Number 9120 was built in March 1932 ( c/n 50007 ) by the Whitcomb Locomotive Works of Rochelle, Illinois, ordered as number 112, delivered as number 9120. It was a 60-ton locomotive equipped with a pair of Climax Blue Streak eight-cylinder inline gasoline engines for a total of 400 horsepower. Westinghouse electrical equipment was used throughout. The trucks were the standard MCB ( Master Car Builders ) design produced by Commonwealth and were equipped with 36 inch diameter wheels and Fafnir-Melcher roller bearing journals. To improve visibility to motorists at grade crossings, the paint was adjusted from the traditional solid Pullman green to green body with a red cab and hood ends and radiator shutters in yellow, with red fuel tanks to indicate gasoline, yellow was used for diesel fuel. The full color Burlington Route herald was applied to the cab sides and circular white Safety First emblems were applied above the footboards. At an unknown date it acquired the standard Burlington switcher paint scheme.

When the 9120 was delivered, it was tested in several locations before settling down in the Wymore Division. Later, the locomotive worked several assignments in Iowa and Illinois. In July 1959 it was sold to shortline Illinois Midland ( Millington to Newark, Illinois ) where it operated until 1964, when both main generators burned up. It was retired and scrapped still wearing the Burlington paint and number.