W.T. Smith Lumber Co. No. 10 is a Heisler - 2 truck built by the Heisler Locomotive Works in 1918 for W. T. Smith Lumber of Chapman, AL, it was numbered #10.

The engine was design to work for logging dutes for the W. T. Smith Lumber company.

Between 1891 and 1941, the Dunkirk Engineering Company of Dunkirk, NY, the Stearns Manufacturing Company of Erie, PA, and finally the Heisler Locomotive Works in Erie built six hundred and twenty-seven geared locomotives of this type.

Seeking to add examples of all the major Philadelphia locomotive builders, the Pennsylvania Historical and Museum Commission bought #5 from Chicago Mill & Lumber in 1965.

The locomotive is seen Today on static display at The Railroad Museum of Pennsylvania while it's repainted and renumbered as Heisler #4.