Prowler Of The Deep

For at least a decade speculation has been rife on two major issues: India’s quest for acquiring a credible sea-based element of the country’s nuclear weapons triad; and the Indian Navy’s (IN) projected plans for acquiring on lease SSGNs of Russian origin. More often than not, it is the Russian mass media that has been more accurate in reporting key developments on these two issues, while its Indian counterpart has been engaging in speculations ranging from the sublime to the ridiculous. What follows below is a detailed analysis of India’s continuing quest for acquiring a fleet of nuclear-powered submarines for strategic nuclear deterrence.

ATV stands for Advanced Technology Vessel (carrying the hull codename P-4102), which will be a technology demonstrator displacing less than 7,000 tonnes dived and will NOT be an operational nuclear-powered submarine. It will be used for validating the ATV’s 90mW nuclear-powered propulsion system, the vessel’s structural integrity as well as the on-board mission sensors, combat management system (CMS), and integrated platform management/battle damage management system. The ATV will thus be used for validating various technologies and performance parameters for two types of fourth-generation operational nuclear-powered submarines that are being proposed for series production the following decade: three attack submarines (SSGN) each displacing 7,500 tonnes when dived, and a single SSBN displacing some 12,000 tonnes dived. The ATV, to be built with NQ-1, a derivative of HY-80 grade steel, will be divided into an engine compartment, reactor compartment (containing a 90mW pressurised water-cooled water-moderated reactor [PWR] using uranium-aluminum dispersed fuel (cermet) housed within zirconium cladding), a forward compartment housing the vessel’s CMS, integrated platform management system (IPMS), depth-finding echosounder, a mid-frequency active/passive sonar suite comprising a bow-mounted sonar transducer array as well as twin hull-mounted flank arrays, and a torpedo compartment containing three 21-inch (533.4mm) torpedo launch tubes designed and built by Larsen & Toubro (L & T) that will be able to launch heavyweight anti-submarine and anti-ship torpedoes (the TEST-71ME and TEST-71ME-NK models built by Russia’s DVIGATEL FSUE and Region State Research & Production Enterprise).

The ATV’s twin flank-array sonars will be used as a torpedo approach warning system, and a stern-mounted distinctive ‘bulb’ on top of the rudder will house an ultra-low frequency thin-line towed active/passive sonar array to be built in future by state-owned Bharat Electronics Ltd (BEL), broadband expendable anti-torpedo countermeasures developed by RAFAEL of Israel, as well as four universal vertical launcher capable of launching submarine-launched ballistic missiles (SLBM). The Navy has already projected a requirement for SLBMs with 8,500km-range and the Defence Research & Development Organisation (DRDO) is expected to develop such an SLBM by 2012.

The related Launch Preparation System and Centralised Real-Time Fire-Control System has been built by BEL as has the CCS Mk3 composite communications system and ATM-based broadband integrated data network. The ATV will feature double-hull construction, dramatically increasing the reserve buoyancy by as much as three times over that of a single-hull vessel. Ballast tanks and other gear will be located between the inner and outer hulls, and limber holes will be provided for the free-flooding sections between the hulls. The ATV’s pressure hull will have four major compartments and the standoff distance between the outer and inner hulls will be considerable, reducing the possibility of inner hull damage. The engine room will feature sound-isolation couplings to prevent transmission of vibrations to the ocean from major fresh-water circulating pumps in the steam cycle. The CMS (comprising a commander’s multi-function console, manoeuvring control console, three weapons management consoles and one EW console), and IPMS (comprising three consoles) are now being developed by TATA Power’s Strategic Systems Division in collaboration with BAE Systems. The retractable masts viewed from bow to stern will include an optronic periscope (to come from the joint venture between Italy’s Riva Calzoni & India’s Larsen & Toubro), along with one I-band surface search/navigation radar and one low-level air defence radar, VLF/VHF/EHF/SHF radio and UHF SATCOM antennae, and one integrated electronic warfare suite [4CH(V)2 Timnex II], all to be supplied by Elbit Systems. The mast fairwater section of the ATV will house a magnetic compass sensor, combined SATCOMS/radio antenna, air supplier for diesel engines, search radar antenna mounted on a non-hull-penetrating optronic search mast, attack periscope housing optronic sensors, plane position indicator, rudder steering unit, course repeater, distance measuring sonar, and a sail plane drive. The ATV will have a double layer silencing system for the power train. Main propulsion machinery will comprise a high-density PWR reactor core rated at 90mW, and a steam turbine developing 35mW. Two auxiliary diesel engines will provide emergency power. The nuclear propulsion system will drive a seven-bladed fixed-pitch propeller with cruciform vortex dissipaters, and provide a maximum submerged speed of 33 Knots and a surface speed of 15 Knots. A reserve propeller system, powered by two motors rated at 370kW, will provide a speed of 4 Knots.

