Booster shot:INS Karanj, the third Scorpene class submarine, being launched in Mumbai in January.Vivek BendreVivek Bendre  

The indigenous Air Independent Propulsion (AIP) module, which enhances the ability of submarines to stay under water, is in an advanced stage of trials, a senior officer of the Navy said on Friday. It is being developed by the Defence Research and Development Organisation (DRDO). All Scorpène submarines will be equipped with it in due course.

“The DRDO AIP is in an advanced stage of experimental trials. Once proven on shore, it has to be tested on a marine platform,” Vice-Admiral Srikanth said, speaking at the launch of a four-part series by the Discovery channel on Indian submariners to commemorate 50 years of the Navy’s underwater arm.

More scorpenes?

Asked whether the Navy would order three additional Scorpène submarines, Vice-Admiral Srikanth said a decision would be made after the current project was completed. “Yes, there is speculation, and even demand, to have three additional submarines at Mazagon Dock Limited. Since we already have the production line, along with expertise, the option can be looked into. But first, the existing project should complete on time.”

Earlier, the Navy planned to install the AIP module on the fifth and sixth submarines. But delays in development meant it could not be done before the last two submarines were launched.

The first Scorpene submarine Kulvari has joined the Navy. It will go for a normal refit in 2023. The next two submarines are in various stages of sea trials. Under a revised plan, the AIP module will be installed on the submarines during upgrades. However, it is a complex and costly task.

Six Scorpene submarines are being made at Mazagon Dock Limited under technology transfer from France.