The Indian Navy commissioned its second nuclear-powered ballistic missile submarine (SSBN), INS Arighat, on 29 August 2024. Defence Minister Rajnath Singh inducted the submarine in a low-key ceremony during his visit to the Eastern Naval Command in Visakhapatnam, Andhra Pradesh.

The induction of the second vessel in the planned five Arihant-class nuclear-powered submarines is expected to strengthen India’s nuclear triad capability and second strike capability.

Nuclear triad capability refers to the ability of a country to launch nuclear weapons from air, sea and land.

Second strike capability refers to a country's ability to launch a nuclear weapon on an enemy after being first hit by the enemy’s nuclear weapon. A nuclear-powered submarine is crucial for any country to achieve second-strike capability as it can remain underwater for a longer period than a diesel/electric-powered submarine.

India’s Nuclear Powered Submarine programme

India launched Project AVT (Advanced Vessel Technology) in the 1970s to build an indigenous nuclear-powered submarine.

The AVT programme is a joint project of the Defence Research and Development Organisation (DRDO), the Department of Atomic Energy (DAE), and the Indian Navy.

The first nuclear-powered submarine under the AVT project was INS Arihant, commissioned in August 2016.

The government initially sanctioned four nuclear-powered submarines to be built under the Project AVT, but this was later increased to five. The submarines being built under the AVT projects are now called INS Arihant class submarines.

The second submarine in the INS Arihant class, INS Arighat, was launched in November 2017 and was commissioned in August 2024. The Indian Navy has started the construction of the S-3 and S-4 submarines of the planned five submarines.

According to reports, India is also planning to build six nuclear attack submarines in three phases.

Feature of the INS Arighat

Like the INS Arihant, the INS Arighat is powered by an 83 MW pressurised light water nuclear reactor with better stealth (noise) capability.

The less noise a submarine produces, the harder it is to be detected by the enemy.

The 112-meter-long INS Arighat can achieve a maximum speed of 12-15 knots on the surface and up to 24 knots when submerged.

It has four missile launch tubes that can carry up to 12 K-15 or 4 K-4 submarine-launched ballistic missiles (SLBMs).

The K-15 Sagarika missiles have a range of 750 kilometres, is operational, and were inducted on INS Arihant.

The K-4 SLBMs developed by DRDO can carry nuclear weapons and have a range of 3,500 km.

The INS Arihant can carry 4 K-15 missiles or one K-4 missile.

Russian help in operating nuclear powered Submarine

After the launch of the AVT project, the Indian government took on the lease of a Soviet nuclear-powered submarine to familiarise the Indian Navy personnel with the operation of nuclear submarines.
The first nuclear-powered Soviet submarine, INS Chakra, arrived in India in 1988 and was returned to the Soviet Union in 1991.
India again signed a 10-year deal with Russia to lease an Akula Class nuclear-powered submarine for around $2 billion.
The submarine was commissioned in India in April 2012 and was named INS Chakra II.
In March 2019, India signed an agreement with Russia to lease another advanced Akula class nuclear-powered submarine for 10 years at $3 billion.
The advanced submarine is expected to arrive in India by 2025.

Submarine Bases in India

India is constructing two modern submarine bases. One is Project Sea Bird in Karwar, Karnataka.

The other is INS Varsha in Kakinada, Andhra Pradesh, which will have underground docking facilities for the submarines.