Diesel: A Utopian Reformer and His Engine

The diesel engine today powers nearly every commercial, industrial and agricultural vehicle in the world, from merchant ships to eighteen-wheelers. But Rudolf Diesel originally saw his engine as a radical method of social reform.

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Rudolf Diesel

 

By the 1890s, the steam engine had transformed human society. In the “Industrial Revolution”, steam-powered factories and mills, run by masses of low-wage workers, produced material goods at a stupendous rate, while steam locomotives and ships had revolutionized the process of transporting both commerce and people around the world.

But in Europe, a young engineer named Rudolf Diesel was working on a new engine. The steam engine had its difficulties. It was dangerous to run: operating at high pressures, it often leaked boiling-hot water, and occasionally exploded. It was also inefficient, converting less than 10% of the energy it used into useful work.

Diesel hoped to improve on this and come up with a more efficient engine that was cheaper to operate. But he also had an ideological goal: Diesel was a utopian socialist, and by making a better and cheaper engine, he hoped that he could empower small businesses to take back the economy from the robber baron corporate monopolies who dominated it, and also free the masses of laborers from the drudgery and dangers of factory life. He wanted to create a social revolution as well as a technological one.

By 1890, there were already a number of new gasoline-powered internal combustion engines in the works, but these were expensive and used a flammable and volatile fuel that was dangerous to store. Then the Hornsby Company in London produced a design for a “heavy oil engine” that ran on paraffin oil, which was much less hazardous than gasoline.

When Diesel examined the Hornsby engine, he realized that it could be improved, and by 1892 he had patented a better version. The core concept of Diesel’s engine is the idea of “compression ignition”. In a gasoline engine, fuel is mixed with air and sprayed into a combustion chamber, where it is ignited by an electrical spark plug. But in a diesel engine, fuel enters a chamber and is compressed rapidly by a piston. This compression heats up the air and fuel, igniting it.

It was revolutionary. Not only was Diesel’s engine three times more efficient than steam, but it required only one person to operate, unlike steam engines with their crews of stokers and engineers and their heavy boilers which often took hours to start. The diesel was also safer and more efficient than the gasoline engine, able to run three times longer on a unit of fuel. And it could operate with virtually any sort of liquid oil—Diesel originally ran his prototypes with peanut oil. After the petroleum industry began producing abundant supplies of cheap energy, diesel engines were designed to utilize fuel oil.

In the United States, one of the first to see the potential of the new engine was beer baron Adolphus Busch, who purchased manufacturing rights and set up a factory in New York to produce diesel engines. In Switzerland, Busch partnered with the Sulzer Company. In Germany, Diesel signed contracts with the Krupp manufacturing giant and with Maschinenfabrik Augsburg. Others followed, including electric companies who adopted diesel generators. Rudolf Diesel became a wealthy man.

But not a happy one. In selling the manufacturing rights, Diesel had lost control over how his engines were being used, and what the pacifist social reformer saw now, horrified him. Rather than destroying corporate behemoths, diesel engines were helping to power new ones in areas like shipping, railroads, and manufacturing, and the military was also turning to the new engines. In addition, Diesel proved himself to be a better engineer than a businessman, and he steadily lost his wealth through a series of bad decisions. By 1913, he was disappointed, disillusioned, and nearly broke, and in September, while traveling on a ferry across the English Channel, a despondent Diesel jumped overboard and drowned. He was 55.

But his engine would live on.

At the time of his suicide, Diesel had been traveling to London for talks with the Royal Navy. They, like other navies in the world, were interested in submarines. Hidden under the surface and armed with torpedoes, the submarine promised to be a lethal weapon of war. Unlike surface vessels, however, submarines could not use the conventional coal-fired steam engines then in use. So the early British subs had been powered with gasoline engines—and that experiment did not work out very well. The engines leaked fumes and flammable fuel, which was immensely dangerous inside a sealed underwater vessel.

The solution lay with the diesel engine, which used far safer fuel oil that did not vaporize or ignite as a liquid. As a bonus, a diesel engine could travel many times further on a unit of fuel than a gasoline engine could, giving the submarine enough long range to travel around the world as it hunted for enemy shipping. When the German U-boats annihilated Allied merchant vessels during the First World War, they were all running on diesel engines. Diesels would continue to power the world’s military submarines until the advent of nuclear power in the 1960s.

