Shown as No. 240 before being renumbered in 1936, eight-wheeled switcher No. 7640 poses in Buffalo, New York on July 19, 1933 for the same unknown photographer who took the preceding photo of No. 7271 in Toledo two days earlier. (He was evidently heading eastward at the time.) All members of class U-3, which numbered 417 locomotives throughout the New York Central System in 1940, had 52-inch drivers (except a few assigned to the Boston & Albany, which had 51-inch drivers) and 25x28-inch cylinders, giving them good leverage when digging into their yard duties. No. 7640 was the first engine of class U-3b, which came from Lima Locomotive Works in 1920-21. This group carried a boiler pressure of 175 pounds, slightly lower than some of the other U-3s. They developed 50,060 pounds of tractive effort and weighed in at 219,500 pounds. Other specification for the U-3b class appear on the page for No. 7643. This member of the class ended her service life in 1955.