The Mysterious Case of Rudolf Diesel: Genius, Power, and Deception on the Eve of World War I

Rudolf Diesel was born in 1858 and grew up in Paris. He was interested in how things worked from an early age and would sketch devices. His father, Theodor, was a strict disciplinarian, but his mother, Elise, was gentler and taught him languages and a love for music and arts. Rudolf was influenced by Paris's vibrant and progressive atmosphere. He attended the 1867 World's Fair, where he was fascinated by the compressed charge internal combustion engine created by engineer Nicolaus Otto. This engine was a more efficient and compact alternative to steam engines, which required coal and many workers. Rudolf admired Otto’s work and was inspired to draw the engine from memory.

Despite Rudolf’s interest in engineering, however, his father wanted him to work in his leather shop. Because they were Bavarian immigrants to France, the family was forced to emigrate to London during the Franco-Prussian War, as anti-German sentiment rose. At the end of the war, Chancellor Otto von Bismarck unified the 39 Germanic states into the country of Germany.

The Diesels found a small two-room flat in East London. The relocation was extremely difficult. Rudolf’s parents struggled to find work, and although they escaped the worst of the possibilities, never ending up in the tenements or workhouses, conditions in East London were horrible. Rudolf, now 12, often saw child laborers beaten and whipped—experiences that would eventually drive his engineering designs. He could, at least, go to museums as he had in Paris.

One day, as he was crossing London Bridge, Rudolf drew a quick sketch of an engine. His goal was clear: to create a better machine to develop better working conditions and environment for laborers. Compared to his father’s workshop, the industrialized mechanical factories of England seemed cruel and inhumane. Rudolf envisioned a machine to rival steam-powered factory equipment that would be accessible to small rural farmers and artisans.

Eventually, Rudolf returned to Germany, living in Augsburg with his cousin Betty and her husband, mathematics teacher Christoph Barnickel. There, Rudolf attended the Royal County Trade School and impressed Barnickel with his innate intelligence. Barnickel quickly took the young inventor under his wing. A budding engineer, the adolescent Rudolf had already been immersed in the cultures of England and France, Germany’s biggest European rivals. He spoke three languages with a high degree of fluency. But, Brunt posits, the most important thing Diesel had come to understand was the fragility of peace and stability.

German railroad engineer Carl Buz had built a railway connecting Munich to Augsburg, which made Augsburg a hub for industry and trade. Buz partnered with Carl August Reichenbach (the inventor of the flatbed printing press) to found the Maschinenfabrik Augsburg (MA), a manufacturing plant of large industrial machinery and equipment. MA quickly dominated the field, and in 1864, Carl Buz's son Heinrich took over and expanded MA, helping to establish Germany as a significant industrial world power. By 1870, Heinrich Buz had gained the moniker "the Bismarck of German Industry" (32). 

After victory in the Franco-Prussian War, Prussian leadership unified the Germanic states into the German Empire, ruled by Kaiser Wilhelm I and Chancellor Otto von Bismarck. Bismarck easily navigated the tumultuous process of German unification, drafting the German Constitution and guiding the complex political landscape. His influence was far-reaching, developing fragile and often contradictory alliances between competing global powers, including France, Russia, and England. However, Bismarck could not predict the tangled influence of royal dynastic lines. Wilhelm I's son, Frederick III, married Queen Victoria's eldest daughter Vicki, who loathed anything German, criticized Bismarck's autocracy and politics, and provided a liberal British education for their son, Wilhelm II. To mitigate the threat, Bismarck took control of Wilhelm II's education, focusing on Prussian sensibilities. Wilhelm II grew distant from his parents, taking on the air of a German military man. Still, Wilhelm II remained close to his cousins in the British royal family and was fascinated by the Royal Navy.

Instead of disparaging his multicultural childhood, Rudolf embraced it. He spoke English, French, and German fluently. He loved visiting museums and appreciated progress in the sciences and humanities. Diesel became a successful Renaissance man.

Bismarck viewed peace as a pragmatic way to shore up Germany's influence and economy. When Rudolf returned to Germany, the unified country was a thriving hub of industry and was becoming a significant global power. However, with Bismarck and Wilhelm II in control, increased militarization led to a rise in nationalist sentiment.

Rudolf flourished in Augsburg despite not having the wealth or status of many of his peers. At the time, European education was based on a track system, with vocational schools that focused on a trade or particular subject. Diesel attended a school that focused on technical education and engineering. While his cousins paid for his room, board, and tuition, Rudolf earned money by tutoring wealthier classmates in French and English, courses not taught at the technical school.

