The ''Flyvefisken''-class patrol vessels ("

Flying fish The Exocoetidae are a family of marine fish in the order Beloniformes class Actinopterygii, known colloquially as flying fish or flying cod. About 64 species are grouped in seven to nine genera. While they cannot fly in the same way a bird d ...

" in Danish) are warships of the

Royal Danish Navy The Royal Danish Navy ( da, Søværnet) is the sea-based branch of the Danish Defence force. The RDN is mainly responsible for maritime defence and maintaining the sovereignty of Danish territorial waters (incl. Faroe Islands and Greenland). O ...

. The class is also known as the Standard Flex 300 or SF300 class. The five vessels sold to the

Portuguese Navy The Portuguese Navy ( pt, Marinha Portuguesa, also known as ''Marinha de Guerra Portuguesa'' or as ''Armada Portuguesa'') is the naval branch of the Portuguese Armed Forces which, in cooperation and integrated with the other branches of the Port ...

are locally referred as ''Tejo'' class.

Containerised weapon systems

The ''Flyvefisken'' ships were constructed using an innovative modular design known as

StanFlex StanFlex (also known as STANFLEX or Standard Flex) is a modular mission payload system used by the Royal Danish Navy. Originally conceived during the 1980s as a way of replacing several classes of minor war vessel with a single class of multi-role ...

: they have a standard hull in which containerised weapons or systems can be placed. This allows them to rapidly change roles, typically in 48 hours. This enables the ships to be configured to perform the following roles: * Surveillance/pollution control * Combat * Mine countermeasures/minehunter (MCM) * Minelayer The containers measure . One container is situated on the foredeck; the other three go on the quarterdeck behind the superstructure and funnel. Furthermore the ships are built using the sandwich principle - a layer of

fiberglass Fiberglass ( American English) or fibreglass (Commonwealth English) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass cl ...

either side of a core of PVC cell foam. This forms the structure from keel to top of mast. This building method reduces maintenance costs - so much so that 20 years later the new ''Diana'' and ''-Holm'' class have been built using the same materials.

Replaced three different vessels

The ''Flyvefisken'' class replaced three different vessels in the Danish Navy: Six

torpedo boats A torpedo boat is a relatively small and fast naval ship designed to carry torpedoes into battle. The first designs were steam-powered craft dedicated to ramming enemy ships with explosive spar torpedoes. Later evolutions launched variants of s ...

of the ''Søløven'' class (1965–90), six

coastal minesweeper Coastal minesweeper is a term used by the United States Navy to indicate a minesweeper intended for coastal use as opposed to participating in fleet operations at sea. Because of its small size—usually less than 100 feet in length—and construct ...

s of the ''Sund'' class (1955–99) and eight seaward defence craft of the ''Daphne''-class (1961–91). It was possible because of the containerised systems and modern technology. The replaced vessels used

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

(or

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, ...

) tactics: The ''Søløven'' boats were light

plywood Plywood is a material manufactured from thin layers or "plies" of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufactured ...

boats propelled by three

turboshaft A turboshaft engine is a form of gas turbine that is optimized to produce shaftpower rather than jet thrust. In concept, turboshaft engines are very similar to turbojets, with additional turbine expansion to extract heat energy from the exhaust ...

s, which attacked the enemy ships with

torpedo A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, and with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, ...

es in

hit-and-run In traffic laws, a hit and run or a hit-and-run is the act of causing a traffic collision and not stopping afterwards. It is considered a supplemental crime in most jurisdictions. Additional obligation In many jurisdictions, there may be an ...

attacks. The ''Flyvefisken'' class is not that fast, but their Harpoon missiles are sufficient for the task. The ''Sund''-class minesweepers were built of wood,

bronze Bronze is an alloy consisting primarily of copper, commonly with about 12–12.5% tin and often with the addition of other metals (including aluminium, manganese, nickel, or zinc) and sometimes non-metals, such as phosphorus, or metalloids suc ...

and other non-magnetic materials. They swept

mine fields A land mine is an explosive device concealed under or on the ground and designed to destroy or disable enemy targets, ranging from combatants to vehicles and tanks, as they pass over or near it. Such a device is typically detonated automatic ...

by trawling through the area with paravanes on tow separating magnetic and acoustic generators for the bottom mines, and chain cutters for the horned mines. The ''Flyvefisken'' class is a

minehunter A minehunter is a naval vessel that seeks, detects, and destroys individual naval mines. Minesweepers, on the other hand, clear mined areas as a whole, without prior detection of mines. A vessel that combines both of these roles is known a ...

and locates the mines with

side-scan sonar Side-scan sonar (also sometimes called side scan sonar, sidescan sonar, side imaging sonar, side-imaging sonar and bottom classification sonar) is a category of sonar system that is used to efficiently create an image of large areas of the se ...

and neutralizes them one by one with a ROV. The ''Daphne'' class attacked

submarine A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely op ...

s by dropping

depth charge A depth charge is an anti-submarine warfare (ASW) weapon. It is intended to destroy a submarine by being dropped into the water nearby and detonating, subjecting the target to a powerful and destructive hydraulic shock. Most depth charges use h ...

s to a preselected depth, while sailing past the submarine. The ''Flyvefisken'' class fights submarines with anti-submarine homing torpedoes.

Ships in class

A total of 14 ships were built in the class, in three series: The difference between the series is mainly in the configuration of the propulsion system. Series 2 is not equipped with hydraulic propulsion, but instead has an additional auxiliary engine, and Series 3 has one further auxiliary engine.

References

External links

Danish Naval History

Naval technology on Flyvefisken class
{{DEFAULTSORT:Flyvefisken Class Patrol Vessel Patrol boat classes