Seaspray is series of a British airborne maritime radar systems, initially developed by

Ferranti Ferranti International PLC or simply Ferranti was a UK-based electrical engineering and equipment firm that operated for over a century, from 1885 until its bankruptcy in 1993. At its peak, Ferranti was a significant player in power grid system ...

for the

Lynx A lynx ( ; : lynx or lynxes) is any of the four wikt:extant, extant species (the Canada lynx, Iberian lynx, Eurasian lynx and the bobcat) within the medium-sized wild Felidae, cat genus ''Lynx''. The name originated in Middle Engl ...

helicopter, built in Edinburgh. It is used primarily as an air-to-surface-vessel (ASV) radar in the

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 ...

and anti- missile-boat roles. The combination of Lynx and Seaspray has been an export success and operates in numerous armed forces around the world, often along with the related

Sea Skua The Sea Skua is a British lightweight short-range air-to-surface missile (ASM) designed for use from helicopters against ships. It was primarily used by the Royal Navy on the Westland Lynx. Although the missile is intended for helicopter use, Ku ...

short-range missile. A new series, Seaspray 7000, was launched in 2002. This is an all-new design sharing only the name with the original design.

History

Original Seaspray

In 1967, Egyptian

missile boat A missile boat or missile cutter is a small, fast warship armed with anti-ship missiles. Being smaller than other warships such as destroyers and frigates, missile boats are popular with nations interested in forming a navy at lower cost. They ...

sank the Israeli destroyer '' Eilat'', immediately revealing the serious threat these new weapons presented. Considering the problem, it appeared that there was no simple ship-mounted solution. Although the

Seacat SeaCat was the marketing name used by Sea Containers Ferries Scotland for its services between Northern Ireland, Scotland and England between 1992 and 2004. The company was originally based in Stranraer later moving to Belfast. The name ori ...

missile had been designed with a secondary anti-shipping role, it lacked the range needed to attack the stand-off missiles on the boats.

Sea Dart Sea Dart, or GWS.30 was a Royal Navy surface-to-air missile system designed in the 1960s and entering service in 1973. It was fitted to the Type 42 destroyers, the single Type 82 destroyer and the s. Originally developed by Hawker Siddeley, t ...

could also be used in this role and had a much longer range, but was too large to fit on the

frigate A frigate () is a type of warship. In different eras, the roles and capabilities of ships classified as frigates have varied. The name frigate in the 17th to early 18th centuries was given to any full-rigged ship built for speed and maneuvera ...

s and smaller ships which made up much of the fleet. The solution was to move the weapons off the ships and mount them on

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 instead. This would mean the missile needed only enough range to keep the helicopter out of range of the guns on the boats, which were typically short-range systems with perhaps effective range. A longer range would be useful as it would hide the helicopter's approach. The result was the

missile, with a maximum range of about . Because the missile boats are small, they can hide under the

radar horizon The radar horizon is a critical area of performance for air traffic, aircraft detection systems, defined by the distance at which the radar beam rises enough above the Earth's surface to make detection of a target at the lowest level possible. I ...

of the ships while closing the range. Detecting these targets before they moved into the range of their

anti-ship missile An anti-ship missile (AShM or ASM) is a guided missile that is designed for use against ships and large boats. Most anti-ship missiles are of the sea-skimming variety, and many use a combination of inertial guidance and active radar homing. ...

s would require the helicopters to carry an

air-to-surface-vessel radar Radar, Air to Surface Vessel, or ASV radar for short, is a classification used by the Royal Air Force (RAF) to refer to a series of aircraft-mounted radar systems used to scan the surface of the ocean to locate ships and surfaced submarines. The fi ...

and patrol the area around their ships out to the approximate range of its primary target, the

P-15 Termit The P-15 ''Termit'' (; ) is an anti-ship missile developed by the Soviet Union's Raduga design bureau in the 1950s. Its GRAU designation was 4K40, its NATO reporting name was ''Styx'' or SS-N-2. China acquired the design in 1958 and created at ...

missile, or ''Styx'' as it was known in the west. The contract for the radar system was given to Ferranti in July 1969. Development was overseen by Sir Donald McCallum.

Adrian Hope, 4th Marquess of Linlithgow Adrian John Charles Hope, 4th Marquess of Linlithgow (born 1 July 1946), styled Viscount Aithrie until 1952 and Earl of Hopetoun between 1952 and 1987, is a British British nobility, peer. His family seat is Hopetoun House, near Edinburgh, Scotl ...

worked on the system. The design traces many of its design features to the pioneering AIRPASS radar developed for the

English Electric Lightning The English Electric Lightning is a British fighter aircraft that served as an interceptor during the 1960s, the 1970s and into the late 1980s. It is capable of a top speed above Mach 2. The Lightning was designed, developed, and manufactured ...

, the first production all-digital radar. The first models were produced as ARI.5979 Mk. 1 version in 1971. Trials of the Seaspray radar system began in 1974. Seaspray is a

monopulse radar Monopulse radar is a radar system that uses additional encoding of the radio signal to provide accurate directional information. The name refers to its ability to extract range and direction from a single signal pulse. Monopulse radar avoids prob ...

that produces 90 kW in the I band (formerly known as the X-band). The semi-parabolic reflector was made of lightweight foam with a wire mesh to make the system as light as possible. The system scanned 180° in azimuth by rotating the reflector and

feed horn A feed horn (or feedhorn) is a small horn antenna used to couple a waveguide to e.g. a parabolic dish antenna or offset dish antenna for reception or transmission of microwaves. A typical application is the use for satellite television rec ...

together and scanned vertically by moving the reflector with the feed horn.

