M997A3 Tactical Humvee Ambulance, United States of America

M997A3 Tactical Humvee Ambulance

The M997A3 tactical High Mobility Multipurpose Wheeled Vehicle (HMMWV or Humvee) ambulance is being built for use by the US Army National Guard (ARNG) in homeland defence and natural disaster relief operations.

The M997A3 is built on an upgraded M997 ambulance box mounted on a modified M1152A1 chassis. It is intended to transport casualties from the theatre to the medical aid stations.

The new M997A3 tactical ambulances are set to supplement or replace the Army National Guard's existing M996 two-litter and M997 four-litter models.

M997A3 Humvee ambulance orders and deliveries

The Army Test and Evaluation Command (ATEC) completed development testing and user evaluation of the M997A3 HMMWV ambulance in February 2012.

The Army partnered with the Rock Island Arsenal Joint Manufacturing and Technology Center (RIA-JMTC) in Illinois to procure the modern M997A3 Humvee ambulances to address the ground ambulance shortage. The ambulance boxes are manufactured and integrated onto the Humvees, supplied by AM General, at the RIA-JMTC.

A total of five prototypes have been built in 2013 and full production was commenced in January 2014.

In September 2015, AM General signed a $428.3m firm-fixed-price, multi-year, indefinite-delivery / indefinite-quantity (IDIQ) contract to supply new M997A3 Humvee chassis vehicles to the US Army, Army Reserve, and Army National Guard.

Up to 654 vehicles will be initially delivered to the Army National Guard under an $89.5m contract.

Design and features of M997A3 tactical Humvee ambulance

"The M997A3 … is intended to transport casualties from the theatre to the medical aid stations."

M997A3, the modern Humvee ambulance in the Army fleet, is built on a steel frame with boxed frame rails and five cross members. It can be transported by land, sea and air, and can accommodate up to four litter patients.

The vehicle features enhanced drive train, improved interior, improved cabin lighting, air conditioning system, ventilation system, oxygen bottles, oxygen concentrator, cargo nets, litter rack, improved medical kits, M1025 doors and M997A2 windshield frame / ballistic glass. It can be optionally fitted with Arctic Cold Start Kit.

The ambulance box is installed with LED lighting systems to provide medics with upgraded lighting. It also features a control panel, allowing medics to control air conditioning and heating systems.

A large door is fitted between the vehicle cab area and the ambulance box to facilitate easy access between them. The fuel tank is fitted with an auxiliary fuel pickup for fuel-fired heater.

Protection features

The M997A3 Humvee is equipped with basic armour protection. Its bulletproof glass offers ballistic protection for the occupants from small arms.

Propulsion system

The M1152A1 chassis is powered by General Engine Products (GEP) V8, 6.5L turbocharged diesel engine, which generates an output power of 190hp at 3,400rpm and produces a torque of 515nm at 1,700rpm.

"The ambulance box is installed with LED lighting systems to provide medics with upgraded lighting."

The engine is coupled to a General Transmission Products (GTP) four-speed automatic transmission system. The front and rear suspension is provided by independent double A-Frame, coil spring, and telescopic shock absorbers.

The vehicle is also equipped with two-speed transfer case; hypoid front and rear differentials; dual disc, independent, hand-operated lever for parking brake function; and discs on the front and rear for service brake function. The run-flat tyres are installed to provide improved mobility on rough terrains.

M997A3 performance

The engine provides a maximum speed of 113kph. The vehicle can negotiate grades of 40% and side slopes of 30% and can climb vertical steps of 0.457m. Its approach, departure and ramp breakover angles are 48°, 39° and 25° respectively.

The vehicle has a track width of 1.82m, a turning radius of 7.62m, a wheelbase of 3.30m, a ground clearance of 0.457m, and a fording depth of 0.76m in deep water. It can be operated under all terrain and weather conditions.