A German mechanical engineer, Rudolf Diesel has been immortalised by the invention that bears his name: the diesel engine. In 1913 he disappeared from the SS Dresden in the English Channel. While his biographer believes that Diesel committed suicide, others maintain that Diesel was murdered to prevent him granting the British Royal Navy access to his invention.
Born in Paris to Bavarian immigrants, Diesel showed early promise at school but was forced to leave the country, alongside many Germans living in France, at the outbreak of the Franco-Prussian War. Initially settling in London, Diesel was sent to live with an uncle after the war who was a mathematics lecturer at the Royal County Vocational College in Augsburg. It was here he was inspired to become an engineer at the age of 14. Two years later, he was offered a merit scholarship to the Royal Bavarian Polytechnic. After graduating, he worked alongside his former teacher, Carl von Linde, developing refrigeration technology.
After striking out on his own, Diesel began work on developing a steam engine which nearly killed him after it exploded during testing. In 1892, he published a treatise considering a heat engine to replace steam engines, which would form the basis of his invention of the diesel engine. In developing an internal combustion engine, Diesel eliminated much of the wastage associated with steam engines (around 90% of the energy available from fuel). The first successful engine was tested in 1897, before Diesel patented his design in Germany and the United States, amongst other countries.
On 29th September 1913, Diesel set out to a meeting of the Consolidated Diesel Manufacturing company in London. Travelling from Antwerp on the German steamer SS Dresden, he retired to his cabin at around 10pm, asking to be woken the following morning at 6:15am. In the morning, crew found his cabin empty and his bed unused. A search of the boat resulted in his hat and overcoat being found neatly folded by the railings of the stern deck.
Ten days later, the crew of a Dutch boat found a corpse floating in the North Sea close to the Norwegian coast. The extended period in the water had rendered the corpse unidentifiable, but personal effects retrieved from the pockets were later identified by Diesel’s son as belonging to his father.
Two biographies of Rudolf Diesel conclude that his death was a result of suicide. However, other researchers believe that he was murdered, potentially on the orders of the German Imperial government due to his refusal to grant the German armed forces exclusive use of his engines. He was also rumoured to be planning to meet Royal Navy personnel to discuss the potential for fitting diesel engines on British submarines.
Two further pieces of information point towards suicide being the more likely explanation. In a diary that Diesel had kept up to the day of his disappearance, he had marked September 29th with a cross, potentially indicating his intention to take his own life on that day. He also gave a bag to his wife before departing, instructing her not to open it until a week later. She found it contained over 200,000 marks, the equivalent of $1.2 million today.