GE 57-ton gas–electric boxcab
Before diesel engines had been developed for locomotive power in the 1920s and 1930s, many companies chose to use the gasoline engine for rail motive power. The first GE Locomotive was a series of four-axle (B-B) boxcab gasoline–electric machines closely related to the "doodlebugs", self-propelled passenger cars built in the early Twentieth Century.
Source: Wikipedia — GE 57-ton gas–electric boxcab (CC BY-SA 4.0)