Sea Wolf missile

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Sea Wolf

A trainable launcher type Sea Wolf missile. The vertical launch missile has a large booster motor in tandem.

Type

Surface-to-air

Nationality

Era

Cold War

Launch platform

Ship

Target

Missile, Aircraft

History

Builder

BAe, MBDA

Date of design

Production period

Service duration

1979 - Current day

Operators

UK, Brazil and Chile

Variants

Electronics;
GWS-25, GWS-26, GWS-27
Vertical Launch

Number built

Specifications

Type

Diameter

0.18 m

Wing span

0.7 m

Length

2.0 m

Weight

80 kg

Propulsion

Blackcap solid fuel sustainer

Steering

Control surfaces

Guidance

Automatic command line of site

Speed

Mach 3

Range

1-5 km (GWS-25)^[1]

1-6 km (GWS-26)^[1] ^[2]

Ceiling

3000 m

Payload

Warhead

14 kg blast

Trigger

Proximity or contact

Sea Wolf is a naval missile system designed and built by BAC, later to become British Aerospace (BAe) Dynamics (now MBDA). It is an automated point-defence weapon system designed as a final line of defence against both sea-skimming and high angle anti-ship missiles and aircraft. It has been fielded by the Royal Navy in GWS-25, GWS-26 (Guided Weapon System) and VLS (Vertical Launch Sea Wolf) forms.

1 History
2 Description
3 Fire Control
4 Combat performance
5 Variants
6 Bibliography
7 References
8 See also
9 External links

[edit] History

The system was developed by the British Aircraft Corporation (BAC) from a 1964 requirement for a replacement for the Sea Cat missile system to give small warships protection against anti-ship missiles and aircraft. A contract was awarded in 1967 to BAC, Vickers and Bristol Aerojet. Testing lasted from 1970 until 1977, with shipborne trials on a modified Leander class frigate, HMS Penelope, from 1976 onwards. Sea Wolf was tested with a vertical launch system early in the missile's development on a modified Loch class frigate, Loch Fada, but for unclear reasons work did not continue in this direction: the GWS-26 "VL Seawolf (VLS)" being a much later (1980s) unrelated development. During trials the missile performed impressively, successfully intercepting a 114mm shell on one occasion. The first deployment, in the GWS-25 form, was on the Type 22 frigate (2 systems) and later on modified Leander class frigates (1 system) in six-round, manually loaded, trainable launchers.

It has been used by the Royal Navy since 1979 and has been fired in anger during the Falklands War. Current deployment is the GWS-26 system on the Type 22 Batch 3 and Vertical Launch Seawolf (VLS) on Type 23 frigates. The latter fields 32 vertical launch missiles (VL Sea Wolf) in its missile silo. It is expected to remain in service until 2020.

[edit] Description

Sea Wolf is powered by the Blackcap solid-fuel rocket to a maximum velocity of Mach 2 and can intercept targets in the range of 1000 to 6000m and 10 to 3000m in altitude. The 14 kg warhead is a proximity fuzed HE-fragmenting type. In the manually loaded form, the missiles are stored onboard in individual maintenance-free canisters, sealed until use and handled like a round of ammunition.

[edit] Fire Control

The system is fully automated and uses an integrated combination of visual (CCTV) and radar tracking. Target detection is carried out using the parent ship's surveillance radars. Originally, in the Type 22 and Sea Wolf equipped Leander class, this was the radar Type 967 / 968 combination; the D-band Type 967 providing long range surveillance and the E-band Type 968 providing short range target indication. Latterly, these functions have been taken over by the radar Type 996 3D surveillance radar. Target data is processed by the ships computers and when the system is live, targets are automatically assigned and engaged without the need for human intervention (although this can be over-ridden in the operations room).

When a target is to be engaged, the ships computer slews one of the pair of Sea Wolf trackers onto the target (there was a single tracker on a Sea Wolf Leander). Originally the Type 910, with a dual-role I/J band radar, was used but this suffered from poor performance locking onto low-altitude targets hidden in the background sea clutter in the Falklands War. Subsequently, the lighter Type 911 supplanted the Type 910, with a separate I-band radar to gather targets and K band radar to provide the lock. This system is based on the Blindfire tracker of the Rapier missile and was fitted in the 7th Type 22 Frigate onwards. Unlike Type 910, Type 911 is not reliant on the CCTV function, although this is retained as a back up and to provide a record of engagements.

When lock has been achieved with the missile tracker a round is fired, and is tracked by a pair of radio transmitters in the missile's tail and visually by the CCTV camera boresighted in the tracker by means of the exhaust flare. The ship-board system constantly measures the angle differences between the target and the missile and issues the relevant guidance commands to the missile through an Automatic Command to Line of Sight (ACLOS) device transmitting on a microwave link and controlling the rear fins of the missile. It is possible for a single tracker to control a salvo of two missiles.

