The Indian Navy's fifth Scorpene-class submarine Vagir is launched at the Mazagon Dock in south Mumbai, November 12, 2020. Image: Indian Navy

France and India have signed an agreement to cooperate on air-independent propulsion (AIP) technology to upgrade the latter’s Kalvari-class submarines, deepening the growing strategic relationship between the two countries.

AIP technology allows conventional submarines to stay submerged for weeks at a time, approaching the underwater endurance of nuclear submarines.

This month, Indian Express reported that Naval Group France and India’s Defense Research and Development Organization (DRDO) had signed an agreement to develop fuel cell AIP to be retrofitted on the first-of-class INS Kalvari, a derivative of the French Scorpene-class submarine.

The report cites a DRDO statement that says senior officials of DRDO New Materials Research Laboratory (NMRL) and Naval Group signed the agreement to extend cooperation for the detailed design phase of integrating India’s indigenous AIP into the INS Kalvari, with Naval Group certifying the integration.

The report did not mention specifics about the AIP’s performance, but did say it is unique in generating hydrogen onboard instead of storing it aboard in liquid form.

India’s new AIP system is most likely derived from Naval Group’s Fuel Cell Second Generation (FC2G) model, which cracks diesel fuel in a reformer to extract hydrogen, using liquid oxygen and nitrogen as oxidizers. When the hydrogen is mixed with oxygen, it generates electricity to charge the submarine’s batteries and produces water used in the cracking process.

Asia Times has reported on France’s assistance to India’s 5th generation fighter and conventional submarine programs. French aerospace company Safran in cooperation with India’s DRDO plans to co-produce jet engines for India’s 5th generation fighter. At the same time, India’s Kalvari-class submarines are built under a 2005 technology transfer program with France.

Still, India’s program is lagging behind its ambitions. In a July 2022 article, The Print reported that India needs help with its ambitious program to acquire 24 submarines by 2030, including 18 conventional and six nuclear-powered submarines. Currently, India operates only 16 submarines, with one nuclear ballistic missile submarine (SSBN) and no AIP submarines.

India’s INS Vagsheer, a Kalvari-class submarine. Photo: Twitter / Naval Group

China’s rising presence in the Indian Ocean and Pakistan’s rapidly modernizing submarine fleet are driving India’s renewed submarine modernization project.

Prakash Panneerselvam, assistant professor at the National Institute of Advanced Studies in Begaluru, notes in a recent article that the Indian Ocean is an attractive area of operations for the People’s Liberation Army-Navy (PLA-N), which unlike the Western Pacific where the US and Japanese navies heavily patrol is relatively safe for PLA-N submarines to operate.

Panneerselvam mentions China’s naval base in Djibouti as facilitating those operations. He also notes the growing presence of China’s hydrographic and surveillance ships and underwater drones in the Indian Ocean, which he suggests may be mapping underwater features and passageways for future submarine operations there.

He argues that China’s increasing footprint in the Indian Ocean poses a challenge to India’s sphere of influence in the region and a security risk in India’s Exclusive Economic Zone (EEZ), as these deployments could spy on Indian naval facilities and vessels in the Bay of Bengal and the Arabian Sea.

Pakistan is also significantly modernizing its submarine fleet to help offset its military asymmetry with India. In an August 2021 article for the Center for International Strategic Studies, Samran Ali notes that historically the Pakistani Navy has operated smaller numbers of ships, submarines and aircraft vis-a-vis the Indian Navy, with the latter having more resources, assets and ambitions of controlling the Indian Ocean.

Ali notes that this disparity requires Pakistan to implement an anti-access/area denial (A2/AD) strategy to restrict the Indian Navy from operating close to Pakistan’s coastline and away from its important trade routes in the Indian Ocean and Arabian Sea.

In line with this strategy, Pakistan ordered eight Hangor-class conventional submarines from China, the export variant of China’s  039A/041 Yuan-class AIP submarines equipped with Stirling engines, Naval News reported in December.

The report notes that four of the submarines are currently under construction at China’s Wuchang Shipbuilding Industry Group (WSIG) and that work on the first of four submarines built in Pakistan by Karachi Shipyard & Engineering Works (KS&EW) began in December 2022, with the first four to be delivered in 2022-2023 and the final four in 2028.

Meanwhile, a stop-gap refit is underway on India’s four aging Russian-made Kilo-class submarines, which now face several issues due to Western-led sanctions on Russia.

This January, the Times of India (TOI) reported that one of India’s Kilo-class submarines sent for refit in Russia is stuck due to problems returning it to India.

“The submarine should have ideally come directly back from Russia. But because of the ongoing Russia-Ukraine war, there are transportation and other problems. So, the plan now is to sail it to a Norwegian port and then carry it on a sea-lift vessel to Mumbai,” said an unnamed source quoted by TOI.

Indian Prime Minister Narendra Modi shakes hands with Russian President Vladimir Putin during a meeting on the sidelines of the 11th BRICS Summit in Brasilia, Brazil, on November 13, 2019. India relies on Russia for much of its weaponry. Photo: Sputnik / Mikhail Metzel

Asia Times has reported on India’s push to reduce its reliance on Russian military equipment. Concerns about the effectiveness of Russian weapons due to heavy losses in Ukraine, the possibility that weapons orders may be redirected or delayed to replace battle losses, and sanctions on Russia’s arms industry are all factoring into India’s rethink about Russia’s viability as its primary weapons provider.

At the same time, India’s concern about being reduced to a US subordinate has prevented it from going all-in on the Quad Alliance, of which France is not a member. Similarly, France’s push for strategic autonomy reflects ex-leader Charles De Gaulle’s vision of creating a European community that is not subordinate to the US, with France playing a leadership role.

India and France are thus well-suited to reinforcing each other’s strategic autonomy through defense cooperation in aerospace and naval technology, creating a security partnership independent of US influence.