(Published SP’s Naval Forces, Aug-Sep 2014)
A modern conventional submarine has a formidable array of weapons at its disposal for dealing with the adversaries, be it a ship, another submarine or a target on land. Torpedoes are a choice when targeting surface ships and submarines in vicinity, and missiles when surface & land targets are far away. Submarines also lay mines clandestinely in enemy harbors ‘as wait and strike’ weapons. Succeeding paragraphs discuss some of the more prominent submarine weapons.
Torpedoes The Mk 48 and the Mk 48 ADCAP wire guided torpedoes are the main underwater weapons of the US submarines. Gould/Honeywell and Hughes Aircraft manufacture them respectively. This thermal torpedo has a range of 30Km at 65kts and 50Km at 40kts. Self-guidance in active/passive acoustic homing mode is also feasible. The Royal Navy uses the Spearfish thermal torpedo by BAE Systems. It has a range of 65Km at a speed of 60kts. It is a wire-guided torpedo with an autonomous active /passive acoustic homing mode. The Swedish Tp-62 (Torpedo 2000 export version) is also a thermal torpedo with a pump jet propulsor and a range of 50+Km at a speed of 45+kts. It is also wire guided with autonomous acoustic homing; Saab Bofors Underwater Systems are the manufacturers. The Russian 53-65KE is a wake homer using kerosene and oxygen for propulsion. It has speeds in excess of 45kts and a range of 50Kms. Whitehead Sistemi Subacquei has developed the Italian A184 also known as Blackshark. It uses electrical propulsion; for guidance, optical fiber as well as autonomous active passive acoustic sonar is used. The Mod 3 has advanced ECCM, better motor design and battery giving it a speed of 50+Km at 50+kts. The German DM2A4Seehecht, manufactured by Atlas Elecktronik (SeaHake mod 4, export version) was the first torpedo to be fitted with a fiber optic wire guidance system. It is the only modular design torpedo offering up to four silver-zinc battery modules to achieve a range of 50+Km and speeds of 50+kts. It has a unique homing head using transducers in conformal array permitting it to detect targets in +/-100 deg in the horizontal plane and in+/-24 Deg in the vertical plane. It also claims the least self-noise among its competitors. Indian Navy has reissued RFI for a heavy weight torpedo for its ships and Scorpene submarines. In future, Indian Navy likely to also deploy the indigenous Varunashtra on its ships as and when it is available.
Missiles BGM-109 Tomahawk manufactured by Raytheon, is perhaps the most famous and widely used submarine fired missile. The current version of this modular missile is equipped with network centric warfare capabilities and can utilize data from a variety of inputs like UAVs, satellites, ground forces etc. Loitering feature enables retargeting of its Tactical version. It can also be preprogrammed to attack targets as per GPS stored data. The latest land attack upgrade can hit hardened targets (including large ships) up to a range of 1700Km. A submarine uses its torpedo tubes to fire The MBDA produced SM39 Exocet missile. It is sea skimming turbojet missile with a range of +180km, GPS waypoint guidance in addition to inertial and active radar, and has a warhead of 165kg. Indian Navy has ordered it for the Scorpene submarines under acquisition. The Klub-S is the Russian anti shipping missile with a warhead of 200kg and a range of 220km. It is subsonic missile with a supersonic terminal speed of 2.9 mach. IDAS (Interactive Attack and Defence System for Submarines) is a new submarine torpedo tube fired missile under development by HDW and Diehl BGT Defence in Germany. It aims to target helicopters, medium sized ships, as well as coastal land targets. The Indian Naval submarines may also field a mix of indigenous Shaurya and Brahmos missiles, as and when they are ready for deployment.