Egide Walschaerts (21 January 1820 – 18 February 1901) was a Belgian

mechanical engineer Mechanical may refer to: Machine * Machine (mechanical), a system of mechanisms that shape the actuator input to achieve a specific application of output forces and movement * Mechanical calculator, a device used to perform the basic operations o ...

, best known as the inventor of the

Walschaerts valve gear The Walschaerts valve gear is a type of valve gear used to regulate the flow of steam to the pistons in steam locomotives, invented by Belgium, Belgian railway mechanical engineering, engineer Egide Walschaerts in 1844. The gear is sometimes name ...

used in

steam locomotive A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material (usually coal, Fuel oil, oil or, rarely, Wood fuel, wood) to heat ...

s. He was born in

Mechelen Mechelen (; ; historically known as ''Mechlin'' in EnglishMechelen has been known in English as ''Mechlin'', from where the adjective ''Mechlinian'' is derived. This name may still be used, especially in a traditional or historical context. T ...

Belgium Belgium, officially the Kingdom of Belgium, is a country in Northwestern Europe. Situated in a coastal lowland region known as the Low Countries, it is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeas ...

. In 1838 he was recognised as an excellent modeller, presenting his work at a local exhibition in Mechelen. Minister Rogier, who opened the exhibition, was so impressed that he arranged a place for Walschaerts at

Liège Liège ( ; ; ; ; ) is a City status in Belgium, city and Municipalities in Belgium, municipality of Wallonia, and the capital of the Liège Province, province of Liège, Belgium. The city is situated in the valley of the Meuse, in the east o ...

University.

Career

In 1842 he joined the

Belgian State Railways The Belgian State Railways ( ; ) was the original state-owned railway of Belgium. Established by an organic law of 1 May 1834, it began construction of its first line, between Brussels and Mechelen on 1 June 1834. This line, which was opened on 5 ...

and two years later had reached the rank of foreman. He was made chief superintendent of the works shortly after but mysteriously, for such a meteoric early career, never rose any higher. He held this position for the rest of his life, first at Mechelen and then at Brussels South.

Walschaerts valve gear

Whilst at Mechelen in 1844 he developed a new type of

valve gear The valve gear of a steam engine is the mechanism that operates the inlet and exhaust valves to admit steam into the cylinder and allow exhaust steam to escape, respectively, at the correct points in the cycle. It can also serve as a reversing ...

(a mechanism that allows for adjustment of the travel of the valves that distribute the steam to the cylinders and enables a

to be put into reverse and to economise steam). He was not permitted by the company to patent the device himself as he was deemed of too lowly a rank. An engineer colleague and friend, M. Fisher, applied for the patent on his behalf but never claimed any contribution to it. Walschaerts's name on the documents erroneously omitted the final 's' causing confusion over its correct spelling over the succeeding years. A locomotive built at the Tubize workshops fitted with the

was awarded a gold medal at the 1873 Universal Exhibition in

Vienna Vienna ( ; ; ) is the capital city, capital, List of largest cities in Austria, most populous city, and one of Federal states of Austria, nine federal states of Austria. It is Austria's primate city, with just over two million inhabitants. ...

. This valve gear came to be used in the majority of steam locomotives, and became almost universal throughout the 20th Century.

Other innovations

According to Payen,Payen Jacques (1987?): "Walschaerts, sa coulisse, sa vie" in Les Cahiers Chapelon, no 5, pp 26–31. in 1874 Walschaerts developed a particularly successful version of the Corliss

stationary engine A stationary engine is an engine whose framework does not move. They are used to drive immobile equipment, such as pumps, generators, mills or factory machinery, or cable cars. The term usually refers to large immobile reciprocating engines, ...

that won a gold medal at the 1878 Exposition Universelle in

Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...

Commemoration

Both of the municipalities in which he worked have named streets after him: Mechelen and St Gillis/St-Gilles in Brussels (Egide is a form of the name Giles).

References

{{DEFAULTSORT:Walschaerts, Egide 1820 births 1901 deaths 19th-century Belgian engineers Belgian mechanical engineers Locomotive builders and designers People from Mechelen