Sea Cat missile

Infobox Weapon
is_missile=yes


caption=Sea Cat GWS-20 series missile
name=Sea Cat
type=Surface-to-air missile
origin=United Kingdom
launch_platform=Ship
target=aircraft
manufacturer=Short Brothers
design_date=
production_date=
service=1962–
used_by= UK, Argentina, Australia, Brazil, Chile, South Africa, Sweden, and New Zealand
wars=Falklands War South African Border War
spec_type=close range anti-aircraft
diameter= 0.22 m
wingspan=0.70 m
length=1.48 m
weight= 68 kg
speed=Mach 0.8
vehicle_range=500–5000+ m
ceiling=
filling=40 lb (18 kg) Continuous Rod
engine=2 stage motor
steering=control surfaces
guidance=CLOS & radio link (see text)
variants=Fire Control (see text)
number=
detonation=proximity

Sea Cat was a British short-range surface to air missile system intended to replace the ubiquitous Bofors 40 mm gun aboard warships of all sizes. It was the world's first operational shipboard point-defence missile system and was designed so that the Bofors guns could be replaced with minimum modification to the recipient vessel using (originally) existing fire-control systems. A mobile land-based version of the system was known as Tigercat.

History

Sea Cat was designed by Short Brothers of Belfast for use against fast jet aircraft that were proving to be too difficult for the WWII-era Bofors guns to successfully intercept. The missile itself was based on the Shorts "Green Light" prototype, itself a development of the Australian Malkara anti-tank missile. It replaced the "Orange Nell" development programme for a lighter weapon than the enormous Sea Slug missile.

Design Features

Sea Cat is a small, subsonic missile powered by a two-stage solid fuel rocket motor. It is steered in flight by four swept, cruciformly arranged wings and is stabilised by four small tail fins. It is guided by Command Line-Of-Sight (CLOS) via a radio-link; i.e. flight commands are transmitted to it from a remote operator with both the missile and target in sight.

Variants

All Sea Cat variants used a common 4-rail, manually-loaded, trainable launcher that incorporated the antennae for the radio command link. All that was required to fit the system to a ship was the installation of a launcher, the provision of a missile handling room and a suitable guidance system. Sea Cat was widely used in NATO and Commonwealth navies that purchased British equipment and has been used with a wide array of guidance systems. The four systems used by the Royal Navy are described below.

GWS-20

This was the initial system, and was intended to replace the twin 40 mm Bofors Mark V gun and its associated fire-control systems. The original director was based on the STD (Simple Tachymetric Director) and was entirely visual in operation. The target was acquired visually with the missile being guided, via a radio link, by the operator inputting commands on a joystick. Flares on the missile's tail fins aided identifying the missile. The more advanced CRBF (Close Range Blind Fire) director equipped with spin-scanning radar Type 262 for automatic target tracking could also be used.

GWS-20 was trialled on board the "Daring" class destroyer, and was subsequently removed. It was carried in active service by, (amongst others) "Fearless" class landing ships and Type 81 "Tribal", updated Type 12 "Whitby", Type 12I "Rothesay" and (originally) "County" class escorts. It was originally intended that all "C" class destroyers should receive it and the class were prepared accordingly. In the event only HMS "Cavalier" and HMS "Caprice" received it, in 1966 refits.

GWS-20 saw active service in the Falklands war onboard the "Fearless" class and the "Rothesay" frigates HMS "Plymouth" and HMS "Yarmouth", who retained the GWS-20 director when upgraded to GWS-22.

GWS-21

GWS-21 was the Sea Cat system associated with a modified MRS-3 (Medium Range System) analogue fire control director with Type 904 radar (based on the USN Mk.56 system). This offered manual radar-assisted ("Dark Fire") tracking and guidance modes as well as CCTV and 'eyeball' visual modes. It was carried as the design anti-aircraft weapon of the Type 12M "Leander" class frigate and on the modified Tiger class helicopter cruisers HMS "Tiger" and HMS "Blake".

