The Alco RS-1 road switcher developed 1000 horsepower, suitable for local freight and switching duties and light passenger service. The engineman regards the photographer with some amusement as RS-1 No. 8107 pauses briefly during switching maneuvers at Pittsfield, Massachusetts, in August 1955. Built in 1949 as a member of class DRS-1b, this unit was later renumbered to 9107 but did not survive to join the Penn Central roster.