A Note About F5s

D&RGW 555A-557D (5551-5574) are sometimes listed as F5s. Even I designated them as such until recently having a change of mind. An F5 was a late F3 (often designated by fans as a Phase IV F3) that had some of the improvements that were slated for the F7 line, but not all. Notably, they had the newer, more robust D27 traction motors, and a better wheel slip control system. Most sources agree that this model was produced between Oct-1948 and Feb-1949, when the F3 officially ended. EMD does acknowledge that some were built, but their own reference data refers to the D&RGW units as F7s. Don Strack has an excellent summary of the confusion. From now on, 555A-557D will be lumped in with the F7s around here.