The Nickel Plate's H-6 class was an upgraded design based on the USRA light Mikado type. Like most "Mikes" they had 63-inch drivers. Their cylinders measured 26x30 inches and they carried 200 p.s.i. of boiler pressure. With a grate area of 66.7 square feet, they had an evaporative heating surface of 3744 square feet and a superheater surface of 882 square feet. The Nickel Plate had 72 locomotives in the six H-6 subclasses, which varied in locomotive weight; No. 662's H-6f group, erected by Lima Locomotive Works in 1924, weighed 318,900 pounds. These 2-8-2s developed 54,700 pounds of tractive force; the last 57 were erected with a booster in the trailing truck that added around 8,200 pounds to the tractive effort while starting a heavy train. This Lima builder's photo comes from the 1951 edition of World Railways.