Feature Specification
Name INS Aridaman (S4)
Class Arihant-class (Stretch Variant)
Type SSBN (Nuclear-powered Ballistic Missile Submarine)
Commissioned April 3, 2026
Displacement ~7,000 Tonnes
Length ~130 Meters
Armament 8 VLS Tubes (K-4 / K-15 / K-5 SLBMs)
Propulsion 83 MW Pressurized Light-Water Reactor (CLWR)

On April 3, 2026, India reached a watershed moment in its maritime history with the commissioning of INS Aridaman (also referred to as Aridhaman). As the third indigenously built nuclear-powered ballistic missile submarine (SSBN), the Aridaman is not merely an addition to the fleet—it is a significant “stretch” in India’s technological and strategic reach.
​The “Vanquisher of Foes”
​The name Aridaman is derived from Sanskrit, meaning “Destroyer of Enemies.” While its predecessors, INS Arihant and INS Arighat, laid the foundation for India’s nuclear triad, the Aridaman represents a significant evolutionary leap in design and firepower.
​Key Technical Advancements
​Unlike the first two boats of the class, the Aridaman features a “stretched” hull, allowing it to carry a significantly larger payload:
​Doubled Firepower: While the earlier vessels house four vertical launch system (VLS) tubes, the Aridaman is equipped with eight tubes. This allows it to carry either 8 long-range K-4 missiles (3,500 km range) or up to 24 K-15 Sagarika short-range missiles.
​Enhanced Stealth: Utilizing refined hydrodynamics and an upgraded 83 MW pressurized light-water reactor, the submarine operates with a much lower acoustic signature, making it exceptionally difficult for enemy sonar to detect.
​Indigenous Core: Roughly 70% of the submarine is built with indigenous components, including advanced USHUS sonar suites and internal communication systems developed by Indian scientists.
​Strategic Significance
​The commissioning of INS Aridaman solidifies India’s Second Strike Capability. Under India’s “No First Use” policy, the ability to maintain a survivable nuclear deterrent underwater is crucial.
​Continuous At-Sea Deterrence: With three SSBNs now in the fleet, the Indian Navy is closer to maintaining a permanent “bastion” where at least one nuclear-armed submarine is always on patrol.
​Indo-Pacific Stability: In an era of increasing maritime friction, a robust underwater nuclear leg acts as a stabilizer, ensuring that any potential aggressor faces a guaranteed retaliatory strike from an invisible location.
​Path to K-5: The Aridaman is designed with the future in mind, capable of eventually hosting the K-5 SLBM, which is expected to have a range exceeding 5,000 km, putting all of Eurasia within reach from the safety of the Indian Ocean.
​Looking Ahead
​The Aridaman is the first of the “S4″ design tier. Work is already underway on the fourth submarine (S4*), which is expected to mirror these upgraded specifications. As India moves toward larger, more powerful 13,000-tonne S5-class submarines in the next decade, the Aridaman stands as the definitive bridge between a nascent capability and a world-class blue-water nuclear navy.
​”It’s not just a word; Aridaman is power.” — Rajnath Singh, Defense Minister of India, during the commissioning.