The specifications of Arihant-class submarines are classified. This sketch is an approximation. (Wikimedia Commons)India inducted its third nuclear-powered ballistic missile submarine (SSBN), INS Aridaman, on Friday, significantly strengthening its sea-based nuclear deterrence capabilities.With INS Aridaman’s induction, India will have three operational ballistic missile submarines at sea for the first time.The indigenous SSBN (ship submersible ballistic nuclear) is designed to carry more long-range nuclear-tipped missiles than INS Arihant and INS Arighaat, which were commissioned in 2016 and 2024, respectively.The latest induction will also strengthen India’s nuclear triad. India is part of a select group of countries with nuclear triad capabilities. These include the US, Russia, China, and France.A nuclear triad refers to the ability to launch nuclear missiles from platforms in the air, land and at sea. In the case of India, such missiles (such as the Agni series) can be launched from land, and fighter aircraft such as the Rafales, Su-30MKIs, and Mirage 2000s can deliver nuclear warheads from the air.Although India’s nuclear doctrine stipulates a “no first use” policy — it is committed to using nuclear weapons solely for deterrence and retaliation — SSBNs guarantee India’s second-strike capability. Should an adversary deliver a first nuclear strike on India’s land and air bases, an SSBN can launch a retaliatory nuclear attack, establishing deterrence.About INS AridamanINS Aridaman, a 7,000-tonne vessel, is believed to have eight vertical launching system tubes — around double the number of its predecessors. This means it can carry more K-15 nuclear-capable submarine-launched ballistic missiles (SLBM), which have a range of more than 700 km. They can also carry the longer-range K-4 SLBMs that can hit targets 3,500 km away.Story continues below this adIt is also powered by advanced reactors — understood to be an upgrade over the ones that power its predecessors — to ensure it can remain submerged for longer durations (months together) without needing to surface every few days.A fourth SSBN is also currently under construction, and, like the Aridaman, will also be able to carry more K-4 missiles owing to its larger size.INS Arihant and INS ArighaatIndia’s nuclear-powered submarine project was initiated more than three decades ago, involving both private firms and the Defence Research & Development Organisation, with help from Russia.INS Arihant was launched in 2009 and commissioned into the Navy in 2016 as its first nuclear-powered submarine. This provided India with a maritime strike capability for the first time.Story continues below this adINS Arihant conducted its first deterrence patrol in 2018, thus establishing India’s nuclear triad. In October 2022, the Ministry of Defence announced the successful launch, “with very high accuracy”, of an SLBM in the Bay of Bengal by Arihant.The induction of the 6000-tonne INS Arighaat in 2024 was yet another boost to this nuclear strike capability.Both INS Arihant and INS Arighaat are powered by 83 MW pressurised light-water nuclear reactors, which allow it to remain submerged and undetected for much longer than conventional diesel-electric submarines. Among the two, INS Arighaat is significantly more technologically advanced than INS Arihant, according to the Ministry of Defence.The construction of Arighaat involved advanced design and manufacturing technology, detailed research and development, utilisation of special materials, complex engineering, and highly skilled workmanship, a statement from the government had noted.Story continues below this adFuture plansIndia is pursuing a nuclear-powered attack submarine (SSN) programme. The Navy plans to build two SSNs indigenously and acquire one on lease from Russia, which is expected to arrive by 2027-28 and bridge the capability gap until India’s own boats are ready.India and Germany are finalising a deal for the Project-75I submarine program, as part of which Germany’s ThyssenKrupp Marine Systems will partner with India’s Mazagon Dock Shipbuilders Ltd to construct six advanced AIP-equipped conventional submarines in India. There is no clarity yet on the plans to get three additional Scorpene-class submarines.India’s submarine strengthAside from the SSBNs, the Indian Navy has 16 conventional submarines in service. This includes six Kalvari-class attack submarines built at India’s Mazagon Dock in partnership with France’s Naval Group, four Shishumar class subs, and seven Kilo (Sindhughosh) class subs.To carry out its full spectrum of operations, the Navy is authorised to have 18 submarines. However, at any time, around 30 per cent of the fleet is under refit (repair and renovation), which brings down the strength of operational submarines.Story continues below this adThe US has 14 Ohio-class SSBNs and 53 fast-attack submarines. China has 12 nuclear submarines, of which six are nuclear-powered attack submarines.Amrita Nayak Dutta writes on defence and national security as part of the national bureau of The Indian Express. In the past, Amrita has extensively reported on the media industry and broadcasting matters, urban affairs, bureaucracy and government policies. In the last 14 years of her career, she has worked in newspapers as well as in the online media space and is well versed with the functioning of both newsrooms. Amrita has worked in the northeast, Mumbai and Delhi. She has travelled extensively across the country, including in far-flung border areas, to bring detailed reports from the ground and has written investigative reports on media and defence. She has been working for The Indian Express since January 2023. ... Read More © The Indian Express Pvt LtdTags:nuclear submarine