Mixermobile Twin Truckmobile powered by twin 90-horsepower engines

Sept. 22, 2023
Built in the early 1940s, the Twin Truckmobile hit a road speed of 50 mph.

Mixermobile Manufacturers of Portland, Oregon, was nothing if not innovative. It built some of the first purpose-built wheel loaders, some of the largest wheel loaders ever built, and the first articulated wheel loaders. They also produced the self-contained, truck-mounted concrete mixer that gave the company its name, a variety of other concrete and material handling machines, and, briefly,  a truck.

Not wanting to rely on commercial road or rail transportation, Mixermobile developed its own truck to haul equipment around the country. Dubbed the Twin Truckmobile, it had two Ford 6-cylinder, 90-horsepower engines mounted side-by-side under the dual Ford hood.

The driver operated two clutches, two gas pedals, and four gear shifts: one for each engine and each of the two-speed tandem rear axles, giving 64 possible forward combinations. The driver didn’t have to run all that; he could use one or both engines and powertrains. On the level, it cruised under load at 50 mph.

The cab was 6-1/2 feet wide and sported triple windshield wipers. The front fender was just under 8 feet wide, and the bed 23 feet long. Gas was supplied by a 40-gallon tank for each engine.

The first Twin Truckmobile was built in 1941, followed within three months by two more. Rather than being in factory service as intended, the first two were sold: the first to a logger near Bellingham, Washington; the second to an oil carrier in southern California. 

As was the case with many commercial machines, the project was killed by wartime production needs. But Mixermobile saw a potential for its revival and dedicated a full page to it in their catalog for the 1947 Road Show in Chicago—complete, strangely, with what appear to be 1941 photos. It’s not known if more were built. Interesting too is that, with its twin parallel engines and powertrains, it predicted Euclid’s famous Twin-Power off-highway haulers that were introduced in 1947.  

About the Author

Tom Berry

Tom Berry is archivist for the Historical Construction Equipment Association (HCEA). Information is available at www.hcea. net, or by calling 419.352.5616 or e-mailing [email protected].

Bureau of Public Roads Manuscript Collection, Idaho State Archives
Knox Yellow road scraper.
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National Inventors Hall of Fame
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