High Mobility Multipurpose Wheeled Vehicle (HMMWV)
The High Mobility Multi-purpose Wheeled Vehicle (HMMWV) was designed as the the replacement vehicle for the M151 series jeeps. The HMMWV's mission was to provide a light tactical vehicle for command and control, special purpose shelter carriers, and special purpose weapons platforms throughout all areas of the modern battlefield. It was supported using the logistics and maintenance structure established for Army wheeled vehicles. The HMMWV is equipped with a high performance diesel engine, automatic transmission and 4 wheel drive, and is air transportable and air-droppable from a variety of aircraft. The HMMWV could be equipped with a self-recovery winch capable of up to 6000 pound 1:1 ratio line pull capacity and the initial series of vehicles could support payloads from 2,500-3,632, depending on the model. The HMMWV was produced in several configurations to support weapons systems, command and control systems, field ambulances, and ammunition, troop and general cargo transport.
When introduced, the HMMWV replaced selected M151 Jeeps (1/4-ton), the M274 Mule (1/2-ton), the M561 Gamma Goat (1 1/4-ton), the M718A1 ambulance (based on the M151 1/4 ton truck), and the M792 ambulance (based on the M561 1 1/4 ton truck). The M998 vehicle was the baseline variant for the HMMMWV family. A prime mover variant was also developed to tow the M119 light howitzer, M167 towed VADS system. A heavy cargo variant capable of handling payloads up to 4,400 pounds was eventually introduced that replaced this version and also supported heavier special purpose shelters. The HMMWV family also became the prime mover for the AN/TRC-170 Radio Digital Terminal and the Pedestal Mounted Stinger System. As a tri-service program, the vehicles and additional variants were also provided to satisfy Marine Corps and Air Force requirements.
In February 1981, the US Government invited proposals for a new High Mobility Multipurpose Wheeled Vehicle, and AM General was one of 5 companies that submitted proposals. AM General's Technical Proposal included drawings depicting the design of AM General's proposed "Humvee" vehicle, including a grille design with 9 vertical pill-capsule-shaped slots that were slightly taller than the round headlights that "book-ended" the slots.
AM General was among 3 companies awarded Phase I contracts in July 1981. Those contracts provided funding for production of prototype HMMWV vehicles for the US military to test. In March 1983, the government selected AM General to manufacture the HMMWV. During the government"s testing of the prototypes, AM General engineers made various design modifications based on performance issues raised by the government. In one of those changes, the engineers moved the headlamps inboard and eliminated the 2 outer slots of the 9-slotted grille. The HMMWV's 7-slotted grille first appeared in a blueprint completed in November 1982. This became standard for initial series HMMWVs.
The final version of the HMMWV was accepted in 1983 and AM General was awarded a $1.2 billion contract to produce 55,000 vehicles over a 5-year period (the contract would be eventually increased to $1.6 billion to produce 70,000 Humvees). On 24 July 1983, American Motors sold its AM General stock and assets to the LTV Corporation. There it bacem a fully-owned subsidiary of the LTV Aerospace and Defense Company. AM General sent production versions of the HMMWV to the military in 1984 for more testing, but did not begin shipping vehicles to the military until March 1985. AM General recieved additional contracts for more vehicles in 1989 and in 1994.
After its introduction, the HMMWV underwent numerous design and configuration updates and changes. In 1989, AM General recieved a contract to produce product improved vehicles, eventually known as the A1 series. Specific changes over the years included technological, environmental, operational, and safety improvements, such as higher payload capability, radial tires, a 1994 Environmental Protection Agency emissions update, commercial bucket seats, 3-point seat belts, 4-speed transmissions, and later.
Experiences during the first Gulf War in 1991 highlighted the lack of protection affored to HMMWVs utilized in the scout role. The United States Army looked into ways to add armor the HMMWV to improve the vehicle's utility in the scout role. The resulting vehicle, based on the A1 series chassis, was designed the XM1109 and featured enhanced ballistic protection and other equipment improvements. The payload capacity of the vehicle, however, hampered its performance.
In 1994, they recieved a contract for further improved vehicles in what became known as the A2 series, as well as vehicles with expanded payload capacities, referred to as the Expanded Capability Vehicle (ECV) series. Delivered in 1995, the A2 incorporated a 4-speed, electronic transmission; a 6.5 liter diesel engine; and improvements in transportability. The ECV HMMWVs also went into series production in 1995. The payload of these vehicle was 5,100 lb, including the crew.
With experiences in Somalia in 1993 and Bosnia in 1994, the US Army began work on developing an up-armored HMMWV using the ECV series chassis. The previous XM1109 vehicles, utilized in Haiti and Somalia, had experiences issues due to the excess weight on the older A1 chassis. These vehicles would later be further improved to include turbo-charged engines and air conditioning based on experiences in Afghanistan and Iraq during Operation Enduring Freedom and Operation Iraqi Freedom respsectively.
Between 2008 and 2009, development began on a further improved Expanded Capability Vehicle 2 (ECV 2) series. The increased weight of armor was found to severely degrade the performance of even the ECV series HMMWVs, and the ECV 2 series was intended recover lost performance without sacrificing too much in payload and protection.
