Calumet Yard, on Chicago's south side, was the home of the last roundhouse built in the United States, completed in 1952. By this late date, NKP 173 was used as protection power for the ALCO PAs on passenger trains, as well as other miscellaneous duties such as Work trains, etc. She was kept hot in the roundhouse awaiting a call. This day she was called to handle a mail train out of Chicago. NKP 173 drifts along the ready track as she heads downtown to pick up her train.
