The M977 military vehicle is one of three vehicles – the M997, M997A1 and M997A2 – that made up the Maxi-Ambulance configuration of the HUMVEE family. These vehicles weighed 7, 000 pounds and were equipped with basic Kevlar armor for transporting their crew and patients safely from the battlefield to the medical station; Kevlar is a type of armor that is fairly effective against low-speed fragments but is totally useless against mines and high-speed fragments. Although not the safest vehicle, the M997 fulfilled the goals of its manufacturer, AM General, whose goal was to create a light, tactical vehicle to provide shelter on the battlefield.


The M997 was capable of carrying four littler patients, or two litter and four ambulatory patients, or eight ambulatory patients along with medical personnel, necessary equipment and a driver; the loading sequence for litter patients is to load the right side first and then the left side, moving from top right to bottom right and then top left to bottom left. The more critically injured patients would be loaded last and taken out first once the vehicle arrived at the medical station.

Patients would be loaded head-first because oxygen equipment is typically located at the front of the vehicle, patients are less likely to suffer from nausea if they are riding head first, and in case there is a rear-end collision; however exceptions would be made if the patient suffered from chest or abdominal wounds, or if patients needed IV fluids they would be placed in the lower racks to allow better IV flow and attention from medical personnel.

Other exceptions would be for persons with wounds on one side of their body or if patients were picked up in several different locations. For patients with wounds on one side, they were positioned however necessary to allow access to the wound; patients picked up in various locations would be loaded as best as possible regardless of their injuries since it would not be advised to unload the ambulance and reload it to organize patients based on injury each time a new patient was picked up.


The M977 could be heated, ventilated or air conditioned depending on the needs of the environment it was operating in; in areas where there might be a nuclear threat, the vehicles were equipped with Gas-Particulate Filter Units (GPFUs) with heaters that could support up to 7 personnel with its M25 or M13 series protective masks; the GPFU would force temperature-controlled, filtered air to each mask face-piece which eased breathing and reduced stress and heat fatigue during extended periods of operating in these dangerous areas.

When fully loaded, the M977 series could climb road grades as steep as 60 percent or ford hard bottom water crossings up to 30 inches deep without a deep water fording kit and 60 inches if the kit was included; the A1 and A2 series’ brought a few improvements and modifications to the vehicle, such as new bumpers, as well as a 9,000 pound self-recovery winch which was available for the A2 models.

Related Posts