DefenceSaturday, 4 April 2026·The Hindu
INS Aridhaman commissioned in Visakhapatnam; India’s third Arihant-class SSBN strengthens nuclear triad
On 3 April 2026, Defence Minister Rajnath Singh commissioned INS Aridhaman (S4) at Visakhapatnam as India’s third indigenous nuclear-powered ballistic missile submarine.
Key highlights
Direct fact
In April 2026, Defence Minister Rajnath Singh commissioned INS Aridhaman (S4) at Visakhapatnam, making it India’s third indigenous nuclear-powered ballistic missile submarine and a key part of the Nuclear Triad.
Key specifics
- INS Aridhaman is the third SSBN of the Arihant-class, after INS Arihant (2016) and INS Arighaat (August 2024).
- The submarine was built at the Ship Building Centre (SBC), Visakhapatnam, under the Advanced Technology Vessel (ATV) project.
- It weighs about 7,000 tonnes, compared with 6,000 tonnes for INS Arihant and INS Arighaat.
- Its missile load can be up to 24 K-15 Sagarika missiles or 8 K-4 missiles, with K-4 having a 3,500 km range.
- A fourth vessel, S4*, is under sea trials, and India plans SSNs by 2036–39.
Exam lens
Question type: Defence match-the-following, nuclear triad, submarine class and missile range. TNPSC one-liner: INS Aridhaman, commissioned at Visakhapatnam in April 2026, is India’s third Arihant-class SSBN and can carry K-4 missiles of 3,500 km range.