Alta class minesweeper
The Alta class minesweeper is a ship class
A ship class is a group of ships of a similar design. This is distinct from a ship-type, which might reflect a similarity of tonnage or intended use. For example, the is a nuclear aircraft carrier of the Nimitz class....
A minesweeper is a small naval warship designed to counter the threat posed by naval mines. Minesweepers generally detect then neutralize mines in advance of other naval operations.-History:...
operated by the Royal Norwegian Navy
Royal Norwegian Navy
The Royal Norwegian Navy is the branch of the Norwegian Defence Force responsible for naval operations. , the RNoN consists of approximately 3,700 personnel and 70 vessels, including 5 heavy frigates, 6 submarines, 14 patrol boats, 4 minesweepers, 4 minehunters, 1 mine detection vessel, 4 support...
. An almost identical class of minehunters is known as the Oksøy class
Oksøy class mine hunter
The Oksøy-class mine hunters are a class of vessels of the Royal Norwegian Navy active since the mid-1990s.Almost identical to the , the only differences are the equipment on the aft deck and aft 1. deck, the sonars , and the length of the superstructure on 1. deck...
The Alta class was built by Kvaerner Mandal during 1996 and 1997, while the related Oksøy class was built in 1994 and 1995. A total of 9 vessels were built, 5 minesweepers and 4 minehunters. HNoMS Orkla was completely destroyed in a fire, and HNoMS Oksøy was damaged when it ran aground in 2005. The pair, along with HNoMS Glomma, are no longer in active service. The catamaran
A catamaran is a type of multihulled boat or ship consisting of two hulls, or vakas, joined by some structure, the most basic being a frame, formed of akas...
hull is built in a fibre-reinforced plastic
Fiberglass , is a fiber reinforced polymer made of a plastic matrix reinforced by fine fibers of glass. It is also known as GFK ....
sandwich of very low magnetic signature.
Two large fans located on each side create an air cushion between the two hulls and a front and aft rubber skirt, lifting the vessel, giving small drag and a high cruise speed, as well as low susceptibility to the shock of exploding mines since only a small portion of the hull is actually exposed in the water. Propulsion by water jet
Water jet has several meanings including :* Water jet cutter, a tool for cutting virtually any material* Water jet cleaning and surface preparation, a tool for cleaning and surface preparation using ultra-high pressure waterjet...
, again one in each hull, gives a low acoustic signature. A degaussing system gives the vessels extremely low electromagnetic signature.