Speculation abounds that the Indian Navy could cancel Project-75 I for submarine production and instead acquire more Scorpene (Kalvari class) submarines — the fifth submarine from this class, INS Vagir, was commissioned into the Navy on January 23. A media report last week claimed that the IN, faced with a single vendor option in Project-75I—with a South Korean company the only bidder in the fray with a proven fuel cell air-independent propulsion (AIP) system — may place a repeat order for Scorpene-class submarines to be built at Mazagon Dock Limited. According to the report, the Navy plans on installing the Defence Research and Development Organisation’s still-to-be-developed AIP on the new submarines, impelled in no small measure by the PLA Navy’s advance in the Indian Ocean.
There are many things wrong with the report. First, it is based almost entirely on conjecture, seemingly intended to dub Project 75I as impractical and “unviable.” There are no indications that the Navy considers the P-75I to be unfeasible. In December 2022, when the Navy Chief, Admiral Hari Kumar, mentioned that the follow-on project for submarines would be cleared by 2023, there were no signs of the Navy’s lack of confidence in P-75I. While the Navy has had issues, with many design collaborators withdrawing their tenders for various reasons (design overreach to unrealistic delivery schedules, impractical liability clauses, and rigid technology transfer requirements), there has never been a sense of doom about the project. In fact, German shipbuilder TKMS, which had earlier withdrawn its bid, has even indicated its willingness to remain in the fray, provided the Indian Navy tempers its expectations.
The need for wait and watch
The most difficult of the IN’s conditions for foreign collaborators is the requirement that the AIP be a proven system. As stated earlier, except for the South Korean firm Daewoo, no vendor that bid for the P-75I has a proven AIP system. Ironically, the DRDO’s AIP is itself unproven. Back in March 2021, the DRDO tested a land-based prototype of the AIP but has reportedly made little progress since. The expectation that the DRDO’s AIP will be installed on the first Kalvari-class submarine when it comes in for refit in 2024 is unrealistic given that it has yet to be tried in field conditions. The Navy is reportedly in the process of designating a Kilo-class submarine as a “test bed” for the indigenous AIP, but the process of installation and testing at sea is likely to be protracted.
This is not to suggest that the DRDO AIP is unsuitable for installation in Kalvari-class submarines; it could well prove its worth in years to come. Even so, the Navy would be ill-advised to base a decision on future submarines on the presumption of the DRDO AIP’s success. If experience is any guide, DRDO’s high claims about technology development ought to be taken with a grain of salt. In particular, the claim that the DRDO AIP prototype underwent 14 days of endurance testing ought to be informed by the reality that the tests were held in simulated underwater conditions. In the circumstances, a wait-and-watch approach is the best way forward for the Navy.
Second, the contention that the cancellation of the P-75I and a repeat order of Project-75 submarines would further ‘Aatmanirbhar Bharat’ is inaccurate. The Navy’s leadership has in the past acknowledged that the Naval Group, the French company that built the Scorpene-class submarines, transferred insufficient technology during Project 75. While MDL has developed valuable submarine-building expertise—which supporters of a P-75 repeat order rightly argue must be leveraged in future projects—the skills obtained ought to be used in a homegrown project such as the P-75I, where foreign collaborators would be contractually bound to transfer technology in ways that would enable Indian shipbuilders to construct future submarines without external help. A repeat of the Scorpene-class submarines at the altar of the P-75I would mean the abandonment of the strategic partnership model. That is bound to adversely impact the IN’s indigenisation initiative. It would also be a blow to the confidence of private shipbuilders, who have invested considerable fiscal and human capital in developing capabilities to build warships and submarines in the hope of contributing to the creation of a defence industrial base.
The issue of battery technology
Third, the claim that lithium-ion batteries are better than AIP—as media reports last week suggested—is flawed. Lithium batteries, while offering better efficiency, power, and charge and discharge dynamics, are unstable and suffer from thermal runaway, fire, and explosion risks. Regardless of the use of lithium batteries in Japan’s new submarines, lithium-ion fuel cell technology has still not reached a stage of maturation for the Indian Navy to consider it reliable.
There is also the larger question of whether the DRDO’s phosphoric acid fuel cell-based AIP is suitable for Indian submarines. The issue is not as clear-cut as many imagine. PAFC technology is certainly more rugged than other fuel cell types and does offer longer life and efficiency. But PAFC is expensive, complex, and difficult to maintain. Its platinum-coated electrodes experience rapid dissolution, and carbon monoxide produced during the chemical process is known to reduce the overall performance of the system. For that reason, PAFCs are not used for submarine propulsion by any navy in the world. The system’s success has so far only been demonstrated in stationary power-generation systems. The only fuel cell technology known to work is the proton exchange membrane (PEM) used in German and South Korean submarines.
This isn’t to cast aspersions on India’s defence scientists and their efforts to find a solution to the AIP problem in conventional submarines. Their efforts are indeed laudable. The aim of this account is only to point out that speculation in the media that Project 75I is ill-suited for the Navy is tendentious misinformation aimed ostensibly to influence the defence decision-making process. There are no signs yet that the Navy is about to — or indeed should — abandon the P-75I.
Abhijit Singh is Head of the Maritime Policy Initiative at the Observer Research Foundation, and a former naval officer