Phalanx CIWS

From Wikipedia,

Phalanx CIWS
Phalanx (Block 1A) live fire test, USS Monterey (CG-61)
Type	Close-in weapon system
Place of origin	United States
Service history
In service	1980-Present
Used by	See operators
Wars	Gulf War
Production history
Designer	General Dynamics (now Raytheon)
Manufacturer	General Dynamics (now Raytheon)
Produced	1978
Specifications
Weight	12,500 lb (5,700 kg), later models 13,600 lb (6,200 kg)
Barrel length	• Block 0 & 1 (L76 gun barrel): 1,520 mm (59.8 in) • Block 1B (L99 gun barrel): 1,981 mm (78.0 in)
Height	4.7 m (15 ft 5.0 in)
Crew	Automated, with human oversight
Shell	• Naval: Armor-piercing tungsten penetrator rounds with discarding sabots. • Land: High-Explosive Incendiary Tracer, Self-Destruct.
Caliber	20×102mm
Barrels	6-barrel (progressive RH parabolic twist, 9 grooves)
Elevation	• Block 0: -10°/+80° • Block 1: -20°/+80° (Rate of elevation: 86°/sec for Block 0/1) • Block 1B: -25°/+85° (Rate of elevation: 115°/sec)
Traverse	• 150° from either side of centerline (Rate of traverse: 100°/sec for Block 0 & 1, 116°/sec for Block 1B)
Rate of fire	3,000-4,500 rounds/minute [Selectable] (50-75 rounds/second).
Muzzle velocity	1,100 m/s (3,600 ft/s)
Effective range	3.6 km (2.2 mi)
Maximum range	Classified
Main armament	1× 20 mm (0.79 in) M61 Vulcan 6-barreled gatling cannon[4]
Guidance system	Ku-band radar and FLIR[5]

The Phalanx CIWS is an anti-ship missile anti-ship missile defense system. It is a close-in weapon system (CIWS) and was designed and manufactured by the General Dynamics Corporation, Pomona Division (now a part of Raytheon). Consisting of a radar-guided 20mm Gatling gun mounted on a swiveling base, the Phalanx is used by the United States Navy on every class of surface combat ship, by the United States Coast Guard aboard its Hamilton-class and Legend class cutters and the navies of 23 allied nations.^{[citation needed]}

A land based variant known as C-RAM has recently been deployed in a short range missile defense role, to counter incoming rockets and artillery fire.

Because of their distinctive barrel-shaped radome and their automated nature of operation, Phalanx CIWS units are sometimes nicknamed "R2-D2" after the famous droid from Star Wars,^[ and in the Royal Navy as Daleks, after the aliens from Doctor Who.

Design

The basis of the system is the 20 mm M61 Vulcan Gatling gun autocannon, used since the 1960s by the United States military in nearly all fighter aircraft (and one land mounting, the M163 VADS), linked to a Ku-band radar system for acquiring and tracking targets. This proven system was combined with a purpose-made mounting, capable of fast elevation and traverse speeds, to track incoming targets. An entirely self-contained unit, the mounting houses the gun, an automated fire control system and all other major components, enabling it to automatically search for, detect, track, engage and confirm kills using its computer-controlled radar system. Due to this self-contained nature, Phalanx is ideal for support ships which lack integrated targeting systems and generally have limited sensors. The entire unit has a mass between 5,500 and 6,100 kg (12,400 to 13,500 lb).

 

 

 

 

 

 

 

 

 

 

 

Comparison of some modern CIWS

	AK-630	Phalanx CIWS	Goalkeeper CIWS	DARDO
Weight	9,114 kg (20,090 lb)	6,200 kg (14,000 lb)	9,902 kg (21,830 lb)	5,500 kg (12,000 lb)
Armament	30 mm (1.2 in) 6 barreled GSh-6-30 Gatling Gun	20 mm (0.79 in) 6 barreled M61 Vulcan Gatling Gun	30 mm (1.2 in) 7 barreled GAU-8 Gatling Gun	40 mm (1.6 in) 2 barreled Bofors 40 mm
Rate of Fire	5,000 rounds per minute	4,500 rounds per minute	4,200 rounds per minute	600/900 rounds per minute
(effective/ flat-trajectory) Range	4,000 m (13,000 ft)	3,600 m (11,800 ft)	2,000 m (6,600 ft)	4,000 m (13,000 ft)
Ammunition stowage	2,000 rounds	1,550 rounds	1,190 rounds	736 rounds
Muzzle velocity	900 m (3,000 ft) per second	1,100 m (3,600 ft) per second	1,109 m (3,638 ft) per second	1,000 m (3,300 ft) per second
Elevation	-12 to +88 degrees	-25 to +85 degrees	-25 to +85 degrees	-13 to +85 degrees
Traverse	360 degrees	-150 to +150 degrees	360 degrees	360 degrees

