Rock Island class P-33 Pacific No. 935 appears here at Kansas City, Kansas in March 1938 in an image from the Harold Vollrath collection that was saved from a discontinued Internet site. This class came from ALCo's Schenectady Works in 1910 with 74-inch drivers and 185 p.s.i. of boiler pressure, with cylinder dimensions that were soon modified to 23&fras12;x28 inches. They weighed 243,025 pounds and developed 32,859 pounds of tractive effort. Grate area measured 45 square feet, with 2951 square feet of evaporative heating surface and a superheating surface of 739 square feet. The whaleback tender was a feature of many of the Rock Island's older locomotives.