Tank origin

The need for improved mobility became increasingly apparent to the U.S. military throughout the 1950s. As a result, it undertook efforts to develop new armored vehicles that met several criteria: lightweight, amphibious, and air-mobile, yet still capable of protecting the infantry they transported. Two prototypes emerged, the steel-bodied T117 and the aluminum-based T113. The latter was chosen and standardized for production as the M113 armored personnel carrier (APC) in 1960. It went on to become one of the most successful Western military vehicles, with over 80,000 units produced and in use with over 40 nations, some to this day.