Upgrades

Mk-15 Phalanx CIWS firing upon a surface target during a sinking exercise, 2010.

 

Due to the continuing evolution of both threats and computer technology, the Phalanx system has, like most military systems, been developed through a number of different configurations. The basic (original) style is the Block 0, equipped with first generation solid state electronics and with marginal capability against surface targets. The Block 1 (1988) upgrade offered various improvements in radar, ammunition, rate of fire, increasing engagement elevation to +70 degrees, and computing. These improvements were intended to increase the system's capability against emerging Russian supersonic anti-ship missiles. Block 1A introduced a new computer system to counter more maneuverable targets. The Block 1B PSuM (Phalanx Surface Mode, 1999) adds a forward looking infrared (FLIR) sensor to allow the weapon to be used against surface targets.This addition was developed to provide ship defense against small vessel threats and other "floaters" in littoral waters and to improve the weapon's performance against slower low-flying aircraft. The FLIR's capability is also of use against low-observability missiles and can be linked with the RIM-116 Rolling Airframe Missile (RAM) system to increase RAM engagement range and accuracy. The Block 1B also allows for an operator to visually identify and target threats.

The U.S. is in the process of upgrading all their Phalanx systems to the Block 1B configuration. The Block 1B is also used by other navies such as Canada, Portugal, Japan, Egypt, Bahrain and the UK.

In May 2009 the US Navy awarded a $260 million contract to Raytheon Missile Systems to perform upgrades and other work on the Phalanx. The work is to be completed by September 2012.

Operation

The CIWS is designed to be the last line of defense against anti-ship missiles. Due to its design criteria its effective range is very short relative to the range of modern ASMs, from 1 to 5 nautical miles (9 km). The gun mount moves at a very high speed and with great precision. The system takes minimal inputs from the ship, making it capable of functioning despite potential damage to the ship. The only inputs required for operation are 440 VAC 3 phase at 60Hz and water for electronics cooling. For full operation including some non-essential functions, it also has inputs for true compass ship's heading and 115 V AC for the PASS and tape drive subsystems.

Radar subsystems

The CIWS has two antennas that work together to engage targets. The first antenna, for searching, is located inside the radome on the weapon control group (top of the white-painted portion). The search subsystem provides bearing, range, velocity, heading, and altitude information of potential targets to the CIWS computer. This information is analyzed to determine whether the detected object should be engaged by the CIWS system. Once the computer identifies a valid target (see details below), the mount moves to face the target and then hands the target over to the track antenna. The track antenna is extremely precise, but views a much smaller area. The tracking subsystem observes the target until the computer determines that the probability of a successful hit is maximized and then, depending on the operator conditions, the system will either fire automatically or will recommend fire to the operator. While firing, the system tracks outgoing rounds and 'walks' them onto the target.

 

Gun and ammunition handling system

The Block 0 CIWS mounts (hydraulic driven) fired at a rate of 3,000 rounds per minute and they could only hold 989 rounds in the magazine drum.^[4] The Block 1 CIWS mounts (hydraulic) also fired at 3,000 rounds per minute with an extended magazine drum holding 1,550 rounds. The Block 1A and newer (pneumatic driven) CIWS mounts fire at a rate of 4,500 rounds per minute and also had the larger 1,550 round magazine. The velocity of the rounds once fired is approximately 3,600 feet per second (1,100 m/s). The rounds are armor-piercing tungsten penetrator rounds or depleted uranium with discarding sabots. The kinetic projectiles are designed to pierce and explode an incoming missile's warhead. The ammunition handling system has two conveyor belt systems. The first takes the rounds out of the magazine drum and to the gun; the second takes either the empty shells or non-fired rounds and routes them back to the opposite end of the drum.

