Following the appearance of the first British tanks on the Western Front, in September 1916, the German War Ministry formed a committee, under the auspices of its Allgemeines Kriegsdepartement, Abteilung 7 Verkehrswesen ("General War Department, Section 7, Transportation"),[4] to investigate tank development.The project to design and build the first German tank was placed under the direction of Joseph Vollmer, one of Germany's foremost automobile designers. It was to weigh around 30 tons, be capable of crossing ditches up to 1.5 metres (4.9 ft) wide, have armament including a cannon at the front and rear as well as several machine-guns, and reach a top speed of at least 12 kilometres per hour (7.5 mph). The running gear was based on the American Holt tractor, copied from examples loaned by the Austro-Hungarian Army. After initial plans were shared with the army in December 1916, the design was extended to be a universal chassis that could be used as a base for both a tank and unarmoured Überlandwagen ("over-land vehicle") cargo carriers.The first prototype was completed by Daimler-Motoren-Gesellschaft at Berlin-Marienfelde and tested on 30 April 1917. A wooden mockup of a final version was completed in May 1917 and demonstrated in Mainz with 10 tons of ballast to simulate the weight of the armor. During final design, the rear-facing cannon was removed and the number of machine-guns was increased to six. The first pre-production A7V was produced in September 1917, followed by the first production model in October 1917. The tanks were given to Assault Tank Units 1 and 2, founded on 20 September 1917, each with five officers and 109 non-commissioned officers and soldiers.