- P75I was first cleared in 2007, but lay dormant until now after undergoing numerous changes.
- The P75I project is part of a 30-year submarine building plan that ends in 2030.
- The project cost is about Rs. 45,000 crore.
- As part of this plan, India was to build 24 submarines — 18 conventional submarines and six nuclear-powered submarines (SSNs) — as an effective deterrent against China and Pakistan.
- This project envisages the construction of six conventional submarines with better sensors and weapons and the Air Independent Propulsion System (AIP).
- The project has been cleared under the strategic partnership model.
- In 1999, the Cabinet Committee on Security had approved a ‘30-Year Plan for Indigenous Submarine Construction’. It was to develop two production lines on which six submarines would be built each named Project 75 and Project 75 (I) with foreign submarine makers.
- These two projects will replace ageing Sindhughosh and Shishumar class submarines of Indian Navy, which numbered around 13.
- The submarines in the P75 Scorpene-Class are powered by the conventional diesel-electric propulsion system.
- The first Scorpene submarine, Kalvari, was commissioned in 2017 and it would go for a normal refit after six years in 2023, during which time the Air-Independent Propulsion (AIP) would be installed.
- AIP technology is being developed by the Defence Research and Development Organisation (DRDO) to provide submarines long-range and extended endurance capabilities undersea.
- Second Scorpene Khanderi was inducted in September 2019.
The third Scorpene submarine, Karanj, will be delivered to the Indian Navy by December 2020.
- The remaining submarines (Vela, Vagir, and Vagsheer) in the series are in advanced stages of manufacturing and trials.
Air-independent propulsion (AIP)
- AIP is any marine propulsion technology that allows a non-nuclear submarine to operate without access to atmospheric oxygen.
- It can augment or replace the diesel-electric propulsion system of non-nuclear vessels.