On August 29, 2024, Defence Minister Rajnath Singh launched India’s second Ship Submersible Ballistic Nuclear (SSBN) submarine at Visakhapatnam at the secretive Ship Building Centre in the Eastern Naval Command. INS Arighat, which translates to ‘destroyer of the enemy’, is the second in its class after INS Arihant, which was commissioned in August 2016. In contrast to INS Arihant, India’s first SSBN, which primarily functioned as a technology demonstrator, INS Arighat is a more operationally focused platform. It has benefited from the extensive testing and validation of INS Arihant’s systems and is combat-capable.
Based on Russia’s deadly Akula class submarines, INS Arighat and INS Arihant have more or less similar capabilities. These nuclear-powered ballistic missile submarines – also known as boomers in the colloquial language of seamen – weigh around 6,000 tonnes each. Both are powered by an 83 MW nuclear reactor and carry K-15 ballistic missiles with 750 km range.
India’s deterrence capabilities will significantly expand with the commissioning of the third SSBN, INS Aridhaman, expected next year. This slightly larger vessel, weighing 7,000 tonnes, will be equipped with K-4 submarine-launched ballistic missiles (SLBMs) that have a striking range of 3,500 km. Following INS Aridhaman, another advanced SSBN, designated S-4, will be introduced, along with an unnamed fifth SSBN, which will carry the K-5 submarine-launched ballistic missiles with 5,000 km range.
Nuclear Triad
With the induction of INS Arighat, India’s strategic planners are closer to achieving their longstanding ambition of acquiring a nuclear triad, giving them multiple options if it comes to a nuclear confrontation. A nuclear triad refers to the three components of atomic weapons delivery: strategic bombers, intercontinental ballistic missiles (ICBMs), and SLBMs.
Of the three elements of the triad, the SLBMs are considered the most important because the nuclear-powered ballistic missile submarine is the hardest to detect, track, and destroy. “No navy can be considered a force to reckon with unless it has nuclear submarines to control oceans,” says former Vice Chief of Naval Staff, Admiral K K Nayyar.
Why India Needs Nuclear-armed Subs
According to Undersea Warfare, the official magazine of the US submarine force, each leg of the triad contributes unique attributes that enhance deterrence and reduce risk, such that the whole is greater than the sum of the parts.
*ICBMs provide a prompt response, the potential to launch under attack, and a hardened, geographically dispersed target base.
*Strategic bombers provide great flexibility in force posturing, signalling intentions, route planning, and recall-ability.
Based on Russia’s Akula class submarines, INS Arighat and INS Arihant have similar capabilities but INS Arighat is a more operationally focused platform. It has benefited from the extensive testing and validation of INS Arihant’s systems and is combat-capable.
*Missile submarines provide a survivable, assured response and the mobility to adapt missile over-flight to targets.
“Together they comprise a robust deterrent capability that complicates a potential adversary’s offensive and defensive planning and a synergistic force that protects against the failure of a single leg.”
Elite League
INS Arighat and INS Arihant take India to an elite league. The 367-foot submarines – longer than a soccer field – are the first SSBNs built by a country other than the five permanent members of the United Nations Security Council.
Richard Sharpe of Jane’s Fighting Ships says a nuclear submarine will give India a ‘colossal advantage’ over its neighbours. “Facing a nuclear submarine is a nightmare; it has unlimited endurance and mobility and there’s no place for a surface ship to hide,” he writes.
Until now India has blissfully carried on without a credible second-strike ability to protect the land-based Agni missiles and nuclear-capable aircraft from an attack by China – or for that matter any other country.
With INS Arighat being India’s first operational boomer, the equation has changed. It guarantees that a nuclear first strike will not destroy India’s ability to strike back. Lurking at the bottom of the oceans and constantly moving, just one SSBN can create doubts in the enemy’s mind that some of India’s sea-launched strategic missiles would be launched in retaliation.
Undersea Warfare
The importance of a second-strike capability based under the sea was acknowledged even by an army general. Former Army Chief K Sundarji wrote that for emplacing a minimum deterrent posture against China, it would be necessary for India to deploy land-based ballistic missiles with fusion warheads or boosted yield fission warheads, partly in soft overground sites and partly rail-mobile, along with some SLBM capabilities.
