Johann Stumpf of the Charlottenburg

Charlottenburg

Charlottenburg is a locality of Berlin within the borough of Charlottenburg-Wilmersdorf, named after Queen consort Sophia Charlotte...

 Technical College in Berlin

Berlin

Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...

 is best known for popularising the uniflow steam engine

Uniflow steam engine

The uniflow type of steam engine uses steam that flows in one direction only in each half of the cylinder. Thermal efficiency is increased in the compound and multiple expansion types of steam engine by separating expansion into steps in separate cylinders; in the uniflow design, thermal efficiency...

, 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

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

, at first in his native Germany

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

 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

North Eastern Railway (UK)

The North Eastern Railway , was an English railway company. It was incorporated in 1854, when four existing companies were combined, and was absorbed into the London and North Eastern Railway at the Grouping in 1923...

 in England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

, 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

Jacob Perkins was an Anglo-American inventor, mechanical engineer and physicist. Born in Newburyport, Massachusetts, Perkins was apprenticed to a goldsmith...

 (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.

Proceedings of the Institution of Mechanical Engineers

The Proceedings of the Institution of Mechanical Engineers were first published by the Institution of Mechanical Engineers in 1847. The Proceedings were published under this single title until 1963, when they began to be published in two parts...

, 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))