Kansas City Southern 2-10-4 No. 906, seen in this photo from J. R. Reid, represents the group of class J locomotives that were fueled by coal. These engines weighed 514,000 pounds and developed 93,000 pounds of tractive effort. With 27x34-inch cylinders and disc drivers of 70 inches, they boasted a boiler pressure of 310 p.s.i. — the highest of any non-experimental steam engine in the United States of which I am aware, with the reported exception of the Norfolk & Western's final group of class A 2-6-6-4s which sustained 315 pounds. The steam piping running atop the boiler was later removed, and all these fine KCS locomotives were retired in the early 1950s.