André Chapelon (26 October 1892 – 22 July 1978) was a French mechanical engineer and designer of advanced steam locomotives.
[4] He achieved a distinction in mathematics and science, and served as an artillery officer during World War I before returning to the École centrale Paris in 1919, from which he graduated as Ingénieur des Arts et Manufactures in 1921.
However, foreseeing poor prospects, he left in 1924 and joined the Société Industrielle des Telephones, soon becoming as assistant manager.
[5] In 1934, Chapelon was appointed Chevalier of the Legion of Honour and awarded both the Plumey Prize of the Académie des Sciences and the Gold Medal of the Société d'Encouragement pour l'Industrie Nationale.
Chapelon realised that in order to produce an efficient, powerful locomotive, every aspect of it had to be improved and dealt with scientifically.
Despite his abilities and track record, he was never presented the opportunity to design a class of entirely-new locomotives that were produced in any numbers.
One notable such designer was Nigel Gresley of the British London and North Eastern Railway, who experimentally used Chapelon's Kylchap exhaust system on a small number of LNER Class A4 locomotives, including the LNER Class A4 4468 Mallard, which set what most historians accept as the world record for speed for steam locomotives in 1938.
There was also an additional level of "superheat" between the high- and low-pressure cylinders, allowing the loco to achieve a tractive effort of 83,700 pounds-force (372 kN)83700 lb.
He was a great admirer of American industrial capacities and the resulting high quality of its engineering,[9] even though his work tended to be ignored in the USA.
One standard Gauge 4-4-2 was owned by the Pennsylvania Railroad Numbered 2512 which gained a Nickname De Glehn.
The 152 (2-10-4) locomotive design had two frames partially constructed, before the decision was made to electrify the SNCF and phase out steam.