When the Diesels returned to Paris, 16-year-old Rudolf had to convince his parents to let him continue his education. Theodor and Elise refused to financially support him, but Rudolf received a scholarship in Germany, returning to the Barnickels’ home.

In the 19th century, the United States prioritized speed in city development, resulting in underdeveloped infrastructure. Social and economic challenges hindered the organized pursuit of scientific advancement. During this time, emerging industries, particularly fossil fuels, provided opportunities for individuals like John D. Rockefeller to amass great wealth.

Rockefeller, born in 1839 in New York, grew up in poverty due to his con artist father's hedonistic lifestyle. Determined to distance himself from his difficult childhood, Rockefeller used his keen business sense to partner with Maurice Clark in the produce industry. They expanded their business, attracting more investors like George W. Gardner, which led to the formation of Clark, Gardner & Company. Eventually, Rockefeller gained sole control by dissolving the partnership; he used his wealth to join Henry Flagler in establishing Standard Oil, an enormously powerful corporation. Rockefeller used his newfound wealth and influence to manipulate the oil industry, eliminating competitors through aggressive business tactics.

Standard Oil monopolized the US oil market, as Rockefeller recognized the three major markets for Gilded Age oil: heat, lighting, and transportation. To maintain his dominance, Rockefeller also worked to eliminate alternative fuels or technologies, ensuring that oil remained the sole choice for fuel.

Diesel graduated from the Augsburg polytechnic school in 1875 with the highest marks in the school's history. In 1877, Diesel gained official German citizenship while he was enrolled at the Technical University of Munich, where he worked with many of the world’s top engineers, including Carl von Linde, a man famous for mechanizing refrigeration. Sponsored by Henrich Buz at MA, Linde would found Linde AG in 1879 so the technology could be licensed for commercial use.

At university, Diesel had a rigorous work ethic. He spent most of his time focused on thermodynamics, researching the theories of engineers like Nicolas Carnot, who pointed out the inherent insufficiencies of steam engines. His obsession grew as he took Carl von Linde’s course on theoretical designs. Linde became Diesel’s mentor as Diesel focused on engine efficiency, determined to invent a more efficient engine than the Otto engine. To do so, he had to replace steam as the power source. Oil might seem like the obvious choice to modern readers; however, at the time, it was in scarce supply in Germany and Diesel wanted to limit any reliance on foreign oil.

In 1879, Diesel came down with typhoid fever. During his recovery, he began working temporarily for Sulzer Brothers, the Swiss company manufacturing Linde’s designs for commercial use. Three months later, he returned to Munich, finished his final exams, and graduated in 1880.

After graduation, Diesel moved to Paris and continued to work for Sulzer Brothers in their ice-machine plant. He was quickly promoted to director, with responsibilities ranging from the design to the installation of the machines. While at Sulzer Brothers, Diesel patented many ice-related inventions, including the ice cube. As his work allotted him a steady income for the first time in his life, Diesel met his soon-to-be wife, Martha Flasche, a German governess who worked for one of his friends. Many of Diesel’s friends looked down on the match, because of Martha’s German background, but Diesel was madly in love and married her anyway. However, as nationalism rose in France once more, Diesel’s professional and personal connections began to dwindle.

In addition to his work at Sulzer Brothers, Diesel continued developing a compact, heat-efficient, and economical engine; his vision was for engineering and mechanization to uplift the working and artisan classes, instead of leaving them behind. When his research started to interfere with his work at Sulzer Brothers,  Linde recognized the work his protege was doing was important and offered him a different position, selling Linde’s refrigeration products.

Linde’s work inspired Diesel, who considered using ammonia for fuel, the same gas used for cooling, but quickly found it was too volatile. His work progressed enough for him to reserve exhibition space at the 1889 World’s Fair, which would be held in Paris. However, he withdrew his own work and instead only exhibited the latest developments of Linde’s refrigeration technology. Diesel was humiliated. His exhibit was overlooked because it wasn’t cutting-edge technology. Moreover, anti-German sentiment made living and working in France increasingly difficult, so  Linde moved Diesel to the Berlin manufacturing plant.

In Berlin, Diesel was met with a caste system that placed military officers above everyone else. The complex alliances that Otto von Bismarck had crafted were developing tensions as Kaiser Wilhelm II worked to gain power independent of the Chancellor. Bismarck’s focus on domestic trade and infrastructure fed the nationalist movement that the Kaiser wanted to use to place Germany at the forefront. German scientists, including Diesel, felt the shift and realized their work would likely go toward military use.

