A Atchison, Topeka & Santa Fe No. 2656 was part of the 2650-class of locomotives, which included GP7s numbered 2650 to 2893. Nos. 2655 and 2656 were the first two delivered, in September 1950. According to Iron Horses of the Santa Fe Trail by E.D. Worley, No. 2656 was equipped with dynamic brakes when EMD delivered it to the railroad.
Of the 13 GP7s built for the Santa Fe during 1950, only four were equipped with dynamic brakes. Units 2650 to 2654 were equipped with steam generators, but did not have dynamic brakes, in part because the air brake reservoirs occupied the area on top of the hood where the cooling fan would have been. — Brad Black, vice president, Virginkar & Associates Inc., Muskego, Wis.