Prasun K Sengupta: Indian Navy hunts for next line of diesel-electric submarines
To arrest the growing obsolescence of its undersea warfare capabilities, the Indian Navy (IN) recently issued Requests for Proposals (RFP) for six newgeneration ocean-going diesel-electric submarines (SSK) to add to the six Scorpene SSKs being built at state-owned Mazagon Docks Ltd (MDL) under a mammoth Rs 187.98 billion project. Global tenders for the six new SSKs will be floated by early next year, with the principal bidders expected to be Armaris of France, and Fincantieri of Italy teamed up with Russias Rubin Central Design Bureau for Marine Engineering. The German Submarine Consortium is not expected to take part in the bidding process as its Class 214 SSK was selected late last year for replacing the Pakistan Navys existing Agosta 70B SSKs. It is almost a foregone conclusion that Armaris SMX-21 SSK, incorporating the MESMA AIP module, will be offered, while Fincantieri will offer the S-800 (see photo), a stretched variant of its S-1000 SSK.
The SMX-21 (see photo) is designed for a wide range of missions, including deep-strike operations, attacks on naval forces and special operations. The combination can carry a range of modular mission packs, each comprising various weapons, sensors, special operations devices, mines, unmanned underwater vehicles (UUV), etc for a variety of missions. The SMX-21s three-in-one operational combination comprises a command submarine, which also provides at-sea support for three smaller submarines, and two smaller UUVs. The command and smaller submarines and UUVs can be docked to form a combination submarine operating as a single vessel. Alternatively, all three can be operated independently. A DCN/THALES-designed Migal Aliran Informasi Pertahanan interface module will expand the SMX-21s combat capabilities by expediting the readying, target sequencing, launching and control of up to four wire-guided torpedoes at a time. Migal modules can also simulate up to four wireguided torpedoes at a time for training exercises. They can also be used to monitor in-tube torpedoes and manage self-testing and maintenance. The Malaysian and Indian navies have already selected the Migal module for theirrespective Scorpene SSKs.
The Royal Thai Navy, on the other hand, is seriously looking at Russias Amur 950 and Armaris SMX-23 Andrasta dieselelectric submarines, both of which displace less than 1,000 tonnes while submerged. As regards the S-800, one may recall that Russia and Italy had jointly presented on October 25, 2006 a mock-up model of a new-generation SSK at the Euronaval international exhibition in France. The S-1000, a 1,000-tonne SSK, which is derived from the Amur 950 SSKs design, and is designed for anti-submarine and anti-ship warfare, reconnaissance missions, and transportation of up to 12 troops. It is 56.2 metres long, has a top speed while submerged of 14 knots and is equipped with a new fuel cellpowered Air Independent Propulsion (AIP) system developed by Fincantieri.
The S-1000s principal competitor in the global export market is the SMX-23 Andrasta from Frances ARMARIS. It is 49 metres long, displaces 860 tonnes, has a maximum submerged speed of 15 Knots, can dive to depths of 200 metres, has a range 1,850 miles while cruising at 8 Knots, has an at-sea endurance of 15 days, can remain underwater for 60 hours maximum by using its batteries, and has a crew complement of 19 sailors and officers. Designed primarily for export, the S- 1000 and its larger S-800 dervative will both feature an impressive array of weaponry, including Whitehead Alenia Sistemi Subaqueibuilt wire-guided Black Shark torpedoes, 220-km range 3M54E1 Club-S supersonic anti-ship cruise missiles and the 290km-range 3M14E subsonic land-attack cruise missile, and the BrahMos vertically launched multi-role supersonic cruise missile (eight of which will be on board each S-800, contained inside an eight cell universal vertical launcher for missiles, or UVLM, fabricated by Larsen & Toubro Ltd).
Both SSKs, when equipped with AIP-based propulsion systems, will be capable of staying underwater for 10 days. The project to jointly develop these two SSKs was launched in April 2004. Due to the combined Italian-Russian offer of the S-800, Rosoboronexport State Corp will henceforth withdraw its earlier offer to the IN for its 1,600-tonne Amur 1650 SSK, which also recently lost out to the Class 209/Type 1200 SSK in a competition involving the supply of six newbuild SSKs by South Korea to the Indonesian Amur 1650.
If the S-800 is selected for procurement, then it will most likely be licence-built by Larsen & Toubro (L & T). It may be recalled that since the 1990s, L & T has forged risk-sharing industrial partnerships with several Italian shipbuilders and naval sub-systems suppliers, such as Riva Calzoni. The bulk of such industrial tie-ups pertained to the companys involvement in the construction of the nuclear-powered Advanced Technology Vehicle (ATV) for Indias defence R & D Organisation (DRDO). L & T has also, along with Italys Cosmos (based in Livorno), fabricated for the DRDO a 200-tonne mini-submarine that will be used as a technology demonstrator in lieu of procuring six such SSKs for conducting covert special operations.
