Gotland HMS (1996
- Sweden)
from Wikipedia
| The Gotland class submarines of the Swedish Navy
are modern diesel-electric submarines, which were designed and built by
the Kockums shipyard in Sweden. They are the first submarines in the world
to feature a Stirling engine air-independent propulsion (AIP) system, which
extends their underwater endurance from a few days to weeks. This capability
had previously only been available with nuclear-powered submarines.
Features
As of 2008, the Gotland-class attack submarine
is one of the most modern submarines of the Swedish Navy in service, mainly
designed for submarine missions such as anti-ship/anti-submarine warfare,
collecting of intelligence (communications intelligence (COMINT), electronic
signals intelligence (ELINT)), forward surveillance, special operations
and mine-laying tasks.
On the water surface, the submarine is powered
by two sets of MTU engines. While submerged, the Kockums-built Stirling
engine Air Independent Propulsion (AIP) system is used to drive a 75 kilowatts
(101 shp) generator for either propulsion or charging the batteries. A
Stirling engine is particularly well suited for a submarine because the
engine is near silent and can use the surrounding sea water as a heat sink
to increase efficiency. Submerged endurance is dependent on the amount
of liquid oxygen stored on-board and is described as "weeks". The class
is characterized by its low acoustic signatures, extreme shock resistance
and a competent combat system.
Kockums touts extreme maneuverability for this
class due to the hull design and a well-placed X rudder. The X rudder provides
four control surfaces, along with two mounted on the sail, which enables
sharp turns and the ability to operate very close to the seabed. Ship automation
and computerized steering allow a single operator to steer the submarine
in depth and course, which also results in a smaller crew complement, leading
to good accommodation standards and low operating costs.
|
HMS Gotland
| Builder Kockums |
|
| Name: |
HMS Gotland |
| In Service: |
2 Febraury 1996 |
| Displacement: |
1494 tons surface
1599 tons submerged |
| Length: |
198 ft 2 in |
| Beam: |
20 fr 4 in |
| Propulsion: |
2 x Diesel engines
2 x Sterling AIP |
| Speed: |
11 knots surfaced
20 knots submerged |
| Compliment: |
24 to 32 |
|
The class has many features that enhance stealth,
helping it to remain undetected. All shipboard machinery are isolated and
mounted on rubber dampeners to reduce vibrations and noises; a hydrodynamic
hull design to reduce noise, infrared signature, and active sonar response;
counteracting its magnetic signature with 27 independent electromagnets;
short circuiting extremely low frequency (ELF) electrical fields; various
hull coatings to reduce active sonar response; and coating the mast with
radar absorbing material. Combined with the near silent operation of the
Stirling generator and slow turning propeller to prevent cavitation, the
boats are very difficult to detect underwater, especially in their normal
area of operations, the Baltic Sea.
Deployments
After being refit and upgraded to sustain the
higher temperatures of tropical water,[4] HMS Halland took part in a multi-national
exercise in the Mediterranean from September 16, 2000. Allegedly, there
she remained undetected while still recording many of her friendly adversaries,
attracting interest from the participating countries. In early November
the same year, she participated in a NATO "blue-water" exercise in the
Atlantic. There she reportedly won a victory in a mock "duel" with Spanish
naval units, and then the same in similar duel against a French SSN, a
nuclear-powered attack submarine. She also "defeated" an American SSN,
the USS Houston.
Secondment to United States Navy
In 2004, the Swedish government received a request
from the United States of America to lease HMS Gotland – Swedish-flagged,
commanded and manned, for a duration of one year for use in anti-submarine
warfare exercises. The Swedish government granted this request in October
2004, with both navies signing a memorandum of understanding on March 21,
2005. The lease was extended for another 12 months in 2006. In July 2007,
HMS Gotland departed San Diego for Sweden.
HMS Gotland managed to snap several pictures of
the USS Ronald Reagan during a wargaming exercise in the Pacific Ocean,
effectively "sinking" the aircraft carrier. The exercise was conducted
to evaluate the effectiveness of the US Fleet against diesel-electric submarines,
which some have noted as severely lacking.
Overhaul
In March 2013, Kockums received an order for an
overhaul for two of the Gotland-class submarines. The overhaul is expected
to be completed by 2017. With these upgrades, the submarines will be able
to remain in active duty until after 2025 alongside the new A26 submarines
(NGU).
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