According to a study by Brigadier (retired) Vijai K Nair, given the pre-emptive quotient of a nuclear environment on the sub-continent, Indian strategy would have to emphasise second-strike capability.
To give credence to a nuclear war-fighting system as well as to the ‘will’ of the leadership to pursue a given strategy, India must demonstrate a potential to survive a pre-emptive attack. This would necessitate a policy to provide a visible survival capability to the civilian population near international borders.
The study says the sea leg of the triad would comprise five SSBNs. Three for deterrence against China (two on patrol, one on reserve) and two for use against Pakistan (one on patrol and one on reserve). Each of the submarines would carry 16 missiles, therefore, the entire SLBM inventory would total 80 missiles.
Stunted Production
While INS Arihant and INS Arighat have received considerable attention, the reality is that during their production timeline, from 1998 to the present day, the power asymmetry between India and China has widened, with China’s PLAN increasing its fleet to 60 submarines, including six SSBNs, six ship submersible nuclear (SSNs) and 48 diesel-electric submarines. India, therefore, has a long way to go before it can match the Chinese fleet.
To be sure, there is more science packed into an SSBN than any other weapon; it is therefore, not a platform that can be mastered easily. The USS Nautilus took 16 years to build – from authorisation in 1944, sea trials in 1955 to fleet induction in 1960; Russia took 16 years to build its first second-generation SSN-093 submarine.
Secondly, India is the only country in the world that has manufactured an SSBN without first building a long-range SLBM. INS Arighat and INS Arihant are equipped to carry twelve K-15 ballistic nuclear missiles with a rather short range of 750 km, which means that before launching their missiles, the subs will have to venture close to enemy waters, endangering their own security.
Still, a rudimentary SLBM is enough to create uncertainty among the likes of China and Pakistan to desist from reaching for the launch button.
Long Gestation
The reason for the two-decade delay is that boomer technology is a closely guarded secret. The history of nuclear submarines shows only two instances of one state actively helping another acquire a boomer. In the 1960s, the Americans passed on SSBN and SLBM technology to their British cousins as a token of their special relationship. (Strategically, however, it is insignificant because the British fleet is tiny and cannot fire its missiles without American approval.) The only other instance is Russia assisting India in building Arihant.
The approval of the construction of an SSBN dates back to 1970, but as is usual with Indian defence projects, nothing came of it. By the mid-1980s the project had soaked up as much as Rs 2,500 crore in research and development costs. The project failed because the agencies concerned couldn’t fabricate high-quality components and equipment, but the constant interference by the civilian bureaucracy certainly took its toll.
INS Arighat brings India’s strategic planners closer to acquiring a nuclear triad, giving them multiple options if it comes to a nuclear confrontation. A nuclear triad refers to the three components of atomic weapons delivery: strategic bombers, intercontinental ballistic missiles, and SLBMs.
The project was re-launched in 1985 under Defence Research & Development Organisation coordination with the codename Advanced Technology Vessel (ATV). With a retired vice admiral in charge, work on a prototype reactor began at the Kalpakkam nuclear power plant.
While Russian designers assisted in building the submarine, its nuclear-powered 83 megawatt pressurised water reactor was developed by the Bhabha Atomic Research Centre with assistance from a design team from Rubin, the Russian submarine-design bureau. Construction of the submarine began in 1998, and the reactor was fitted in the hull nine years later.
How Many SSBNs are Needed?
According to the US Navy Institute, only the US, Russia, France, and the UK (which uses US Trident missiles) can sustain continuous-at-sea deterrent patrols, providing continuous launch capability of an SLBM by maintaining at least one SSBN on station at any one time that could fire a nuclear missile. “A continuous patrol requires a minimum of four SSBNs,” it says. This assumes one submarine is on patrol for, say, two to three months; another is in port on standby; while the third and fourth may be undergoing repairs or refits.
Over the next five years, India plans to have as many as four boomers – the same number as the UK and France have. The INS Aridhaman is due to be delivered next year and is expected to be double INS Arihant’s displacement at 12,000-13,000 tonnes, with a complement of eight K-4 missiles. Another two boats after INS Aridhaman are planned to be commissioned. “Following these first four Arihant-class boats, another batch of even larger SSBNs is expected,” says the Maryland, US-based institute. These new vessels will be equipped with brand new SLBMs having ranges up to 7,000 km, allowing them to strike Chinese and Pakistani targets from well outside the Indian Ocean.
