On 9 October 1946 the first the Unimog prototype was taken for its maiden test run, with chief designer Heinrich Rößler behind the wheel.
The Prototype 1 had no bonnet and was fully laden with wood and driven on rough forest roads.
The idea for the Unimog was developed by Albert Friedrich, who had headed up aircraft engine development at Daimler-Benz AG. After WWII Germany suffering supply shortages, including a distressing lack of food. This gave Albert Friedrich his idea of an agricultural motorised vehicle which should help to increase agricultural productivity.
He wanted to help with the reconstruction of Daimler-Benz AG and at the same time contribute his idea of an agricultural motorised machine. On 4 August 1945 in Stuttgart-Untertürkheim, an engineer for Daimler-Benz AG, under the leadership of Friedrich, drew up the first blueprint for such a vehicle.
Friedrich then passed the leadership of the project on to his former subordinate, designer Heinrich Rößler, early in 1946.
In only a few weeks, a new overall plan was developed, with the engine and gearbox positioned directly to the right of the middle line of the vehicle. This meant that the torque tubes – which protect the drive shafts – could be at right angles to the axles. As a result, only four drive joints were needed for the chassis. This was a brilliant design which, 70 years later, is still used for the Unimog of the highly mobile U 4023/U 5023 series.
The final definition of the “engine-driven multi-purpose machine” was finalised as having:
- top speed of 50 km/h (a tractor was only half as fast)
- sprung and damped axles
- all-wheel drive and differential locks at the front and rear
- brakes on the front and rear axles
- frame design similar to cars and trucks
- two-seater cab with a closed cover and upholstered seats
- auxiliary load area over the rear axle with 1.0 t load-bearing capacity
- static weight distribution: 2/3 on the front axle, 1/3 on the rear axle
- implements attachable on the front, middle, sides and rear
- power take-off shafts at the front, middle and rear
- power take-off for implements
- The story of a truly remarkable vehicle
In March 1946, Hans Zabel from Gaggenau, who had been part of the project from the beginning, coined the term Unimog (Universal-Motor-Gerät, i.e. universally applicable motorised machine). The Unimog went into production in 1948 and it has continued to this day.