On July 13, the Defence Acquisition Council gave the “acceptance of necessity” for the purchase of three further diesel-electric Scorpene-class submarines.

By the end of the year, the contract for these submarines is projected to be finalised, and the first submarine is planned for delivery in 2031.

India had previously purchased six Scorpene-class submarines from the French-based Naval Group under a $3.5 billion agreement that was signed in 2005. Under a technology transfer agreement, these submarines were built by Mazagon Dock Shipbuilders Limited.

the INS Khanderi in September 2019, the INS Karanj in March 2021, the INS Vela in November 2021, and the INS Vagir in January 2023. The first submarine in the series, the INS Kalvari, was commissioned in December 2017.

In early 2024, the sixth submarine, INS Vagsheer, which is now undergoing testing, is anticipated to be delivered to the Indian Navy.

The three more submarines, according to the Defence Ministry, would have more indigenous components and the DRDO-developed air independent propulsion (AIP) technology, which will increase their endurance.

According to a defence official, if the Defence Research and Development Organisation (DRDO) delivers a tested and functional AIP module in accordance with the building timetable, the submarines will use it.

Additionally, Naval Group and DRDO are working together to include the indigenous AIP module into the operational Scorpene submarines as part of routine refits.

When INS Kalvari undergoes its initial refit at the end of 2024 or the beginning of 2025, this process will start.

The preparation for the integration of the submarines, which requires dividing the submarine in half, safely integrating the AIP, and reassembling the submarine with the new AIP portion, is being actively supported by Naval Group as DRDO works to identify an indigenous supplier for the liquid oxygen tank.

The Indian Navy currently employs 16 conventional submarines, including five Scorpene-class submarines and seven Russian Kilo-class submarines.

However, as the older submarines start to retire, the number is expected to drop during the following ten years. As a temporary remedy, the medium-refit life certification process is being used to extend the lives of four submarines from the Kilo class and three German HDWs.

The Indian Navy will be able to significantly improve its maritime capabilities after the new submarines are delivered, which is scheduled to happen in 2031.