ASME-Landmark:William Tod Rolling-Mill Engine

In steel-making, iron ore is converted to molten heat in a blast furnace, refined into steel in a steelmaking furnace, cast into solid shapes, and then squeezed into its final form in rolling mills. This work required a great deal of energy and horsepower in an age before high-horsepower electric motors and steam turbines, so massive reciprocating steam engines had to do the job.

The William Tod Company of Youngstown was one of a handful of builders of very large machinery for the American steel industry. The landmark engine, with cylinders of 34- and 68-inch bore by 60-inch stroke, is representative of the firm's—and the industry's—application of steam power to rolling-mill drive early in the period of gradual transition to electric drive. As a cross-compound, non-reversing merchant mill engine, it featured cylinders located across form one another on two separate bedplates. The frame, cylinder, and flywheel castings, and the crankshaft, piston-rod, and connecting-rod forgings of these engines are typical of the largest work pieces produced by the nation's foundries and forges.

Practically all integrated steel plants built in 1890 through 1920 used at least one rolling mill engine; in the Youngstown steel district alone, some 40 or 50 engines were in use, thanks to the leading manufacturing companies—the William Tod Company, Mesta Machine (Homestead, Penn.), and Allis Chalmers (Milwaukee, Wis.). The landmark rolling-mill-engine is one of the last surviving engines in North America. See ASME website for more information