The Auto Tractor

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A touring car was backed over the under carriage of the Auto Tractor. Notice the hub gear which will be meshed with a bull gear on the huge steel traction wheel; the rear wheel is raised off the ground. When fully hitched, both rear wheels act as flywheels, and the undercarriage rests on the ground. When hitched, it will be tied to the front axle of the car. The driver's seat is on the vehicle's right side.
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The hub gears and rear axle saddles. It would be absolutely essential for the automobile to be held firmly so that the hub gears could engage and operate the large bull gears. Note the absence of tire tread.
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The Auto Tractor unit went under and behind the automobile. Note the huge bull gear inside the traction wheel. Hub gears from the car mesh with this gear when aligned. There must have been extensive wear on those gears operating in the open. The contraption had to have been noisy as well. No doubt the hub gears had to be replaced frequently. Additionally, there is a smaller gear inside the traction wheel. We can only speculate that it had to do with driving the belt pulley. The additional radiator can be seen on the axle between the traction wheels. Note the hoses near the front of the frame which connected with the car engine. Presumably a car would slide back and stop at the angles on the rear of the frame, and was held in place by the forementioned saddles.
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The Auto Tractor pulling a road grader: Hard to believe, but this is the direct ancestor of today's road patrols. This picture gives a good perspective on the relation of the rear car wheels to the traction wheels. Also, this is an "action" photo: Note the  blur of the rear wheel spokes.

Back in 1988, when I “retired” for the first time, I decided to give all the pictures I had shot for various farm magazines to the public, by making them available to the University of Illinois Archives. Bob Chapel, the archivist, showed me where they would be filed. In the process, I “discovered” a box of pictures filed there in 1920. It was a veritable treasure trove of old tractors, many of which I’d never heard of.

I commented to Bob then how fortunate I thought it was to have discovered this “lost” file. He chided me for the use of the word lost. “What do you mean, ‘lost’?” he asked. “They’ve been here all the time.”

True enough, but no one had checked out any of the pictures I selected – including those of the Auto Tractor – since 1920.

The Auto Tractor’s origins are shrouded in mystery. I cannot find the name of the inventor in any of the available literature. Adding to the puzzle is this: In a search of patent office files, I found an “Auto Tractor” invented by H.T. Preble, with paperwork filed on Nov. 13, 1912. However, Preble’s invention looks more like an army halftrack. It had an automobile body, but featured a set of tracks to drive it.

Also, C.L. Best of California – the father of the present-day Caterpillar tractors – filed a patent on an “Auto tractor” on June 4, 1912. Best’s machine looks like a tractor. It has tracks at the center, an obviously heavy engine, and a huge roller in front to control the steering. It is easy to see in this patent how Best anticipated present-day crawler tractors.

That said, consider the Niles, Mich., Auto Tractor. As outrageous as it looks, I think that more than other tractors of its day (probably 1912 or earlier), the Niles, Mich., Auto Tractor anticipated the lighter-weight school of tractors, putting the farm horse out of business. The Auto Tractor made use of car-size engines, those from 20 to 90 horsepower. Also, while high in price for its day, the Auto Tractor was a more affordable alternative for most farmers.

In what literature I’ve found, there is also the subtle suggestion that since a car could also be used for a tractor, justification existed for going ahead and buying that car, and maybe even a bigger one! In 1912, no doubt, there were many questions about buying cars: “Should we or shouldn’t we?”

I’ve done my level best to find the remnants of an Auto Tractor, but have been unsuccessful. If any reader knows of one, please let me know. Also, if anyone knows of the inventor or a patent number, that information would be helpful.

If no Auto Tractor exists, perhaps a skilled machinist could build a reasonable replica. Right now, the best material available for such a project is a detailed owner’s manual preserved by Karl Ekblaw at the University of Illinois Archives. Although it provides extensive information, it includes neither the name of the inventor nor any patent numbers. The “secrets” of the Auto Tractor could be traced if those numbers were available.

Another part of the mystery is that the Auto Tractor manual lists several sales offices, including F.B. Piatt, 922 S. Harvard Blvd., Los Angeles; Auto Tractor Sales Co., Medford, Ore.; and R.C. Atkinson, Niles, Mich. (Could Atkinson be an inventor, given that address?)

The Auto Tractor manual does a good job of both illustrating and describing the machine, even with a few shortcomings. Among the highlights:

Auto Tractor

The Auto Tractor

“During the first days of the development of the automobile, the inventor of the Auto Tractor saw the possibility of working out a method that would make the automobile of greater use by adapting it to pulling heavy loads at slow speeds, and for operating stationary machinery.

“The fundamental principle employed in the first Auto Tractor is now used in the construction of the latest machines. Two years of practical use of the Auto Tractor in more than a dozen states has proved that the automobile can do the work.”

General Description

“The Auto Tractor is an attachment for any automobile and is so designed that when attracted to the automobile, the road speed of the latter is decreased and the pulling power increased about 14 times. This ingenious machine attaches to any standard automobile, making it possible to plow, disc, harrow, sow, harvest, and thresh and do other similar work, using the automobile engine and transmission to furnish the power and the Auto Tractor to convert this power, so that it is available for use on the farm.

“The Auto Tractor attachment consists of a steel frame, the rear of which is carried by two traction wheels. Gearing is provided for transmitting the power from the automobile wheels to the traction wheels. A radiator for the water cooling system, a water supply tank, a circulating pump and connections are provided for furnishing additional cooling capacity to ensure the automobile engine being properly cooled under all conditions. At the rear end of the frame is an adjustable draw bar to which the plows or other implements are attached.”

Method of Attaching

“Before the automobile is attached to the Auto Tractor, two saddles are clamped to the rear axle and steel gears are fastened on each rear wheel hub. The gears are centered and held in place by special steel hub caps which replace the regular hub caps. It is only a moment’s work to remove them whenever desired.

“To attach the automobile to the Auto Tractor, the car is backed up, straddling the Auto Tractor frame, until the saddles on the rear axle ride the inclined top of the frame. The automobile is then drawn back into place with its own power by means of ropes wound around the hub gears which act as winding drums. The frame is designed so that when the automobile is back in position, the rear wheels are raised off of the ground about six inches, and the hub gears are in mesh with the large spurs of the Auto Tractor. The front end of the Auto Tractor frame is carried by a bolster which is attached to the front axle of the automobile. The method of attaching the automobile has been simplified so that one person can do the work easily in from five to ten minutes, and it can be detached in much less time, leaving the car available for ordinary use.”


“As the automobile engine is the source of power, the amount of work that can be done depends on the horsepower and condition of this engine. The following table shows the number of horses necessary to do the work which we guarantee can be done with the Auto Tractor when attached to automobiles of various horsepower. This is provided that the automobiles are in good mechanical condition.”

20 horsepower 4 to 6

30 horsepower 6 to 9

40 horsepower 10 to 14

50 horsepower 14 to 18

60 horsepower 18 to 24

90 horsepower 24 to 30

The owner’s manual contains other information (including the facts that quite a production line had been established, and the completed models were shipped by rail) too detailed to include here. Surely the Auto Tractor has not vanished without leaving some trace. FC

Do you have information relating to this unique piece? Please contact C.F. Marley, 26288 Oconee Ave., Nokomis, IL 62075. 

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