Andr Chapelon

André Chapelon was a pioneering French steam locomotive engineer whose work significantly advanced the field during the mid-20th century. Known for his innovative designs and emphasis on efficiency, Chapelon focused on enhancing locomotive performance through meticulous rebuilds and technological advancements.

He collaborated with several major French railway companies, including PO and SNCF, where he modernized existing locomotives by integrating features like compound expansion and superheating. Notable projects included the high-efficiency 4-8-4 design (242A1), which set records for power and efficiency, and exported locomotives that blended American engineering with his own innovations.

Chapelon's legacy is marked by his contributions to steam technology, though many of his proposed advanced designs were unrealized due to the industry's shift towards electrification. His work remains influential, particularly in highlighting the potential of steam locomotive optimization.