GBW  #310 was less than a year old when Deb Fifield captured it while working the Winona yard.  At the time of delivery the #310 was the highest-horsepower-per-axle diesel in operation in the United States.

On the other hand,  FA-1 GBW #507 had little more than a year of service left when this photo was taken.  Its sister #506 had already been traded in on the purchase of GBW #310 and the remaining FA-1s would be retired as other high-horsepower locos arrived in the early 1960s.

There are several interesting things in this photo... notice how much larger the steel 40' boxcars are compared to the steam-era boxcars and reefers coupled behind them?  The pilot in front of the FA-1 seems to be a different color red than the rest of the locomotive; was this a result of it being repaired and repainted at some time?