ASME-Landmark:Lombard Steam Log Hauler
Lumbering in Maine, which began along the coast with cutting pine for masts for the Kings Navy, was limited to the suitable timber growing near enough to the water to permit its transportation by oxen to water on which it could be floated to the ship—so the type of tree was limited to those that would float. As a result of these limitations, there were at the turn of the century uncounted thousands of acres of fine maple, white and yellow birch, beech, and ash, which, with the equipment available, could not be gotten to any market.
In the 1890s, vehicles powered by gasoline engines were running successfully, but these ran on wheels on the ground. But the log hauler must run on snow, and a wheel with its very limited surface in contact with the surface of its roadbed would certainly slip if the surface were snow and ice. Mechanic Alvin Lombard created the solution: A crawler-tread vehicle, which he patented in 1901 and which has since become the mark of the internal combustion engine-driven agricultural and construction equipment and military tank in current use.
The first log hauler had an upright boiler and two upright engines, which were soon replaced by a horizontal boiler and engine, and in its final form, the steam log hauler was a railroad yard engine, known as a saddle back thanks to the water tank draped over the boiler. This arrangement—with the boiler and water tank putting the greater weight of the machine on the tracks—gave maximum traction and was especially suited to the log hauler. See ASME website for more information