The Reading's class K-1sa 2-10-2s were rebuilds from the railroad's class N-1sa 2-8-8-2s between 1927 and 1939. As a result they were extremely large and heavy, having an engine weight of 439,900 pounds. With a driver diameter of 61½ inches, they had cylinder dimensions of 30½x32 inches and a boiler pressure of 220 p.s.i., and developed 90,514 pounds of tractive effort. Grate area totaled 108 square feet, evaporative heating surface 5502 square feet, and superheating surface 1840 square feet. When later equipped with disc driver centers on the main driving axle they were reclassified to K-1sd. This photo of No. 3009 of the group, for which no information is available, comes to our Random Steam Collection courtesy of Donna Harrison-Rodeghiero.