Laser quest: Phalanx, LaWs and the future of close-in weapon systems

18 June 2014 (Last Updated January 30th, 2020 13:14)

Close-in weapon systems (CIWS) remain a shipboard necessity for detecting and engaging missiles and aircraft at short range. Julian Turner assesses the latest upgrades to Raytheon’s ubiquitous Phalanx CIWS and analyses LaWS, a revolutionary laser-based defence system being field-tested by the US Navy.

Laser quest: Phalanx, LaWs and the future of close-in weapon systems

Phalanx

Designed to engage and destroy supersonic anti-ship missiles and high-speed aircraft that have penetrated outer fleet defensive envelopes, close-in weapon systems such as Raytheon's Phalanx remain the primary point defence solution for close-in air and surface threats.

In September 2013, the US Navy awarded Raytheon a $136.2m contract to upgrade 19 Phalanx CIWS and produce four SeaRAM anti-ship missile (ASM) defence systems. In May 2014, the UK Ministry of Defence (MoD) - one of 25 allied navies to employ Phalanx on its surface combatant ship classes - took delivery of four 1B kit modifications and two conversions of the land-based system.

Building upon the original rapid-fire, computer-controlled radar and 20mm gun system, the Phalanx 1B weapon package incorporates a side-mounted forward looking infra-red camera (FLIR) to counter the threat of unmanned aerial vehicles (UAVs), mines and small surface craft in littoral waters.

SeaRAM uses advanced Phalanx Block 1B sensors and replaces the Gatling gun with an 11-round Rolling Airframe Missile guide, and is intended to enlarge Phalanx's keep-out range against evolving anti-ship missiles as well as rotary and fixed-wing aircraft.

"Close-in weapon systems remain the primary point-defence solution to counter close-in air and surface threats."

"Phalanx is a vital ship self-defence system, providing the critical inner layer of protection to sailors, marines and ships," said Rick Nelson, vice president of Raytheon Missile Systems' Naval and Area Mission Defense product line. "With SeaRAM comes a significant extension of that inner-layer battlespace and the capacity to effectively engage multiple high-performance threats."

The Block 1B Phalanx close-in weapon system

The Phalanx CIWS developed by Raytheon is a rapid-fire, computer-controlled, radar-guided gun system designed to defeat anti-ship missiles and other close-in air and surface threats. A self-contained package, it automatically carries out a range of functions usually performed by multiple systems, including search, detection, threat evaluation, tracking, engagement and kill assessment.

Phalanx Block 1B, the latest upgrade, features surface mode configuration and augments the proven anti-air warfare capability by adding a forward-looking infrared sensor and optimised gun barrels to the Block 1A configuration. This not only allows Phalanx to be used against littoral threats such as helicopters and high-speed surface vessels, but also adds control stations with situational awareness that allow operators to visually track and identify targets before engagement.

Phalanx's advanced 3D search radar extracts slow-moving targets from high-clutter environments by employing digital moving target identification processing and narrow correlation windows. The on-screen radar display allows the operator to rapidly locate targets using both infrared and radio frequency tracking, meaning that the system can detect small boats when other radars cannot.

The superior sensor suite features enhanced operability in the shape of day and night detection as well as fire-control and sensor capability for other shipboard gun and missile systems. The Phalanx 1B package also offers improved firepower in the shape of enhanced lethality cartridges that increase kinetic energy and mass by up to 50%. Optimised gun barrels are 48cm longer, 8.6kg heavier and reduce both dispersion and projectile yaw.



The £330m Merlin Life Sustainment Programme will convert 25 RAF AW101 Merlin helicopters for maritime use.


In summary, the Phalanx Block 1B system offers positive threat identification, augments the ship's radar performance in sea and land clutter, increases its outer defence perimeter and counters subsonic and supersonic ASMs, UAVs, fixed-wing aircraft, helicopters high-speed surface vessels.

The system also compares favourably with rival European CIWS systems such as Goalkeeper and DARDO in terms of key metrics such as armaments, range and rate of fire.

The SeaRAM anti-ship missile defence system

Configured to provide the highest level of ship self-defence and extended keep-out range capability, SeaRAM extends the inner layer battlespace and enables ships to effectively engage with multiple high-performance, supersonic and subsonic threats.

SeaRAM combines key attributes of the Phalanx CIWS, including its high-resolution search and track sensors and quick response capability, with Raytheon's leading-edge Rolling Airframe Missile (RAM) guided weapon system. SeaRAM takes advantage of RAM's superior accuracy, extended range and high manoeuvrability, while an 11-missile RAM launcher assembly replaces Phalanx's 20mm gun.

Crucially, with military budgets under increased scrutiny, SeaRAM is also an affordable capability upgrade - the above-deck system fits the exact footprint of the Phalanx, uses the same power and requires minimal shipboard modification.

Announcing the remanufacture, overhaul and upgrade deal with the US Navy in September 2013, Nelson said: "Raytheon's ability to remanufacture Phalanx equivalent to new manufacture condition, in appearance, operation and performance, provides a significant cost savings to our customers."

The contract, which also has a $94.8m option for 2014, bringing its potential cumulative value to $231m, offers purchases for the US Navy, the US Army, Japan and Pakistan under the foreign military sales programme.

LaWS: analysing next-generation CIWS technology

The US Navy is set to take CIWS technology into unchartered territory this summer when it sea-tests a revolutionary directed-energy laser weapon on board the USS Ponce in the Persian Gulf.

Scientists working under the Office of Naval Research (ONR) Quick Reaction Capability programme have proved that targets identified by a Phalanx CIWS can just as easily be tracked using the Laser Weapon System (LaWS). In 2011, an earlier version of the high-energy laser was used to defeat small boat threats from a destroyer and the following year LaWS downed multiple unmanned aircraft.

"Phalanx automatically carries functions usually performed by multiple systems, including search, detection, threat evaluation, tracking, engagement and kill assessment."

The system comprises a single laser weapon control console manned by a surface warfare weapons officer on board the USS Ponce, who can operate all functions of the laser and, if commanded, fire the weapon. Using a video-game-like controller, that sailor will be able to manage the laser's power to accomplish a range of effects against a threat, from disabling to complete destruction.

Experts believe that high-energy lasers now offer an affordable way to target asymmetric threats such as unmanned aircraft and small attack boats at the speed of light and with extreme precision.

Data from the deployment aboard the USS Ponce will guide the development of combat-ready laser prototypes under the ONR's Solid-State Laser Technology Maturation (SSL-TM) programme. Teams led by Northrop Grumman, BAE Systems and Raytheon will develop combat-ready laser prototypes for installation in 2016 on guided-missile destroyers and the US Navy's Littoral Combat Ship in 2016.

"We are in the midst of a pivotal transition with a technology that will keep our sailors and marines safe and well-defended for years to come," said Peter Morrison, ONR programme manager for the SSL-TM project. "We believe the deployment on Ponce and SSL-TM will pave the way for a future acquisition program of record so we can provide this capability across the fleet."

The navy will decide next year which, if any, of the three industry prototypes are suitable to move forward and begin initial ship installation for further testing.

"This is a revolutionary capability," said Chief of Naval Research Rear Admiral Matthew Klunder. "It's absolutely critical that we get this out to sea with our sailors for these trials, because this very affordable technology is going to change the way we fight and save lives."

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