The M151 belongs to the Military Unit Tactical Truck (MUTT) family of vehicles. It was designed in 1951 by the Ford Motor Company in an attempt to replace the WWII Jeep. At this time, the Jeep was the go-to mode of transportation to get through the trenches and to the front line. The M151 was first used in Vietnam, and was the primary combat Jeep of that time. It was retired from military service in the 1990s when the Humvee went into production. It is a modified version of the M38 designed and prototyped by Ford and then later manufactured by AM General.
Design Variations of the M151
The first modification to the original M151 was made in 1969 when it became necessary for the vehicles to be able to carry heavier loads. It was also adapted to correct a stability problem that made it susceptible to rolling over around tight corners. The main reason for the M151’s tendency to roll over was that its design was meant for Off Road use. It was not designed fro high speeds on flat surfaces. The tires are specifically designed using Non-Directional Tread meaning that there is no discernable tread pattern. This means that the tire was able to grip soft wet soil or other wet surfaces.
Special Training For M151 Use
Military personal that would be operating the M151 were required to receive special training. The military initially observed that troops were attempting to drive and handle them as they would any other vehicle. This practice was increasing the number of injuries due to roll-overs. The M151 were classified as hazards to public safety by the National Highway Traffic Safety Administration and they are therefore not permitted for use outside the military. The Department of Defense must therefore decommission them by crushing them or cutting the suspension.
Over the years, the following variants of the M151 were made:
- M151 (1960) – Initial version.
- M718 – Front-line ambulance variant.
- M151A1 (1964) – Incorporated minor changes in the rear suspension so that vehicle could carry heavier loads.
- M151A1C – The M151A1C equipped with a 106 mm recoilless rifle on a pedestal-mount. Could transport a driver and 2 passengers over 275 miles.
- M151A2 (1970) – Incorporated improvements to rear suspension that lead to safer cornery
- M151A2 TOW – tube-launched, optically-tracked, wire-guided [TOW] anti-tank missile variant.
- M1051 – Fire fighting variant (used exclusively by the United States Marine Corps)
Details of the design improvements
The first branch of the Unites States Military that was selected to test the M151 were the 9th Infantry division. An assessment of crew who used the vehicle showed that the vibrations cause by the vehicle were a serious health hazard. There were reports of kidney as well as back injuries. The assessment lead to a redesign that included an increase in seat padding to reduce the shock and vibration as well as an overhaul of the suspension system to improve shock absorbency.
The later designs were made so that they could be produced quickly and in large quantities. They were also made to be more rugged for the conditions they would endure on the terrain in developing countries. The redesign also made the M151 more affordable and easily maintained in the field.