''Sea Fighter'' (FSF-1) is an experimental littoral combat ship in service with the

United States Navy The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 millio ...

. Its hull is of a small-waterplane-area twin-hull (SWATH) design, provides exceptional stability, even on rough seas. The ship can operate in both

blue Blue is one of the three primary colours in the RYB color model, RYB colour model (traditional colour theory), as well as in the RGB color model, RGB (additive) colour model. It lies between Violet (color), violet and cyan on the optical spe ...

and

littoral The littoral zone, also called litoral or nearshore, is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely i ...

waters. For power, it can use either its dual gas-turbine engines for speed or its dual diesel engines for efficient cruising. It can be easily reconfigured through the use of interchangeable mission modules.

Helicopter A helicopter is a type of rotorcraft in which Lift (force), lift and thrust are supplied by horizontally spinning Helicopter rotor, rotors. This allows the helicopter to VTOL, take off and land vertically, to hover (helicopter), hover, and ...

s can land and launch on its deck. Smaller water craft can be carried and launched from its stern. The vessel is being developed under the program title Littoral Surface Craft-Experimental (LSC(X)) with a hull type designation Fast Sea Frame. The first vessel has been assigned the

hull classification symbol The United States Navy, United States Coast Guard, and United States National Oceanic and Atmospheric Administration (NOAA) use a hull classification symbol (sometimes called hull code or hull number) to identify their ships by type and by ind ...

FSF 1 and also has been referred to as the X-Craft. The vessel was designed by British company BMT Nigel Gee who continue with a role in the development of the vessel.

Description

''Sea Fighter''s hull is a small-waterplane-area twin hull (SWATH) design, constructed out of

aluminum Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...

. With twin gas turbine engines, quad water jets, and streamlined hulls, ''Sea Fighter'' is capable of speeds of and greater. It is designed to be a sea frame that can carry interchangeable mission modules resembling shipping containers. These modules allow it to be easily reconfigured to meet a variety of mission requirements, including mine warfare,

anti-submarine An anti-submarine weapon (ASW) is any one of a number of devices that are intended to act against a submarine and its crew, to destroy (sink) the vessel or reduce its capability as a weapon of war. In its simplest sense, an anti-submarine weapon ...

operations,

amphibious assault Amphibious warfare is a type of offensive military operation that today uses naval ships to project ground and air power onto a hostile or potentially hostile shore at a designated landing beach. Through history the operations were conducte ...

support, surface warfare, transport and logistical missions, cruise-missile launch, and special-forces interdiction operations. The mission modules are easily loaded and stored on ''Sea Fighters inner deck. The vessel has the capability of launching small craft up to in length from the stern, including assault craft and

submersible A submersible is an underwater vehicle which needs to be transported and supported by a larger ship, watercraft or dock, platform. This distinguishes submersibles from submarines, which are self-supporting and capable of prolonged independent ope ...

s by means of a custom dual-purpose ramp that also enables RORO operations for

HMMWV The High Mobility Multipurpose Wheeled Vehicle (HMMWV; colloquial: Humvee) is a family of Military light utility vehicle, light, four-wheel drive Military vehicle#Military trucks, military trucks and utility vehicles produced by AM General. It ...

and other vehicles. The vessel also has a twin-pad

helicopter A helicopter is a type of rotorcraft in which Lift (force), lift and thrust are supplied by horizontally spinning Helicopter rotor, rotors. This allows the helicopter to VTOL, take off and land vertically, to hover (helicopter), hover, and ...

deck capable of operating aircraft up to the size of an H-60 type, including

unmanned aerial vehicle An unmanned aerial vehicle (UAV) or unmanned aircraft system (UAS), commonly known as a drone, is an aircraft with no human pilot, crew, or passengers onboard, but rather is controlled remotely or is autonomous.De Gruyter Handbook of Dron ...

s, and landing helicopters while travelling at speeds of up to . A special deck-lighting system has been developed for ''Sea Fighter'' using low-intensity green lighting around the vessel's edges and helipads. This lighting is particularly effective when using night-vision goggles, making landings on the vessel easier than on conventional warships, even at the higher speeds in which ''Sea Fighter'' operates. The basic design has a displacement of 1,100 tons while measuring long at waterline and broad. Power is provided by a CODOG arrangement comprising two MTU 595

diesel engine The diesel engine, named after the German engineer Rudolf Diesel, is an internal combustion engine in which Combustion, ignition of diesel fuel is caused by the elevated temperature of the air in the cylinder due to Mechanics, mechanical Compr ...

