Relevance: Mains: G.S paper III: Defence and security
Why in news?
- It has been witnessing operation of land-based prototype of DRDO India Air Independent Propulsion system at Naval Materials Research Laboratory in Ambernath.
- The DRDO on Wednesday tested a land-based prototype of an Air Independent Propulsion (AIP) submarine.
- The prototype operation at the Naval Materials Research Laboratory in Ambernath, Maharashtra, is considered to give a boost to the DRDO’s plan to build AIP systems for Indian naval submarines.
- The land-based prototype was engineered to the form-and-fit of a submarine.
News in detail:
- Air-independent propulsion (AIP) is any marine propulsion technology that allows a non-nuclear submarine to operate without access to atmospheric oxygen (by surfacing or using a snorkel).
- AIP can augment or replace the diesel-electric propulsion system of non-nuclear vessels.
Air Independent Propulsion (AIP) technology used in submarines:
- Submarines are essentially of two types: conventional and nuclear.
- Conventional submarines use a diesel-electric engine, and must surface daily for oxygen for fuel combustion. If fitted with an Air Independent Propulsion (AIP) system, the sub needs to take in oxygen only once a week.
- Many naval powers, including India, have acquired nuclear-powered submarines for deep-sea operations, conventional diesel-electric variants are considered useful for coastal defence.
- The latter are optimised for stealth, and their weapons and sensors provide for effective operations close to the shore.
- Because diesel-electric submarines require to come to the surface frequently to charge their batteries, their underwater endurance time is less.
• ‘Air-independent’ propulsion technology helps to make the diesel generator less dependent on surface air. - In a fuel cell AIP, an electrolytic fuel cell releases energy by combining hydrogen and oxygen, with only water as the waste product.
- The cells are highly efficient, and do not have moving parts, thus ensuring that the submarine has a low acoustic signature.
- Older submarines can be adapted to the AIP system by retrofitting.
- A fuel cell-based AIP, like the one developed by DRDO, is known to deliver better performance compared to other technologies.
- According to the Defence Ministry press release, the AIP system enhances the submerged endurance of diesel-electric submarines several times, thus having a multiplier effect on its lethality.