page_title: Humvee
section_title: Modifications
hierarchical_section_title: Humvee / History / Modifications
caption_attribution_description: Humvee maintenance by Czech Army in Afganistan
context_page_description: The High Mobility Multipurpose Wheeled Vehicle is a family of light, four-wheel drive, military trucks and utility vehicles produced by AM General. It has largely supplanted the roles previously performed by the original jeep, and others such as the Vietnam War-era M151 jeep, the M561 "Gama Goat", their M718A1 and M792 ambulance versions, the Commercial Utility Cargo Vehicle, and other light trucks. Primarily used by the United States military, it is also used by numerous other countries and organizations and even in civilian adaptations. The Humvee saw widespread use in the Gulf War of 1991, where it navigated the treacherous desert terrain; this usage helped to inspire civilian Hummer versions. After going through a replacement process, the Joint Light Tactical Vehicle was chosen as its successor.
context_section_description: In December 2004, Secretary of Defense Donald Rumsfeld came under criticism from U.S. troops and their families for not providing better-equipped HMMWVs. Rumsfeld pointed out that, prior to the war, armor kits were produced only in small numbers per year. As the role of American forces in Iraq changed from fighting the Iraqi Army to suppressing the guerrilla insurgency, more armor kits were being manufactured, though perhaps not as fast as production facilities were capable. Even more advanced kits were also being developed.  While these kits are much more effective against all types of attacks, they weigh from 1,500 to 2,200 lb (680 to 1,000 kg) and have some of the same drawbacks as the improvised armor. Unlike similar-size civilian cargo and tow trucks, which typically have dual rear wheels to reduce sway, the HMMWV has single rear wheels due to its independent rear suspension coupled with the body design.
  Most up-armored HMMWVs hold up well against lateral attacks, when the blast is distributed in all different directions, but offer little protection from a mine blast below the truck, such as buried improvised explosive devices (IEDs) and land mines. Explosively formed penetrators (EFPs) can also defeat the armor kits, causing casualties.
  The armor kits fielded include the Armor Survivability Kit (ASK), FRAG 5, FRAG 6, as well as upgrade kits to the M1151. The ASK was the first fielded, in October 2003, adding about 1,000 pounds (450 kg) to the weight of the vehicle. Armor Holdings fielded an even lighter kit, adding only 750 pounds (340 kg) to the vehicle's weight. The Marine Armor Kit (MAK), fielded in January 2005, offers more protection than the M1114, but also increases weight. The FRAG 5 offered even more protection but was still inadequate to stop EFP attacks. The FRAG 6 kit is designed to do just that, however its increased protection adds over 1,000 lb (450 kg) the vehicle over the FRAG 5 kit, and the width is increased by 2 feet (61 cm). The doors may also require a mechanical assist device to open and close.
  Another drawback of the up-armored HMMWVs occurs during an accident or attack, when the heavily armored doors tend to jam shut, trapping the troops inside. As a result, the U.S. Army Aviation and Missile Research, Development, and Engineering Center (AMRDEC) developed the Humvee Crew Extraction D-ring in 2006. The D-ring hooks on the door of the HMMWV so that another vehicle can rip the door off with a tow strap, chain, or cable to free the troops inside. The D-ring was later recognized as one of the top 10 greatest Army inventions of 2006. In addition, Vehicle Emergency Escape (VEE) windows, developed by BAE Systems, were fielded for use on the M1114 up-armored HMMWV, with 1,000 kits ordered.
  The soldier manning the exposed crew-served weapon on top of the vehicle is extremely vulnerable. In response, many HMMWVs have been fitted with basic gun shields or turrets, as was the case with M113 APCs after they were first deployed in Vietnam. The U.S. military is currently evaluating a new form of protection, developed by BAE Systems as well as systems designed by the Army, which are already in theater. The new gunner's seat is protected by 1.5 to 2 feet (46 to 61 cm) high steel plates with bullet-proof glass windows. Additionally, some HMMWVs have been fitted with a remotely operated CROWS weapon station, which slaves the machine gun to controls in the back seat so it can be fired without exposing the crew. The Boomerang anti-sniper system was also fielded by some HMMWVs in Iraq to immediately give troops the location of insurgents firing on them.
  Another weakness for the HMMWV has proven to be its size, which limited its deployment in Afghanistan because it is too wide for the smallest roads and too large for many forms of air transport compared to jeep or Land Rover-sized vehicles (which are nearly two feet narrower). This size also limits the ability for the vehicle to be manhandled out of situations.
caption: Humvee maintenance with engine exposed by Czech Army in Afghanistan
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