Project 75 India Diesel-electric Submarine Programs (SSK) : Updates and Discussions
- Thread starter Himanshu
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TKMS will have to upscale the present AIP. So that's the issue.
Scaling shouldn't be much of a problem if they're offering FC AIP which is already operational on Type 214s sold to Greece, Turkey, etc. TKMS is apparently also pitching LIB which is supposed to go on their latest Type 212C/D for Germany and Italy. That one needs testing at sea.
"Proven AIP" was euphesm for Non-DRDO AIP.
The procurement issue is that if we take 15 years to procure a system, it is already out of date by the time it enters service another 10 years later. Arguably DRDO AIP could be inducted, proven and possibly even better than Spanish BEST but decisions are taken 25 years ago.
There will be a conflict between the Indian Navy and the Ministry of Defence. The former will want the TKMS bid, while the latter will want the Navantia bid. Or the other way round 
.
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More delays for Project 75I: AIP Dilemma – Stuck Between Germany and Spain
India’s ambitious Project 75I, aimed at enhancing its submarine fleet, continues to face significant delays. The primary hurdle is the selection of the right Air Independent Propulsion (AIP) system, with the Indian Navy yet to decide between two key contenders: Germany’s ThyssenKrupp Marine Systems (TKMS) and Spain’s Navantia. This decision has become complicated by technical evaluations, cost considerations, and the growing urgency to modernize India’s underwater capabilities.
Update:
According to sources in the defence and security establishment, the outcomes of the trials carried out earlier this year are being reviewed again. “This means that the Project-75I will get delayed further,” they added.
The Role of AIP in Submarine Warfare
Submarine warfare is a crucial element of modern naval defence, providing nations with the ability to conduct covert operations and deliver precise strikes both on land and underwater. AIP technology is central to modernizing conventional submarines, as it allows them to stay submerged for extended periods without the need to surface or use a snorkel. For India, the integration of AIP into six new submarines under Project 75I is crucial not just for operational range but also for improving stealth and survivability.However, selecting the right AIP system is not just about performance specifications. Milind Kulshreshtha, an Indian Navy veteran and expert in defence technologies, explains that choosing an AIP system involves more than just theoretical comparisons. “Submarine warfare is the most potent arm any country can field today, with lethal land and undersea attack capabilities. An AIP system must be evaluated based on its at-sea performance and engineering reliability—key factors like MTBF (Mean Time Between Failures) and other operational parameters that emerge only through real-world testing,” he notes.
He further clarifies, “An AIP system that has undergone real-world testing offers valuable data for comparison. The Spanish system, for instance, uses bioethanol technology, while the German system has been tested in smaller boats but has not yet been applied to the larger, more complex submarines that India requires.” Kulshreshtha, with an expertise in technologies related to C4I solutionshighlights that the decision ultimately comes down to engineering and real-world performance, rather than just theoretical specifications.
Germany’s TKMS Offering: Proven, But Not Ideal
Germany’s TKMS offers the Type 214 submarine, which features an AIP system already proven in smaller vessels like the Type 212 submarines in the German Navy. While the German AIP is reliable, it is designed for smaller submarines, and adapting it to the larger submarines required by the Indian Navy presents significant challenges. The system has not been tested on the scale of the submarines India plans to build under Project 75I.The Indian Navy veteran explains, “The German system has a solid track record in smaller submarines, but India’s requirements for larger submarines with greater endurance and stealth capabilities demand a more powerful AIP system.” This discrepancy raises concerns within the Indian Navy about whether the German technology, despite its proven success, can be scaled appropriately for larger vessels.
Spain’s Navantia Offering: Advanced, But Delayed
Spain’s Navantia, on the other hand, offers the S-80-class submarine, which integrates an advanced bioethanol-based AIP system. The bioethanol-based technology has been tested extensively and selected for the Spanish Navy. The key advantage of this technology is its environmental benefits and the availability of bioethanol as a refueling option worldwide.However, the timeline for operational readiness is a significant issue. The S-80-class submarines, equipped with this AIP technology, are not expected to enter service until 2026. For the Indian Navy, which is keen to expand its submarine fleet quickly in light of growing security challenges, this delay could be a critical factor.
As Kulshreshtha observes, “The Spanish AIP is technologically advanced, but the delay in its availability means India will have to wait several years to deploy this system, which might not meet the urgent needs of the Navy.” While the Spanish AIP offers great potential, its readiness timeline creates a gap that could undermine the Indian Navy’s strategy for immediate fleet expansion.
Cost Considerations and Strategic Implications
The cost of the two options also plays a major role in the decision. Germany’s TKMS would require designing a completely new submarine to meet India’s specifications, which would come with a higher price tag. This includes adapting its smaller AIP system to meet the demands of larger vessels, which would increase the overall cost of the project.In contrast, Navantia’s offering involves the already developed S-80-class submarine, which could potentially reduce costs and shorten the integration timeline. However, the delay in the operational readiness of the Spanish AIP system could offset some of these savings.
Kulshreshtha notes, “The Indian Navy must weigh both short-term and long-term factors when deciding between these two options. While the cost of the German solution may be higher due to the need for new designs and integration, the Spanish solution might save costs initially but comes with the risk of delays.”
