Yuma Proving Ground, Arizona—

In 1962, the Army tested a machine known as The Overland Train at Yuma Proving Ground in Arizona. It was designed to carry equipment and supplies over both on- and off-road terrains. The train consisted of the control car, ten cargo carrs, and two power generating cars. It was 565 feet long and could haul 150 tons of cargo. The control car also contained living quarters for a crew of six, complete with sleeping, eating and sanitation facilities. For a memoir of how the train was designed and built, click here.

The control cab is all that remains of The Overland Train today, and it may be viewed at the Yuma Proving Ground Heritage Center. The rest of the Overland Train was sold to a Yuma scrap dealer.

Mark Holloway
September, 2001

Bonnie Duncan's memoir about the design and construction of the Overland Train:

"In the late 1950's R.G. LeTourneau's brother-in-law gave him the idea of a vehicle which could be both moved and steered by having each wheel powered by its own electric motor. LeTourneau advertised for an engineer, and my late husband, Sam Duncan, was hired to implement the idea.

"When Sam went to Longview, Texas (headquarters for the LeTourneau Company), the train was in the design phase, and the U.S. government was interested in the concept. It was designed to travel on terrain which could not be traversed otherwise -- snow, ice, and even crevasses. It was for defense of Alaska, but by the time it was completed, the Cold War was over, and there was no need for the train.

"The train had a power car which provided power to the whole thing,
including rather elegant living quarters, very modern cooking facilities, and even an automatic laundry. The men who worked on it called it a mobile city.

"One feature of the train was its near perfect tracking. Where it was driven on sand, the tracks looked like they could have been made by only two wheels, even around a curve.

"It was a wonderful piece of machinery -- totally unique as far as I know."

—Bonnie Duncan
9/4/05

Another version of the Overland Train was constructed to haul equipment used in the construction of the Alaskan oil pipeline. Here is an article with some photos of this historic device.

LeTourneau, Inc, is still building massive equipment -- they produce and sell a dirt loader with a bucket capacity of 160,000 pounds that is run by a 2,300 horsepower engine. Click here to see some photos of these huge rubber-tired tractors at work.