Defence Minister Nirmala Sitharaman has announced the launch of the second indigenously designed Arihant-class nuclear-powered ballistic missile submarine (SSBN) on order for the Indian Navy.

The launch of Arighat, which took place during a low-key ceremony held at the Ship Building Centre (SBC) at Visakhapatnam on 19 November, entailed flooding the dry dock housing the SSBN to enable it to float into the surrounding waters for additional fitments ahead of its commissioning in 2020-21.

INS Arighat will be succeeded in the dry dock by two similar SSBNs that have been temporarily designated S4 and S4*.

The launch of the INS Arighat follows India’s first domestically built nuclear-powered ballistic missile submarine (SSBN), the IHS Arihant, being inducted into the Indian Navy in August of last year. That submarine made India only the sixth country after the United States, Russia, the United Kingdom, France and China to build a SSBN. The first Indian SSBN is believed to carry twelve Sagarika (K-15) submarine launched ballistic missiles (SLBMs) that have ranges of 700 km. However, India’s Defence Research and Development Organisation (DRDO) is also developing a longer-range SLBM, the K-4, which its SSBNs will also carry. The IHS Arihant is only equipped to handle four of the larger K-4s (the submarine has four launch tubes but three K-15s can fit in each launch tube). The submarine can also carry torpedoes and submarine launched cruise missiles (SLCMs), including possibly a sea-launched version of the supersonic BrahMos cruise missile.

The IHS Arihant was built primarily to serve as a trainer. That is, to train sailors to operate the new Arihant-class submarines, of which Delhi plans to build four boats. Thus, the new INS Arighat will pack a lot more firepower than its sister ship. The second SSBN has eight vertical launch tubes, allowing it to carry twenty-four K-15 missiles or eight K-4 missiles.


In addition, the new boat will have a reactor more powerful than the INS Arihant’s 83 MW pressurised light-water reactor. That reactor uses uranium as fuel and light water as a coolant and moderator, which allow it to operate quietly and stay submerged for about two months at a time. The new SSBN will be able to travel at speeds of 24 knots when submerged. The Arighat will also carry more advanced sensors than its sister boat and feature the indigenously-developed USHUS integrated sonar system and the Panchendriya sonar, a unified submarine sonar and tactical control system used for detecting and tracking submarines, torpedoes, as well as underwater obstacles. It can also be used for underwater communication.

The Arighat SSBN can be armed with up to eight K-4 missiles. The K-4 is an intermediate-range nuclear-capable submarine-launched ballistic missile (SLBM). It has an an estimated range of up to 3,500 kilometers. The Arighat will also be able to accommodate up to 24 K-15 Sagarika SLBMs with an estimated range of 700-750 kilometers.

The indigenous boats are loosely based on the designs of the Russian Project 971 Akula I-class nuclear-powered attack submarines. India has leased the Akula I-class SSN from Russia in the past. The launching of the first non-trainer SSBN is a significant milestone for the Navy. India’s quest to build a nuclear-powered ballistic missile submarine reportedly began in 1970, code-named the Advanced Technology Vehicle (ATV) program, its existence was kept under wraps for more than three decades, before the former chairman of India's Atomic Energy Commission, PK Iyengar, revealed it at a public forum back in 2007.

Enhancing Operational Procedures

The SSBNs will give India a complete nuclear triad, which consists of land, air, and sea-based nuclear delivery systems. In one sense, this could seen as a good development for strategic stability in the region as submarines out at sea are far less vulnerable to surprise attacks compared with airplanes and land-based missiles. This is especially critical for a country like India which maintains a modest-sized nuclear arsenal.

At the same time, the new leg of the triad could produce a sea change in India’s nuclear operating procedures. As a country with a no-first use declaratory policy, India’s current nuclear warheads and missiles are kept demated and likely in separate locations. This is fine for the air and land-based legs of the triad because they can be brought together if needed. This is not possible for SSBNs. To provide any deterrent benefit, the missiles and warheads will need to be kept together on the submarines, eliminating any actual demonstration of its no first use policy beyond words. This is a challenge that is also being confronted by China, another country with a no-first use policy that also recently began deterrent patrols.

The emergence of India’s SSBNs is another example of a growing technological arms race among the so-called nuclear duo of India and China. From a purely technological perspective the Islamic State of Pakistan is nowhere in the picture.

In 2012, India first tested its Agni-V ICBM, which is capable of reaching all parts of China. China also recently acquired its first operational SSBNs, which began conducting deterrent patrols sometime in 2016. China also recently began deploying multiple independently targetable reentry vehicle (MIRVs) on its ballistic missiles, a step India is also likely to take if it already hasn't. Both India and China have also been improving their targeting capabilities through improved intelligence surveillance and reconnaissance (ISR) capabilities. On the other hand, Pakistan, India's arch enemy has been focusing on buying up a large tactical nuclear weapon arsenal from the Chinese to repeal any Indian conventional attacks. (With input from Agencies)

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