Rudolf Diesel, Inventor of the Diesel Engine

Inventor Rudolf Diesel at Desk

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The engine that bears his name set off a new chapter in the Industrial Revolution, but German engineer Rudolf Diesel (1858–1913), who grew up in France, initially thought his invention would help small businesses and artisans, not industrialists. In truth, diesel engines are commonplace in vehicles of all types, especially those that have to pull heavy loads (trucks or trains) or do a lot of work, such as on a farm or in a power plant.

For this one improvement to an engine, his impact on the world is clear today. But his death more than a century ago remains a mystery.

Fast Facts: Rudolf Diesel

  • Occupation: Engineer
  • Known For: Inventor of the Diesel engine
  • Born: March 18, 1858, in Paris, France
  • Parents: Theodor Diesel and Elise Strobel
  • Died: September 29 or 30, 1913, in the English Channel
  • Education: Technische Hochschule (Technical High School), Munich, Germany; Industrial School of Augsburg, Royal Bavarian Polytechnic of Munich (Polytechnic Institute)
  • Published Works: "Theorie und Konstruktion eines rationellen Wäremotors" ("Theory and Construction of a Rational Heat Motor"), 1893
  • Spouse: Martha Flasche (m. 1883)
  • Children: Rudolf Jr. (b. 1883), Heddy (b. 1885), and Eugen (b. 1889)
  • Notable Quote: "I am firmly convinced that the automobile engine will come, and then I consider my life’s work complete."

Early Life

Rudolf Diesel was born in Paris, France, in 1858. His parents were Bavarian immigrants. At the outbreak of the Franco-German War, the family was deported to England in 1870. From there, Diesel went to Germany to study at the Munich Polytechnic Institute, where he excelled in engineering. After graduation he was employed as a refrigerator engineer in Paris, at Linde Ice Machine Company, beginning in 1880. He had studied thermodynamics under Carl von Linde, head of the company, in Munich.

His true love lay in engine design, however, and over the next few years he began exploring a number of ideas. One concerned finding a way to help small businesses compete with big industries, which had the money to harness the power of steam engines. Another was how to use the laws of thermodynamics to create a more efficient engine. In his mind, building a better engine would help the little guy, the independent artisans, and entrepreneurs.

In 1890 he took a job heading the engineering department of the same refrigeration firm in its Berlin location, and during his off time (to keep his patents) would experiment with his engine designs. He was aided in the development of his designs by Maschinenfabrik Augsburg, which is now MAN Diesel, and Friedrich Krupp AG, which is now ThyssenKrupp.

The Diesel Engine

Diesel engine: internal combustion engine, color drawing
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Rudolf Diesel designed many heat engines, including a solar-powered air engine. In 1892 he applied for a patent and received a development patent for his diesel engine. In 1893 he published a paper describing an engine with combustion within a cylinder, the internal combustion engine. In Augsburg, Germany, on August 10, 1893, Rudolf Diesel's prime model, a single 10-foot iron cylinder with a flywheel at its base, ran on its own power for the first time. He received a patent there for the engine that same year and a patent for an improvement.

Diesel spent two more years making improvements and in 1896 demonstrated another model with the theoretical efficiency of 75 percent, in contrast to the 10 percent efficiency of the steam engine or other early internal combustion engines. Work continued on developing a production model. In 1898 Rudolf Diesel was granted U.S. patent #608,845 for an internal combustion engine. 

His Legacy

Rudolf Diesel's inventions have three points in common: They relate to heat transference by natural physical processes or laws, they involve markedly creative mechanical design, and they were initially motivated by the inventor's concept of sociological needs—by finding a way to enable independent craftsmen and artisans to compete with large industry.

That last goal didn’t exactly pan out as Diesel expected. His invention could be used by small businesses, but the industrialists embraced it eagerly as well. His engine took off immediately, with applications far and wide that spurred the Industrial Revolution's rapid development.

Following his death, diesel engines became common in automobiles, trucks (starting in the 1920s), ships (after World War II), trains (starting in the 1930s), and more—and they still are. The diesel engines of today are refined and improved versions of Rudolf Diesel's original concept.

His engines have been used to power pipelines, electric and water plants, automobiles and trucks, and marine craft, and soon after were used in mines, oil fields, factories, and transoceanic shipping. More efficient, more powerful engines allowed boats to be bigger and more goods to be sold overseas.

Diesel became a millionaire by the end of the 19th century, but bad investments left him in a lot of debt at the end of his life.

His Death

In 1913, Rudolf Diesel disappeared en route to London while on an ocean steamer coming back from Belgium to attend the "groundbreaking of a new diesel-engine plant—and to meet with the British navy about installing his engine on their submarines," the History Channel says. He is assumed to have drowned in the English Channel. It's suspected by some that he committed suicide over heavy debts, due to bad investments and poor health, information that didn't come out until after his death.

However, theories immediately began that he was helped overboard. A newspaper at the time speculated, "Inventor Thrown Into the Sea to Stop Sale of Patents to British Government," the BBC noted. World War I was at hand, and Diesel's engines made it into Allied submarines and ships—though the latter were primarily for World War II.

Diesel was a proponent of vegetable oil as fuel, putting him at odds with the ever-growing petroleum industry and leading, the BBC says, to the theory that Diesel was "Murdered by Agents From Big Oil Trusts." Or it could have been coal magnates, yet others speculated, because steam engines ran on tons and tons of it. Theories kept his name in the papers for years and even included an assassination attempt by German spies to prevent his sharing details about the development of the U-boat.


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Bellis, Mary. "Rudolf Diesel, Inventor of the Diesel Engine." ThoughtCo, Aug. 28, 2020, Bellis, Mary. (2020, August 28). Rudolf Diesel, Inventor of the Diesel Engine. Retrieved from Bellis, Mary. "Rudolf Diesel, Inventor of the Diesel Engine." ThoughtCo. (accessed March 24, 2023).