CB&Q F7 164, Naperville, IL, July 28, 1965, photo by Chuck Zeiler

Chicago Burlington & Quincy F7 164, Naperville, Illinois, July 28, 1965, photo by Chuck Zeiler

I was fortunate to be able to read the model plate on the side of the locomotive, identifying it as an F7. Otherwise, I could not tell the difference between a Phase IV F3 and a Phase I F7, since EMD utilized the same carbody for both models. The following is from the Burlington Route Historical Society's Bulletin #10: In May 1950, the CB&Q proper acquired its only F7's - 10 A's and three B's. These units had a 36 " dynamic brake fan ahead of the four radiator fans, thus differentiating them from the Phase IV F3's. Nine of the F7's were numbered as three-unit drawbar-coupled A/B/A sets 167-169, while the other four A's were 163A through 166A. With the delivery of the F7's, two of the previously delivered four-unit F3 sets (137A-D and 138A-D) were broken up and reassembled with the remaining single F7 A-units to make up three-unit F3-A/F3-B/F7-A sets 163 through 166. The renumbering went as follows: 137A became 163C, 137B became 163B, 137C became 164B, 137D became 164C, 138A became 165C, 138B became 165B, 138C became 166B, 138D became 166C. The units in these F3-7 sets matched well, the only outwardly visible difference between the A-units being in the rooftop dynamic brakes. From the ground, the 163-166 sets appeared identical the "pure" F7 sets 167-169. Later, most of them were split into separate units, coupler equipped at both ends. The three-unit A/B/A sets were not split up until well into the 1960's, with the 167 trio finally being broken up into individual units late in 1965. Suffix letters had been assigned to the locomotives for maintenance purposes, but only appeared in small 1 inch lettering on the side below the word BURLINGTON, until the locomotives were broken up and equipped with couplers at both ends.