The ATV’s pressure hull will be rated for diving down to a hull-crush depth of 600 metres. The vessel will carry sufficient supplies for an endurance of 80 days and will be operated by a crew complement of 50. The outer hull will be fitted with anechoic and vibration damping coatings to reduce the vessel’s acoustic signature to no more than 110 decibels. The indigenously developed rubber-based anechoic tile will contain thousands of tiny voids, and their function will be two-fold: to absorb the sonar sound waves of active sonar, and reduce and distort the return signal thereby reducing its effective range. The tiles, each of which are 4 inches (100mm) thick, will also attenuate the sounds emitted from the vessel, typically its engines, to reduce the range at which it can be detected by passive sonar. The ATV’s scheduled operational cycle will be divided into 2.5 years, five years and 7.5 years. To mount a patrol, the ATV will require 15 days to be prepared for a 60-day endurance cruise, following which 10 days will be required for replenishing provisions and changing the crew complement. The period between two cruises will be 25 days, while dock repairs and storage battery replacements will be conducted within a 20-day period. Yard repair for the ATV will be conducted over a 12-month period.

Up until 2004 a casual stroll around the Central Government Office Complex or Kashmir House—the current seat of the armed forces’ HQ Integrated Defence Staff in Delhi—revealed the Indian Ministry of Defence’s (MoD) unique approach towards managing this project. A simple, twisted signboard marked the office of the Director-General, ATV project, from where the ATV’s planning, design and fabrication efforts were being directed. The ATV’s design-cum-industrial coordination effort was directed from the Standing Conference of Public Enterprises (SCOPE) Building, located near the HQ of India’s Research & Analysis Wing. In 2005, both these offices were relocated under one roof to ‘AAKANGSHA’ (Hope), a heavily guarded building located behind the United Services Institution and within an Indian Army enclave near Palam Airport. The Prime Minister heads the Steering and Funding Committee of the project, which is monitored by the Scientific Adviser to the Defence Minister, who is also Secretary of the MoD-owned Defence Research & Development Organisation (DRDO). The ATV Project’ Directors have always been Vice Admirals who upon their retirement from the IN had been re-employed at Secretary-level. In addition, there are six retired IN officers of the rank of Rear Admiral who run various segments of the programme (such as weapon systems, CMS, IPMS, acoustic signature management and sonars, integrated powerplant/propulsion system, and communications/electronic warfare). Overall, it is the DRDO that is running the entire project, while the DAE is responsible for developing the close-cycle nuclear propulsion system, a task the latter was entrusted with in 1976. However, since neither the DRDO nor the IN’s Directorate of Naval Design have any hands-on experience in designing submarines, the DRDO in 2002 contracted Russia’s St Petersburg-based Malachite Marine Engineering Bureau under Project 78 to produce production engineering drawings (using TRIBON CAD/CAM software) for the ATV’s hull sections. This drawings were delivered to L & T by late 2003 and included those for the pressure hull, shrouded propulsor, upper and lower rudder segments, starboard hydroplane, aft anchor light, aft rudder and hydroplane hydraulic actuators, Nos1,2,3 and 4 main ballast tank, propeller shaft, high-pressure bottles, towed-array sonar’s cable drum and winch, main ballast venting system, aft and forward pressure domes, air treatment units, naval stores, propeller shaft thrust block and bearing, circulating water transfer pipes, lubricating oil tank, starboard condenser, main machinery mounting raft, port and starboard turbo-generators, combining gearbox, main turbines, steam delivery ducting, aft equipment compartment, watertight bulkheads, manoeuvring room citadel, manoeuvring room’s isolated deck mounting, switchboard room, diesel generator room, static converters, main steam valve, reactor section, forward air-lock, air-handling compartment, waste management system, air-conditioning ducting, galley, forward section’s isolated deck mountings, batteries, junior ratings’ mess, RESM office, commanding officer’s cabin, portside communications office, diesel exhaust mast, snort induction mast, VLF/VHF/SHF/EHF masts, ESM mast, search radar mast, UHF SATCOM mast, integrated comms mast, starboard and portside visual masts, navigation mast, bridge fin access, junior and senior ratings’ bathrooms, battery switchroom, control room consoles, sonar operator’s consoles, senior ratings’ bunks, medical berth, weapons stowage-cum-handling compartment, bow-mounted sonar array, maintenance workshop, depth-sounder and obstacle/mine avoidance sonar room, forward hydroplane and its hydraulic actuators, hydroplane hinge mountings, main administrative office, junior ratings’ berths, torpedo tubes, water transfer tank, torpedo tube bow caps, air turbine pump, weapons embarkation hatch, rigid-hull inflatable boat stowage area, hinged fairlead, anchor windlass, and anchor cable locker. All these sections will be ready for final assembly within the pressure hull by 2011. Final assembly work will take place at the Vizag-based Shipbuilding Centre (SBC) that is headed by a retired Vice Admiral and lies adjacent to the IN’s Naval Dockyard. The entire hull-section welding effort (with the help of 25 major industrial contractors and 250 other vendors) is overseen by the Hyderabad-based Defence Material Department, headed by a retired Rear Admiral.

