Warships target other warships withmerchantmen as the secondary target, and theweapon options for what is now called Anti-Surface Warfare (ASuW) are surprisingly broad
Since the 1960s the prime weapon for ASuW has been the missile both in the air-to-surface version, first used with spectacular success to sink the battleship Roma in 1943, and the surface-to-surface version whose value was demonstrated by the Egyptian Navy’s stand-off sinking of the Israeli destroyer Eilat in 1967. The latter was achieved with a first generation weapon still much used in Asia, the Russian P-15 Termit, better known by the NATO designation SS-N-2 ‘Styx’.
In its original version ‘Styx’ continues to be used by India, North Korea and Vietnam while China has produced an improved version HY-2 (CSS-N-3 ‘Seersucker’). All are characterised by a large launch weight (2.5 tonne) with simple autopilot guidance augmented by active radar (HY-2 can use an infra-red seeker) powered by a rocket motor fuelled by kerosene and nitric acid with a sub-sonic speed (Mach 0.9). They have a maximum range of some 21.5-43 nautical miles (40-80 kilometres), although HY-2 can reach 51 nautical miles (95 kilometres), but it is a crude, relatively dumb weapon, with a powerful (454 kilogramme) warhead while its corrosive fuel system requires careful maintenance.
The ‘Styx’ family are essentially ship-launched weapons, in major surface combatants such as destroyers and frigates as well as smaller ones such as corvettes and fast attack craft, but the second-generation of weapons are more versatile and can be used from ships, aircraft and even submarines. The most famous are Harpoon, used by eight Asian navies, and Exocet used by six Asian navies, but they have similar sub-sonic speeds and are more sophisticated.
Guidance is based upon inertial navigation systems which receive inputs of launch platform co-ordinates and approximate target co-ordinates and then use accelerometer motion sensors and gyroscopic rotation sensors to provide data to a computer which continuously calculates the location, direction and velocity of the missile and compares own location with that of the target. Within proximity to the target the missile activates its own radar to detect it and to control the terminal phase, this sensor having the ability to guide the weapon into either the horizontal or the vertical centre of the radar image.
These missiles also have a degree of intelligence approaching their target indirectly, turning at a predetermined way point or even way points, and at varying heights depending upon whether or not the mission requirement is for fuel efficiency, to achieve greater range or a covert approach, flying just above the waves to make them more difficult for the target’s radars to detect. Alternatively, the missiles can be pre-set to dive upon the target at a steep angle for greater lethality.
Because they are designed to strike the most vulnerable part of a ship both Harpoon and Exocet have smaller warheads than ‘Styx’; 221 and 165 kilogrammes respectively. The turbo-jet powered Harpoon had the longer range, up to 130 nautical miles (240 kilometres) compared with 38 nautical miles (70 kilometres) in the rocket-powered Exocet MM40 but Exocet Block 3 has a turbo-jet engine giving a range of 97 nautical miles (180 kilometres) with greater accuracy thanks to the incorporation of a Global Positions System (GPS) unit using satellite navigation inputs. Similar weapons are MBDA’s Otomat Mk 2 used by Bangladesh and Malaysia, the Russian 3M24 Uran (Uranium) selected by India and Vietnam and China’s YJ-83 or CSS-N-6 ‘Saccade’ whose export version is designated C-802 with version used by Bangladesh, China, Indonesia, Myanmar, Pakistan and Thailand. Asian-produced weapons are Japan’s Mitsubishi Heavy Industries Type 90 (SSM-1B) and South Korea’s LIG Nex1 Haeseong (Sea Star) or SSM-700K as well as Taiwan’s Hsiung Feng II (Brave Wind II).
There is a growing Asian interest in supersonic anti-ship missiles which have the advantage of reducing a target’s reaction times; indeed they can halve the effective range of close-in weapon systems. But their very velocity is the problem, and the reason they are not more widely used for they have less time for their radar processors to evaluate information from the sensor and allow the guidance system to react. Indeed it has been suggested they may be more vulnerable to electronic counter-measures than sub-sonic weapons which have sufficient fuel to re-acquire lost targets.
India uses both the Russian 3M80/3M82 Moskit (Mosquito) or SS-N-22 ‘Sunburn’ and the PJ-10 Brahmos, jointly developed with the Russians, while China also uses ‘Sunburn’ but only in Russian-built Sovremenny class destroyers. ‘Sunburn’ is capable of Mach 3, has a range of 65 nautical miles (120 kilometres) and carries a 320 kilogramme warhead while Brahmos is a Mach 2.8 ramjet-powered weapon with a range of 160 nautical miles (290 kilometres). Air and submarine-launched versions are under development and recent tests indicate the weapon now has a manoeuvring approach capability while Russia and India have recently agreed to develop hypersonic BrahMos 2 missile capable of flying at speeds of Mach 5-Mach 7. Taiwan has developed a supersonic weapon, Hsiung Feng III for the Cheng Kung (Oliver Hazard Perry) class frigates. It is reported to have a range of 110 nautical miles (200 kilometres) a speed of Mach 2 and a 190 kilogramme warhead.
Shorter range weapons are a major requirement for navies which operate in archipelagos and use fast attack craft both for patrol purposes to restrict similar, hostile, craft and also to combat amphibious warfare threats. Taiwan was the first Asian country to develop weapons to operate in this threat scenario producing Hsiung Feng I as a development of the Israeli Gavriel (Gabrial) II, a rocket propelled weapon also acquired by Sri Lanka. This has semi-active radar and manual guidance, a 225 kilogramme warhead and a range of 20