December 10, 2010: After two years of talking about it, and doing some tinkering, the U.S. Army finally mounted a Centurion anti-rocket/mortar system on a heavy truck, and successfully fired it. This Centurion was originally developed six years ago, as "C-RAM". It is basically the Phalanx naval gun system with new software that enables it to take data from other radar systems, and shoot down just about any kind of artillery shell or rocket within range. Renamed Centurion, it uses high explosive 20mm shells, that detonate near the target, spraying it with fragments. By the time these fragments reach the ground, they are generally too small to injure anyone. At least that's been the experience in Iraq and Afghanistan. The original Phalanx used 20mm depleted uranium shells, to slice through incoming missiles. Phalanx fires shells at the rate of 75 per second. Another advantage of Centurion, is that it makes a distinctive noise when firing, warning people nearby that a mortar or rocket attack is underway, giving people an opportunity to duck inside if they are out and about.
The Mobile Centurion is basically the Centurion and a generator on a U.S. Army HEMTT (for Heavy Expanded Mobility Tactical Truck, which is a flatbed truck). This enables the Centurion to be easily moved to protect areas that were suddenly getting hit with rocket or mortar fire. This keeps people in the target area safe until troops could hunt down and kill or arrest the attackers. It's usually a small group of people, or even an individual, responsible for these attacks. But with enough time, and the use of UAVs and special radars, the attackers can be located and caught.
The HEMTT is also known as the M-977. These vehicles have a diesel electric drive, thus there is plenty juice for the radar and electric motors of the Centurion system. The 8x8 HEMTT trucks are built for cross country operations and were able to keep up with armored formations during the 1991 and 2003 wars. Most of the 13,000 army HEMTT's normally haul ten tons of cargo or 2500 gallons (10,000 liters) of fuel. A Phalanx/Centurion system weighs six tons. The HEMTT began to enter service in the late 1980s, and cost about $200,000 each (depending on special equipment and configuration.) Starting five years ago, the HEMTT fleet began a refurbishment program (at about half their original cost) to give the trucks another ten years of life. This included development of a version that used the diesel-electric drive.
Meanwhile, the navy has upgraded the radar and heat sensors on its Phalanx CIWS (Close In Weapons System) so that that the sensors can detect speedboats, small aircraft and naval mines. The upgrades will cost $4.7 million per system. Of the 57 systems being upgraded to this Block B standard, 17 of them are the land based, Centurion, version of Phalanx.
The first Centurion was sent to Iraq in late 2006, to protect the Green Zone (the large area in Baghdad turned into an American base). It was found that C-RAM could knock down 70-80 percent of the rockets and mortar shells fired within range of its cannon. Since then, the U.S. Army has received 22 Centurion systems (and Britain got ten). The U.S. Centurions have so far defeated hundreds of rocket and mortar attacks against American bases. Not bad, since it only took about a year to develop Centurion. Each one costs $15 million.