Overland train

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In the 1960s the US Army developed two experimental overland trains, essentially oversized semi-trailer trucks that could travel over almost any terrain. Their intention was to be able to handle logistics without being dependent on local road systems, thereby improving their ability in the field.

The train concept was developed in response to problems supplying the construction of the DEW Line, which was being studied in the late 1950s. LeTourneau, a heavy-equipment maker based in Longview, Texas, contacted the Army's Transportation Command and offered several possible ideas.

In 1955 LeTourneau was given a contract for a development vehicle that became known as the LCC-1. It consisted of a large control cab containing a diesel-powered generator that sent power to all of wheels on both the cab and the four cargo trailers. The wheels were just over 10 feet tall and very wide, in order to allow the vehicle to have a low ground pressure and be able to travel over tundra. The control cab was itself articulated into two compartments; a heated driving compartment in front for the crew of three, and a rear section containing the 600 hp diesel engine, generators and fuel tanks. The cab also sported a powered crane on the rear. The LCC-1 was widely tested on everything from sand dunes to snowdrifts, and was shipped to Greenland for arctic testing as the "Sno Train".

LCC-1 was so successful that the Army contracted for a larger version, the Overland Train Mark II. Generally similar in concept, the Mark II included a number of features to allow the train to grow to any length. For instance, it was not possible to steer such a train from the front alone, the friction from trying the drag the huge wheels sideways until they followed would be immense. In order to solve this the Mark II included an innovative steering system that turned the wheels on the individual cars, but only once they reached the position where the driver had initially turned the wheel. Likewise the power was no longer provided only from the cab, but could be increased by adding additional power cars along the train. To save weight the power was now being provided by gas turbine engines instead of a traditional diesel.

The Mark II had a much larger six-wheeled cab that was over 30 feet tall and was no longer articulated due to the ability for all the wheels to be steered. The turbine engine was much smaller than the diesel it replaced, allowing the interior to support a crew of six with sleeping quarters, toilets and a galley. An additional two power cars and ten cargo cars were built for testing. In total the train now stretched over 570 feet. On flat ground it could carry 150 tones of cargo at about 20 mph.

Mark II was tested at the Yuma Proving Ground in Yuma, Arizona starting in 1962. Generally it performed well, but in the end the Army gave up on the idea as spending tightened due to Vietnam War. All that remains of the Mark II is the control cab, the rest was sold off to a local scrap dealer.