Trackmobile began as an in-plant project at Whiting Corporation, Harvey, Illinois. In 1947 a young ex Navy fighter pilot and engineer named Marshall Hartelius was assigned to modify an old industrial locomotive Whiting had used for years inside their plant. Their locomotive was constantly being trapped on dead-end tracks, losing hours of productivity. Hartelius was charged to find a way to move it by road to avoid bottlenecks to railcar movements. He first designed a road wheel system to mount on the locomotive, but found it was cumbersome and complicated. Furthermore, in spite of the added utility of road-to-rail capability, the locomotive consumed a lot of fuel and oil and required constant repair. Marshall scrapped his first design and in its place submitted to his boss a concept for a vehicle specifically designed for in-plant rail movement. It had hard rubber tires to move by road and flanged steel wheels to work on rail.
The central problem was how to design a machine that was light enough for road movement and yet heavy enough to start and stop railcars. Hartelius' solution to this engineering dilemma: borrow weight from coupled railcars to increase the vehicle weight for traction. He designed a coupler head that could be operated from the driver's seat, and that would raise hydraulically to lift the railcar, transferring up to half the weight of the car body and load to the wheels of the vehicle.
A prototype was built in 1948, and designated the "Mule." It went to work in the Whiting plant and was an immediate success: railcar movement was accomplished in a fraction of the time the locomotive had required. It consumed little fuel, required little maintenance, and dramatically lowered operating costs compared to the locomotive. Hartelius had solved a difficult railcar switching problem for his company.
One day in 1950 Marshall wondered if other companies might be interested in a Mule.
He put one on a trailer and took it around the country, demonstrating the advantages of a mobile railcar mover.
Since that day, more than 12,000 Trackmobile units have been put into service in 54 countries.
We think Marshall Hartelius had a good idea.
By 1980 Trackmobile had outgrown the Whiting plant in Harvey and moved to LaGrange, Georgia as a separate division. In 1987 The Marmon Group of Chicago acquired Trackmobile, Inc. and merged it with their Switchmaster product line. Today Trackmobile is a company within the Marmon Transportation Services Division.