Trackmobile最初是作为位于伊利诺斯州Whiting公司的内部业务，在1947年，一个名为Marshall Hartelius的年轻离役战机机师与工程师被指派修整一辆Whiting厂内适用了数年的旧式工业机车，其总是被困在末端轨道上，数小时不能运转。Hartelius被要求寻找一种新的使其在路面运转方法，以避免轨道式移动的难题。他首先设计出了一种装载于机车上的路面轮式系统，但发现其笨重又复杂，而且，尽管它增加了适用于路面——轨道的选择，但耗费掉大量的燃料与燃油，且需要经常的维修。Hartelius废弃掉这个设计，向其老板提交了一种专门设计适用于厂内轨道移动的概念，它拥有可运转于路面的结实橡胶胎，还有可运转于轨道上的凸缘钢轮。

　　核心问题是如何设计出一种既足够轻以在路面上行走，又足够重以起动及阻止轨道运行的机械，Hartelius对于这一工程两难问题的方案是：借助于双轨道的重量以增加车辆牵引的重量。他设计出一种操作于驾驶座位的车钩头，通过它可以增加轨道车举升的液压，转换为到车辆轮子的49,000磅重量。

　　1948年，其原型被制造出来，取名为“Mule”，运作在Whiting工厂，立即取得了成功，其轨道式移动只占用于旧机车运行的一小部分时间，并耗费小量的燃料，需求的维修少，与旧机车相比，极大地减少了运作成本，Hartelius为他的公司解决了这一轨道车辆转换的难题。1950年的一天，Hartelius想到其他的公司可能也会对“Mule”感兴趣，其在拖车上放置了一辆产品，携带它到全国展示此移动轨道车的优势，自那天起，已有10,000多辆Trackmobile车辆服务于54个国家。

　　到1980年，Trackmobile从Whiting厂独立出来，并作为一个独立的部门搬至乔治亚州的另一个市，在1987年，芝加哥Marmon集团收购了Trackmobile，并将其与他们的Switchmaster生产线合并，今天，Trackmobile是从属于Marmon运输服务领域内的子公司。

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.