Self-propelled railcar No. 2506, headlight glowing, prepares to exit the diesel house in this photo taken during our shops tour of May 1958. Whether the six-cylinder engine resting on the floor at left was a spare for these "doodlebugs" I do not know. These former Alton Route cars had been converted from gasoline to diesel engines by 1950, as a result of a decision by the U.S. Post Office to stop shipping mail in the more dangerous gasoline-fueled cars.