafting’ machinery and shaping moving parts such as propellers they are much quieter, indeed so much so that in 2009 British and French nuclear submarines collided without being aware of each other’s presence. The endurance of diesel-electric boats has been greatly extended through the introduction of air independent propulsion allowing them to remain on station far longer, compensating for a decline. It is also worth nothing that US anti-submarine forces have difficulty detecting foreign diesel-electric boats during training exercises.

The submarine can now deploy sophisticated torpedoes, such as wave-homers, as well as anti-ship missiles, but another option is to use the mine, which can be laid covertly and with great precision as well as being carefully activated and operated. All submarines can carry mines in lieu of other weapons and the presence alone of mines can disrupt trade as demonstrated by incidents around the Arabian Peninsula during the mid 1980s.

The past half century has seen a new threat emerge from under the sea, the ballistic missile submarine. These can vanish into the world’s oceans beyond the ability of any potential enemy to detect them and remain on station almost indefinitely, the limitation being food for the crew. Nuclear-powered vessels can deliver colossal fire power across the globe, and while once the prerogative of the Great Powers they are now in the inventories ofAsia’s Great Powers.China has had the Xia since 1987 and is adding the Jin (Type 094) class with a dozen JL-2 missiles with a 4,300 nautical mile (8,000 kilometre) range, while India’s first domestically-produced nuclear submarine, INS Arihant, will be similar but with dozen Sagarika ballistic missiles with a more modest 400 nautical mile (750 kilometres) range. While the capital costs of these strategic deterrents are very high, while India’s first domestically-produced nuclear submarine, INS Arihant, will be similar but with dozen Sagarika ballistic missiles with a more modest 400 nautical mile (750 kilometres) range. While the capital costs of these strategic deterrents are very high the operating costs are relatively low. The Trident force, which provides 54 per cent of the US strategic deterrent, uses 35 per cent of Washington’s strategic budget but only 1.5 per cent of naval personnel.

The successors to INS Arihant are scheduled to receive ‘cruise’ or ‘air breathing’ missiles, turbofan-powered miniature aircraft with inertial navigation systems capable of flying long missions at low level and concluding with a precision attack upon the target. These weapons have been launched from torpedo tubes by attack submarines of the US Navy and the Royal Navy since 1991 and provide an impressive, non-nuclear means of strategic strike hundreds of kilometres from the sea. It is a capability that will increasingly be at the disposal of major Asian navies that wish to acquire it, and it is worth recalling that 40 per cent of the world’s population lives within 100 nautical miles (185 kilometres) of the sea in an area which produces 67.6 per cent of the world’s Gross Domestic Product (GDP).

Significantly, India’s Russian-built Kilo (Project 877) or Sindhughosh class submarines are being upgraded at Severodvinsk to operate the Klub missile system family, and while most boats are being adapted to use the 3M54 (SS-N-27) anti-ship missile two have been adapted to take 3M14 (SS-N-30) land attack missiles with a 160 nautical mile (300 kilometre) range. India is also developing a submarine-launched version of the supersonic Brahmos missile, which has a similar range to the 3M14, and while this might be primarily for anti-ship, a land attack role cannot be ruled out. In fact, conventional land attack now lies within the reach of smaller navies using anti-ship missiles for manufacturers have responded to the growing demand for littoral warfare by adapting these weapons initially to engage vessels operating in the radar clutter from the coast or a harbour and later directly to attack land targets. This capability exists in the latest Exocets, supplied to Malaysia for its Scorpenes, and the turbojet-propelled Block 3 version has a range of 95 nautical miles (180 kilometres).

The submarine has a key role even in peace time, or in crises short of hostilities, by providing covert Intelligence, Surveillance and Reconnaissance (ISR) a legacy capability enhanced by modern technology. During the war against Japan submarines regularly exploited the high magnification rates of their optical periscopes to conduct visual and photographic reconnaissance; indeed, using them to count the number of latrines, US Navy intelligence was able to determine with great accuracy the size of the garrison on the island of Tarawa in 1943.

The introduction of mast-mounted television cameras, which can be augmented by image intensifier and/or thermal imager systems, has enhanced this capability. These masts can be raised, turn up to 360 degrees capturing and recording an image with a television camera and then be lowered all within 10 seconds and the images can then be studied at leisure upon a console. Interestingly, the new Japanese Souryu class submarines have the licence-built Thales Optronics CM 10 mast-mounted system and it seems likely this technology will be acquired by other Asian navies in the coming years especially in new-build vessels such as Australia’s Collins successor.

