View Full Version : Navy Gatling guns to defend Iraq bases

06-23-05, 06:08 AM
June 27, 2005

Navy Gatling guns to defend Iraq bases

By Greg Grant
Special to the Times

The Army hopes it has found the answer to Iraqi insurgents’ lethal mortar and rocket attacks in its Counter-Rocket Artillery Mortar system, or C-RAM, designed to shred incoming projectiles in a curtain of lead fired from a huge Gatling gun.
When its radar picks up an incoming round, C-RAM can set off strobe lights to alert people to take cover, unleash a blast of 20mm shells and dispatch an armed unmanned aerial vehicle to kill whoever fired it.

C-RAM is built around the Raytheon Phalanx Close-In Weapons System, or CIWS, a radar-guided, multibarrel gun used on Navy warships to shoot down incoming missiles.

The system networks a ground-based version of Phalanx with the Army’s Lightweight Counter Mortar Radar and Q-36 Target Acquisition Radar, which detect incoming rounds and pinpoint their origin. Even before the projectile lands, the system can feed the firing location to a Hunter UAV armed with Viper Strike laser-designated munitions.

The first two C-RAM systems arrived in Iraq in mid-May, the product of an early 2004 demand from Army Gen. Peter Schoomaker. The service chief of staff demanded some means of protecting U.S. troops on the sprawling American bases that dot Iraq. These bases have become a daily target of insurgent mortar and rocket strikes.

Green Zone danger

The Green Zone in downtown Baghdad, seat of the newly installed Iraqi government as well as the U.S. Embassy and other government and military installations, is another favorite target of Iraqi indirect fire attacks.

Despite nearly constant U.S. aerial and ground surveillance of suspected firing points, mortar and rocket attacks into the Green Zone spike whenever the Iraqi parliament gathers or news of visiting dignitaries reaches insurgents.

C-RAM uses the Phalanx Block 1B system, which uses a forward-looking infrared sensor to track incoming objects — even very small ones — and its outgoing shells. Tests since its fielding in 1977 have shown Phalanx to be effective in shooting down high-speed maneuverable missiles, unguided rockets and even 155mm heavy artillery rounds.

But a city presents a tougher challenge for radar engineers than the open ocean, where there are no buildings to clutter the sensor picture. Raytheon modified the radar system’s software package, but left the Phalanx basically unchanged.

C-RAM’s Phalanxes are loaded with different rounds than the 20mm depleted-uranium slugs used aboard warships. Army officials decided that the slugs, fired at a rate of up to 4,500 rounds a minute, were not appropriate for use in densely populated cities.

So officials went looking for a round that would blow up in midair, before it could cause accidental death or damage on the street.

The answer was provided by the 1960s-era Vulcan program, an air-defense system designed to operate directly behind friendly ground forces. The Vulcan used a 20mm high-explosive round that explodes in midair.

The rounds work not so much like “punching metal, but more like raining metal,” said Col. Rickey Smith of the Army’s Futures Center, which developed and fielded C-RAM. “It’s more like BBs blowing out there that rip through and shred” incoming projectiles.

Smith said one of the greatest benefits of C-RAM is its early warning of indirect fire attack.

When it detects incoming rounds, strobe lights go off and “incoming” flashes on computer screens, giving people nearby the vital seconds to get down flat on the ground or to duck into bunkers. He said such measures have been shown to reduce casualties by 65 percent.

A prototype of the modified Phalanx was tested in December at Yuma Proving Ground, Ariz., against 60mm and 81mm mortar rounds. Sources familiar with the tests said the CIWS shot down 78 percent of incoming projectiles.

In later tests of the system’s ability to send targeting data to the Hunter UAV, the Viper Strike munitions hit all identifiable targets.

Smith said they were able to field the first systems barely 11˝ months after the original request because of the center’s ability to rapidly integrate off-the-shelf systems and facilitate their fielding.

He said it’s a new approach to getting vital capabilities out to soldiers during wartime.

The Army received two CIWS systems via a March 3 Navy contract with Raytheon.

C-RAM was funded in the 2005 supplemental budget at $75 million, with an additional $183 million allocated in the House version of the 2006 defense spending bill.

Greg Grant is a staff writer for Defense News.