Kaiser Wilhelm I and his son Frederick III died within the same year, 1888. The German empire was left to 29-year-old Wilhelm II. Bismarck was not prepared for the sudden change in monarchs. And while he’d had a hand in educating and forming Wilhelm’s views, the new Kaiser was far more interested in expanding Germany’s colonial and naval power. In the constitution Bismarck had written for the unified Germany, the Chancellor limited the Kaiser’s powers. However, the constitution also granted the Kaiser the power to appoint the Chancellor, which meant that Wilhelm could always replace Bismarck.

Bismarck had held up Germany’s fragile alliances with other nations for 20 years. Bismarck’s strategy was to have close connections with three out of the four other great powers of the Western world: the UK, France, Austria-Hungary, and Russia. One key part of this strategy was a secret alliance and mutual defense treaty with Russia in 1887.

On a tour of Europe, Wilhelm charmed many sovereigns. However, he did not have Bismarck’s ability to dexterously manage German diplomacy; his brash attitude and nationalism put him at odds with Bismarck’s pragmatism, leading to Bismarck’s ouster. As traditional antagonism between Germany and Russia returned with Bismarck no longer in power, Wilhelm refused to renew the defense treaty. Instead, in 1889, he developed the most robust and active intelligence service in Europe: One arm, part of the navy, was focused on the UK, while another part monitored France and Russia. In response, in 1894, Russia instead formed an alliance with France as a bulwark against future German aggression.

Wilhelm’s ambition for German naval strength and domination differed from that of Bismarck. He wanted to match or surpass the British fleet, and to establish German colonies to fuel industry. Diesel’s technology would play an important role in Wilhelm’s plans and the growing power struggle in Europe.

Limitations of metallurgical knowledge made building an engine capable of withstanding the degree of compression needed for Diesel’s theories to work extremely difficult. However, Diesel was not discouraged; he believed that careful fabrication and a stable fuel would allow him to build an engine that would quadruple the power of the world's natural resources.

Diesel’s designs envisioned an engine that would run on only 10% of the fuel used by steam engines. Linde supported Diesel's ideas, but believed that from a practical standpoint, Diesel could only expect about one-third of the efficiency he had calculated. With Linde's support, Diesel filed the first patent for the “Diesel Engine” in 1893. The proposed model was complicated and expensive to build, but would make up for the cost in performance and efficiency. Diesel needed a lot of funding to pay for continued development and testing. 

Diesel's patent received mixed reviews. Some believed his concepts of compression-based ignition and the cold-start engine were fantastic. Others thought that they were unoriginal. Many large manufacturing firms that used steam engines dismissed Diesel, but his small group of European engineer supporters grew. Eventually, Diesel gained the financial support of Heinrich Buz, who had MA sponsor the development. Diesel convinced Buz to commit a section of the MA plant to the Diesel Engine's development; MA paid Diesel an annual salary of 30,000 marks in return for the rights to manufacture and market the first successful model. 

In 1894, Diesel completed his first test engine, successfully proving his theories. However, it also presented a new challenge: controlling the energy released by the initial ignition. Diesel determined that the right fuel was vital to that control. He experimented with heavier, more viscous oils and coal tar. Despite his persistence, Diesel struggled to make further breakthroughs and eventually determined that he needed to move on from the first engine design. In 1895, Diesel and his team of engineers at MA settled on the design of the second test engine.

Diesel wrote to Martha about his struggles and successes. Martha and their three children lived in Berlin, far away from the Augsburg plant, so Buz helped them secure housing in the much closer German metropolis of Munich. After his family was resettled, Diesel returned to MA to build the third version of the Diesel engine.

Finally, it was time to share the engine with outside observers. On February 17th, 1897, Diesel officially tested his engine before many potential investors, manufacturers, and engineers. Professor Moritz Schröter, an early investor, conducted the test. The engine was quiet compared to the steam engine, its exhaust nearly invisible and odorless. Most importantly, Schröter verified that the Diesel engine's efficiency surpassed all others. Diesel's primary goal had been efficiency. However, the additional benefits of a cold start and spark ignition, coupled with the more robust material needed for compression, gave the engine more torque and far greater commercial application than Otto's internal combustion engine ever did. When Diesel's presentation results were shared with the Association of German Engineers, there was a frenzy of positive response, only slightly marred by criticism from skeptics and legal challenges.

Influential manufacturing firms made deals with Diesel and MA to begin fabricating and selling the engines. This is when the aspirations Diesel held for his design gave way to reality: With these licensing agreements, Diesel signed away any control of his invention’s use.