A ballast tamper maintains the high-speed roadbed.

Fast through freight service was a hallmark of the Green Bay Route, and in order to give that level of service a well-maintained right-of-way was essential. This postcard view from about 1969 shows a ballast multiple tamper in operation, with a track gang in the background. Machines like this were used to compact the ballast under crossties to maintain the grade and surface of the track.

This view is from a postcard.