Due to the hard condictions of Russian terrain during the mud seasons and inspired by the Red Army tractors like the STZ-5, the German Army started the design of a full-tracked prime mover and support vehicles in early 1941.

Development took place at the well-known Austrian Steyr works where the Porsche designed V-8 air-cooled gasoline engine was already in production.

The result was called "Raupenschlepper Ost", in short "RSO".

Due to its high tractive effort in first gear of 6,700 pounds and its good payload capability of 3,360 pounds, it soon proved an invaluable improvement of the German transport situation on the Eastern Fornt.
The trade-off, however, was the loud and fuel intensive engine (3 to 5.5 miles per gallon), the slow speed of only 9 miles per hour that made it unsuitable for any cooperation with motorized units, and the difficult steering accomplished through upright steering levers to four hydraulic brakes on the sprockets and idlers

As a result, its main tasks remained hauling mortars, light guns and howitzers and supplying all kind of freight to the front line.

More than 25,000 exemplars were made by Steyr as well as Wanderer, Magirus (different engine) and Gräf & Stift from 1942 to 1945.