The high-mobility multipurpose wheeled vehicle (HMMWV or Humvee) is a tactical vehicle designed and produced to replace the US Army’s current tactical vehicles in the 0.25t to 1.25t range.
It is manufactured by AM General LLC at its Mishawaka industrial plant. More than 50 countries and military organisations operate these vehicles.
In 1979, the US Army issued a draft specification for the new tactical vehicle which led the development of the Humvee. The US Army gave contracts to three contenders, AM General LLC, Chrysler Defense and Teledyne Continental, to design and develop eleven prototype HMMWVs, comprising of six weapon carriers and five utility vehicles. Testing was conducted over rocky hills, deep sand, 60in-deep water, desert heat and arctic snow over 600,000 miles.
In 1981, the US Army awarded a contract to AM General to produce additional prototypes of the tactical vehicle for further tests. The development and operational testing were conducted in 1982. In 1983, the US Army awarded a contract to AM General to manufacture 55,000 HMMWVs, of which 39,000 were for the US Army and the remaining vehicles for the US Marine Corps, US Air Force and US Navy.
In 1989, the HMMWV entered combat as part of Operation Just Cause, the US invasion of Panama.
M-1151A1 HMMWV upgrade
In 2008, the US Army fielded a new variant, the M-1151A1, to the National Training Centre. The M-1151A1 is fitted with a fragmentation kit five (FK 5) and objective gunner’s protection kit.
The FK 5 provides IED blast protection and small arms protection, while the objective gunner’s protection kit provides the gunner to view the battlefield with high safety through the transparent armoured glass. Later, in 2009, AM General launched the high-end armour fragmentation kit seven (FRAG 7) for the M1151 up-armoured Humvee.
HMMWV orders, deliveries and recapitalisation
In 1983, AM General received an initial production contract worth $1.2bn to produce 2,334 Humvees as a first increment of the total order of 55,000 vehicles. Production began in 1984 and the first deliveries were made in 1985. By 1991, 72,000 HMMWVs had been produced, including international sales.
Multiyear contracts to produce the HMMWV were awarded to AM General for another 33,000 vehicles. Orders for an additional 20,000 vehicles from over 40 international governments have been received since 1991. In total, 190,000 units had been produced by 2008.
In 2000, a production contract to manufacture 2,962 trucks in the M998A2 series was awarded to AM General. The contract included six single-year increments. The contract period was later extended until 2009. AM General delivered more than 85,000 trucks under this contract.
In August 2010, the company signed a $619m contract with the US Army to deliver 2,526 HMMWVs for the Afghan police force and National Guard. The US Army Tank-Automotive and Armaments Command (TACOM) placed two contracts for 153 HMMWVs in May 2010.
In April 2011, the US Army released a second request for information (RFI) for the competitive HMMWV recapitalisation programme. The programme is intended to upgrade around 60,000 older model HMMWVs to like-new condition, with high levels of protection. The major contenders, BAE Systems, Oshkosh and AM General, developed kits for the HMMWV recap programme. The first RFI published in January 2010 was denied by the US Congress.
In August 2017, AM General was awarded a $2.2bn firm-fixed-price foreign military sale (FMS) contract to deliver 11,560 new Humvees by 2022. AM General was awarded an $800m five-year contract for up to 2,800 M997A3 HMMWV ambulances in September 2018.
In October 2018, AM General received an order from the US Army for 740 new M1152A1 HMMWVs.The US Army placed a $185m order for 648 M997A3 HMMWV ambulances in April 2019.
The HMMWV is a lightweight, diesel-powered, four-wheel-drive tactical vehicle built on the M998 chassis common to all of its configurations, allowing it to carry military equipment, including machine guns and anti-tank missile launchers.
The vehicle is 6ft high, 7ft wide and 15ft long. The chassis is a steel frame with boxed frame rails and five cross members constructed from high-grade alloy steel. The body is made of aluminium, which reduces its weight and provides high resistance to corrosion.
The gross vehicle weight rating (GVWR) of the M998 HMMWV is 7,700lb, with a curb weight of 5,200lb. At its maximum payload of 2,500lb, the vehicle can reach a maximum speed of 65mph. It has seating options of 1+1 or 2+2 based on the configuration. It uses a 12V/24V electrical system and has a fuel tank with a capacity of 95l.
