The 4-S demonstrator was tested by a number of railroads, including the Louisville and Nashville, Seaboard Air Line, Mississippi Export Railroad, Gulf, Mobile and Ohio, and the Southern Railway; however no orders materialized for the type, or for any other of Ingalls' proposed locomotives.[2] The lack of orders combined with issues with the supply of components resulted in Ingalls electing to abandon its plans for locomotive construction;[1] the sole 4-S was the only locomotive they ever built.[4] It was sold to the Gulf, Mobile and Ohio Railroad for US$140,000 in June 1946, where it received the road number 1900.[2]
The 4-S served with the GM&O, operating primarily from Mobile, Alabama, to Jackson, Mississippi, but also served around Meridian and Laurel. It was used in switching duty, earning a reputation for toughness;[1] it once derailed, landing inverted, but was repaired and returned to service in short order.[2] In 1966, the railroad traded it in to EMD as partial payment for new SD40s.[1] It was offered to the Illinois Railway Museum for US$3,000, but the museum was unable to raise the funds.[2] When no other buyers materialized,[1] it was sold to Pielet Brothers in 1967, where it was scrapped.[2]