The Strategic Decision: More Than Just a Procurement Choice
The decision between TKMS and Navantia is not just a matter of selecting the best AIP technology; it carries broader strategic implications. A choice in favor of TKMS could create closer defence ties between India and Germany, fostering deeper technological collaboration. On the other hand, selecting Navantia would expand India’s defence relationships within Europe, particularly with Spain.Kulshreshtha argues that, while diversifying partnerships is important, the primary concern should be the operational readiness of the submarine fleet. “India’s decision will reflect its strategic priorities, and the Navy’s main focus should remain on selecting a system that best meets its immediate operational needs,” he explains.
A Well-Informed Decision Ahead
India’s decision on which AIP system to adopt for Project 75I remains crucial not just for the future of its submarine fleet but for its broader defence strategy. The German and Spanish options both offer distinct advantages, but each comes with its own set of challenges. While the German AIP system is proven in smaller submarines, it may not scale well for India’s needs. The Spanish bioethanol-based system offers promising technology but will not be ready for service until 2026, potentially delaying India’s fleet modernization.Ultimately, the Indian Navy will need to consider both the immediate operational requirements and the long-term sustainability of its submarine fleet. With the technical expertise within the Navy the final decision will likely be well considered, factoring in both the short-term and long-term needs of India’s naval defence.
For issues as complicated as submarines, you should ask the Australians for advice, as they are very good at dealing with disasters.
Scaling requires a new design. And even the German sub itself is a new design.
LiB is supposed to be Indian, I guess the same stuff is meant for all our other subs.
There will be a conflict between the Indian Navy and the Ministry of Defence. The former will want the TKMS bid, while the latter will want the Navantia bid. Or the other way round
The IN would prefer T1 over L1, but they are a lot more pragmatic about these things.
Indian Navy will get next generation submarine
Submarines will be built under Project 76
Mazagon Dock-DRDO will jointly develop design and prototype
More
MAZDOCKSources Says Indian Navy will get next generation submarine
Submarines will be built under Project 76
Mazagon Dock-DRDO Will jointly develop design and prototype
Total cost of the project is likely to be ₹35,000-40,000 crore - Zee business
Submarines will be built under Project 76
Mazagon Dock-DRDO will jointly develop design and prototype
More
MAZDOCKSources Says Indian Navy will get next generation submarine
Submarines will be built under Project 76
Mazagon Dock-DRDO Will jointly develop design and prototype
Total cost of the project is likely to be ₹35,000-40,000 crore - Zee business
Hope L&T doesn't lose out. They're the only pvt sector yard with extensive hull fabrication and integration capability, courtesy the ATV prog. They've even developed the SOV-400 midget sub that apparently hasn't found favor with the IN. They should ideally be involved from the design stage itself and not as a subcontractor.
Deal signed for integration of EHWT on Scorpene subs.
Another deal with MDL for AIP plug construction.
MoD inks Rs 1,990 crore contract with MDL for construction of Air Independent Propulsion Plug for DRDO-AIP system & its integration to enhance endurance of conventional submarines
Rs 877 crore contract signed with Naval Group, France for integration of Electronic Heavy Weight Torpedo to augment fire power capabilities of Kalvari-Class submarines
Another deal with MDL for AIP plug construction.
MoD inks Rs 1,990 crore contract with MDL for construction of Air Independent Propulsion Plug for DRDO-AIP system & its integration to enhance endurance of conventional submarines
Rs 877 crore contract signed with Naval Group, France for integration of Electronic Heavy Weight Torpedo to augment fire power capabilities of Kalvari-Class submarines
MoD inks Rs 1,990 crore contract with MDL for construction of Air Independent Propulsion Plug for DRDO-AIP system & its integration to enhance endurance of conventional submarines
Ministry of Defence has signed two contracts, worth approx. Rs 2,867 crore, for the construction of
www.pib.gov.in
As long as MDL and L&T get two separate projects, it's fine.
Deal signed for integration of EHWT on Scorpene subs.
Another deal with MDL for AIP plug construction.
MoD inks Rs 1,990 crore contract with MDL for construction of Air Independent Propulsion Plug for DRDO-AIP system & its integration to enhance endurance of conventional submarines
Rs 877 crore contract signed with Naval Group, France for integration of Electronic Heavy Weight Torpedo to augment fire power capabilities of Kalvari-Class submarines
MoD inks Rs 1,990 crore contract with MDL for construction of Air Independent Propulsion Plug for DRDO-AIP system & its integration to enhance endurance of conventional submarines
Ministry of Defence has signed two contracts, worth approx. Rs 2,867 crore, for the construction ofwww.pib.gov.in
Should have been resolved years ago.
No point waiting for the Leonardo Blackshark any longer imo. Just order the latest French F-21 version and be done with the old tender. It'll probably be the easiest to integrate with the SUBTICS combat management system on the Kalvari class. In any case, EHWT and the under-dev Jalastra torpedo will soon end our dependence on foreign suppliers in future.
If we are paying to integrate EHWT, i assume that it's close to being ready.
And as long as EHWT is better than SUT and our Soviet era torpedos, i say no need for F21 too.
EHWT in the interim and thereafter future developments.
I'd be surprised if the IN chose EHWT as the primary torpedo for Kalvari over Blackshark, etc. IIRC, they now want a smaller number of torpedoes as stop-gap until indigenous ones mature.
In any case, they will most likely still order the latest German DM2A4 variant as part of P-75I even if EHWT was proven effective. Just as they bought Mk-54 LWT for the MH-60R fleet, even when the ALWT has finished development.
Americans aren't flexible with weapons integration. That's an issue.
Anyways I don't see P75I getting signed anytime soon.