India's fifth S-4 Class SSBN Armed With K-5 SLBM Missiles Completes 50% Construction work

In a significant boost to India's naval capabilities, the construction of the fifth S-4 class nuclear ballistic missile submarine (SSBN) is reportedly progressing steadily at the Ship Building Center (SBC) in Visakhapatnam. This new addition will elevate the Indian Navy's fleet of nuclear ballistic missile submarines to a total of five units, further solidifying the country's strategic deterrence.

The existing SSBNs, INS Arihant and INS Arighat, are sister ships with a submerged displacement of around 6,000 tons. While they share the same basic design, INS Arighat boasts significant internal upgrades, making it more advanced than its predecessor.

The S4 and S4* (Star), successors to the Arihant class, feature a stretched design and a submerged displacement of approximately 7,000 tons. Satellite images have captured these submarines at the outdoor fitment area at the SBC, offering glimpses into their development. Although this is the first official confirmation of a fifth submarine under construction, it is highly probable that its development is well underway.

Considering the S4's rollout from dry docks in 2022, it is estimated that the fifth submarine might already be over 50% complete. Nevertheless, it could still take a couple of years before it transitions from dry docks to the outdoor fitment area for further construction and sea trials.

The S4, S4*, and the unnamed fifth SSBN will mark a crucial milestone as the first Indian nuclear submarines equipped with the K-5 submarine-launched ballistic missiles (SLBMs). These missiles possess a range of 5000 kilometers, substantially bolstering India's nuclear deterrence capabilities.

In addition to these developments, the Indian Navy is also planning to develop the S5 Class of SSBNs, featuring a submerged displacement of around 13,000 tons. The S5 Class program is expected to gain momentum in the coming years, with the first submarine slated for induction in the mid-2030s. These submarines will reportedly be armed with K-6 SLBMs with a range exceeding 6000 kilometers and the highly classified K-8 missiles.