Wartime submarines were also used to deliver special forces both for reconnaissance and commando raids. Modern special forces may be delivered through the traditional inflatable boat but it is more likely they will use swimmer delivery vehicles (SDVs) which can pull them through the water saving time and energy. Major navies are looking at dedicated miniature submarines attached to nuclear-powered attack submarines to deliver special forces from longer ranges, and the concept has already been accepted by some Asian navies such as North and South Korea as well as Pakistan which operate conventional miniature submarines specifically for this role.

Modern submarine design is increasingly incorporating features to support special operations and these will undoubtedly filter into Asian navies. Germany’s new batch of Type 212A submarines will include a lock-out chamber for up to four special forces troopers at a time while Israel’s German-built Dolphins have a similar feature and the four 650mm (25.6 inch) torpedo tubes in these boats are reported to be for SDVs. Kockums recently revealed their design for the Swedish Navy’s A26 which included a bay on the casing for an SDV or even a miniature submarine, while the conventional torpedo compartment has been replaced by a multi-role space which can also house SDVs that will depart or enter through a 1.5 metre wide multi-mission portal in the bow between the torpedo tubes. Behind this is a 6-metre long airlock which can hold up to eight personnel.

Submarines can also use their electronic sensors in the ISR role. Sonars can not only monitor traffic and build up a picture of maritime and naval movements but also be used to create a library identifying individual ships to provide further detail of naval activity. This is not new; in 1943 US submarines were able to identify a particular Japanese destroyer operating in the waters of what is now Indonesia because it had nicked a propeller blade and had a very distinctive signature. The sophisticated processing of modern sonar systems carries this further forward by monitoring, and recording, the whole of a ships’ acoustic signature.

Electronic signal measures (ESM) systems are in all submarines, detecting and monitoring radar and communications signals in order to alert them to the presence of hostile ships and aircraft. The same systems can also be used to monitor radio traffic and to detect and to locate radar stations and help a nation covertly build up a picture of potentially hostile activity in a neighbour. This picture can include technical details of aircraft and of ships, organisation of command and control assets with supporting sensor and weapons as well as clues to strategic intentions as well as operational capabilities.

The development of robot submarines, both remotely operated vehicles (ROVs) and Autonomous Underwater Vehicles (AUVs), may well extend this ISR function. They could be deployed through torpedo tubes- after all heavyweight torpedoes are wire guided so wire guidance should not be impossible- but there remain questions of control, and the difficulties of recovering these vehicles make it likely they will be disposable assets; but they could be used for hydrographical surveys, to plot enemy minefields (whose presence would be discovered by the submarine’s mine detection and obstacle avoidance sonar) and possibly to neutralise them. Indeed, if mine fuzes can be designed to switch on or off based upon a timer, then it is technically feasible for ROVs to attach disposal charges with their own timer fuzes to neutralise the mines at a preferred time such as when an amphibious group arrives off its objective. Interestingly the US Navy has announced plans to deploy Unmanned Air Vehicles (UAV) from submerged submarines during the RIMPAC (Rim of the Pacific) exercise possibly adding an aerial reconnaissance capability to the submarine’s already broad inventory of tasks.

The existing and potential capabilities of submarines mean that the Asian market remains dynamic with new build and upgrades. In the past 12 months Indonesia has ordered two submarines from South Korea, and Daewoo Shipbuilding & Marine Engineering (DSME) has been awarded a contract to build the first two 3,000-tonne Korean Submarine Phase 3 (KSS 3) boats with Seoul having a requirement for up to nine. Singapore has received the second former Swedish Västergötland class boat, RSS Swordsman which, like RSS Archer, has been comprehensively upgraded, refurbished and tropicalised.

Building of Scorpenes to meet India’s Project 75 requirement has slipped at least a year although New Delhi’s preparing to launch the Project 75A programme while Australia is in a similar position with the Collins class successor in Project Sea1000. In the distaff side there is no sign of Taiwan getting its longed for new submarines, while Thailand’s plans to acquire German Type 206 coastal boats was scuttled by inter-service financial wrangling. Thailand retains a submarine requirement while Bangladesh and the Philippines would both like submarines, Manila defining the requirement at three boats, but financial hurdles remain too high to overcome. Upgrade programmes continue but news is muted; Pakistan’s Khalids (Agosta 90B) are receiving MESMA air independent propulsion systems and Australia’s Collins will have their Scylla sonars improved, while Russia continues to upgrade India’s Kilo class boats.

  ● Asian Military Review