The beginning of the 1920s was very significant for the development of fast utility vehcles. For the first time, in the research area, intensive thoughts were being had about the conception of trucks. Were there really only two possibilities, slow vehicles for heavy loads and faster ones for the lighter transport?

The specific target was, to exceed the scanty speed of just under 20 km/h when carrying up to 5 tons of pay-load. Of course, the years before 1923 were marked by the first world war and the resulting economic- and inflation crisis, thus it was only after this period, that the door was even opened for new developments.

What they had in mind, was an experimental utility vehicle, capable of a little more than 2 tons of pay-load, which was also accordingly also realised. It was to be able to easily travel at 50 km/h on level roads, even with a full load. It had a four-cylinder engine with a bore of 110 mm and a stroke of 160 mm, giving it a good 6 liters of capacity. In the upper regions of 370 to 1400 RPM it developed 44 kW (60 hp).

Although the RPM-range would suggest otherwise, this was a petrol driven engine. This was still too early for the Diesel engine in road traffic. Because of the unfavourable octane-ratings, the compression ratio was limited to 5,7:1. One astonishing thing about this vehicle, was the abundant use of aluminium, e.g., the pistons, the engine block (excluding the sleeves) and other engine casings.

If one ignores the, nowadays no longer usual, separation of engine and gearbox, then the construction of the following engines wasn't all that different. Indeed, what was unusual, was the long thrust-pipe, in which the drive shaft ran and, that the rigid rear axle was supported against a chassis-crossbeam. Basically however, the axle-drive, with it's relatively large crown- and bevel wheel differential, could also go through today.

Measured by today's standards, and to put it mildly, the brakes were adventurous and were only found on the individual rear wheels, which had much larger tyres. The front wheel brakes were just starting to come into fashion in normal motor cars and racing vehicles. Apart from the foot- and hand brakes, which were applied separately through independant linkages, to the rear drum-brakes, there was also an engine brake, where apart from closing the throttle-flap, the intake valves were permanently closed and the exhaust valves permanently opened.

Thus, despite ambitious weight reducing, they had a dead weight of 3 tons, and when loaded, a total weight of almost 5,4 tons. For the testing, the still conventional solid rubber- or pneumatic tyres were used. If one subtracted the performance losses caused by rolling friction and also the air-resistance (10%), at a good 50 km/h and fully loaded, about only half the horse power at the clutch was left over in reserve. Thereby, the fourth and highest gear could already be used at 15 km/h, the third gear however, only managed a maximum of 30 km/h.

The very high fuel consumption in first gear of up to 200 liters per 100 kms, was reduced to less than 20 liters per 100 km/s in fourth gear. Although the vehicle could reach a maximum speed of 60km/h, in long distance haulage, it only managed an average of 40 km/h. The poor efficiency of the solid rubber tyres was formidable, although they did have the disadvantage of having a smaller rolling radius. An interesting factor is, how much damage to the roads was avoided, through the impact absorbtion of the pneumatic tyres. 02/14