| Union Pacific Railroad SD24 446 and Slug S4 at Pine Bluffs, Wyoming on an unknown day in August 1984, Kodachrome by Edward M. DeRouin, Chuck Zeiler collection. Number 446 was built in August 1960 (c/n 26035) as EMD SD24 demonstrator 7201, intended for the SP and painted in SP's gray and red nose paint scheme. It was sold to the UP in August 1961, eventually paired (around 1980) with Slug S4 and used in track sled maintenance service until retired in May 1985 (the last operating SD24 on the UP), when it was traded to EMD and scrapped by Pielet Brothers. Number S4 was built in September 1957 (c/n 23722) as GP9B 316B, rebuilt at Omaha in August 1975 as Slug S4, additional sand boxes (DD35 design) were added in October 1980. Slug S4 was retired in January 1990 and scrapped. |