s and two LM2500

gas turbine A gas turbine or gas turbine engine is a type of Internal combustion engine#Continuous combustion, continuous flow internal combustion engine. The main parts common to all gas turbine engines form the power-producing part (known as the gas gene ...

s. Diesel power is used for cruising while the turbines provide high-power output for high-speed operation. The two gas turbines power the vessel's four water jets, drawing water from the bottom stern of each hull and powering it through large water turbines, which are responsible for the vessel's high operating speed. Each water jet has thrust vectoring and thrust reversers making it possible to move sideways while docking, or even travelling in astern. Thrust vectoring also makes it possible for ''Sea Fighter'' to make evasive maneuvers while travelling at high speed. This would prevent the craft from being forced to shore or into the path of enemy vessels. ''Sea Fighter''s forward

superstructure A superstructure is an upward extension of an existing structure above a baseline. This term is applied to various kinds of physical structures such as buildings, bridges, or ships. Aboard ships and large boats On water craft, the superstruct ...

consists of a bridge on the lower deck, and a flight operations station on top. The bridge is relatively small, and generally manned by a crew of three. The bridge control stations incorporate glass displays using the modern navigational aids to assist ''Sea Fighter'' in patrolling coastal areas while operating at high speed. Above the bridge is a small flight-operations station with room for only one operator. This glass-enclosed station provides an unobstructed view of the entire flight deck and allows the operator to coordinate the approach and landing of helicopters, and loading of the vessel's mission containers, as well as providing visual aid for navigation. The ship has a computer system to control its systems and for navigation. Steering and throttle control are done by

wire file:Sample cross-section of high tension power (pylon) line.jpg, Overhead power cabling. The conductor consists of seven strands of steel (centre, high tensile strength), surrounded by four outer layers of aluminium (high conductivity). Sample d ...

rather than mechanical linkage. The first vessel of the type (FSF 1) was constructed at the Nichols Bros. Boat Builders shipyard at Freeland, Washington, under contract to Titan Corporation, a subsidiary of

L-3 Communications L3 Technologies, formerly L-3 Communications Holdings, was an American company that supplied command and control, communications, intelligence, surveillance and reconnaissance ( C3ISR) systems and products, avionics, ocean products, training ...

. Nichols Shipyard was selected because of their previous experience in the construction of aluminium-hulled high-speed ferries.

Role

''Sea Fighter'' is destined for employment by the

Office of Naval Research The Office of Naval Research (ONR) is an organization within the United States Department of the Navy responsible for the science and technology programs of the U.S. Navy and Marine Corps. Established by Congress in 1946, its mission is to plan ...

as a testbed for technologies related to the Navy's littoral combat ship effort, as well as direct testing of the hull design. Once trials are completed, the Navy will have the option of outfitting the vessel for operational deployment.

Future development

The Navy and Coast Guard are jointly exploring the possibility of further development of ''Sea Fighter''–type vessels for use in patrolling U.S. coastal waters. With an effective range of unrefueled, the type could also be deployed quickly overseas. ''Sea Fighter'' is expected to pave the way for a future line of fast, long-range destroyers capable of travelling fast enough to avoid or outmaneuver most of the current generation of torpedoes. Such vessels would be capable of crossing the

Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

unrefueled, and have a very low radar signature, making detection difficult. They would be able to respond quickly to targets located by air or satellite and aggressively attack surface and submerged vessels using their speed to evade torpedo and missile attack.

Concerns

Some concern has been raised with regard to the use of

aluminium alloys An aluminium alloy (British English, UK/International Union of Pure and Applied Chemistry, IUPAC) or aluminum alloy (North American English, NA; see American and British English spelling differences, spelling differences) is an alloy in which al ...

almost exclusively in the construction of ''Sea Fighters hull, as well as future vessels based on the design. While aluminum alloys have a high

specific strength The specific strength is a material's (or muscle's) strength (force per unit area at failure) divided by its density. It is also known as the strength-to-weight ratio or strength/weight ratio or strength-to-mass ratio. In fiber or textile applic ...

, they melt at a lower temperature than steel. Some lay concern has been expressed about aluminum hulls actually burning, but only aluminum dust or powder is considered flammable.. Additionally

galvanic corrosion Galvanic corrosion (also called bimetallic corrosion or dissimilar metal corrosion) is an electrochemical process in which one metal corrodes preferentially when it is in electrical contact with another, different metal, when both in the prese ...

may result between the aluminum hull and steel fittings, as happened to the littoral combat ship USS ''Independence''.

References

External links