The HMMWV has disk brakes fitted on all four wheels. The disk brakes are mounted inboard the wheels, outside of each differential.
The changing requirements of armies across the world have driven the changes in the HMMWV models and equipment. The Humvee has four different models, namely A2 series vehicles, reliability extended vehicles, expanded-capacity vehicles and international vehicles.
Humvee A2 Series
The A2 series HMMWVs are fitted with a 6.5l V8 diesel engine with 160hp power rating and a four-speed automatic transmission. The common A2 series vehicles have a GVWR of 10,300lb and can carry a payload of 4,400lb at a maximum speed of 70mph.
Key additional features include an improved steering wheel and column, new rear seats, increased cargo capacity, improved brake pedal, and an improved 9,000lb winch.
The vehicles under this model include the M1097A2, M1097A2, M1123, M1097A2, M1025A2, M1043A2/1045A2, M997A2, and M1035A2.
Reliability extended HMMWVs
In 2006, AM General began the development of reliability extended Humvees. Key inclusions are a geared fan drive, new cool pack and shroud, new shock absorbers, new A-arm bushings, re-engineered geared hub assembly, and new parking brakes. The M1151, M1152 and M1165 are the three vehicles under this model.
HMMWV ECV expanded capacity vehicle
The expanded capacity vehicle (ECV) HMMWV has been developed to carry high payloads with the same performance levels. The most common vehicle weighs 2.5t and has a payload capacity of 5,100lb. It is powered by a turbocharged 6.5l V8 diesel engine. The key vehicles of this model comprise of the M1113, M1114, M1116, M1151 w/AC, M1151A, M1151A1 w/B1, M1152 w/AC, M1152A1, M1152A1 w/B2, M1165 w/AC, M1165A1 and M1165A1 w/B3.
International models are vehicles produced in collaboration with foreign companies. AM General has collaborated with many international players, such as the Swiss firm Mowag and the Turkish company Otokar, which have designed, tested and manufactured exceptional vehicles. The Eagle and Cobra are the two international models.
The HMMWV has over 15 configurations such as cargo carriers, troop carriers, armament carriers, ambulance and shelter carriers.
All of the variants have a common chassis, engine and transmission, as well as 44 interchangeable parts fitted in various positions.
Engine of Humvee
The M998 HMMWV is fitted with a 6.2l V8 fuel-injected, liquid-cooled, diesel compression-ignition engine that generates 150hp at 3,000rpm. It also has three-speed automatic transmission with a two-speed, locking, chain-driven transfer case.
The HMMWV is fitted with double A-arm independent suspension at the front and rear, coil springs and hydraulic double-acting shock absorbers for high off-road mobility. This system provides 16in ground clearance in normal load conditions. It has a track of 72in. The vehicle offers 40% slide slope, 60% slope-climbing and 60in of water fording capacities, making it an outstanding off-road vehicle.
The HMMWV is air-transportable, droppable and can be sling-loaded by helicopters. A C-13 Hercules aircraft can carry three HMMWVs and a C-5A Galaxy 15. In addition, the vehicle can be dropped by the low-altitude parachute extraction system.
|Mass||5,200 to 5,900 lb (2,359 to 2,676 kg) curb weight, 7,700 to 8,500 lb (3,493 to 3,856 kg) gross weight|
|Length||15 ft (4.57 m), wheelbase 10 ft 10 in (3.30 m)|
|Width||7 ft 1 in (2.16 m)|
|Height||6 ft (1.83 m), reducible to 4 ft 6 in (1.37 m)|
|Multiple, see design features|
|Engine||6.2 L (380 cu in) V8 diesel or 5.7 L gasoline or
6.5 L (400 cu in) V8 turbo diesel and non-turbo diesel: 190 hp (142 kW) @ 3,400 rpm / 380 lb·ft (515 N·m) @ 1,700 rpm
|Transmission||3-speed automatic or 4-speed automatic|
|Fuel capacity||25 U.S. gal (95 L)|
|Maximum speed||55 mph (89 km/h) at max gross weight
Over 70 mph (113 km/h) top speed