Benz's first foray into tractor production came in 1907 when one of its board members, Georg Wiss, began work on a motor plough design. Wiss had entered the company via a merger with his firm, Suddeutsche Automobilfabrik GmbH (SAG), and he had already been experimenting with tractor designs for several years by the time he joined Benz. What emerged was a huge 65hp machine that weighed more than six tons and featured a hinged plough frame that was raised an lowered with engine power. Unfortunately this design failed to impress Benz and Wiss was eventually ousted from the company in 1910, going on to develop his motor plough designs with Daimler instead. Meanwhile, Benz had moved all of its commercial vehicle production to SAG's former Gaggenau plant and by 1912, Benz-Werke Gaggenau had been created as a subsidiary of Benz & Cie.

During the First World War, Benz's Gaggenau plant produced trucks and artillery tractors for the army, and when hostilities these designs were modified for agricultural and road-haulage use. Of principal interest here is the Benz-Gaggenau-Traktor, which first appeared in December 1919 and was intended for use on the farm and road, as well as in the forestry and construction industries. Powered by a four-cylinder petrol engine (later diesel), this was a very modern-looking machine with some consideration given to driver comfort. Nevertheless, it does not seem to have sold in great numbers. At around the same time a pure road-haulage tractor, the 50-55hp Benz-Gaggenau-Strassenzugmaschine, was also produced, and it is reported that Benz even converted some surplus WWI military tractors to cable ploughing use.

The year 1919 was a significant one for Benz, as it also saw the creation of Benz-Sendling Motorpfluge GmbH as a joint venture with Motorenfabrik Munchen-Sendling of Munich. The latter already had significant experience of tractor building, having introduced their first design as early as 1909, and for the Benz-Sendling project they were assisted by George Wiss acting as consultant. The Benz-Sendling Model T3, which appeared later that year bore all the hallmarks of a Wiss design, and was built by Leipziger Automobil & Aviatik AG, a subsidiary company of Benz. This three-wheeled machine with chain-drive to the rear wheel proved much more successful than Benz's previous venture, and received a silver medal at the German Agricultural Society's trials at Magdeburg in 1919. Two years later production shifted to Mannheim, and by 1923 a new version of the Benz-Sendling was ready, this time fitted with a two-cylinder diesel engine an named the Model S6. Key to this design was the gifted engineer Prosper l'Orange, who pioneered the use of high-speed diesel engines in motor vehicles. The three pre-production S6 tractors exhibited in East Prussia in June 1923 soon found homes on some of the region's huge estates, and the following year another 200 tractors were sold. A number of improvements were introduced into later versions of the three-wheeled design, most notably a more powerful engine, and sales continued to grow, with some tractors being shipped as far afield as Australia.

Cover of English-language brochure for Mercedes-Benz Model OE (click on image to enlarge)

Meanwhile, back in Germany, Benz & Cie. merged with Daimler-Motoren-Gesellschaft (DLG) in 1926 to form Daimler-Benz AG and the "Mercedes-Benz" name and now-legendary three-pointed star began to appear on the new company's products. By the late 1920s, many German manufacturers were beginning to abandon multi-cylinder engine designs in favour of the much simpler single-cylinder horizontal unit popularized by Lanz. Daimler-Benz followed suit, introducing the Mercedes-Benz Model OE Diesel Tractor in 1928. Also marketed by the Benz-Sendling division, the Model OE represented a radical change from Benz's earlier designs, with the emphasis now on simplicity and economy with an eye towards the overseas market. The single-cylinder crude oil engine was able to run on a variety of cheap low-grade fuels and the tractor itself was simple to maintain. A road version was offered with solid rubber or pneumatic tyres, and an optional radiator and fan could be fitted for hotter climates. However, the tractor was not as successful as Benz had hoped, due mainly to the dominance of the Lanz and the prevailing economic climate at the time. Some Model OE tractors did make it as far as Namibia and Australia, and an attempt was made to break into the French market by renaming it the "Helios", but by 1933 production had come to an end. This marked the end of Daimler-Benz's involvement in tractor building for quite some time, although the company would later enjoy great success with its Unimog and MB-Trac ranges.

Benz-Sendling T3
The three-wheeled Benz-Sendling Model T3 used a two-cylinder engine of 135 x 185 mm bore and stroke that developed 20-25hp at 800rpm and ran on benzene. Cooling was via a fan and radiator with water pump, while lubrication was automatic using a gear-driven oil pump. A high-tension magneto was used for ignition and a patented starting device and governor were standard. Only one forward and reverse gear was provided, with chain-drive to the rear wheel, but the speed could be varied from 3 to 4km/h by changing sprockets. All moving parts were enclosed in dust-proof casings. The T3 weighed just 2000kg and was 4.71m long and 1.7m wide, while the drive wheel was 1.4m in diameter and the front wheels 0.85m. These front wheels were sprung and featured automobile-type steering. Extension rims could be attached to the ends of the rear axle to increase stability and grip, but a pair of small auxiliary stabilising wheels was also included with every tractor.

Benz-Sendling S6, S7 and S8
The Benz-Sendling S6 was externally very similar to the T3, with the same single-speed transmission, but the key difference was the use of Benz's two-cylinder diesel engine. This was a compressorless, pre-chamber design, which was started by turning over at reduced compression with lighted touch paper inserted into the pre-chamber. The bore and stroke were 135 x 200 mm and it produced 25hp at 800rpm. The engine was much smoother running than a direct-injection diesel, but was let down by the complicated and unreliable starting procedure, and stories are told of farmers leaving their tractors running all night to avoid having to restart them in the morning! The first three prototypes of the S6 appeared in 1922, with production commencing the following year - over the next few years the design was modified slightly and the horsepower increased in the S7 and S8 models.

Mercedes-Benz OE
The 1928 Mercedes-Benz Dieselschlepper Model OE represented a significant departure from previous Benz designs. It featured a horizontal single-cylinder engine of 135 x 240 mm that produced 24hp at 800rpm, although the power output was later increased to 26hp when the bore was enlarged to 150mm. The engine was still of the same four-stroke pre-chamber diesel design as on previous models, but was now started using an ignition cartridge and automatic compression release. It also featured a removable cylinder head and liners, pressure-feed lubrication plus an automatic centrifugal governor for speeds between 300 and 800rpm. Hopper cooling was standard, but an optional radiator/fan was also available at extra cost. Three forward speeds of 3.2, 4.8 and 9.5 km/h and reverse of 4 km/h were provided on the original agricultural version of the OE, although these were increased for the road version to give a top speed of 12 km/h or more if desired. A belt pulley and choice of either paraffin or electric headlights were also optional extras.