In March 2007, the MoD decided to hike the project’s financial allocation to Rs140 billion (US$3.3 billion) of which some $2.5 billion is being sourced from the Rupee-Rouble debt settlement scheme that was bilaterally worked out by New Delhi and Moscow way back in 1993. Now, instead of the debt settlement taking place in 2037 as originally envisaged, successive payment tranches to the tune of Rs8 billion ($200 million) per annum will be made by India through to 2016 and in return Russia will help the DRDO realise all the R & D mission objectives of the ATV project (over a three-year period starting 2012, when the ATV will commence its sea trials, and culminating in the conclusion of the sea trials three years later), and subsequently assist in initiating the production of the three SSGNs and one SSBN over a 15-year period starting starting 2015 as currently envisaged by the MoD. Under a separate, yet-to-be-inked contract, Russia will provide technical expertise to the IN for building two planned underwater naval bases (one each along the coastline of Andhra Pradesh and Kerala), each of which will cost some $1.5 billion to build and will contain twin underwater submarine tunnel entrances leading to separate berths for accommodating both SSGNs and the SSBN, a hardened underground tunnel for storing nuclear warheads for the SLBMs, plus a command-and-control centre. Subject to approval from the Cabinet Committee on National Security at a later date, both the SSGNs and SSBN will be built by L & T’s Defence Engineering Division at a new $500 million state-of-the-art mega-shipyard that will be operational in Kakinada, Orissa, from 2010. The ATV fabrication facility within this shipyard as well as L & T’s existing fabrication facility in Hazira, Gujarat, are now being built and equipped with the help of Russia’s Krylov Central Research and Scientific Institute, Central Research Institute for Shipbuilding Technology, and the Region Scientific Production Association.

