The S1 was run in place. Per Wikipedia:
The S1 was displayed at the New York World's Fair of 1939 with the lettering "American Railroads" rather than "Pennsylvania Railroad". At the Fair the drive wheels operated under the locomotive's own steam power. This was done by placing the S1 on a platform that had rollers under the drive wheels. After the World's Fair the S1 was re-lettered and numbered for the Pennsylvania Railroad fleet. The S1 was used by the PRR for publicity purposes as well and its image was featured in calendars and brochures. The S1 class locomotive was so large that it could not negotiate the track clearances on most of the lines of the PRR system. In its brief service life it was restricted to the main line between Chicago, Illinois and Crestline, Ohio. It was assigned to the Fort Wayne Division and based at the Crestline enginehouse. The S1 hauled passenger trains such as The General and The Trailblazer on this route.
