New Delhi: Amid a diplomatic dispute with Canada, India discreetly launched its fourth nuclear-powered ballistic missile submarine (SSBN), at the Ship Building Center (SBC) in Visakhapatnam, to bolster its nuclear deterrence capabilities.
India’s second SSBN, INS Arighaat, was commissioned by Defence Minister Rajnath Singh on August 29, 2024, and the third, INS Aridhaman, is slated for commissioning next year. On October 9, the Cabinet Committee on Security (CCS) approved the construction of two nuclear-powered attack submarines by the Indian Navy, aimed at deterring adversaries in the Indo-Pacific region.
The Modi government remains reserved about its nuclear deterrence strategy, but the fourth SSBN codenamed S4*, was launched on October 16, following the inauguration of a Very Low-Frequency Naval Station by Defence Minister Rajnath Singh in the Damagundam forest area of Vikarabad district, Telangana, which will serve for command and control communications with the Indian Navy’s strategic assets.
The newly launched S4* SSBN, with approximately 75% indigenous components, is armed exclusively with the 3,500km-range K-4 nuclear ballistic missiles, deployable via vertical launch systems. The first in its class, INS Arihant, is equipped with 750km-range K-15 nuclear missiles, while subsequent submarines are enhanced versions carrying only K-4 ballistic missiles. The operational capacity of an SSBN is limited only by food supplies, crew fatigue, and maintenance requirements. INS Arihant and INS Arighaat are currently on deep-sea patrols, and a Russian Akula-class nuclear-powered attack submarine is expected to join the fleet on lease in 2028.
India’s national security planners have designated the country’s first leased nuclear attack submarine as INS Chakra, or S1, followed by INS Arihant as S2, INS Arighaat as S3, and INS Aridhaman as S4. The newly launched submarine is the last of its class, referred to as S4*, awaiting a formal name. The forthcoming class of Indian SSBNs will have a displacement double that of the 6,000-ton Arihant class, equipped to carry nuclear missiles with ranges exceeding 5,000 kilometres.
The Narendra Modi government’s emphasis on sea-based submarine deterrence, particularly against formidable adversaries like China, stems from the vulnerability of aircraft carriers to long-range PLA missiles such as the Dong Feng-21 and Dong Feng-26, which could render them ineffective in dire situations. Consequently, the government has prioritized nuclear attack and ballistic missile submarines over the third aircraft carrier for the Indian Navy. Additionally, the government has enhanced conventional submarine deterrence by commissioning the sixth diesel attack submarine of the Kalvari class, INS Vagsheer, this December.
Furthermore, the government is set to approve the construction of three additional advanced diesel attack submarines at Mazagon Dockyards, in partnership with the French Naval Group. Given the presence of 10-11 PLA warships in the Indian Ocean each month since the previous year and the anticipation of carrier-based long-range patrols by 2025-26, strategic submarines are poised to become pivotal in safeguarding India and asserting dominance in the Indian Ocean Region (IOR).