Editing Phalanx CIWS (section)

==Design==
[[File:USS King (DLG-10) with Phalanx CIWS prototype in 1973.jpg|thumb|The Phalanx prototype on {{USS|King|DLG-10|6}} in 1973.]]
[[File:US Navy 101027-N-8913A-252 Rounds from a Mk-15 Phalanx Close-in Weapon System (CIWS) from the guided-missile destroyer USS Mitscher (DDG 57) impact.jpg|thumb|right|Rounds from a Mk-15 Phalanx CIWS on {{USS|Mitscher|DDG-57|6}} hit [[RFA Stromness (A344)|ex-USNS ''Saturn'']] during a sinking exercise]]
[[File:CIWS Radar.jpg|thumb|right|A technician checks the radar transmitter and microwave assemblies of a Phalanx CIWS In the background, the search radar is at the top left with the vertical, tracking radar below it.]]
The basis of the system is the 20 mm [[M61 Vulcan]] [[rotary cannon]], used by the United States military on various tactical aircraft since 1959, linked to a [[Ku band|K<sub>u</sub> band]] [[fire control 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. Owing 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 {{cvt|12400|to|13500|lb}}.{{Cn|date=April 2024}}

Because of their distinctive barrel-shaped [[radome]] and their automated operation, Phalanx CIWS units are sometimes nicknamed "[[R2-D2]]" after the [[droid (Star Wars)|droid]] from the ''[[Star Wars]]'' films.<ref>{{cite web|url=http://www.spacewar.com/reports/Phalanx_Has_A_Future_999.html |title= Phalanx Has a Future |last= Sieff |first= Martin |website=Spacewar.com |date= November 3, 2006 |access-date= October 2, 2017}}</ref><ref>{{cite web |url=http://home.mytelus.com/telusen/portal/NewsChannel.aspx?CatID=National&ArticleID=news/capfeed/national/n111837A.xml |title=TELUS, news, headlines, stories, breaking, canada, canadian, national |publisher=Home.mytelus.com |access-date=2010-04-13 |url-status=dead |archive-url=https://web.archive.org/web/20110714144716/http://home.mytelus.com/telusen/portal/NewsChannel.aspx?CatID=National&ArticleID=news%2Fcapfeed%2Fnational%2Fn111837A.xml |archive-date=2011-07-14 }}</ref>

===Upgrades===
The Phalanx system has been developed through several configurations. The basic (original) is the Block 0, equipped with first-generation, solid-state electronics and with marginal capability against surface targets. The Block 1 (1988) upgrade improved radar, ammunition, computing power, rate of fire, and an increase in maximum engagement elevation to +70 degrees. 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 make the weapon effective against surface targets.<ref name="raytheon.com">{{cite web|url=http://www.raytheon.com/capabilities/products/phalanx/ |title=Raytheon Company: Phalanx |publisher=Raytheon.com |access-date=2010-04-13}}</ref> This addition was developed to provide ship defense against small vessel threats and other "floaters" in [[littoral zone|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.<ref name="raytheon.com"/>

Since the end of FY 2015, the US Navy has upgraded all Phalanx systems to the Block 1B variant. In addition to the FLIR sensor, the Block 1B incorporates an automatic acquisition video tracker, optimized gun barrels (OGB), and Enhanced Lethality Cartridges (ELC) for additional capabilities against asymmetric threats such as small maneuvering surface craft, slow-flying fixed and rotary-winged aircraft, and [[unmanned aerial vehicles]]. The FLIR sensor improves performance against anti-ship cruise missiles, while the OGB and ELC provide tighter dispersion and increased "first-hit" range; the Mk 244 ELC is specifically designed to penetrate anti-ship missiles with a 48 percent heavier tungsten penetrator round and an aluminum nose piece. Another system upgrade is the Phalanx 1B Baseline 2 radar to improve detection performance, increase reliability, and reduce maintenance. It also has a surface mode to track, detect, and destroy threats closer to the water's surface, increasing the ability to defend against fast-attack boats and low-flying missiles. As of 2019, the Baseline 2 radar upgrade has been installed on all U.S. Navy Phalanx system-equipped vessels.<ref>{{usurped|1=[https://web.archive.org/web/20131217204500/http://defensetech.org/2013/08/21/navy-overhauls-phalanx-ship-defense-weapon/ Navy Overhauls Phalanx Ship Defense Weapon]}} – Defensetech.org, 21 August 2013</ref> The Block 1B is also used by other navies, such as [[Canadian Forces Maritime Command|Canada]], [[Vasco da Gama class frigate|Portugal]], [[Japan Self-Defense Forces|Japan]], [[Military of Egypt|Egypt]], [[Military of Bahrain|Bahrain]], and the [[Royal Navy|UK]].<ref>{{cite web |url=http://www.prnewswire.com/cgi-bin/micro_stories.pl?ACCT=149999&TICK=RTN&STORY=/www/story/04-19-2006/0004342799&EDATE=Apr+19,+2006 |title=Raytheon Awarded Phalanx 1B Upgrade Order for Royal Navy |publisher=Prnewswire.com |access-date=2010-04-13 |archive-url=https://web.archive.org/web/20100901031737/http://www2.prnewswire.com/cgi-bin/micro_stories.pl?ACCT=149999&TICK=RTN&STORY=%2Fwww%2Fstory%2F04-19-2006%2F0004342799&EDATE=Apr+19%2C+2006 |archive-date=2010-09-01 |url-status=dead }}</ref>

[[File:CIWS Test USN.ogv|thumb|left|US Navy Phalanx CIWS maintenance and live firing test]]
In April 2017, Raytheon tested a new electric gun for the Phalanx allowing the system to fire at varying rates to conserve ammunition. The new design replaces the pneumatic motor, compressor, and storage tanks, reducing system weight by {{cvt|180|lb}} while increasing reliability and reducing operating costs.<ref>[http://www.prnewswire.com/news-releases/new-electric-gun-for-phalanx-close-in-weapon-system-passes-first-test-300434415.html New electric gun for Phalanx® Close-In Weapon System passes first test] – PRNewswire.com, 4 April 2017</ref>