For some reason we all know André Chapelon, the great French designer of steam locomotives, the man who brought French production of these machines to a level of efficiency unmatched anywhere in the world.
Characteristic of his machines is the use of double expansion.
Less well known is his cousin, Anatole Chapelon-Dubraque, son of an aunt, responsible for design at the Usine Nationale Française Locomotive Vapeur et Tirabuçon in Neuville sur Loire.
Although not endowed with great specific preparation Anatole designed and built several locomotives of great prestige and premise that unfortunately were not sufficiently appreciated because of a certain tendency to exaggeration that characterized him.
A clear example was this P 251, developed for the Nord and which, although it never went beyond the prototype stage, laid the groundwork for the construction of the magnificent 2'D 1' 241 P.
The prototype, completed in August 1939 at the Usine etc., was put into test service on the Paris-Lille line towing heavy passenger trains, which soon turned into trains bound for the front due to the beginning of World War II.
Unfortunately the machine fell into German hands almost immediately and was transferred to Grünwald, where it was carefully studied by RAEUDL for further development and dismantled around the end of 1942 to use important parts for the construction of secret German prototypes.
Anatole Chapelon-Dubraque disappeared in 1946 apparently following an attack of rubella, while he was at the drawing board intent on designing increasingly interesting, beautiful and improbable locomotives.