For the first 27 years after its completion in 1910, the SP&S Railway was powered by hand-me-down locomotives from its parents, the Great Northern and Northern Pacific. But in 1937 and 1938, it took delivery of its first brand-new locomotives, the 900-series 4-6-6-4 Challengers and 700-series 4-8-4 Northerns. This card proudly describes these new locomotives, which it accurately describes as “giants” compared with the railway’s existing locomotive roster.
Both types of locomotives were designed by and for the Northern Pacific, though SP&S’ versions burned oil instead of coal. NP put all of its articulated locomotives, regardless of exact wheel arrangements, in a Z class, and its first Challengers were class Z6, a number that the SP&S also used despite not having any Z1 through Z5 locomotives. NP’s Northerns (a wheel arrangement named after the NP) were in its A class, and the 1938 editions were A3. SP&S, however, put its three Northerns–700, 701, and 702–in the E1 class, probably because it still had some other locomotives in an A class. The 700 still survives and operates occasionally, especially at Christmas time in Portland, Oregon.