The complete history of the diesel engine is a long story full of innovation and triumph, creativity and disappointment, and even a little mystery. The diesel engine was a major invention, one that pushed its field much further than its inventor could have predicted.
In our hyper-technologically advanced world, one where engineers try to improve machine efficiencies by fractions of percentages, we forget that there was a time in history in which someone could design an engine that doubled the efficiency of what was previously available. But that is exactly what we saw with the advent of the diesel engine—all thanks Rudolph Diesel.
Rudolph Diesel’s Invention
The diesel engine, though popular in North America today, was originally developed in Europe by a German man named Rudolph Diesel, born 1858. In 1878, Diesel was a student at the Polytechnikum in Munich when he attended lectures on thermodynamics delivered by the famous scientist, engineer, and businessman Carl von Linde. Based on von Linde’s theories, Diesel was struck by inspiration: he would develop an engine that could convert 100 percent of its heat into work. This was truly ambitious; at that time, no engine could convert more than 10 percent.
Gasoline engines have always compressed fuel and air to prepare the gas for ignition. Diesel thought he could make his engines more efficient by compressing only the air, not the fuel. Though he initially sought out to build the most efficient engine humanly possible, at 100 percent efficiency, he never surpassed approximately 25 percent, which was still twice more than what had been developed previously.
Diesel applied for patents in 1892 and 1893. The diesel engine is still considered the most efficient engine on the planet. It was a major step forward, though Diesel would not be able to see much of its success in his lifetime.
Rudolph Diesel’s Death
Unfortunately, Diesel was plagued by financial difficulties for much of his adult life. The early diesel engines, used to power factories or generators, ran into frequent technical problems and required many refunds. By the early 1900s, just when his work was being used on military transports, he was too far in debt to reap the benefits.
In September of 1913, as Diesel prepared for a trip to Belgium across the English Channel, he gave a bag to his wife and advised her not to open it until the week had passed. On the evening he boarded, Diesel fell overboard and drowned. When his wife opened the bag the next day, she saw cash and papers that revealed the true depths of their horrifying debt.
While his death was ruled a suicide, historians still wonder if foul play was involved, making this incident the biggest mystery of the complete history of the diesel engine.
Diesel Engines During World War I
Diesel’s military applications were seen early in its development. France had purchased the engines for their submarines during World War I. Great Britain also wanted diesel engines for their submarines, but was unable to procure them because of Diesel’s death, further adding speculation to theories that he was murdered.
Improvements in the 1920s and 30s
The 1920s and 1930s saw massive strides in the technology and uses for diesel engines. Even though the engine’s inventor and namesake died before he could see the full potential of his invention, we can be happy knowing how proud he would have been to watch his invention change the world.
In 1925, Swiss inventor and engineer Alfred Büchi developed a way to combine the diesel engine with turbocharging technology, increasing efficiency by over 40 percent. Those who enjoy the thrill of using their vehicle’s turbocharger today have him to thank.
In 1927, a German industrialist and inventor named Robert Bosch improved upon the fuel-injection pumps of earlier designs. The result was an increase in fuel economy and efficiency of the engines.
In part because of these innovations, throughout the 1920s, manufacturers started to use diesel engines for the trucking industry. To do this day, diesel engines are still very popular for trucks, with many diesel truck parts still on the market. Diesel engines are also popular among other large vehicles, like tractors and SUVs.
The 1930s also saw great strides for the diesel engine, with many train companies adopting it for their locomotives. In the 1930s, Daimler-Benz experimented with diesel engines especially designed for passenger cars. In 1935, the company released the Mercedes-Benz 260 D, the first mass-produced passenger car with a diesel engine.
Diesel in the 1950s and 60s
Following World War II, diesel engines grew in popularity for commercial applications, like delivery station wagons, taxis, and ambulances. Since Diesel was German, Mercedez-Benz has long prided itself on its work with the engine. And many of these developments were powered by Mercedes-Benz, as the company was a leader taxi car production.
In the 1960s, diesel engines were the number one source of power for commercial trucking. The United States government instituted the Clean Air Act in 1936, which was designed to limit air pollution. Throughout the decade, truck manufacturers worked to meet the guidelines set by the law.
Diesel Today and Into the Future
Diesel engines have improved drastically over the years, but they still owe everything to the original design. Today’s compression-ignition diesels have efficiencies of up to 44 percent. That is not exactly 100 percent, but it better than 25—and far better than 10.
Various advancements have been added to diesel vehicles since the mid-2000s to limit their emissions and make them more environmentally friendly. Cummins, for instance, released in 2017 next-generation diesels that have redesigned emission controls.
These days, not so many people are familiar with Rudolph Diesel the man, but many know of his great contribution to mankind. The fuel efficiency of a diesel engine is the backbone of the trucking industry, which is what allows so many people across the world to enjoy the food in their groceries.
It is a shame that Rudolph never lived to see the full impact of his invention. He had hoped his work would revolutionize what people could expect from their engines, but even he could not have predicted the adoption of the diesel engine in so many industries. Though Rudolph Diesel is gone, his work survives on the streets, in the air, out at sea, and in our hearts.