One of the more unusual of the German vehicles of World War II was the SdKfz 2 Kettenkrafttrad, popularly known as the "Kettenkrad". The Kettenkrad was a halftrack prime mover with a single motorcyle style wheel in the front which was steered by handlebars. In addition to the driver there were accomodations for two passengers. It was powered by a 4-cylinder, liquid-cooled automobile engine capable of 43 mph. The Kettenkrad's performance was excellent -- it could go anywhere a tank could go and could ascend a 60 percent grade. The Kettenkrad was versatile enough to be used in a variety of roles. Although intended to be a prime mover for cargo or small field artillery, the Kettenkrad also was used for messenger duty in areas where wheeled vehicles could not go. Some versions were adapted to lay communications cables, utilizing a variety of spools that unwound the cable as the driver traversed the terrain. Another use for the Kettenkrad was to move the Luftwaffe's jet fighters and bombers from dispersal to the runway and back, thus minimizing the use of aviation fuel which was very scarce at the later stages of the war.
Doyle, David. Standard Catalog Of German Military Vehicles. Iola, WI: KP Books, 2005.