The
Swedish
Swedish or ' may refer to:
Anything from or related to Sweden, a country in Northern Europe. Or, specifically:
* Swedish language, a North Germanic language spoken primarily in Sweden and Finland
** Swedish alphabet, the official alphabet used by ...
''Södermanland'' class of
diesel-electric submarines consists of and . These two submarines were originally launched as s in 1987 and 1990, and have been relaunched as a new class after extensive modernization in 2003 and 2004 by
Kockums AB
Saab Kockums AB is a shipyard headquartered in Malmö, Sweden, owned by the Swedish defence company Saab Group. Saab Kockums AB is further operational in Muskö, Docksta, and Karlskrona. While having a history of civil vessel construction, ...
. The
pressure hull
A submarine hull has two major components, the ''light hull'' and the ''pressure hull''. The light hull (''casing'' in British usage) of a submarine is the outer non-watertight hull which provides a hydrodynamically efficient shape. The pressure ...
had been cut in two after the
sail and a long new section with an
air-independent propulsion system was inserted. It contains two
Stirling engine
A Stirling engine is a heat engine that is operated by the cyclic compression and expansion of air or other gas (the ''working fluid'') between different temperatures, resulting in a net conversion of heat energy to mechanical work.
More specif ...
s which are coupled to
electric generators and heated by burning
diesel fuel
Diesel fuel , also called diesel oil, is any liquid fuel specifically designed for use in a diesel engine, a type of internal combustion engine in which fuel ignition takes place without a spark as a result of compression of the inlet air and ...
with
liquid oxygen
Liquid oxygen—abbreviated LOx, LOX or Lox in the aerospace, submarine and gas industries—is the liquid form of molecular oxygen. It was used as the oxidizer in the first liquid-fueled rocket invented in 1926 by Robert H. Goddard, an app ...
stored in
cryogenic tanks. The AIP system can provide electric energy to extend the submarine's submerged time from days to weeks.
, ''Södermanland'' is planned to remain in service until at least 2024-25 when it was to be replaced by the future s. However, the ''Östergötland'' was decommissioned in 2021, and is in material reserve.
Two submarines of similar design, known as the are in service with the
Republic of Singapore Navy.
Units
References
External links
Kockums page about the Södermanland classKockums AIP Stirling system
Submarines of the Swedish Navy
Submarine classes of the Swedish Navy
Naval ships of Sweden
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