The High Mobility Multipurpose Wheeled Vehicle (HMMWV; colloquial: Humvee) 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 (CUCV), 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 negotiated the treacherous desert terrain; this usage helped to inspire civilian Hummer versions. After going through a replacement process, the Joint Light Tactical Vehicle (JLTV) was chosen as its successor.
Since the World War II ¼-ton reconnaissance truck was green-lit for mass-deployment, and became known as the "jeep", the United States military had continued to rely heavily on jeeps as general utility vehicles, and as a mass-transport for soldiers in small groups. Although the US Army had let Ford redesign the jeep from the ground up during the 1950s, and the resulting M151 jeep incorporated significant innovations, it firmly adhered to the original concept—a very compact, lightweight, low profile vehicle, with a folding windshield, that a layman could barely distinguish from the preceding Willys jeeps. The jeeps were shorter than a Volkswagen Beetle and weighed just over one metric ton, seating three with an 800 lb (360 kg) payload. During and after the war, the very light, 1⁄4-ton jeeps were complemented by the 3⁄4-ton Dodge WC and Korea War M37 models.
By the mid-1960s, the U.S. military clearly felt a need to reevaluate their aging light vehicle fleet. For starters, from the mid 1960s, the U.S. Army had tried to modernize, through replacing the larger, purpose-built Dodge M37s by militarized, "commercial off the shelf" (COTS) 4×4 trucks—initially the M715 Jeep trucks, succeeded in the later 1970s by the Dodge M880 series, but these didnt satisfy newer requirements either—what was wanted was a truly versatile light military truck, that could replace multiple outdated vehicles. When becoming aware of the U.S. Armys desire for a versatile new light weapons carrier / reconnaissance vehicle, as early as 1969 FMC Corporation started development on their XR311 prototype, and offered it for testing in 1970. At least a dozen of these were built for testing under the High Mobility Combat Vehicle, or HMCV program, initially much more as an enhanced capability successor to the M151 jeep, than as a general purpose load lugger. In 1977, Lamborghini developed the Cheetah model in an attempt to meet the Army contract specifications.
In 1979, the U.S. Army drafted final specifications for a High Mobility Multipurpose Wheeled Vehicle (HMMWV), which was to replace all the tactical vehicles in the 1/4 to 1 1/4-ton range, namely the M151 quarter-ton jeep and M561 Gama Goat, as one "jack-of-all-trades" light tactical vehicle to perform the role of several existing trucks.[unreliable source?] The specification called for excellent on and off-road performance, the ability to carry a large payload, and improved survivability against indirect fire. Compared to the jeep, it was larger and had a much wider track, with a 16 in (410 mm) ground clearance, double that of most sport-utility vehicles. The new truck was to climb a 60 percent incline and traverse a 40 percent slope. The air intake was to be mounted flush on top of the right fender (or to be raised on a stovepipe to roof level to ford 5 ft (1.5 m) of water and electronics waterproofed to drive through 2.5 ft (0.76 m) of water were specified. The radiator was to be mounted high, sloping over the engine on a forward-hinged hood.
Out of 61 companies that showed interest, only three submitted prototypes. In July 1979, AM General, a subsidiary of American Motors Corporation began preliminary design work. Less than a year later, the first prototype was in testing. Chrysler Defense and Teledyne Continental also produced competing designs. In June 1981, the Army awarded AM General a contract for development of several more prototype vehicles to be delivered to the government for another series of tests. The original M998 A0 series had a curb weight of 5,200 lb (2,400 kg), a payload of 2,500 lb (1,100 kg), a 6.2 L (380 cu in) V-8 diesel engine and 6.3 L gasoline, and a three-speed automatic transmission.
The three companies were chosen to design and build eleven HMMWV prototypes, which covered over 600,000 miles in trials which included off-road courses in desert and arctic conditions. AM General was awarded an initial contract in 1983 for 2,334 vehicles, the first batch of a five-year contract that would see 55,000 vehicles delivered to the U.S. military, including 39,000 vehicles for the Army; 72,000 vehicles had been delivered to U.S. and foreign customers by the Persian Gulf War of 1991, and 100,000 were delivered by the Humvees 10th anniversary in 1995. Ft. Lewis, Washington and the 2nd Battalion 1st Infantry, 9th Infantry Division was the testing unit to employ HMMWV in the new concept of a motorized division. Yakima Training Center in Yakima, Washington was the main testing grounds for HMMWVs from 1985 through December 1991, when the motorized concept was abandoned and the division inactivated.
HMMWVs first saw combat in Operation Just Cause, the U.S. invasion of Panama in 1989.
