The Berlin-based Stock company with its founder Robert Stock is considered the inventor of the motorised plough, a tractor with a plough attached to the frame. The Stock company started building these motorised ploughs in 1908 and soon became one of the leading manufacturers in Germany.
After the market for motorised ploughs became smaller and smaller, Stock developed the first tractor, a crawler tractor with an unusual appearance, in 1927. The track has large wheels at the front and small wheels at the back, so the centre of gravity of the track is very far forward.
The track is powered by a four-stroke two-cylinder engine of its own making with a displacement of 3,618cc, which can run on benzene, monopoline or petroleum. Depending on the fuel, the crawler tractor produces between 25 and 28 hp.
The gearbox has 3 forward and 1 reverse gears and was also made by Stock itself. The crawler was discontinued after only three years due to financial difficulties, but over 4,000 units were sold during that time.
In 1935, Stock's first wheeled tractor was introduced. A successful block-built design with pneumatic tyres. The Stock diesel tractor was powered by Deutz's water-cooled two-cylinder F2M313 diesel engine with an output of 20 hp. The transmission with 3 forward and 1 reverse gears was developed by Stock itself.
In 1938, the Stock diesel tractor was completely revised. A Deutz F2M414 engine with 22 hp was now installed. In fact, the gearbox now had 6 forward and 2 reverse gears in 2 groups, which was very advanced for the time.
From 1941, all manufacturers had to switch to wood gas generators, including Stock. Most of these tractors were converted back to diesel engines after World War II. After the end of the war in 1945, the Stock company lost its entire production facility in Berlin, so no more tractors were built.
Unfortunately, not many Stock tractors have survived to the present day. Well-preserved specimens are very rare and are traded at a high price.
From time to time, a Stock diesel tractor is offered for sale on Online Classic World.
