India is preparing to commission its third indigenously developed nuclear-powered ballistic missile submarine, INS Aridhaman, around April–May this year, with the timeline expected to coincide with the anniversary period of Operation Sindoor. According to sources, the induction of the submarine into active service will mark a significant milestone in strengthening India’s sea-based nuclear deterrent and enhancing overall strategic preparedness at a time when maritime security remains a key national priority.
Earlier reports had indicated that the submarine was on course for commissioning in 2026 after Navy Chief Admiral Dinesh K Tripathi confirmed progress on the project publicly in December. Since then, INS Aridhaman, designated as S4, has reportedly entered the final phase of sea trials. Officials familiar with the development stated that system validation exercises and weapon integration processes are nearing completion, bringing the platform closer to operational readiness pending the successful conclusion of remaining evaluations.
The submarine has been developed under the highly classified Advanced Technology Vessel (ATV) programme and constructed at the Ship Building Centre. Compared to its predecessors, INS Arihant and INS Arighaat, the new submarine represents a notable advancement in size and capability. While the earlier vessels displace approximately 6,000 tonnes, INS Aridhaman has a displacement of around 7,000 tonnes, allowing for enhanced endurance, improved operational flexibility, and greater payload capacity.
A key feature of INS Aridhaman is its ability to carry longer-range K-4 submarine-launched ballistic missiles. This capability significantly expands India’s strategic reach while improving survivability by enabling launches from safer stand-off distances. The addition of such platforms supports India’s nuclear doctrine, which is built around the principles of credible minimum deterrence and an assured second-strike capability, ensuring the country can maintain deterrence even under adverse circumstances.
Admiral Tripathi had earlier indicated that the submarine had successfully crossed several major developmental milestones, signalling steady progress toward commissioning. Sources now suggest that timelines are becoming more definitive, with the early summer window being targeted for induction, subject to the successful completion of final trials and operational clearances. Once commissioned, INS Aridhaman is expected to further strengthen India’s nuclear triad by reinforcing the maritime leg of its strategic forces.
