Indian Navy may place another order for Kalveri class submarines.

The Indian Navy is prepared to abandon new acquisitions made under Project 75 I and may repeat its Project 75 order to MDL so that the air-independent propulsion system developed by the DRDO is installed in the new submarines built under “Aatmanirbhar Bharat.”

When Manohar Parrikar was India’s Defence Minister, he advised then-Navy Chief Admiral Robin K. Dhowan to use the option of three additional Kalveri (Scorpene class) submarines rather than pursuing the purchase of six additional Project 75 I submarines with air-independent propulsion. The options clause for Project 75, approved by the Atal Behari Vajpayee government back in 2003, was canceled in September 2016 due to Admiral Dhowan’s disagreement.

The Ministry of Defence issued a proposal request (RFP) on July 20, 2021, asking for bids to outfit six Project 75 I class submarines with AIP for 40,000 crores. The following 75 I class submarines will be built in the late 2030s with a new massive investment in the submarine line, which means that the current Scorpene submarine line at MDL will go to seed. It is typical for the Indian military-civilian bureaucracy to take at least 10-15 years to complete any significant acquisition. 

The most recent Japanese Soryu class submarines have replaced the AIP-equipped ones because they have higher endurance lithium-ion batteries and quicker recharge. The range of the submarine is significantly increased by the lithium-ion batteries’ double the storage capacity of conventional lead acid batteries.