Doppler Seaspray

In the late 1980s, improved versions were developed, adding

doppler radar A Doppler radar is a specialized radar that uses the Doppler effect to produce velocity data about objects at a distance. It does this by bouncing a microwave signal off a desired target and analyzing how the object's motion has altered the fre ...

techniques. These were introduced in the early 1990s as the Seaspray 2000 and 3000 and found use on a variety of aircraft, including the Lynx,

Lockheed C-130 Hercules The Lockheed C-130 Hercules is an American four-engine turboprop military transport aircraft designed and built by Lockheed Corporation, Lockheed (now Lockheed Martin). Capable of using unprepared runways for takeoffs and landings, the C-130 w ...

Westland Sea King The Westland WS-61 Sea King is a British licence-built version of the American Sikorsky S-61 helicopter of the same name, built by Westland Helicopters. The aircraft differs considerably from the American version, with Rolls-Royce Gnome eng ...

Bell 212 The Bell 212 (also known as the ''Bell Two-Twelve'') is a two-blade, twin-engine, medium helicopter that first flew in 1968. Originally manufactured by Bell Helicopter in Fort Worth, Texas, United States, production was moved to Mirabel, Queb ...

and

Fokker F27 The Fokker F27 Friendship is a turboprop airliner developed and manufactured by the Dutch aircraft manufacturer Fokker. It is the most numerous post-war aircraft manufactured in the Netherlands; the F27 was also one of the most successful Europe ...

AESA Seaspray

A completely redesigned Seaspray 7000E version was launched in July 2002 by BAE System Avionics. This replaced the mechanically scanned feed horn with an

active electronically scanned array An active electronically scanned array (AESA) is a type of phased array antenna, which is a computer-controlled antenna array in which the beam of radio waves can be electronically steered to point in different directions without moving the a ...

that provided the elevation scanning and fine pointing of the azimuth using beam steering. Two larger versions were also built using the same electronics. Seaspray 5000E equips the

Sikorsky S-92 The Sikorsky S-92 is an American twin-engine medium-lift helicopter built by Sikorsky Aircraft for the civil and military helicopter markets. The S-92 was developed from the Sikorsky S-70 helicopter and has similar parts such as flight control ...

, Embraer EMB-111 patrol conversions, and Canadair CL-604 Challenger. The even larger Seaspray 7500E is used on

US Coast Guard The United States Coast Guard (USCG) is the maritime security, search and rescue, and law enforcement service branch of the armed forces of the United States. It is one of the country's eight uniformed services. The service is a maritime, mi ...

C-130s. The division of Ferranti that developed Seaspray became GEC-Marconi, then

BAE Systems BAE Systems plc is a British Multinational corporation, multinational Aerospace industry, aerospace, military technology, military and information security company, based in London. It is the largest manufacturer in Britain as of 2017. It is ...

, then Selex ES, and is today part of Leonardo. Seaspray 7500E V2 is an enhancement of the operationally proven 7500E

Operations

The

Royal Danish Navy The Royal Danish Navy (, ) is the Naval warfare, sea-based branch of the Danish Armed Forces force. The RDN is mainly responsible for maritime defence and maintaining the sovereignty of Denmark, Danish territorial waters (incl. Faroe Islands and ...

bought the system in the late 1970s. 709 Naval Air Squadron were the first to have Seaspray-equipped Lynx helicopters in 1978. 24 Royal Navy Lynx HAS.2s were sent to the

Falklands War The Falklands War () was a ten-week undeclared war between Argentina and the United Kingdom in 1982 over two British Overseas Territories, British dependent territories in the South Atlantic: the Falkland Islands and Falkland Islands Dependenci ...

, and 16 of these were equipped with Seaspray. In 1992, the Seaspray 2000 was sold to the

Scottish Fisheries Protection Agency The Scottish Fisheries Protection Agency (SFPA) was an Executive Agency of the Scottish Government. On 1 April 2009, the Scottish Fisheries Protection Agency and Fisheries Research Services were merged with the Scottish Government Marine Dire ...

for £0.5m. In January 1999, the

German Navy The German Navy (, ) is part of the unified (Federal Defense), the German Armed Forces. The German Navy was originally known as the ''Bundesmarine'' (Federal Navy) from 1956 to 1995, when ''Deutsche Marine'' (German Navy) became the official ...

(''Deutsche Marine'') bought the system for £15m for its Lynx helicopters. In August 2005, the

United States Coast Guard The United States Coast Guard (USCG) is the maritime security, search and rescue, and Admiralty law, law enforcement military branch, service branch of the armed forces of the United States. It is one of the country's eight Uniformed services ...

bought the Seaspray 7500E radar system for £69m for its 22

HC-130 Hercules The Lockheed HC-130 is an extended-range, search and rescue (SAR)/combat search and rescue (CSAR) version of the Lockheed C-130 Hercules, C-130 Hercules military transport aircraft, with two different versions operated by two separate service ...

aircraft.

References

{{reflist

External links

Helicopter Museum
1970s in Edinburgh 1971 establishments in the United Kingdom 1971 in aviation 1971 in military history Helicopter radars I band (NATO) radar Ferranti Military radars of the United Kingdom Science and technology in Edinburgh Military equipment introduced in the 1970s