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McCullough’s “Road King” – A Four Wheel Steer Trailer Without a Tractor

.In the early-1950s William L McCullough of Leighton, PA apparently used the earlier Fageol 1950 TC CargoLiner chassis design and updated it with a conventional single beam axle up front and a rear-mounted power plant to drive one of the rear axles (illustrations below) for his new concept vehicle. The one-off Fageol chassis used a swinging front axle and a mid-engine design. The lead image contains the revised and final third version of McCullough’s unique new offering with an added front axle.

  • William L McCullough’s first patent application drawings filed in 1953 (above and below.)             .
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  • McCullough later updated the design of the three axle truck and filed a patent application in February of 1954 which was granted in 1956. In October of 1954 the inventor filed a revised and second patent application which he was awarded in October of 1958. His designs resulted in improved front end geometry, enhanced rear axle traction, and a power plant that could be quickly be removed from the rear end of the chassis for replacement or repair. However, is not known at this point if any three axle trucks were constructed.
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At a later time, the inventor added a second front axle that increased the payload capacity of the rig. The advertisement (above) for the unique “Road King” states that this offering has a payload capacity of ten-thousand pounds higher than a heavier conventional tractor-trailer unit.

A possible second benefit of the McCullough truck was a higher overall fuel economy due the rounded front end of the body being more aerodynamic than that of a combined truck and trailer body. The overall fuel economy of 9.1 mpg stated in the ad may have reflected this advantage. The truck body was constructed by the Brightbill Body Works that was also the distributor of the “Road King” and continues to remain in operation today building school bus bodies in Lebanon, PA.

View a period photo of a “Road King,” and a surviving truck that is located at the Museo del Transporte in Caracas, Venezuela.

Share with us what you find of interest or can add to this post.

4 responses to “McCullough’s “Road King” – A Four Wheel Steer Trailer Without a Tractor

  1. I believe these were created to get around length laws for tractor trailers. I can’t find out what power they used, the Fageol used IH power, so I’m assuming the same. 9.1 mpg??? HA! Maybe empty downwind both ways, but fully loaded, it would be half that. I believe these had a purpose for short city runs, but not suited for long travel. I pity the poor sap that had to drive these.

    • Yeah, that caught my eye, 9.1. I went to and there was an article that states the average in the US is 6.5 today. They profiled a truck with every aero aid possible and it gets 7 to 8 overall and maybe 9 on the highway.
      Had a uncle that was a trucker in the 50s to early 80s. Mostly interstate and he got maybe 6.5 on the highway.

  2. Some trade magazine writers have a CDL. Mack recently had some of them test the new Anthem tractors. The very best, with all the goodies, including 6×2, barely broke 10 mpg with a gross of 66,000. No links allowed, so you need to google mack anthem fuel test for more details.

  3. I think 9 mpg is great. My 1934 Packard 8 averaged about that maybe less. On a long trip I might have gotten 12! My 1990 Chevy truck doesen’t get 9 unless I get a good amount of highway driving! You guys must drive a Pries or a Yaris!

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