The new technology also came to dominate surface shipping, both military and civilian. In 1912, the first diesel-powered passenger liner was launched, the Selandia. Unintentionally, the use of diesel engines during World War One provided a ready test bed for the engine designs to be improved, modified and strengthened. By the end of the war, diesel engines had gotten lighter and more powerful, and merchant cargo ships as well as navies were quick to adopt them. Most Navy ships would later turn to turbine engines, which are faster. But today, nearly all of the super container ships in service, which are more interested in efficiency and cost than in speed, are propelled by immense marine diesel engines. They carry some 95% of all world trade.

The diesel engine also transformed land travel. In the 1890s, the standard method of transporting people and cargo over long distances was the railroad and the steam locomotive. By 1918, however, companies in the United States were beginning to produce diesel-electric train engines. These designs got around an awkward difficulty—diesel engines at this time were large and it took a lot of room to efficiently connect them to a drive mechanism, which was easy to do in a ship, but challenging within the small confines of a train. So the early diesel locomotives used their diesel engine basically as an electric generator, which produced electricity for a battery bank to drive an electric motor which actually turned the train’s wheels. It turned out to be a good design, and it soon powered most of the world’s locomotives. Today, most light passenger rail and subway systems use electric motors that are powered by electricity that is supplied directly to the train through the track, but the vast majority of modern cargo trains are still powered by diesel-electric locomotives.

The size and weight of the early diesel engines, however, made it difficult to adapt the design for use in automobiles. The earliest “horseless carriages” used steam engines, and these were quickly replaced by battery-powered electric motors until the gasoline engine became dominant in the 1920s.

Then a British mechanic named Harry Ricardo, who had designed tank engines during World War I, began studying the problem. In a gasoline engine, the fuel was mixed with air in a carburetor before being fed into the cylinder, and this mixture could burn very rapidly to provide maximum power. The diesel engine had no such system. So the solution that Ricardo developed in 1931 was the “swirl chamber”. This was a small hollow “pre-chamber” in which fuel oil would be sprayed in a stream of small droplets and mixed with air before being fed into the cylinder. This resulted in an enormous increase in power, and finally allowed for diesel engines that were small and light enough to fit inside a passenger automobile. The first commercial diesel-engined car was the Citroen Rosalie, introduced in France in 1934.

Later, the swirl chamber would itself become obsolete, replaced with a new fuel-injection system that squirted an atomized spray of fuel oil directly into the combustion cylinder. But the diesel automobile did not really catch on with consumers until the 1970s, when the Arab oil embargo and resulting spike in gasoline prices led to the introduction of a number of small diesel models like the VW Rabbit. Today, diesel passenger cars have once again fallen out of favor. But in the field of commercial trucking, diesel dominates. Nearly all cargo and supplies worldwide travel their last few miles by eighteen-wheeler, and nearly all of those are run on diesel.

The diesel engine was also adopted for use in agricultural machinery, and it soon conquered nearly the entire market. Diesel tractors, combines, tillers, threshers and harvesters have been feeding the world for half a century.

And while diesel has been feeding people around the world, it has at the same time also been killing them. In a trend which the pacifist Rudolf Diesel would surely have condemned, nearly every modern military land vehicle, from tanks to self-propelled artillery to armored personnel carriers to humvees to transport trucks, uses a diesel engine.

Today, in an age of global climate change, the diesel engine, like all fossil fuels, has come under critical scrutiny, and governments are imposing stricter emissions requirements to combat future catastrophe. Unfortunately, while they are more efficient and cheaper to run (and can even run on unconventional fuels like used French-fry oil), diesel engines are more expensive to modify to meet new emissions standards, and they may not be able to keep up. Plans are already being made for vehicles to go “carbon-neutral” using engines that run on electricity or hydrogen or ethyl alcohol. But even though bio-diesel fuels may remain as a part of our future fuel mix, it is apparent that the 100-year history of the diesel engine is coming to  a close.