Kockums submarine engines

In the mid-1980s Kockums installed Stirling engines and a LOX (Liquid Oxygen) system from AGA Cryo aboard the French 500 ton civilian research submarine Saga which has an operating depth of 600 meters and is fitted with a diving system for work at depths as deep as 450 meters.


In the late 1980s Kockums fitted a Stirling engine in the Royal Swedish Navy submarine Näcken. The submarine was put into drydock and cut in two. A fully outfitted eight meter section was the inserted.

SSK Gotland Class (type A19) Stirling powered submarines

The Stirling Air Independent Propulsion (AIP) is now installed in three, Swedish Navy, Gotland Class submarines to satisfy the energy needs for prolonged underwater missions. These submarines, HMS Gotland, HMS Uppland HMS Halland, were launched by Kockums in 1995.

HMS Uppland

HMS Gotland

sub engine sun engine

Kockums V4-275R Stirling Air Independant Propulsion Unit (AIP) one of two fitted in each vessel.

sub engine  sub engine   sub engine

The main feature of Kockum´s Air Independent Propulsion (AIP) System is the use of Stirling engines burning pure oxygen and diesel fuel in a pressurized combustion chamber. The combustion pressure is higher that the surrounding sea water pressure, thereby allowing the exhaust products, dissolved in seawater, to be discharged overboard without using a compressor. Oxygen is stored in liquid form (LOX) in cryogenic tanks.