India's second nuclear-powered ballistic missile submarine (SSBN), INS Arighat, will be commissioned by Defence Minister Rajnath Singh at an event in Visakhapatnam on Thursday. The formal induction of the vessel almost seven years after it was launched is being seen as a huge leap towards bolstering the country's 'nuclear triad’.
INS Arighat is one of three SSBNs possessed by the Navy. While first-of-class INS Arihant was launched in July 2009 and commissioned in August 2016, a third yet-to-be-named vessel was launched in November 2021.
Reports state that the SSBN will be deployed for long-range patrols in the Indo-Pacific. It will be armed with 12 K-15 Sagarika submarine-launched ballistic missiles (SLBMs) developed by India's state-owned Defence Research and Development Organisation (DRDO).
Sub's specifications
Built with Russian steel equivalent to US HY-80 grade, INS Arighat is said to have seven compartments, with main divisions for the propulsion and combat management systems, platform management centre, and the torpedo room.
It has a length of 111.6 m, a beam of 11 m, a draught of 9.5 m, and a displacement of 6,000 tonnes.
They are powered by 83 MW pressurised light-water reactors at their core, developed with Russian help. This helps the sub to achieve a top speed of speed of 24 kt, and a surfaced speed of 10 kt. There are also miniature nuclear reactors in the sub's hulls which helps it stay submerged for months. This gives it an edge over diesel-powered submarines which have to surface (or cruise just below the surface using a snorkel) to run the diesel engines. Only after the batteries are fully charged can a diesel sub go underwater.
Arighat also features a double hull, encompassing ballast tanks, two standby auxiliary engines, and a retractable thruster for emergency power and mobility.
As for armaments, Arighat has four large vertical launch system (VLS) tubes that carry the Sagarika SLBMs. Sagarika is a hybrid propulsion,
two‐stage, solid‐propellant missile with a range of more than 700 km. The submarines are 95% indigenously built.
The third yet-to-be-named submarine is said to be slightly larger than the second one with the capacity to carry K-4 missiles with a range of 3,500 km. The Indian Navy is also building the fourth nuclear-powered submarine.