To improve its submarine capabilities, the Indian Navy must choose the finest Air Independent Propulsion (AIP) system, especially in light of regional threats and developments by nearby militaries. AIP technology greatly increases stealth and operational flexibility by enabling submarines to operate for extended periods of time underwater without coming to the surface.
uses chemical reactions between hydrogen and oxygen to produce energy. This kind is perfect for covert operations because of its low exhaust emissions and quiet functioning. South Korea’s KSS-III submarines and Germany’s Type-212 are two examples. On November 26, Spanish defense major Navantia stated that the Air Independent Propulsion System (AIP), which is based on hydrogen, has been installed into a S80 class submarine at its shipyard in Cartagena.
Siemens proton exchange membrane (PEM) fuel cells, which run on compressed hydrogen and oxygen stored outside the crew space, are used in the AIP system of Howaldtswerke-Deutsche Werft AG (HDW) Type 212 submarines. This concept addresses safety issues that have historically dogged submarine AIP technologies by minimizing the risks connected with gas storage in livable areas.
With the AIP system, Type 212 submarines can remain submerged for up to three weeks without surfacing, significantly increasing their stealth capabilities compared to conventional diesel-electric submarines that must surface or “snort” to recharge batteries. This capability allows them to conduct covert operations without revealing their position.
Silent slow cruising, made possible by the AIP, is essential for evading enemy forces’ discovery. The submarines are essentially undetectable on long voyages because they can transition from high-speed diesel propulsion to the quieter AIP mode.
Performance Details: The AIP system is made up of nine PEM fuel cells, each of which can produce 30–50 kW; upgraded models can produce up to 120 kW per module. This power keeps the acoustic signature low while enabling efficient operation.
The Navantia-built Spanish S-80 class submarines also have a cutting-edge Air Independent Propulsion (AIP) technology called BEST (Bio-Ethanol Stealth Technology). These submarines’ operational capabilities are improved by this novel technique, which lowers the chance of discovery while enabling them to stay underwater for extended periods of time.
Bioethanol, a renewable fuel made from organic feedstock, is used by the BEST AIP system to produce hydrogen. A major tactical and safety benefit of this technique is that it allows the submarine to create hydrogen on demand, doing away with the necessity for hydrogen that is kept on board.
Compared to traditional diesel-electric submarines, which usually need to surface more frequently to replenish batteries, S-80 submarines equipped with the AIP technology may stay underwater for up to three weeks.
Safety and Stealth: The submarines are safe and stealthy since they run softly thanks to a fuel cell that produces electricity. For contemporary naval operations, where evading detection is critical, this stealth capacity is essential.
employs a Stirling engine to produce power using liquid oxygen and diesel fuel. The Swedish Gotland-class submarines have successfully employed this technique, which offers significant underwater endurance.
Although they are typically less effective than fuel cell or Stirling systems, these technologies enable submarines to operate on diesel fuel while submerged without the requirement for air oxygen.
Currently, the Indian Navy has a fleet of diesel-electric submarines that aren’t equipped with AIP. Nonetheless, it is making a concerted effort to incorporate local AIP technology into its Kalvari-class submarines. It is anticipated that the fuel cell-based AIP technology created by the Defence Research and Development Organization (DRDO) will greatly increase these submarines’ operational endurance, enabling them to stay below for up to 14 days in endurance mode.
Conventional diesel-electric submarines are vulnerable to detection because they must periodically surface or snorkel. Submarines with AIPs are more survivable during missions since they can remain underwater for longer. Therefore, improved endurance is important from a strategic standpoint for India.
Maintaining a strategic balance in the region depends on India’s efforts to create its own AIP system, especially as Pakistan is purchasing sophisticated AIP-equipped submarines from China.
The successful deployment of an indigenous AIP system would not only bolster India’s maritime capabilities but also showcase its growing defence technology sector.
The best AIP system will be selected by the Indian Navy based on a number of criteria, such as cost-effectiveness, technological dependability, and operational needs. This achievement is a major step towards improving India’s underwater combat capabilities and guaranteeing maritime security in a geopolitically complex world, as the DRDO gets ready to incorporate its fuel cell-based AIP into the Kalvari-class submarines by 2024.
