The building of an extra S-4 class nuclear ballistic missile submarine (SSBN) has been approved for the Indian Navy. This will increase the number of nuclear ballistic missile submarines with the Indian Navy to five.
The two current SSBNs, INS Arihant and INS Arighat, are sister ships that have the same basic design and have a submerged displacement of about 6,000 tons. But INS Arighat is more sophisticated than INS Arihant since it has a lot of internal improvements.
Stretched designs of the Arihant class, the S4 and S4* (Star) have a submerged displacement of around 7,000 tons. Satellite photographs of the Ship Building Center (SBC) at Vishakhapatnam’s exterior fitment area have shown these submarines on several occasions. Though it’s the first time the public has heard of