[edit] Combat performance

During the Falklands War, Sea Wolf was present on board HMS Brilliant and HMS Broadsword. As the Royal Navy's only modern point-defence weapon at the time, the two Type 22 frigates so equipped were assigned "goalkeeper" duties; close anti-aircraft defence of the carrier task force. Unlike the long-range Sea Dart, Sea Wolf lived up to expectations and performed well in combat. On May 12, 1982, Brilliant was attacked by and drove off a flight of four Argentine A-4 Skyhawk aircraft; destroying 2 and causing a third to crash trying to avoid the missile. Sea Wolf accounted for two confirmed 'kills' and three further possible successes from eight launches.

In an attempt to overcome the fleet's evident air defence deficiency, a new tactic was devised. A Type 22 frigate and a Type 42 destroyer (a 22/42 combo) were deployed together some distance from the main fleet, covering likely attack routes, in an attempt to draw attacking aircraft into a 'missile trap'. It is indicative of the compromised Type 42's shortcomings that the Navy's newest air-defence destroyer required an anti-submarine frigate to act as close air-defence. Broadsword however was unable to successfully defend HMS Coventry when the pair were attacked on May 25. The latter, moving evasively, crossed in front of Broadsword and broke the Sea Wolf's lock on the attacking aircraft. Sea Wolf also suffered from problems with hardware failure causing launches to fail, and broken lock resulting from the extreme sea conditions and the Argentine's low altitude hit-and-run tactics, and multiple targets and crossing targets - neither of which it was designed to intercept.

As of 1991 Sea Wolf is said to have a 70% hit chance and VLS is said to have 80% kill rate.

[edit] Variants

[edit] Vertical Launch Sea Wolf (VLS)

Instead of an aimed launcher, the VLS missile is a vertical launch system. The missiles are carried in 4-tube cells forming a silo on the deck. Missiles are launched vertically by a booster motor to clear the ship's super-structure and rapidly flipped onto their flight path by thrust vectoring. The boost and vectoring stages then separate.

Although vertical launch aspects had been explored much earlier in Seawolf's development, it was not until the 1980s that a production design was undertaken. VLS went into service, using the GWS-26 system, on the Type 23 frigate HMS Norfolk.

[edit] Block 2 Sea Wolf

Block 2 Sea Wolf is a replenishment upgrade to the existing stocks of Sea Wolf missiles. Block 2 missiles will replace all Sea Wolf missiles, both on Type 22 and Type 23 frigates, as part of the normal ammunition replenshiment. In a parallel programme, the associated Type 911 tracker is being upgraded by the addition of an infra-red camera, enhanced tracking software and new operator's consoles.

[edit] GWS-27

Sea Wolf is not a "fire-and-forget" missile; it relies on target data from the parent ship all the way to intercept. A variant with a fire-and-forget capability, GWS-27, was cancelled in 1987.

[edit] Lightweight Sea Wolf

Sea Wolf was not designed as a particularly lightweight system, the original GWS-25 variant with Type 910 tracking required 13.5 tonnes of tracking and below decks fire control equipment, reduced to 5 tonnes with the upgraded Type 911 tracker. The "broad-beam" Leander class frigate of 2,500 tons (standard displacement) could carry only a single missile system, and required some significant structural "surgery" of the upperworks to counteract the weight of the new missile system. Sea Wolf in its original guise cannot therefore be easily added to existing vessels. For this reason a variant was designed to use a four-missile launcher, similar in form to that of the obsolete Sea Cat system; Lightweight Sea Wolf. It was to equip the Royal Navy's Invincible class carriers and Type 42 destroyers to supplement the medium range Sea Dart system, which was not as capable of intercepting sea-skimming missiles. However, it was cancelled before it entered service.

[edit] Bibliography

"BATTLE ATLAS of the FALKLANDS WAR 1982, by Land, Sea, Air" Gordon Smith, 2006 ( [1])
"Tras un manto de neblina. Breve crónica de la Guerra de las Malvinas", Mario Díaz Gavier, Córdoba, 2004
"Modern Combat Ships 4: Type 22" Leo Marriot, Ian Allan, 1986
"Royal Navy Frigates 1945-1983" Leo Marriot, Ian Allan, 1983
"Naval Armament", Doug Richardson, Jane's Publishing, 1981

[edit] References

^ ^a ^b Britain's Modern Royal Navy, Paul Beaver, Patrick Stephens Limited, 1996 ISBN 1-85260-442-5
^ Naval Armament, Doug Richardson, Jane's Publishing, 1981, ISBN 0-531-03738-X