Rudolf Diesel

In 1893 Diesel published a theory of a heat engine in which air is compressed until it is hot enough to ignite fuel injected into it, and from 1893 to 1897 he developed the engine at the Maschinenfabrik Augsburg with backing from Krupp. In February 1897 Professor Moritz Schröter of the Munich technical college tested the resulting 20 h.p. engine and reported that it used less fuel per horsepower than the other oil engines of the time. Other engineers had worked on related ideas, and the engines built later departed in part from Diesel's original theory.

From 1893 Diesel licensed the engine to manufacturers in several countries, including Carels in Ghent (1894), Adolphus Busch for the United States (1897) and Mirrlees in Glasgow, which built a British engine in 1897-98. By 1912 Diesel engines were in use in power stations, factories and ships, and he presented their development to the Institution of Mechanical Engineers in London that March.

In 1905 Diesel, the Sulzer firm and the railway engineer Adolph Klose founded a company to build a Diesel-powered locomotive. Developed with Borsig, the locomotive made trial runs in Switzerland in 1912, and after his patents expired in 1908 Diesel also worked on small engines and an engine for road vehicles.

In his own 1897 account of the Augsburg trials, Diesel wrote that the first test engine gave violent explosions that destroyed the measuring indicator, and that one later stretch of ten months produced no useful results despite repeated rebuilding. About two years passed before a new test engine could be built. The Deutsches Museum holds his handwritten test journals for each stage from 1893 to 1897.

Keeping the programme going through four years of failed and partial results is consistent with the high persistence score in this profile. Persistence

Soon after the single-cylinder engine succeeded in 1897, Diesel built a 150 h.p. compound engine in which air was compressed and gases expanded in two stages. By his own account, written in reply to a question at the Institution of Mechanical Engineers in 1912, more than a year of careful trials showed such large heat and pressure losses that he judged the design useless. The Deutsches Museum's archive records the compound-engine trial journals of 1898.

Dropping a design he had long planned once the measurements went against it offers one example of the belief-updating pattern scored here. Belief Updating

From 1883, while working for Carl von Linde's refrigeration company in Paris, Diesel tried to build a high-efficiency engine driven by highly compressed ammonia vapour. According to the Deutsches Museum archive and his son's biographical entry, he judged the work a failure in 1890 and turned to an engine using air as the working medium. That same year he moved to Berlin to represent Linde's firm there.

Changing the working medium while keeping the goal of a more efficient engine sits alongside the adaptability score in this profile; his son's account, one of the two sources here, is an insider's view. Adaptability