GWS-22

GWS-22 was the Sea Cat system associated with the full MRS-3 fire control director with Type 903 radar and was the first "ACLOS"-capable (Automatic, Command Line-Of-Sight) Sea Cat. It was fitted to most of the "Leander", "Rothesay" and "County" class escorts as they were refitted and modified in the 1970s, as well as the aircraft carrier HMS "Hermes". It could operate in automatic radar-guided ("Blindfire"), manual radar-guided, manual CCTV-guided or, in an emergency, 'eyeball' guided modes. It saw active service in the Falklands onboard all these classes.

GWS-24

The final Royal Navy Sea Cat variant, this used the Italian Alenia Orion RTN-10x fire control system with Type 912 radar and was fitted only to the Type 21 frigate. This variant saw active service in the Falklands.

Tigercat

A land-based mobile version of Sea Cat based on a 3-round, trailer-mounted launcher towed by a Land Rover, and a second trailer carrying the fire control equipment. Tigercat was used exclusively within HM Forces by No.48 Squadron of the RAF Regiment between 1967 and 1978, being replaced in service by Rapier. Tigercat ware also operated by Argentina, India, Iran, Jordan, South Africa [cite web |url=http://www.saairforce.co.za/the-airforce/weapons/88/hilda-tigercat-sam |title=The Airforce - Weapons |accessdate=2008-07-18 |author= |last= |first= |authorlink= |coauthors= |date= |format= |work= |publisher= |pages= |language= |doi= |archiveurl= |archivedate= |quote= ] and Qatar. Argentina deployed it operationally during the Falklands conflict. No kills were achieved and 7 units were captured by British forces.

ervice

Sea Cat rapidly became obsolescent due to increasing aircraft speed and the introduction of supersonic, sea-skimming anti-ship missiles. In these cases the subsonic, manually guided Sea Cat was totally unsuited to all but head-on interceptions with adequate warning and response time.

Despite being obsolete, Sea Cat was still widely fielded by the Royal Navy during the Falklands war. Indeed, it was the sole anti-aircraft defence of many ships. However, unlike the modern and more complex Sea Dart and Sea Wolf systems, Sea Cat rarely misfired or refused to respond, in even the harshest conditions. It was capable of sustained action which compensated for its lack of speed, range, and accuracy, and more importantly, it was available in large numbers. Ships firing Sea Cat made claims on only one confirmed "kill" of Argentine aircraft an A-4C Skyhawk of FAA Grupo 4 on 25 May (the pilot, Lt Lucero ejected) from over 80 launches. That aircraft over the task force were engaged with every available weapon makes it difficult to assign many kills to individual ships or weapons.

After the Falklands conflict, a radical and urgent re-appraisal of anti-aircraft weaponry was undertaken by the Royal Navy. This saw Sea Cat rapidly removed from service and replaced by modern weapons systems such as Vulcan-Phalanx and Goalkeeper "CIWS", modern 20 mm and 30 mm anti-aircraft guns, and new escorts carrying the Sea Wolf missile, including the vertical launch version.

The missiles were fitted to the four Swedish "Östergötland"-class destroyers, replacing three Bofors L/70 guns (a more modern and heavier variant than the Royal Navy's L/60) with a single launcher on each ship. The "Östergötland"-class destroyers of late 1950s origin were retired in the early 1980s.

Sea Cat was mounted on all six "River"-class destroyer escorts of the Royal Australian Navy and was removed from service when the final ship of this class was decommissioned in the late 1990s. In their final variant, fire control was provided by a GWS-21 guidance system supported by a Mk 44 fire control computer. Secondary firing positions based on visual tracking of the target through binoculars mounted on a syncro-feedback mount was also available. HMAS "Torrens" was the final ship to live fire the system prior to its removal from service, and this was also the only time three missiles were on the launcher and fired in sequence, resulting in one miss and two hits on towed targets.

Operators

; ARG; AUS; BRA; CHI; GER; IND; IRN; JOR; LBY; MYS; NZL; NLD; NGA; QAT; RSA; SWE; THA; UK; VEN; ZIM

ee also

* Rainbow Codes

References

* "Naval Armament", Doug Richardson, Jane's Publishing, 1981, ISBN 0-531-03738-X
* "Modern Combat Ships 5; Type 21", Captain John Lippiett RN, Ian Allan, 1990, ISBN 0-7110-1903-7