The HMMWV was designed primarily for personnel and light cargo transport behind front lines, not as a front line fighting vehicle. Like the previous jeep, the basic HMMWV has no armor or protection against chemical, biological, radiological or nuclear threats. Nevertheless, losses were relatively low in conventional operations, such as the Gulf War. Vehicles and crews suffered considerable damage and losses during the Battle of Mogadishu in 1993 due to the nature of the urban engagement. However, the chassis survivability allowed the majority of those crews to return to safety, though the HMMWV was never designed to offer protection against intense small arms fire, much less machine guns and rocket-propelled grenades. With the rise of asymmetric warfare and low intensity conflicts, the HMMWV was pressed into service in urban combat roles for which it was not originally intended.
After Operation Restore Hope in Somalia, the military recognized a need for a more protected HMMWV and AM General developed the M1114, an armored HMMWV to withstand small arms fire. The M1114 has been in production since 1996, seeing limited use in the Balkans before deployment to the Middle East. This design is superior to the M998 with a larger, more powerful turbocharged engine, air conditioning, and a strengthened suspension system. More importantly, it boasts a fully armored passenger area protected by hardened steel and bullet-resistant glass. With the increase in direct attacks and guerrilla warfare in Iraq, AM General diverted the majority of its manufacturing power to producing these vehicles.
Humvees were sent into Afghanistan following the 9/11 terrorist attacks, where they proved invaluable during initial operations. In the early years before IEDs became prevalent, the vehicle was liked by troops for its ability to access rough, mountainous terrain. Some soldiers would remove features from Humvees, including what little armor it had and sometimes even entire doors, to make them lighter and more maneuverable for off-road conditions and to increase visibility. With the onset of the Iraq War, Humvees proved very vulnerable to IEDs; in the first four months of 2006, 67 U.S. troops died in Humvees. To increase protection, the U.S. military hastily added-on armor kits to the vehicles. Although this somewhat improved survivability, bolting on armor made the Humvee an "ungainly beast", increasing weight and putting strain on the chassis, which led to unreliability. Armored doors that weighed hundreds of pounds were difficult for troops to open and the newly armored turret made Humvees top heavy and increased the danger of rollovers. The U.S. Marine Corps decided to start replacing Humvees in combat with Mine-Resistant, Ambush Protected (MRAP) vehicles in 2007, and the U.S. Army stated that the vehicle was "no longer feasible for combat" in 2012.
The HMMWV has become the vehicular backbone of U.S. forces around the world. Over 10,000 HMMWVs were employed by coalition forces during the Iraq War. The Humvee has been described as "the right capability for its era" to provide payload mobility in protected areas, but that conflicts exposing it to full-spectrum threat environments that it was never designed to operate or be survivable in led to adding protection at the cost of mobility and payload.
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 vehicles 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 gunners 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.
The Army purchased a purpose-built armored car, the M1117 Armored Security Vehicle also known as an armored personnel carrying vehicle (APC), in limited numbers for use by the United States Army Military Police Corps. In 2007, the Marine Corps announced an intention to replace all HMMWVs in Iraq with MRAPs due to high loss rates, and issued contracts for the purchase of several thousand of these vehicles, which include the International MaxxPro, the BAE OMC RG-31, the BAE RG-33 and Caiman, and the Force Protection Cougar, which were deployed primarily for mine clearing duties. Heavier models of infantry mobility vehicles (IMV) can also be used for patrol vehicles. The MaxxPro Line has been shown to have the highest rate of vehicle rollover accidents to its very high center of gravity and immense weight. The massive weight of these vehicles combined with their high center of gravity also greatly reduces their utility in off-road situations versus the HMMWV, which was the primary cause for the push for the Oshkosh M-ATV to be developed quickly.
The Humvee replacement process being undertaken by the U.S. military focused on interim replacement with MRAPs and long-term replacement with the Joint Light Tactical Vehicle (JLTV). The HMMWV has evolved several times since its introduction and was used in tactical roles for which it was never originally intended. The military pursued several initiatives to replace it, both in the short and long terms. The short term replacement efforts utilized commercial off-the-shelf vehicles as part of the Mine Resistant Ambush Protected (MRAP) program. These vehicles were procured to replace Humvees in combat theaters. The long term replacement for the Humvee is the JLTV which is designed from the ground up. The Future Tactical Truck Systems (FTTS) program was initiated to make an analysis of potential requirements for a Humvee replacement. Various prototype vehicles such as the MillenWorks Light Utility Vehicle, and the ULTRA AP have been constructed as part of these efforts. The JLTV contract was awarded to Oshkosh in August 2015.
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