Indigenous nuclear submarine INS Arihant was commissioned into service in August, a report said on Tuesday. By inducting the 6,000-tonne submarine into service, India has quietly completed its nuclear triad. That means India can launch nuclear weapons from sea, land and air-based systems.

It was built under the Advanced Technology Vessel Project at the Ship Building Centre. An advantage of such a submarine is that they are harder to track and destroy than land and air nuclear launch platforms.

India has now joined group of five other elite countries – USA, UK, France, Russia, China – to have developed nuclear-armed submarines.

INS Arihant gives second-strike capability to India, which has a clearly declared policy of “no first-use” of nuclear weapons.

About INS Arihant:

INS Arihant  is the lead ship of India’s Arihant class of nuclear-powered ballistic missile submarines.The 6,000 tonne vessel was built under the Advanced Technology Vessel (ATV) project at the Ship Building Centre in the port city of Visakhapatnam.

Arihant was launched on 26 July 2009, the anniversary of Vijay Diwas (Kargil War Victory Day) by the then Prime Minister of India, Dr Manmohan Singh. After fitting out and extensive sea trials, on 23 February 2016, she was confirmed as ready for operations, and was quietly commissioned in August 2016.

The Arihant-class submarines are reported to be based on the Akula-class submarine, which the Indian Navy leased from Russia. Arihant has four vertical launch tubes, which can carry 12 (three per launch tube) smaller K-15 missiles or four larger K-4 missiles. The K-4 has a longer range of 3,500 km (2,200 mi) and has commenced trials.