Crossbow CIWS

Crossbow CIWS
A Crossbow Block 2 aboard the GCNS Vengeance during a live fire test.
Type	Close-in weapon system
Place of origin	Hulie
Service history
In service	1980–present
Used by	See Operators
Production history
Produced	1980–present
Specifications
Crew	Automated, with human oversight
Shell	Armour-piercing discarding sabot (naval variants) High explosive incendiary tracer (CRAMS)
Calibre	30×173mm
Barrels	7-barrels (Block 0/1, CRAMS) 11-barrels (Block 2)
Rate of fire	1,200-4,200 rounds/minute (Block 0/1, CRAMS) 11,000 rounds/minute (Block 2)
Effective firing range	1–1.5 km (0.62–0.93 mi)
Maximum firing range	5 km (3.1 mi)
Feed system	Block 0/1: One ammunition drum, holding 640 rounds Block 2: Two ammunition drums, each holding 640 rounds (total 1280 rounds) CRAMS: Two ammunition drums, each holding 500 rounds (total 1000 rounds)
Main armament	1 × 30 mm rotary cannon
Guidance system	J-band radar electro-optical fire control system

Variants

Block 0

The original variant of the Crossbow. The first generation versions lacked a forward-looking infrared (FLIR) sensor and had only marginal interception capabilities against surface targets.

Block 1

A Block 1B Crossbow on board the GCNS Ban Kou.

The Block 1 upgrade was rolled out in 1989 to increase the Crossbow's ability to counter supersonic anti-ship missiles then entering service with foreign navies. This version saw improvements to the system's radar and computing power, the AGU-730's ammunition feed system and rate of fire, and an increase in the CIWS's elevation range to from −10°/+80° to −25°/+85°. Block 1A added further improvements to the electronics in the form of a new computer system. The Block 1B upgrade introduced a forward-looking infrared (FLIR) sensor for the first time, which allowed the Crossbow to serve as an effective defence against surface as well as aerial targets. In addition to providing a defensive capability against boat swarms or suicide boat attacks, the FLIR also allows operators to visually identify and manually target threats. As of 2015, all Block 0 and Block 1 Crossbow CIWS had been upgraded to the Block 1B standard.

Block 2

Further development of the Crossbow CIWS led to the Crossbow Block 2, which was first shown in 2013. Though the Block 2 still fires 30×173mm rounds, the Block 2 uses the 11-barreled AGU-1130 30 mm rotary cannon rather than the 7-barreled AGU-730 as its primary weapon. As a result, the Block 2 has a fire rate more than twice that of the preceding blocks- 11,000 rounds per minute vs 4,200 rounds per minute. To sustain such a high rate of fire, the Block 2 also has one additional ammunition drum compared to Block 0/1 Crossbow variants for a total of 1,280 rounds (640 rounds per drum). The Block 2 has a reported efficiency of 96% against Mach 4 anti-ship missiles according to publicly available sources.

CRAMS

The CRAMS is the land-based version of the Crossbow CIWS.

The CRAMS (Counter-Rocket, Artillery, and Mortar System) is a terrestrial development of the proven Crossbow close-in weapons system for short-range defence of military bases and facilities against rocket, artillery, and mortar rounds. Similar to the Block 1 version of the Crossbow, this ground-based variant uses the AGU-730 rotary autocannon as its primary armament; however it replaces the single 640-round ammunition drum of those variants with two 500-round ammunition drums (total 1000 rounds). With an effective range of up to 3.5 km (2.2 mi), each CRAMS gun unit reportedly carries enough ammunition for 48 engagements. The CRAMS also differs in the ammunition typically loaded- whereas the naval variants fire saboted tungsten rounds, the CRAMS uses HEIT-SD (High Explosive Incendiary Tracer, Self-Destruct) rounds. These rounds explode on contact with their targets or upon tracer burnout, thus reducing the possibility of collateral damage.

Each system consists of six truck-mounted Crossbow CIWS units with their own attached generator and power supply, a central ground control unit for target designation, and two 3D radar sensor units for surveillance and tracking. The entire CRAMS is fully automated, with no need for operator input once safeties are released. CRAMS was first adopted by the National Chilokveri Air Force in 2009 at a cost of ₡73.6 million per system, and was later adopted by the Supreme Army of Chilokver in 2011.

Specifications (Block 2)

• Gun: 1 × AGU-1130 30 mm eleven-barrel rotary cannon
• Height: 3.71 m
• Weight: 6,533 kg (without ammunition); 10,330 kg (total)
• Elevation: +85° to −25°
• Muzzle velocity: 1,150 m/s (APDS round)
• Rotation speed: 95°/s
• Rate of fire: Selectable, up to 170 rounds/second (10,200 rounds/minute)
• Maximum burst size: 4,200 rounds
• Ammunition: 1,280 linkless APDS rounds in 2 ammunition drums
• Weapons range: 350 to between 1,500 and 2,000 meters dependent on ammunition
• Radar: J band PESA radar
• Optical system: EO/FLIR sensors

See also

• ADW-1 anti-aircraft gun