CIWS contact target identification

The CIWS does not recognize identification friend or foe, also known as IFF. The CIWS has only the data it collects in real time from the radars to decide if the target is a threat and to engage it. A contact has to meet multiple criteria for it to be considered a target. Some of the criteria are listed below.

1. Is the range of the target increasing or decreasing in relation to the ship? The CIWS search radar will see contacts that are out-bound and discard them. The CIWS will only engage a target if it is approaching the ship.
2. Is the contact capable of maneuvering to hit the ship? If a contact is not heading directly at the ship, the CIWS looks at its heading in relation to the ship and its velocity. It then decides if the contact can still perform a maneuver to hit the ship.
3. Is the contact traveling between the minimum and maximum velocities? The CIWS has the ability to engage targets that travel in a wide range of speeds, however it is not an infinitely wide range. The system has a target maximum velocity limit. If a target exceeds this velocity, the CIWS will not engage it. It also has a minimum target velocity limit. Any contact below that velocity will not be engaged by the CIWS. The operator also has the option to adjust the minimum and maximum limits within the limits of the system.

THE AEGIS COMBAT SYSTEM

 

The Aegis Combat System (ACS) is an advanced command and control (command and decision, or C&D, in Aegis parlance), and weapon control system (WCS) that uses powerful computers and radars to track and guide weapons to destroy enemy targets.

The ACS is composed of the Aegis Weapon System (AWS), the fast-reaction component of the Aegis Anti-Aircraft Warfare (AAW) capability, along with the Phalanx Close In Weapon System (CIWS), the Mark 41 Vertical Launch System  (VLS) adopts a modular design concept, which result in different versions that vary in size and weight. The length comes in three sizes: 209 in (5.3 m) for the self-defense version, 266 in (6.8 m) for the tactical version, and 303 in (7.7 m) for the strike version. The empty weight for a 8-cell module is 26,800 lb (12,200 kg) for the self-defense version, 29,800 lb (13,500 kg) for the tactical version, and 32,000 lb (15,000 kg) for the strike version, thus incorporating anti-submarine warfare (ASW) systems, and Tomahawk Land Attack Cruise Missiles (TLAM). Shipboard torpedo and naval gunnery systems are also integrated.

AWS, the heart of Aegis, comprises the AN/SPY-1 Radar, MK 99 Fire Control System, WCS, the Command and Decision Suite, and SM-2 Standard Missile family of weapons; these include the basic RIM-66 Standard the RIM-67extended range missile, and the newer RIM-161designed to counter ballistic Missile threats. A further SM-2 based weapon, the RIM-174 Standard ERAM is currently in testing, and may be integrated into the system in the near future. Individual ships may not carry all variants; weapons load-outs are adjusted to suit assigned mission profile. The Aegis Combat System is controlled by an advanced, automatic detect-and-track, multi-function three-dimensional passive electrinically scanned array radar, the AN/SPY-1. Known as "the Shield of the Fleet", the SPY high-powered (6 Megawatt) radar is able to perform search, tracking, and missile guidance functions simultaneously with a track capacity of well over 100 targets at more than 100 nautical miles (190 km). However the AN/SPY-1 Radar is mounted lower than the AN/SPS-49 radar system and so has a reduced radar Horizon.

The Aegis system communicates with the Standard missiles through a radio frequency (RF) uplink using the AN/SPY-1 radar for mid-course guidance of the missile during engagements, but still requires the AN/SPG-62 radar for terminal guidance. This means that with proper scheduling of intercepts, a large number of targets can be engaged simultaneously.

The computer based command-and-decision element is the core of the Aegis Combat System. This interface makes the ACS capable of simultaneous operation against almost all kinds of threats. The Aegis Ballistic Missile Defense System  program is intended to enable the Aegis system to act in a sea-based ballistic missile defense function, to counter short- and medium-range ballistic missiles of the variety typically employed by a number of potential opponent states.

