Supreme Power and Propulsion
An elusive goal ever since the first submarines were built is the ability to remain submerged for extended periods of time. This has now been realized with the development of the Stirling Air-Independent Propulsion (AIP) system by Kockums. Essentially, this is an engine that coverts heat into mechanical work that extends submerged endurance of non-nuclear submarines from a few days to several weeks through eliminating the need to surface and recharge batteries every few days.
Kockums Stirling engine
In addition to increasing a submarine’s mission range, a Kockums Stirling technology enhances a vessel’s stealth properties to offer:
- High efficiency/low heat transfer to sea water
- Small low-weight engine with low noise level
- Low magnetic and infrared signature
- Little maintenance
- No extra crew
A mature proven technology
In a Kockums Stirling engine, the heat is generated by burning diesel fuel with liquid oxygen (LOX) in a pressurized combustion chamber. The mechanical output from the engine is converted to AC electrical energy, which is then rectified to DC current for use in the submarine.
As the combustion pressure is higher than the surrounding seawater pressure, the exhaust products, dissolved in seawater, can be discharged overboard without using a compressor. The Stirling AIP system is an add-on system: when the LOX supply is exhausted, the submarine remains a powerful conventional submarine.
That the Kockums Stirling AIP system is mature technology has been continually proven in operational service. In 1988, the AIP system was first installed in a Swedish Royal navy submarine and ran successfully from the very beginning. Today, it is a standard feature of Gotland submarines, the only AIP submarine class operational worldwide. Moreover, any submarine can be converted by Kockums to include an AIP system.
Further information regarding Kockums Stirling AIP system can be found at:
Page updated Monday, November 23, 2009.
