Rudolf Diesel

Diesel's parents (Theodor and Elise Diesel) were Bavarian immigrants living in France according to the book by John F. Moon. Theodor Diesel's home town was Augsburg, Bavaria (Germany) according to the same book. Rudolf Christian Karl Diesel was born in Paris, France in 1858. Rudolf Diesel spent his childhood in France. The Franco-Prussian War broke out in 1870. In this war, Prussia was backed by other German states including Bavaria against France; afterwards, the German states including Prussia and Bavaria except Austria were unified as the German Empire in January 1871. Under this background, Diesel's family left France for London. Subsequently, Rudolf Diesel moved back to Germany (the newly formed German Empire) and eventually became a German citizen. Rudolf Diesel was educated at Munich Polytechnic. One of his professors was Carl von Linde. After graduation he was employed as a refrigerator engineer. However, his true love lay in engine design. Rudolf Diesel designed many heat engines, including a solar-powered air engine.


After graduation, he had success for two years as a machinist and designer in Winterthur, Switzerland. After this, he returned to Paris, where he was employed as a refrigeration engineer at Linde Refrigeration Enterprises. His early research into fuel efficiency led him to build a "steam engine" using ammonia vapour. Under test, this exploded with almost fatal consequences. It resulted in many months in the hospital, and a great deal of ill health and eyesight problems in later life.

In Paris he became a connoisseur of the fine arts and an internationalist. He married Martha Flasche in 1883, and had three children (Eugen, Hedi and Rudolf). He set up his first shop-laboratory in 1885 in Paris, and began full-time work on his engine. This continued when he moved to Berlin, working again for Linde Enterprises.

He decided that he didnt like Karl Benz's engine so he made his own engines. He tried to design an engine based on the Carnot Cycle. However, he gave up on this and tried to develop his own approach. Eventually he designed his own engine and obtained patent for his design. In his engine, fuel was injected at the end of compression and the fuel was ignited by the high temperature resulting from compression. In 1893, he published a book in German with the title "Theory and design of a rational thermal engine to replace the steam engine and the combustion engines known today" (English translation of the original title in German) with the help of Springer Verlag, Berlin. He managed to build a working engine according to his theory and design. His engine is now known as the diesel engine. Heinrich von Buz (1833-1918) was director (MAN AG) of an engine factory in Augsburg, Germany. From 1893-1897, he gave Rudolf Diesel the opportunity to test and develop his ideas according to the book by John F. Moon. Rudolf Diesel obtained patents for his design in Germany and other countries including USA, for example, US Patent 542846 and US Patent 608845.

In the evening of 29th September 1913, he took a ship (SS Dresden) to cross the English Channel from Antwerp, Belgium to Harwich, England. He took dinner on board the ship and then retired to his cabin at about 10PM, leaving word for him to be called the next morning at 6:15AM. Afterwards, he could not be found the next morning. 10 days later, he was found dead in the water off the Dutch coast because of an unknown reason which might be suicide. However, his body was thrown back into water. The First World War broke out about one year later. There was quite some speculation regarding the real cause of his death. Rudolf Diesel has no known grave. Just a simple carved piece of rock in the Rudolf Diesel Memorial Grove in Augsburg, Germany and the magnificient musemum in the M.A.N. (MAN AG) factory in the same town, exist as a direct memorial to one of the finest and saddest engineers the world has known according to the book by John F. Moon.

After Diesel's death, the diesel engine underwent much development, and became a very important replacement for the steam engine in many applications. Because the diesel engine required a heavier, more robust construction than a gasoline engine, it was not widely used in aviation (but see aircraft diesel engine). However, the diesel engine became widespread in many other applications, such as stationary engines, submarines, ships, and much later, locomotives, and in modern times automobiles. Recently, diesel engines have been designed, certified and flown that have overcome the weight penalty in light aircraft. These engines are designed to run on either Diesel fuel or more commonly jet fuel.

The diesel engine has the benefit of running on cheaper fuels; Diesel was especially interested in using coal dust or vegetable oil as fuel. Although these fuels were not immediately popular, recent rises in fuel prices coupled with concerns about oil reserves have led to more widespread use of vegetable oil and biodiesel. The primary source of fuel remains what became known as Diesel fuel, an oil byproduct derived from refinement of petroleum.

Diesel's inventions

Diesel developed a theory that revolutionized the concept of the combustion engine. He envisioned an engine in which air is compressed to such a degree that there is an extreme rise in temperature. When fuel is injected into the piston chamber with this air, the fuel is ignited by the high temperature of the air, exploding it, forcing the piston down. Diesel soon received a patent for his design and began building experimental models of his engine. The first working model ran in 1893 with 26% efficiency, more than double the efficiency of the steam engine. In 1897 the first diesel engine suitable for practical use operated at a remarkable efficiency of 75%.


The crowning achievement for Rudolph Diesel's invention came at the 1900 Paris Exposition where the diesel engine took the Grand Prix. To the amazement of all in attendance his engine was fueled by 100% peanut oil. It is essential to understand that Diesel believed the utilization of a biomass fuel to be the real future of his engine. He wanted to provide farmers, small industries and those in isolated communities the opportunity to produce their own fuel and to compete with the large monopolies that controlled all energy production at that time. diesels engine

Vegetable oils were used as fuel for the diesel engine until the 1920's, when diesel engine manufacturers modified the injection system of the engine to handle the lower viscosity of fossil fuels, which were widely available and low in cost. The oil tycoons of the day also wielded influence over every aspect of the transportation industry and shaped the development of the engine to favor their interests.


Rudolph Diesel, like the engine that bears his name, fell victim to the industrialist powers of the early twentieth century. In 1913, Diesel was on his way to England when he disappeared over the side of the ship; his body was later found floating in the English Channel. Some suspect suicide, but others believe that there were political reasons behind his death. The French navy was already using diesel engines and may not have wanted to see the English navy acquire them. Diesel also opposed the politics of Germany and did not want the German navy to utilize his engine. His untimely death made it possible for the German submarine fleet to be powered solely by the diesel engine and soon after inflict heavy damage upon Allied shipping in World War I.

Today, people are paying homage to the legacy and vision of Rudolph Diesel by returning to the roots of the diesel engine. The growing use of biodiesel, a modified vegetable oil, signals that the time is ripe for a shift away from the use of fossil fuels and toward a plant-based fuel economy. So spread the truth about Rudolph Diesel; make and use biodiesel and teach others what you have learned, and help reclaim the diesel engine.

Diesel's problems

Rudolf Diesel was pursued by patent quarrels, and scruplesless businessmen succeeded in acquiring rights for diesel's engine, so that he finally couldn't develop on his own engine any more. Only 1908, when the patents had run, he developed still smaller engines for the use in cars and trucks, together with the Swiss pioneer company Saurer. When he impoverished completely and didn't beleave any more in a successful advancement of his engine, he set an end to his life 1913 (see also biografie Rudolf Diesel).

Finally: Fuel injection pumps

About ten years after Diesel's dead, engineers succeeded in developing a pump which was able to inject heavy liquid fuel into highly compressed air directly. In the air-injection that was usual before, small fuel portions were hurled by compressed air into the cylinder.

The company Bosch, Germany, was considerably involved in this development. 1927, Bosch produced a injection pump that was ready for the production. This brought finally the desired spreading of the diesel engine with itself. In the following animation a modern diesel engine is shown, which works with fuel injection.


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