A project put forward in 1916-1917, by the request of the German War Ministry, was placed upon the commercial firm of Hansa-Lloyd works of Bremen. They were to design a battlewagon, Germany’s one and only "big wheel" design, which progressed further than its British counterpart.
The Treffas-Wagen was finished on February 1, 1917.It had two large steel wheels, about 11ft in diameter, on each side of a rectangular armoured body. At the rear was a large castor like roller for steering. In front of the body was a 2cm TUF gun, with machine guns on either side for firing into trenches. The crew consisted of four men. It weighed 18tons. One prototype was built, and thoroughly tested during February and March of 1917.
Meanwhile the decision was made in favor of the A7V. The Treffas-Wagen was not developed any further, and was dismantled in October of 1917.
German Tanks in World War One: Schneider/Strasheim
British & German Tanks of World War One: Chamberlain/Ellis
Armoured Fighting Vehicles of World War One: Doubleday
The German A7V Tank: Hundleby/Strasheim
Special thanks to Mr. Strasheim for the extra help, and photos.