The DAE’s Trombay-based Bhabha Atomic Research Centre (BARC) in 1976 began work on designing a generic, miniaturised PWR. Altogether, four different types of designs were considered. The first, a water-cooled, water-moderated reactor, used 248 fuel assemblies as its core. The fuel was cermet in zirconium cladding. However, this design was rejected in late 1976, while the second was discarded in 1979, and the third in 1981. The BARC had shelved the first three PWR designs because of engineering objections from the IN. Despite this, BARC succeeded in fabricating a pilot PWR in the early 1990s using the fourth design. By late December 1995 the DRDO had made considerable progress in the design of a 600-tonne pre-test capsule made of titanium that was fabricated in 1994 by Mumbai-based Godrej & Boyce Manufacturing Co Ltd’s Precision Equipment Division. From there the capsule was transported to the PTC. The capsule, containing the BARC-built PWR (with a diameter of 10 metres) was unsuccessfully subjected to on-shore and submerged structural integrity tests in November-December 1995. In June 1996 the programme suffered further setbacks following additional failed tests of the PWR and its containment vessel. This was attributed to the unsuitable design of the reaction control-rod insertion and withdrawal mechanism. Throughout the 1980s and 1990s, the DAE tried in vain to buy a rod-worth minimiser (RWM) used by reactor operators to guide and monitor the proper sequences for the remotely-controlled withdrawal and insertion of reaction control-rods. By early 1997, the DRDO made serious and successful overtures to Russia for procuring shipborne PWRs and related machinery off-the-shelf. On October 5, 2000, after India and Russia inked an agreement on a news blackout on sensitive information exchanges in the areas of defence and nuclear cooperation and appointed watchdogs to enforce compliance with the new agreement, Moscow agreed to supply an initial two VM-5 PWRs, their related propulsion machinery, plus their detailed engineering drawings off-the-shelf. These arrived at Vishakapatnam in late 2000. These propulsion systems, however, were not brand new, but were unused and originally built for usage on board civilian ice-breaking ships. In addition, Moscow insisted that such hardware be used for replication only, and be integrated with the propulsion system on-shore, and not be installed on any shipborne platform. Adoption of this approach meant that while Russia was not violating its obligations made under the NPT and START-2 nuclear non-proliferation and arms reduction treaties, it was, on the other hand, helping the DRDO and the DAE to overcome the R & D ‘know-how’ challenges by leapfrogging straight ahead to the ‘know-why’ stage. By early 2003, L & T as prime industrial contractor was contracted for fabricating the ATV’s hull sections (with technical assistance from Russia’s Malachite Marine Engineering Bureau, Krylov Central Research and Scientific Institute and the St Petersburg-based Central Research Institute for Shipbuilding Technology), while the DRDO’s Naval Chemicals and Metallurgical Laboratory and Mumbai-based Advani Oerlikon Ltd began supplying indigenously developed metal-cutting and welding solutions to the SBC, where the ATV’s final hull assembly began in 2004 and. The universal vertical launcher to be used for launching the SLBM is being indigenously designed and built by L & T. The IN has also built a Russia-designed facility--the Special Safety Service—adjacent to the SBC for monitoring the health of the people working inside the ATV and the radiation leaks emanating from the vessel. State-owned Bharat Heavy Electricals Ltd (BHEL) was contracted by the DRDO to develop the PWR’s heat exchanger in cooperation with Godrej & Boyce, electrical generator and the propulsion system’s geared turbine (connected via a set of reduction gears to a fixed-pitch propeller), transmission shaft and gearbox, with L & T fabricating the seven-bladed fixed-pitch propeller. Pune-based KSB Pumps Ltd (an Indian subsidiary of KSB AG of Germany), is supplying the power-driven centrifugal and eccentric screw pumps and butterfly valves each comprising a cast-iron body with ductile iron or stainless steel disc and EPDM/nitrile rubber liners. Seamless piping is coming from the Maharastra Seamless Ltd subsidiary of the D P Jindal Group. Advani-Oerlikon Ltd is producing welding electrodes and machines for welding the ATV’s hull sections and pipelines, while Kirloskar Electric Company Ltd is building the switchgears, water, air and chemical flowmeters, plus electrical cables, transformers and capacitors. Russia’s St Petersburg-based Malachite Marine Engineering Bureau has been roped in to act as the DRDO’s principal designer-cum-independent design consultant and validate the ATV’s hydrodynamic design/performance parameters. By October 2004, the first PTC-built and VM-5-derived indigenous PWR went critical on-shore at Kalpakkam. The highly enriched uranium fuel for the PWR was supplied by the DAE’s Ratnahalli-based Rare Materials Project (RMP) near Mysore. Two months later, the reactor was integrated on shore with the propulsion system. On November 16, 2005, the then Defence Minister Pranab Mukherjee (now external Affairs Minister) stated in Moscow during the 5th session of the India-Russia Inter-Governmental Commission for Military-Technical Cooperation (IRIGC-MTC) that Russia had agreed to help India build both the ATV and the 37,500-tonne Project 71 Integrated Aircraft Carrier through technology transfers. By mid-2006, a fully integrated and closed-cycle PWR-powered propulsion system was shipped to Vizag, which has since been encased within the ATV’s L & T-fabricated reactor and engine compartments. By late last year, a propulsion simulator and an IPMS simulator co-developed by TATA Power and BEL were installed at the SBC.

The integrated sonar suite is being developed by the DRDO’s Kochi-based Naval Physical and Oceanographic Laboratory and will be series-produced by BEL. The flank-array sonars’ underwater omnidirectional transducers are 60mm hollow spherical elements fabricated from lead zirconate titanate type-4 material. Fabrication of the light (outer) hull and pressure (inner) hull sections has been undertaken directly at the SBC and is the most challenging part of the ATV’s fabrication process. The hull has been constructed with very high precision, since the inevitable minor deviations are resisted by the stiffener rings, but even a 1-inch (25mm) deviation from roundness results in more than 30% decrease of hydrostatic load. The total pressure force of several million tonnes must be distributed evenly along the hull and be oriented longitudinally, as no material will resist such force by bending. The entire ATV hull thus uses expensive transversal construction, with the stiffener-rings located more frequently than the longitudinals. The welding technique involves twin tandem submerged-arcs for rotated sub-unit circumferential butts, and for frame-to-hull and web-to-table tee butts. Pressure hull static circumferential butts and sub-unit vertical seams are being welded by a mechanised (positional) FCAW process, and semi-auto FCAW is used for all other welding. For non-destructive testing and examination of the butt welds, digitised ultrasonics (using time-of-flight diffraction techniques) are being employed.

For destroying ASW helicopters equipped with dunking sonars, the DRDO and RAFAEL of Israel in early 2006 began co-developing a submarine-launched air defence missile system that will include twin three-cell vertical canisters each containing a ready-to-fire Python 5 missile that can be launched by the ATV from a submerged depth of 50 feet. This variant of the Python 5 air combat missile will have a 12km range. The ATV’s eight torpedo tubes will be capable of launching the TEST-71 family of torpedoes.--Prasun K. Sengupta