MK-15 Phalanx CIWS

- , April 2018



Block 0

Block 1

Block 1A

Block 1B

Block 2C

Role and Mobility Ship-based air and missile defense for the ship; Fixed position(s) on ship
Interceptors and Range

20mm Armor Piercing Discarding Sabot (APDS);


Effective Range: 1,625yds (.9mi)[i]

Max Range: 6,000yds (3.4mi)[ii]

Depleted Uranium or Tungsten sub-caliber penetrator

3,000 rounds/min; Later models 4,500 rounds/min

989 rounds capacity; Later models 1,550 rounds


Self-contained search and track radar

Search radar – Ku-band; Digital MTI

Track radar – Ku-band; Pulse Doppler monopulse

E/O sensor – FLIR Imaging System with Automatic ACQ Tracker

Fire Control – Director with closed-loop spotting

Targets Aircraft, cruise missiles, Standard aircraft missiles


All U.S. Navy surface combatant ship classes[iii] and 24 allied nations

Designer/Producer Raytheon Systems Company


The MK 15 Phalanx provides ships protection against incoming missiles and aircraft.[vi] It is composed of six 20mm gun barrels, and fires up to a rate of 4,500 rounds per minute. The Phalanx is also equipped with its own search radar and tracking radar, which allows for the system to work independently of other systems.[vii] The Phalanx is capable of detecting an incoming attack, track the missile or aircraft, and engage the threat automatically. This provides a faster reaction time to ensure safety of the vessel. The Phalanx has had several versions throughout its career.

Block 0: The block 0 was the original CIWS, designed to engage and destroy low altitude anti-ship cruise missiles.[viii]

Block 1: Extended the range to high altitude missiles with an improved antenna, and improved ammunition capacity by 50%.

Block 1A: Modified software and processing power to allow the CIWS to perform more efficiently against multiple targets.[ix]

Block 1B Phalanx Surface Mode (PSUM): Added a Forward Looking Infrared Radar (FLIR), which allows the CIWS to engage hovering or slow-moving aircraft and surface craft.

Baseline 2C: Integrated multi-weapon capability. [x]

Strategic implications

The Phalanx is a necessity for U.S. naval ships to enter disputed seas, or seas with a U.S. adversary conducting “Anti-access/area denial” (A2/AD) operations within the territory. A2/AD is an increasing issue in areas such as the South China Sea and the Baltic territories. Without systems such as the Phalanx, U.S. naval vessels would be vulnerable to cruise missile, ballistic missiles, or aerial attacks. Having the capability to shoot down incoming threats can give U.S. sailors confidence to maintain the balance of power on the sea.


1978: Phalanx production started  with the Block 0 configuration

1980: Block 0 was installed on the USS Coral Sea.

1988: The Block 1 configuration was installed on USS Wisconsin.

1999: The first Block 1B installation was aboard USS Underwood (FFG-36).

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