Era / Cold War
Launch platform / ship
Builder / British Aerospace
Service duration / 1973
Operators / UK (Royal Navy), Argentina
Number built / 2,000+
Diameter / 0.42 m
Wing span / 0.9 m
Length / 4.4 m
Propulsion / Chow solid fuel booster motor
Bristol Siddeley Odin ramjet cruise motor
Steering / control surfaces
Ceiling / Greater than 10,000 metres
Warhead / Blast-fragmentation
Trigger / proximity and contact

Sea Dart – SAM or ASM

WEAPON / Difficulty / DAM / PEN / Speed / Guidance / Warhead / RNG
Mod 0 / Diff / C:16 B:41 / 25c / Mach 2+ / SAR / 68kg / 3.7-55.5km
Mod 1 / Average / C:16 B:41 / 25c / Mach 2+ / SAR+ / 68kg / 3.7-55km
Mod 2 / Average+1 / C:16 B:41 / 25c / Mach 2+ / SAR+IR / 68kg / 2.5-150km
Mod 3 / Average+2 / C:16 B:41 / 25c / Mach 2+ / SAR+IR+ / 68kg / 2.5-150km
WEIGHT / 550kg
PRICE
OTHER

Sea Dart or Guided Weapon System (GWS) 30 is a Britishsurface-to-air missile system designed by Hawker Siddeley Dynamics and built by British Aerospace (BAe). It has been fitted to Type 42 (UK and Argentina) and Type 82 guided missile air defence destroyers and Invincible class light aircraft carriers of the Royal Navy.

History

Sea Dart began as Hawker Siddeley project CF.299, a weapon to replace the Royal Navy's first-generation long-range surface-to-air missile, Sea Slug. It entered service in 1973 on the sole Type 82 destroyer HMS Bristol before widespread deployment on the Type 42 destroyer. The missile system was also fitted to Invincible classaircraft carrier but was removed during refits in the 1998-2000 period to increase the area of the flight deck and below-decks stowage associated with the operation of RAFHarrier GR9 aircraft.

Design

Sea Dart is a two-stage, 4.4 m long missile weighing 550 kg. It is launched using a drop-off Chow solid-fuelled booster that accelerates it to the supersonic speed necessary for the operation of the cruise motor, a Rolls-Royce (Bristol Aerojet) kerosene-fuelled Odinramjet. This gives a cruise speed of over Mach 2.5, and unlike many rocket powered designs the cruise engine burns for the entire flight, giving excellent terminal manoeuvrability at extreme range. It is capable of engaging targets out to at least 30 nautical miles over a wide range of altitudes. It has a secondary capability against small surface vessels, tested against a 'Brave' Class FPB, although the warhead is too small to inflict major damage on larger vessels.

Guidance is by proportional navigation and a semi-active radar homing system using the nose intake cone and four aerials around the intake as an interferometer aerial, with targets being identified by a Type 1022 surveillance radar (originally radar Type 965) and illuminated by 1 of a pair of radar Type 909. This allows two targets to be engaged simultaneously in initial versions, with later variants (see below) able to engage more. Firing is from a twin-arm trainable launcher that is loaded automatically from below decks. The original launcher seen on the Bristol was significantly larger than that that appeared on the Type 42 and Invincible classes. Initial difficulties with launcher reliability have been resolved.

Combat Service

Falklands War

Sea Dart was used during the Falklands War and is credited with seven confirmed kills (plus one British Gazelle helicopter by friendly fire). One kill was against a high-flying Learjet reconnaissance aircraft beyond the missile's stated technical envelope. In another engagement, a high-flying ArgentinianCanberra bomber was shot down. Other kills were made against low-flying attack aircraft. However, Sea Dart was found to be unsuitable when operating close inshore as it was unable to lock onto targets at distance obscured by land and fast-moving low-level targets obscured in ground clutter or sea-returns. These shortcomings were more damning of the Type 42 destroyer than Sea Dart itself, as the former were fitted with obsolete 1950s-era radar Type 965 and had no other defence against aircraft apart from a pair of World War 2-vintage 20 mm guns.

Sea Dart on HMS Invincible

Gulf War (1991)

In February 1991 during the first Gulf War the battleship USS Missouri, escorted by the Sea Dart carrying HMS Gloucester and the Phalanx CIWS-equipped USS Jarrett, was engaged by an IraqiSilkworm missile (also known as a Seersucker). After an unsuccessful response from the Phalanx 20 mm CIWS of Jarrett, having targeted chaff launched by the Missouri rather than the incoming missile, the Silkworm missile was intercepted and destroyed by a Sea Dart fired from Gloucester. This engagement was the first validated, successful engagement of a missile by a missile during combat at sea.

Variants

The Sea Dart has been upgraded over the years - notably its electronics - as technology advances. The following Modification standards have been fielded:

  • Mod 0 — Basic 1960s version, used in the Falklands. Vacuum-tube technology. Range circa 40nm.
  • Mod 1 — Improved Sea Dart. Upgraded version 1983-1986. Updated guidance systems possibly allowing some capability against sea-skimming targets and much greater reliability.
  • Mod 2 — 1989-1991. Upgrade included ADIMP (Air Defence IMProvement) which saw the replacement of six old circuit cards in the guidance system with one, allowing the spare volume to be used for an autopilot. Used alongside a command datalink (sited on the Type 909 pedestal) it allows several missiles to be 'in the air' at once, re-targeted during flight etc. and allows an initial ballistic trajectory, doubling range to 80nm with the upgraded 909(I) radar for terminal illumination only.
  • Mod 3 — Latest version with new Infraredfuze. Delayed eight years from 1994 to 2002.

The Sea Dart Mark 2, GWS 31, (a.k.a. Sea Dart II - not to be confused with Mod 2, above) development was cancelled in 1981. This was intended to allow 'off the rail' manoeuvres with additional controls added to the booster. The Mark 2 was reduced to Advanced Sea Dart, then Enhanced Sea Dart and finally Improved Sea Dart.

Guardian was a proposed land-based system of radars, control stations and a box-launched version of Sea Dart ('Land Dart'?) proposed in the 1980s for use as a land-based air defence system for the Falkland Islands. A similar lightweight box-launched version was also proposed for small naval craft.

Withdrawal

The Sea Dart equipped Type 42s are reaching the end of their service lives, with some vessels already retired. Construction has begun on the Type 45 class which, with the much more capable PAAMS missile system, will replace the Type 42 from 2009.