Meanwhile, several new design/performance data pertaining to the INs six Scorpenes have now emerged. Each Scorpene SSK displace 1,570 tonnes surfaced and 1,960 dived, and features a circular outer hull built of HLES-90 highstrength steel, with this outer hull also being the pressure hull. At the bow the cross-section of the hull will narrow to an oval shape, ensuring the minimum underwater hydrodynamic resistance. A lot of effort is being made to reduce self-generated noise, resulting in a clean, streamlined casing and noise damping of all equipment. An array of hydrophones will be fitted all round the hull to measure the radiated noise level and provide immediate identification of areas of self-generated noise. The Scorpene SSK will be armed with four bow torpedo tubes fitted with a pneumatic ram discharge system. The bow tubes allow weapon discharge, irrespective of the speed of the SSK, down to its maximum diving depth. The SSK will also incorporate a rapid reload system. Fire-control will be exercised through a single, centralised computer using the DLA-2A system, which will also feature an automatic navigational plotting system. The Scorpene SSKs sensors include an 8kHz active search/attack sonar, passive ranging and passive towed-array sonars. Intercept sonars and a torpedo-attack warning systems will also be fitted. The Scorpene SSKs primary propulsion system will comprise two SEMT-Pielstick 16 PA4 V 185 VG diesels developing 2.65mW driving two Jeumont Schneider 1.7mW alternators. A single watercooled 3.4mW electric motor with double armature will directly drive the propellers. There will be an intermediate clutch in order to reduce noise level to a minimum. In addition, there will be a 23kW electric motor provided for cruise speeds. The SSKs two independent banks of batteries use an electrolyte agitation system with water circuit cooling to extend service life and improve efficiency. Crew accommodation-related power services will be provided by two generators, with the alternating current being provided by means of five converter sets with two solid-state inverters. There will also be oxygen generating units and independent CO2 absorption units. The core of the SUBTICS combat management system (CMS) will be an open and modular architecture based on standard data processors (TMS 320 C30 processors on a speed ring network), redundant databus and six multi-function common consoles equipped with two highdefinition 19-inch colour AMLCD monitors.The dual redundant Ethernet databus will offer reliable and continuous communications in the event of damage, the multi-function common consoles and allow manning and configuration flexibility, and together provide function and data operational availability. The sonar sub-system will include a set of acoustic arrays and appropriate detection (or transmission), tracking, and analysis and localisation processing modules, together with a set of common processing modules for contact motion analysis, classification, identification and track management using broadband, narrowband, demon and pulse (passive interception and ranging) processing channels. The basic set of acoustic arrays will include a cylindrical or conformal bow array, an active array, a distributed array, an intercept array, a thin-line towed-array, a flank array, and optionally an obstacle avoidance array. The contact motion analysis module will include automatic and interactive processing functions. The classification and identification module will include audio and spectrum analysis processing functions, plus interactive hypothesis generation and verification functions. The track management module include interactive association and fusion processing functions, plus sorting of best representative acoustic track function. The basic components of the command and weapon control sub-system will include a set of situation elaboration modules, a set of command and decision modules, and a set of engagement and launching modules. The set of situation elaboration modules will include acoustic and non-acoustic sensors track association and fusion functions, interactive target motion analysis functions, and track management functions able to sort out tracks of particular tactical interest among a set of 100 recorded tracks. The set of command and decision modules will include threat evaluation of localised and classified tracks, plus attack and escape manoeuvre planning tools. The SSK will be fitted with Thales TIT tactical information processor, DSM submarine detection system, LAS air-surface warfare and navigation system using the SAGEM Défense Sécurité of Frances SIGMA-40XP strapdown ring laser gyro inertial navigation system, DLA launch control system, TSM-22/23 forward panoramic sonar, DR-3000 ESM system, SAGEMs MICIN Mod 3 inertial navigation control unit and SS Mk1 steering control station, Safare-Crouzets Velox DUUG-7A/Velox-M7 sonar interceptor, Sopelem-Sofretecs Type J and ST-5 periscopes, Kelvin-Hughes navigation radar, and CEACs electrical energy storage batteries. The principal WAASs C-303 expendable torpedo decoys L & Ts submarine masts SMX-21 SSK 88 armament suite will comprise the MBDA-built Exocet SM-40 Block 3 submarine-launched anti-ship missile, and up to 16 Whitehead 533mm torpedoes.
Meanwhile, as part of the second mid-life refit of its existing four Class 209/Type 1500 SSKs, the IN has installed on the first two vessels ATLAS Elektroniks ISUS-90 combat management system, CSU-90 cylindrical active/passive bow-mounted sonar, passive planar flank arrays and intercept arrays (for providing warning against approaching torpedoes), passive ranging array, a three-dimensional mine and obstacle avoidance sonar, and a thin-line towed-array winch system; along with Alenia Sistemi Subacqueis C-303 submarine-fired torpedo decoy dispensers and a self-noise monitoring system. A similar refit on the remaining two Class 209/Type 1500 boats is now underway.
The INs six Scorpenes too will have on board the C-303 decoy systems. The hunt is now on for reelable thin-line towed-array sonars to be installed on board the six Scorpene SSKs (thus optimising them for littoral warfare in shallow waters) for which systems from THALES Underwater Systems, ATLAS Elektronik and L-3 Communications/Ocean Systems are being looked at.
LiveFist: Prasun K Sengupta: Indian Navy hunts for next line of diesel-electric submarines