At the same time, India will require a complementary fleet of SSNs – the fast, hunter-killer subs that will detect and track Chinese and Pakistani undersea activity and surface ships. They can also be despatched to patrol the western Pacific Ocean and the South China Sea where they will play cat and mouse with Chinese SSBNs and warships – as a quid pro quo for PLA Navy activity close to Indian shores.
The Indian Navy plans to acquire as many as six SSNs, and discussions are on with shipbuilders from France and the US to participate in the project. In fact, a Rs 40,000-crore project is currently under consideration by the Cabinet Committee on Security for building two 6,000-tonne ‘hunter-killer’ nuclear-powered attack submarines, armed with torpedoes and land-attack and anti-ship missiles. However, their construction will reportedly take at least a decade.
Richard Sharpe of Jane’s Fighting Ships says a nuclear submarine will give India a ‘colossal advantage’ over its neighbours. “Facing a nuclear submarine is a nightmare; it has unlimited endurance and mobility and there’s no place for a surface ship to hide,” he writes.
Project Varsha
As an indicator of how seriously India is taking the safety of its undersea assets, the Indian Navy has commenced Project Varsha – the construction of a massive nuclear submarine base south of Visakhapatnam. Reportedly costing Rs 30,000 crore, the base will house India’s SSBN fleet in concrete pens blasted out of the hills at Rambilli, 50 km south of the strategically located city. Project Varsha’s location offers a strategic advantage by positioning the Indian Navy closer to the critical shipping lanes of the Indo-Pacific. This proximity allows for a swift response to regional threats.
Maintenance and Cost Factor
SSBNs require long-range operational support involving submarine tenders, and maritime patrol craft as well as an efficient shore side maintenance, repair and overhaul regime with the technical capacity to manage the boomer’s complex systems.
According to the US Navy Institute, a complete technological ecosystem that goes beyond just the boat itself or the missile for that matter will be needed for India’s SSBNs. It’ll include achieving complete self-sufficiency for the pressurised water reactor propulsion, in the area of quieting, combat systems, etc. In particular, to have a complete technical ecosystem for this, a strong indigenous nuclear industry base is necessary, which not only includes the ability to develop safe, functioning PWR technologies, but also the know-how for the life cycle of nuclear propulsion, which involves safe disposal, refuelling and so on.
Secure communications being a critical aspect of SSBN operations, the Indian Navy has invested heavily in very low frequency (VLF) underwater transmissions. It has constructed a VLF broadcasting station named INS Kattabomman near Tirunelveli, Tamil Nadu. The 3,000 acre naval base, which hosts the VLF transmitting grid, is the only one of its kind in the country.
INS Arighat ensures that a nuclear first strike will not destroy India’s ability to strike back. Lurking at the bottom of the oceans and constantly moving, just one SSBN can create doubts in the enemy’s mind that some of India’s sea-launched strategic missiles could be launched in retaliation.
Never Again
In the 1971 India-Pakistan war, after the Indian Army defeated the Pakistan Army in the east, the political leadership had drawn up a secret plan to attack Pakistan in the west and destroy its army so that Pakistan would never ever present a threat to India. However, a mole in the Cabinet leaked the plan to the CIA. In order to protect their vassal state, the US and British fleets made a threatening pincer against India. While the nuclear-armed US Seventh Fleet from Southeast Asia sailed towards Kolkata, a British flotilla from Madagascar steamed towards the west coast. However, the Russian Pacific Fleet sailed into the Indian Ocean and threw a cordon around India, forcing the American and British warships to retreat. The standoff ended after Washington got an assurance from Moscow that India had abandoned its plan to invade West Pakistan.
Once a fleet of Indian boomers and nuclear attack subs start patrolling the world’s oceans, India can ensure no foreign navy will threaten it again.
–The writer is a globally cited defence analyst. His work has been published by leading think tanks, and quoted extensively in books on diplomacy, counter terrorism, warfare and economic development. The views expressed are of the writer and do not necessarily reflect the views of Raksha Anirveda
