Although the 12 ton tractor was strong enough to tow all known loads, development of the 18 tonne tractor was started in 1935 and designated as the Sd.Kfz.9.
SdKfz 9 18 tonne Heavy Tractor (The Bull) (for Poser)
Although the 12 ton tractor was strong enough to tow all known loads, development of the 18 tonne tractor was started in 1935 and designated as the Sd.Kfz.9.