INS Arihant (SSBN 80), meaning 'Vanquisher of the Enemy', is India's first nuclear-powered ballistic missile submarine (SSBN) — and one of the most strategically significant warships ever commissioned by the Indian Navy. Her service marked the completion of India's nuclear triad: the ability to deliver nuclear weapons from land, air, and now the sea.

Why the Nuclear Triad Matters

A nuclear triad is considered the gold standard of nuclear deterrence. Land-based missiles can be targeted by an adversary's first strike. Aircraft can be grounded. But a submarine-launched ballistic missile (SLBM) capability, hidden silently in the ocean depths, guarantees a second-strike ability — no adversary can ever be certain they have neutralised all of India's nuclear capability. INS Arihant gave India that assurance.

Development — The ATV Project

Arihant was built under the classified Advanced Technology Vessel (ATV) project, initiated in the 1980s with substantial indigenous effort and Russian assistance. The submarine was built at the Ship Building Centre (SBC) in Visakhapatnam — a facility constructed specifically for this programme. The nuclear reactor achieved first criticality in 2013, and Arihant was formally commissioned on 18 August 2016 by Prime Minister Narendra Modi, who received her crew in person.

India joined a very exclusive club — only five nations (USA, Russia, UK, France, China) had previously operated nuclear ballistic missile submarines.

Armament

• ▸K-15 Sagarika submarine-launched ballistic missiles (SLBMs) — 4 launch tubes, range ~750 km, nuclear-capable
• ▸K-4 SLBMs — longer-range variant (~3,500 km) under development for future boats
• ▸Torpedoes — conventional heavyweight torpedoes for self-defence

General Characteristics