Dynamic Load Allowance for Military Tracked and Wheeled Vehicles: Experimental Results

The ability of tracked fighting vehicles (e.g. tanks) to cross bridges is a critical aspect of military operations. Military vehicles, specifically tanks, are continuously increasing in mass, while bridge infrastructure capacity remains relatively unchanged. This can significantly affect mobility on military operations. The North Atlantic Treaty Organization (NATO) utilizes a Military Load Classification (MLC) system that provides a method to compare the load effects of vehicles to the capacity of bridges in order to determine the feasibility of crossing. Tracked vehicles exhibit significantly different behavior than wheeled vehicles; yet frequently the MLC system is applied using the same vehicle-related factors when determining the capacity for both wheeled and tracked vehicles. One of these factors, Dynamic Load Allowance (DLA), is not based on recent research for modern tracked vehicles. Bridge load testing was carried out with one tracked vehicle and three wheeled vehicles. Results of the dynamic effects generated on a smooth surface are presented and indicate that a lower DLA for tracked vehicles, than wheeled vehicles, is likely appropriate. A lower DLA for tracked vehicles would result in increased bridge capacity for tanks.