The first 65 class R-65 Northerns of the Rock Island were delivered by ALCO-Schenectady in 1929 and 1930. They had a driver diameter of 69 inches and were primarily intended for service with freight trains. Some later received 74 inch wheels to be more suitable for passenger trains and were renamed the R-67 class as a result. In the years 1944 and 1946 further R-67b were built, which had larger wheels from the start. Although they had a higher boiler pressure and a larger firebox, they had a smaller tube heating area and a significantly smaller superheater. The 1944 batch were oil fired while the rest were coal fired. 