Stealth ship
Under a stealth ship (English stealth ship) means a ship, is tried in which, with the help of stealth technology to make it a difficult location or prevent. Both the detection by radar and other sensors, is meant, such as infrared sensors.
History of stealth ships
As early as World War I tried to British and American warships, German submarines by camouflage, also known as camouflage to deceive. Thus, the U- boats in the size, direction of travel and the speed should be deceived. Also in the struggle among surface ships was this technique, together with deceptive constructions dummies are used.
When, towards the end of the 1930s the first working radar systems were developed and built, new questions were raised for the camouflage of ships. It was now possible to locate ships over long distances. Later missiles were added, which are controlled by radar, infrared detectors and magnetic recording systems. Even countries without their own warships, it was now possible to sink warships.
Therefore, it was necessary to construct vessels that are difficult to detect for the radar and other sensors can be deceiving. Experiences from the aerospace industry have confirmed the techniques related to design and radar-absorbing coatings. In the German U- boat construction of the Second World War snorkel were used, for example, to the less frequently drive surfaced and thus reveal less the Allied radar need. With improvement of the radar, which enabled the localization of the snorkel, has also worked on camouflage for the snorkel itself, including by radar-absorbing coatings. A ungetarnter snorkel reduced the echo effect to around 20% of a U- boat and lowered the detection range to around 25% of a U- boat. With development of blended snorkel the residual reflection could be reduced to about 10 % and the detection range can be reduced by up to a further 65%.
In addition to the attenuation of the intrinsic noise, measures used, which should not hinder the detection by the enemy ASDIC ( precursor of the sonar ) came. Thus damps Opanin cover, an approximately 4 mm thick rubber coating, the sound reflection in the frequency band 10 to 18 kHz up to 15%. The effect of the preservative is highly dependent on salinity, air content and temperature of the water. This technique was first applied in 1943 when the German U 480, which is considered the first stealth submarine in the world.
Broad camouflage
A main feature of the camouflage is to minimize radar cross-sectional area, i.e., minimizing the radar signature. It should minimize the radar radiation to be reflected back to the transmitter, which is accomplished by avoiding right angles to the deck of the ship. The ship encountered radar beams are thus radiated in other directions. Even cylindrical forms are to be avoided because they reflect incident radar beam from any direction directly. In many stealth ships there will therefore be no conventional round structures ( masts, chimneys, etc.). In addition radar absorbent coatings and construction materials are in use.
To reduce the thermal signature is tried on many ships to minimize the emitted infrared radiation. There are, for example, the exhaust gases cooled or discharged into the water, further special infrared absorbing coatings. In order to reduce the magnetic signature of a ship, the active measure is used magnetic self-protection (MES ). In submarines non- magnetizable submarine steel is used as a passive measure also.
By silent drive systems, the noise signature is minimized. In addition, an attempt is made to minimize the noise caused by the propellers, and the resulting bubbles ( cavitation ), for example using techniques such as the Great Plains Masker System. In the U- boat construction also quiet drive techniques such as the Air Independent Propulsion be used to fuel the German - Italian submarine class 212 A.
To minimize the wake of the vessel, the surface of the vessel, which cuts through the water at the surface is kept as small as possible. This is achieved by a separation of the hull in a permanent water and a permanently submerged part. Both parts are connected only by narrow walkways that. Than single cut through the water surface ( SWATH hull )
Also, optical camouflage as camouflage or misting options continue to play a role.
List of stealth ships and ship classes
The following list contains the ships that are like stealth aircraft completely coated with radarabsorbierendem material and also in shape, possess certain radar -absorbing properties:
- Sea Shadow (US- American)
- La Fayette - class (French)
- Visby - class ( Swedish)
- Skjold - class (Norwegian)
- Daring Class ( British), destroyer
- Independence -Class ( US-American )
- Freedom -Class ( US-American )
- Sea Fighter ( U.S. American)
- Ada-/F-100-Klasse ( Turkish )
- Stereguschtschi class ( Russian)
Future projects:
- Seawraith ( British)
- Future Surface Combatant ( British)
- Zumwalt - class (US- American)
In hinau strive most modern warship types, at least by the shape of a reduction in the radar cross section and thus certain stealth characteristics. In the German Navy corvette K130 and F124 in the so-called X shape were designed, for example, doing all the side surfaces of the hull and superstructure are inclined towards each other, to distract largely incident radar beams in other directions.