In the previous post Jack Delano photographed a pair of workers in the cab of a steam locomotive under repair. Afterward he headed to the front half of the steamer to find this young man. With Stillson wrench in hand and folding rule in his pocket, and surrounded by rods, pipes and wheels, he is busy working with the machine’s valve gear. We’re at the C&NW railroad’s 40th Street shops near Chicago in December of 1942.