India launches 4th nuclear-missile submarine

India’s fourth nuclear-powered ballistic missile submarine (SSBN), referred to as S4*, was launched into water at the Ship Building Centre in Visakhapatnam last week, official sources confirmed. This submarine is bigger and more capable than the first INS Arihant (S2), a technology demonstrator developed under the Advanced Technology Vessel program.

Multiple sources confirmed that the S4* was launched into water on October 16 at SBC. It has significant indigenous content, with Indian industry being extensively involved, according to a source.

India currently has two operational SSBNs. INS Arihant was quietly commissioned into service in August 2016. It has a displacement of 6,000 tonnes and is powered by an 83 MW pressurized light-water reactor with enriched uranium. The second SSBN, INS Arighaat (S3), which retains the same reactor and dimensions with several technological upgrades, was commissioned at the end of August.

Sources said that the 3rd SSBN Aridhman (S4) is currently undergoing sea trials and is expected to be commissioned and put into service next year.

Responding to questions on the launch at a press conference on Tuesday (October 22, 2024), Vice Chief of the Navy, Vice Admiral Krishna Swaminathan, without directly commenting, said, “The SSBN program is a successful one. Two submarines have been commissioned, and, naturally, others will follow.”

The first two SSBNs share the same reactor, while the S4 and S4* have an improved reactor, another source said.

Sources added that the S4* is more extensive and can carry a number of the K-4 submarine-launched ballistic missiles (SLBM).