|Type:||Ballistic missile submarine|
|Length:||112 m (367 ft)|
|Beam:||15 m (49 ft) (Est.)|
|Draft:||10 m (33 ft) (Est.)|
|Propulsion:||83MW PWR using 40% enricheduranium fuel; 1 turbine (47,000hp/70MW); 1 shaft; 1 7-bladed, high-skew propeller|
|Speed:||12–15 knots (22–28 km/h) (surfaced); 24 knots (44 km/h) (submerged)|
|Range:||unlimited except by food supplies|
|Test depth:||300 m (980 ft) (est)|
|Armament:||Torpedoes: 6 x 21″ (533mm) torpedo tubes – est. 30 charges (torpedoes, missiles or mines)
4 launch tubes (2.4 meter dia each)
The Arihant class submarines (Sanskrit: अरिहंत:, meaning “Slayer of Enemies”) are nuclear-powered ballistic missile submarines under development by the Indian Navy. The lead vessel of the class, INS Arihant, is expected to complete its harbour acceptance trials in February 2012. Four vessels of the class are under development and expected to be in commission by 2015.
The Arihant class vessels are India’s first indigenously designed and built nuclear submarine. They were developed under the US$2.9 billion Advanced Technology Vessel (ATV) project to design and build nuclear-powered submarines.
The Indian Navy’s Advanced Technology Vessel (ATV) Project to design and construct a nuclear submarine took shape in the 1990s. First confirmation of the project came in 1998 from then Defence Minister, George Fernandes. The initial intent of the project was to design nuclear-powered fast attack submarines, though following Pokhran-II and Indian pledge of no first use, the project was re-aligned towards the design of a ballistic missile submarine in order to complete India’s nuclear triad.
The ATV project overcame many challenges, the primary one being the design and miniaturization of the nuclear reactor. The lead vessel was first floated from its dry dock at a symbolic launch ceremony on 26 July 2009.
The Arihant class submarines are powered by an 83 MW pressurized water reactor (PWR) with highly enriched uranium fuel. The miniaturized naval-version of the reactor was designed and built by the Bhabha Atomic Research Centre (BARC) at the Indira Gandhi Centre for Atomic Research (IGCAR) in Kalpakkam. A land-based prototype of the marine PWR was first built at Kalpakkam. It included a 42-meter section of the submarine’s pressure hull containing the shielding tank with water and the reactor, a control room, as well as an auxiliary control room for monitoring safety parameters. The prototype reactor became critical on 11 November 2003 and was declared operational on 22 September 2006. Successful operation of the prototype for three years yielded the data and the confidence that enabled the production version of the reactor for Arihant.
Separately, infrastructure for testing the reactor subsystems was setup at the Machinery Test Centre in Visakhapatnam. Facilities for loading and replacing the fuel cores of the naval reactors in berthed submarines were also established at the Ship Building Centre.
The hulls for this class were built by Larsen and Toubro at their Hazira shipbuilding facility. Tata Power SED built the control systems for the submarine. The steam turbines and associated systems integrated with the PWR were supplied by Walchandnagar Industries.
The lead vessel underwent a long and extensive process of testing after its “launch” in July 2009. Every sub-system of the propulsion and power systems on board the submarine was repeatedly tested with high-pressure steam trials of all pipelines. Finally, the reactor on board INS Arihant went critical in 2011 when the control rods in the reactor were gradually removed. This was followed by harbour-acceptance trials that included submersion tests by flooding its ballast tanks and controlled dives to limited depths. The sea-acceptance trials are expected to begin in February 2011. This will include operation at different speeds and different depths, before the final weapons acceptance trials, consisting of test-firing of all her SLBMs and torpedoes. Data gathered from her acceptance trials is expected to aid the development of nuclear submarines to follow. INS Arihant is expected to be ready for operational deployment by the end of 2012.
Three more submarines of her class were under construction, as of January 2012. India has decided to construct two more nuclear powered Arihant class submarines.