Rudolf Dührkoop - Johannes Stumpf (1907) (KTHzB)

Johann Stumpf of the Charlottenburg Technical College in

Berlin Berlin ( , ) is the capital and largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's most populous city, according to population within city limits. One of Germany's sixteen constitue ...

is best known for popularising the uniflow steam engine, in the years around 1909, and his name has always been associated with it. The basic uniflow principle had been invented many years before.

Idea

Stumpf's 'Uniflow' system aroused interest among engine designers in the years before the

First World War World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

, at first in his native

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

and later elsewhere. The Uniflow principle was known previously, and Stumpf's work was really its practical application. In Stumpf's system steam was admitted at one end of the cylinder, and the used steam left through a ring of ports at the other end of the cylinder. This allowed the admission end to stay hot, as it was not cooled by the exhaust on its way out, and so improved efficiency. In a double-acting engine the exhaust ports were in the middle of the cylinder. Almost all uniflow engines were large stationary types, but the system was tried by, among others, the North Eastern Railway in

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, as described by Tuplin (see sources). Briefly, the system worked well and obtained a small increase in economy by decreasing fuel consumption, but at the price structure prevailing at that time the extra constructional and maintenance costs were greater than the coal economy. H.W. Dickinson's ''A Short History of The Steam Engine'' makes it clear that the concept of the uniflow engine reached back to Montgolfier and

Jacob Perkins Jacob Perkins (9 July 1766 – 30 July 1849) was an American inventor, mechanical engineer and physicist. Born in Newburyport, Massachusetts, Perkins was apprenticed to a goldsmith. He soon made himself known with a variety of useful mechanical ...

(who patented the idea) and Leonard Jennett Todd (Patent No. 7801): Dickinson then gives Stumpf of Charlottenburg University his due citing a paper by T.B. Perry '' Proc. Inst. Mech. Eng.'', 1920 (1922?).

Patents

*5429/1908 Application (original: 7 March 1908), UK 6 March 1909, Accepted 15 July 1909. Improvements in four-cylinder locomotive engines *25,531/1910 Application 3 November 1910, Accepted 2 March 1911. Improvements relating to manoeuvring and like gear for uni-directional flow steam engines *16,442 /1910 Application (original: 5 March 1910) 9 July 1910, Accepted 23 March 1911. Improvements relating to valves *16,383/1910 Application (original: 18 June 1910) 8 July 1910, Accepted 20 October 1910. Improvements relating to uni-directional flow steam engines

Sources

*''The Unaflow steam engine''. 1912 (translated Stumpf Uniflow Engine Co., Syracuse (NY)) * {{DEFAULTSORT:Stumpf, Johann Year of birth missing 19th-century births Year of death missing 20th-century deaths Steam engine engineers Engineers from Berlin German mechanical engineers