Trackmobile最初是作為位于伊利諾斯州Whiting公司的內部業務，在1947年，一個名為Marshall Hartelius的年輕離役戰機機師與工程師被指派修整一輛Whiting廠內適用了數年的舊式工業機車，其總是被困在末端軌道上，數小時不能運轉。Hartelius被要求尋找一種新的使其在路面運轉方法，以避免軌道式移動的難題。他首先設計出了一種裝載于機車上的路面輪式系統，但發現其笨重又復雜，而且，盡管它增加了適用于路面——軌道的選擇，但耗費掉大量的燃料與燃油，且需要經常的維修。Hartelius廢棄掉這個設計，向其老板提交了一種專門設計適用于廠內軌道移動的概念，它擁有可運轉于路面的結實橡膠胎，還有可運轉于軌道上的凸緣鋼輪。

　　核心問題是如何設計出一種既足夠輕以在路面上行走，又足夠重以起動及阻止軌道運行的機械，Hartelius對于這一工程兩難問題的方案是：借助于雙軌道的重量以增加車輛牽引的重量。他設計出一種操作于駕駛座位的車鉤頭，通過它可以增加軌道車舉升的液壓，轉換為到車輛輪子的49,000磅重量。

　　1948年，其原型被制造出來，取名為“Mule”，運作在Whiting工廠，立即取得了成功，其軌道式移動只占用于舊機車運行的一小部分時間，并耗費小量的燃料，需求的維修少，與舊機車相比，極大地減少了運作成本，Hartelius為他的公司解決了這一軌道車輛轉換的難題。1950年的一天，Hartelius想到其他的公司可能也會對“Mule”感興趣，其在拖車上放置了一輛產品，攜帶它到全國展示此移動軌道車的優勢，自那天起，已有10,000多輛Trackmobile車輛服務于54個國家。

　　到1980年，Trackmobile從Whiting廠獨立出來，并作為一個獨立的部門搬至喬治亞州的另一個市，在1987年，芝加哥Marmon集團收購了Trackmobile，并將其與他們的Switchmaster生產線合并，今天，Trackmobile是從屬于Marmon運輸服務領域內的子公司。

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 49,000 lbs (22,680 kg) 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 10,000 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.