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Goalkeeper CIWS

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This is an old revision of this page, as edited by 65.242.250.130 (talk) at 12:11, 16 June 2009 (Specifications: I band (8-10GHz) is X band. See http://www.copradar.com/preview/xappA/xappA.html. 'I' is less widely known than 'X' as a label for this band.). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Goalkeeper CIWS on a British Invincible class aircraft carrier

Goalkeeper is a Dutch close-in weapon system (CIWS), which defends ships against incoming missiles and ballistic shells. This system consists of an autocannon and an advanced radar which tracks incoming fire, determines its trajectory, then aims the gun and fires in a matter of seconds. The system is fully automatic, needing no human input once activated. The name comes from the football/soccer position. The system is made by Thales Navy Netherlands. The system can also be deployed to protect airfields.

Development

Development of the system began in 1975 with Signaal (now Thales Nederland) working with General Electric, who supplied the GAU-8 gun. A prototype, the EX-83 was first demonstrated to the Royal Netherlands Navy in 1979.

Description

Target selection

Goalkeeper has two radar sub-systems; search and track, which operate in conjunction with one another to identify and prioritise targets before engaging the highest priority.

The 2D I band search radar, which can track up to 18 targets at once, generates a threat picture which the gun system uses to identify threats and prioritise. Once a target has been prioritised the engagement radar is slewed to the target bearing indicated by the search radar. The tracking radar operates in both I band and K band to enable quick acquisition on the threat bearing. Data from both the I band and K band return signals indicate target range and can be used to identify, and respond to the use of, electronic countermeasures (ECM). The dual band system also reduces the effect of clutter, which can mask the target at low altitude. A camera system on the assembly provides a visual fallback for the system operator.

Target hit by Goalkeeper

Target engagement

The GAU-8/A Avenger 30 mm Gatling gun, as used by the A-10 Thunderbolt II, was selected for the system. The 30mm round has a greater mass than the M61 Vulcan used in Phalanx so that it has greater stopping power despite the similar muzzle velocity and range.

The 30mm round has a discarding nylon sleeve, or sabot, with a 21mm sub-calibre tungsten penetrator. The nylon sabot reduces barrel wear.

The tracking radar is capable of monitoring the line of fire and commanding minor adjustments.

Supersonic missiles that are damaged may still have enough momentum to hit the ship—the only way to ensure the protection of the ship is either detonate the warhead of the missile or obliterate the missile.

The system's reaction time to a Mach 2 sea-skimming missile like the Russian SS-N-22 Sunburn from automatic detection to kill is reported[citation needed] to be 5.5 seconds with the firing synchronised to start the engagement at a range of 1500 m and ending with a kill at 300 m.

Specifications

  • Gun: GAU-8/A Avenger 30 mm seven-barrel Gatling gun.
  • Height: 3.71 m (above deck) 6.2 m (including deck penetration).
  • Weight: 6,372 kg with 1,190 rds of ammunition (above deck), 9,902 kg (total).
  • Elevation +85 to −25 degrees at 80 degrees/sec.
  • Muzzle velocity: 1,109 m/s (MPDS round).
  • Turret Speed 360° in 3.8 seconds
  • Rate of fire: 70 rounds/second (4,200 rounds/minute).
  • Maximum burst size: 1000 rounds.
  • Ammunition: 1,190 linkless (HEI, API, TP, MPDS, FMPDS) rounds in a below-deck magazine.
  • Reload time: 9 minutes (loading is done below deck)
  • Weapons range: 350 to between 1,500 and 2,000 meters dependent on ammunition.
  • Search radar: I band / linear array. I band is X band. Beamsize 1.5 degrees horizontal, 60 degrees vertical. Rotates at 60 rpm. Range approx 30 km.
  • Engagement radar: I band and K band monopulse cassegrain.
  • Optical system: TV
  • 100% Kill distance: 500 meters
  • Cost: 16 million euros

Operators