Is it possible to design steam engines that carry out the full cycle without being too complicated? Rudolf Diesel asked himself this question at the age of 20 before completing his studies in Engineering. Steam engines set the pace of industrialisation in the 19th century; they were used on the railways for example. Maschinenfabrik Augsburg was one of the largest steam engine manufacturers in Europe.

The right place for the invention

In 1892, Rudolf Diesel wrote to the management of MAN. He was looking for assistance in the construction of a new engine that he had designed. His idea was to compress air in the engine's cylinder. Only then would the fuel be supplied, in order to allow self-ignition due to the compression heat. This process was designed to achieve higher efficiency and therefore lower fuel consumption than all previous drive motors and engines.

Shortly before writing to MAN, Diesel had applied for a patent for his "heat engine" which was issued to him in February 1893. Heinrich von Buz, the Director of MAN at the time, initially rejected Diesel's request. Diesel submitted new calculations. On 20 April 1892, Buz then expressed his willingness to build an experimental engine on a non-binding basis and in small stages. He realised that it would be worth pursuing the idea of such an engine further and investing in the development. 

The burning idea

The early days were anything but easy. Diesel was faced time and time again with false starts. Firstly, a suitable fuel had to be found. Tests were conducted with gaseous ammonia and solid carbon, amongst other things.

10 August 1893 would be remembered by the employees at Maschinenfabrik Augsburg for the rest of their lives. On that day, Rudolf Diesel put an engine cylinder that he had invented into operation for the first time. When the petrol exploded in the hot interior of the piston, there was a deafening bang and a rattling of windows. Parts of the measuring device flew through the air, but the engine remained intact.

It would take another four years until the diesel engine worked correctly. It produced a whole 20 hp and, at 26 percent, efficiency was about double that of steam engines. And: It was able to operate using fuels that were cheap at the time, such as heavy fuel oil and heating oil. The news spread around the world like wildfire.

The diesel engine conquers the world

From the first run, the diesel technology picked up enormous speed. From 1898 to 1900, MAN delivered 16 diesel engines with an output of 580 hp. The diesel engine ultimately spread around the world. It was used in stationary equipment and, from 1903 onwards, also for marine propulsion and is still the most economical of all heat engines to this day. Diesel expressed his visions on the subject of fuels of the future as follows: "The use of vegetable oil as a fuel might be insignificant today. But these types of product may become just as important over time as petroleum and the coal tar products of today."

Diesel's brilliant idea would change the world. At the start of the 1920s, the mobile age experienced a significant acceleration due to self-ignition.

Today

Today, engines based on his invention power trucks, buses, family cars, ships and generator sets. Diesel engines have always been drivers of innovation time and time again – for example when they power huge modern container ships which break all size records with capacities of over 19,000 standard containers. In 1897, Rudolf Diesel's first engine ran at 20 hp; today, the most powerful diesel engine produced by MAN generates over 110,000 hp.