Development

Aegis was initially developed by the Missile and Surface Radar Division of RCA which was then acquired by General Electric. The division responsible for the Aegis systems became Government Electronic Systems. This, and other GE Aerospace businesses, were sold to Martin Marietta in 1992. This became part of Lockheed Martin in 1995.

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Large screen displays on USS Vincennes typical of early Aegis platforms

By the late 1950s, the US Navy replaced guns with guided missiles on its ships. These were sufficient weapons but by the late 1960s, the U.S. Navy recognized that reaction time, firepower, and operational availability in all environments did not match the anti-ship missile threat.

As a result, the US Navy decided to develop a program to defend ships from anti-ship missile threats. An Advanced Surface Missile System (ASMS) was promulgated and an engineering development program was initiated in 1964 to meet the requirements. ASMS was renamed "Aegis" in December 1969 after the Aegis  the shield of the Greek god Zeus The name was invented at the suggestion of Captain L. J. Stecher, a former Tartar Weapon System manager, after an internal U.S. Navy contest to name the ASMS program was initiated. Captain Stecher also submitted a possible acronym of Advanced Electronic Guided Interceptor System although this definition was never used. The main manufacturer of the Aegis combat system, Lockheed Martin, makes no mention of the name Aegis being an acronym, nor does the U.S Navy.

Because the Aegis combat system is the key component of several cruiser and destroyer class vessels, the ships are often incorrectly referred to as "Aegis class cruisers" or "Aegis class destroyers". In reality, the radar system and the class of ship it is installed on are unrelated to each other.

Large screen displays on USS John S. McCain, circa 1997. Destroyers have two displays while cruisers have four.

The first Engineering Development Model (EDM-1) was installed in a test ship, the USS Norton Sound, in 1983. During this time frame, the Navy envisioned installing the Aegis combat system on both a nuclear powered "Strike Cruiser" (or CSGN) and a conventionally powered destroyer (originally designated DDG 47). The CSGN was to be a new, 17,200 ton cruiser design based on the earlier California- and Virginia-class cruisers. The Aegis destroyer design would be based on the gas turbine powered Spruance class. When the CSGN was cancelled, the Navy proposed a modified Virginia class design (CGN 42) with a new superstructure designed for the Aegis combat system and with a displacement of 12,100 tons. As compared to the CSGN, this design was not as survivable and had reduced command and control facilities for an embarked flag officer. Ultimately this design was also cancelled during the Carter Administration due to its increased cost compared to the non-nuclear DDG 47. With the cancellation of the CGN 42, the DDG 47 Aegis destroyer was redesignated as CG 47, a guided missile cruiser.

The first cruiser of this class was the Ticonderoga, which used two twin-armed Mark-26 missile launchers, fore and aft. The commissioning of the sixth ship of the class, the Bunker Hill opened a new era in surface warfare as the first Aegis ship outfitted with the Martin Marietta Mark-41 Vertical Launching System (VLS), allowing a wider missile selection, more firepower, and survivability. The improved AN/SPY-1B radar went to sea in the Princeton, ushering in another advance in Aegis capabilities. The Chosin introduced the AN/UYK-43/44 computers, which provide increased processing capabilities.

During 1980, a destroyer was designed using an improved sea-keeping hull form, reduced infrared and radar cross-sections, and upgrades to the Aegis Combat System. The first ship of the Arleigh Burke class, the USS Arleigh Burke, was commissioned during 1991.

Flight II of the Arleigh Burke class, introduced in 1992, incorporated improvements to the SPY radar, and to the Standard missile, active electronic countermeasures, and communications. Flight IIA, introduced in 2000, added a helicopter hangar with one anti-submarine helicopter and one armed attack helicopter. The Aegis program has also projected reducing the cost of each Flight IIA ship by at least $30 million.

Aegis Open Architecture

The Multi-Mission Signal Processor (MMSP) will be installed in US Navy ships starting in 2012. This will result in the merger with Aegis Ballistic Missile Defense System.

 

Technical development and issues

There are some reports that Aegis radar systems on board some individual warships are not being maintained properly. A Navy panel headed by retired Vice Adm. Phillip Balisle has issued the "Balisle report," which asserts that over-emphasis on saving money, including cuts in crews and streamlined training and maintenance, has led to a drastic decline in readiness, and has left Aegis combat systems in low state of readiness.