On November 5, 2018 India's first indigenous SSBN (ship submersible ballistic nuclear) INS Arihant completed its maiden deterrence patrol, meaning that the submarine is fully ready for its role as a strategic deterrent. Deterrence patrol refers to a submarine disappearing into the depths of the ocean, carrying its deadly cargo of nuclear-tipped missiles. The Arihant's month-long deployment compares favourably with submarines of the US Navy which go on patrols from 30-70 days.
With the completion of the patrol, India's strategic planners have finally achieved their longstanding ambition to have 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 submarine launched ballistic missiles (SLBMs).
Of the three elements of the triad, the SLBMs are considered the most important because the nuclear powered ballistic missile submarine - also known as a boomer in the colloquial language of seamen - 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. Missile submarines provide 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 provides protection against the failure of a single leg."
The 6,000 tonne Arihant - which means Slayer of Enemies in Sanskrit - takes India to an elite league. The 367 feet submarine - which is longer than a soccer field - is the first SSBN to have been built by a country other than one of the five permanent members of the United Nations Security Council.
According to Richard Sharpe of Jane's Fighting Ships, 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 option. This means if China - or for that matter any other country - launches a surprise first strike and decapitates the land based Agni missiles and nuclear capable aircraft, there's very little India can do except throw in the towel.
Having an SSBN changes the equation. It guarantees a nuclear first strike will not destroy India's ability to strike back. Lurking at the bottom of the oceans and constantly moving, even a handful of SSBNs can sow doubt in the enemy's mind that some of India's sea-launched strategic missiles will be launched in retaliation.
While the Arihant's first deterrence patrol has received global attention, the reality is that India is the only country in the world that has built an SSBN without first building a long range SLBM. The Arihant is equipped to carry twelve K-15 ballistic nuclear missiles with an abysmally short range of 750 km. This means before launching its missiles, the sub will have to venture close to enemy waters, endangering its own security.
A 3,500 km range missile named the K-4 is currently in development, but one wonders why it takes so long for the Indian defence establishment to achieve incremental increases in missile range. India tested its first nuclear capable ballistic missile in 1989, after nearly three decades of development its longest ballistic missile, the Agni V, has a claimed range of 5,000 km. It could take several years before Indian SSBNs are equipped with missiles having intercontinental range. Still, even a rudimentary SSBN force is enough to create uncertainty among the likes of China and Pakistan to desist from reaching for the launch buttons.
Search for second strike
The entire process, from steel cutting in 1998 to the completion of deterrence patrol, has taken 20 years. In the meantime, China has built 10 nuclear-powered submarines and is building an equal number of bigger, faster and deadlier submarines. India has a long way to go before it can match China's SLBM fleet.
The reason for the two-decade delay is that boomer technology is a closely guarded secret. In fact, in the entire history of nuclear submarines, there are only two known 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 of no significance because the British fleet is not only tiny but it reportedly cannot fire its missiles without American approval.) The only other instance is Russia providing assistance to India in building the Arihant.
The approval of the construction of an SSBN dates back to 1970, but as is usual with Indian defence projects, nothing came off it. The project was revived in 1985 and in 1989 DRDO sought design assistance from former engineers and defence workers of the former Soviet Union. By 1996, when India had spent $285.7 million on the nuclear submarine - codenamed Advanced Technology Vessel - work on the project came to a crawl because of US pressure.
However, with the exit from the Kremlin of pro-American elements, the Russians returned in full strength. While Russian designers assisted in building the vessel, its nuclear-powered 80MW pressurised water reactor was developed by the Bhabha Atomic Research Centre with assistance from a design team from Rubin, the Russian submarine-design bureau.
It is worth mentioning that because there is more science packed into an SSBN than any other weapons platform, it is for the faint hearted. 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. "The Arihant achievement must be judged as such, and lauded," says Commodore Rai, a former Director Naval Intelligence.
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.
A second SSBN has reportedly completed sea trials. Named INS Arighat, the boat is due to be delivered next year and is expected to be double the Arihant's displacement at 12,000-13,000 tonnes, with a complement of eight K-4 missiles. Another two boats after Arighat are planned to be commissioned by 2023. "Following from 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 7000 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 ship submersible nuclear (SSN) submarines - these are fast, hunter killer subs that will be required to detect and track Chinese and Pakistani undersea activity and warships. They are also likely 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 for participating in the project.
Plus, 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, 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. The first phase of the project will be completed by 2022.
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, US got wind of it. 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. The Indian Air Force was on alert after receiving intelligence that American warplanes might attack the Indian Army's communications in the west. However, the Russian Pacific Fleet sailed into the Indian Ocean and threw a cordon around India, forcing the American and British warships to retreat.
Once a fleet of Indian boomers and nuclear attack subs start patrolling the oceans, India can ensure no foreign navy will threaten it again.