Chapelon: Genius of French Steam
As a small boy, Andre' Chapelon was a steam locomotive enthusiast; he spent much of his time watching PLM trains on the branch line near his home, and in reading everything about his hobby that he could find, it was an enthusiasm that never left him, and, after serving with distinction as an officer of heavy artillery in World War 1, he became within a comparatively few years, the greatest steam locomotive engineer that the world had ever known.
The proof of Chapelon's genius was made manifest on November 19, 1929 when No 3566, his rebuild of one of the early Paris-Orleans Pacifics, emerged from that Railways Tour works, almost exactly a centenary since Stephenson's 'Rocket' ran her trials at Rainhill. Seldom has a centenary been so effectively marked; for it is safe to assert that never since the 'Rocket' has any one engine had such a profound influence on locomotive design. The performance of No 3566 was so outstanding that other French railways either acquired locomotives of the same design or rebuilt their own to incorporate Chapelon's principles; and from England, Gresley sought Chapelon's advice with regard to his own 'Cock o' the North' and four cylinder compound No 10000, and used this advice in the building of his A4 Pacifics.
Yet No 3566 was only the first of a string of great achievements, which culminated in the great 4-8-4 No 242 A1 with its ability to develop continuously at the drawbar over 4 000 hp; that is more than any single diesel locomotive yet running.
Chapelon was never to have the fortune to stock French Railways with the range of powerful three-cyiinder compounds which he had designed, for the decision to end steam was taken whilst the first of them, a 2-10-4 freight locomotive, was under construction.
Jacket photograph: Andre Chapelon standing in front of 160 A1 at Laroche depot.