With their established air independent propulsion systems, South Korean Daewoo and Spanish Navantia are prepared to collaborate with Indian MDL and L&T defence companies to construct long endurance submarines for Indian Navy’s P-75i Program.
South Korean Daewoo and Spanish Navantia have expressed interest in building the long endurance diesel submarine under the strategic partnership model with India, even though the Defence Ministry has once more extended the deadline for submitting the Request for Proposals (RFP) for the advanced submarine project to November 30. The RFP was initially released in July 2021 and had a deadline of June 30, 2022 that was extended to November 30, 2022.
As of right now, Project 75 India of the Indian Navy is interested in the submarines being built by the South Korean Daewoo Shipbuilding and Marine Engineering and the Spanish company Navantia, both of which have demonstrated AIP technology.
Although the national security planners had considered adding three more submarines to the current Project 75 diesel attack submarine production line at MDL, the decision was made to instead continue forward with the fuel-based AIP project since it is more powerful and has a longer range.
In simple terms, an AIP submarine must surface once per week to recharge its batteries while a diesel attack submarine must surface once per day. Because of the lateral inversion in the tropics, the AIP equipped submarine with a land attack ballistic missile on board is a more effective weapon in equatorial waters.
The South Korean and Spanish defence majors are eager to get involved in the project, but French Naval Group, Russian Rosoboronexport, and TKMS Germany have not. Instead, the French are concentrating on nuclear-powered sub-surface platforms, and Germany is using the most recent lithium cell technology.
The first submarine outfitted with AIP, the Dosan Ahn Changho, was already commissioned by South Korean defence giant Daewoo in 2019, while the Spanish Isaac Peral was launched at Cartagena Shipyards on April 22, 2021. Both submarines are equipped with ballistic and cruise missiles for land attack.
The AIP technology was created by the Indian Defence Research and Development Organization (DRDO) and will be retrofitted to Project 75 submarines when they are due for a mid-life upgrade. In 2017, the Indian Navy commissioned INS Kalveri, the first of the six indigenous Scorpene class submarines. Since then, the Indian Navy has commissioned an additional three people.