Eimco Power Horses: The Tractor That Drives Like A Horse

When one control lever is pulled to the rear and the other is left in its forward position, the Power Horse turns toward the side upon which the rein is pulled. The sharpness of the turn depends upon how far the levers are pulled back, or allowed to go forward, if in reverse. Steering is accomplished by the steering clutch disengaging power to both wheels on the turning side. If one lever is released, and the other is pulled all the way to the rear, the wheels on each side will turn in opposite directions, and the tractor will spin around in its own tracks.

To reverse, the control levers are pulled all the way back. This causes the steering clutch on each side to disengage, while the reversing band on each side engages and, through a set of planetary gears, the Power Horse moves backward at half the corresponding forward speed. The tractor can be steered in reverse by releasing the pressure on the rein toward the desired direction of turn, and holding back on the other rein.

To stop, both levers are pulled simultaneously to the middle position, where they lock into neutral and remain until a light pull on either line instantly releases the neutral lock, allowing the machine to move forward or back, depending on how the reins are positioned.

Options available for the later model Power Horses included a PTO and belt pulley, as well as electric start and lights, power hoist, foot-operated hydraulic brakes, and a buck-rake hitch. While the Power Horse was primarily intended to use horse-drawn machinery, the manual shows a rear-mounted mower that was adapted from the International Harvester 16A or 25A PTO mowers. A mounted, two-way plow was available, but no manufacturer is listed. Photos of these two mounted implements show the operator sitting on a pan-type seat mounted over the tractor's rear axle.

No one knows how many Power Horse tractors were built before manufacturing was shut down for World War II, but there probably weren't more than 300. Allis-Chalmers seems to have acquired rights to the design and experimented with a four-wheel drive tractor through the war's end. There is some evidence that Bert Bonham went to work for A-C, and was involved in the project. Allis-Chalmers built and tested six prototype 'Model H' machines, but dropped the idea sometime in 1945. The problem A-C had with the design was the fact that, in order to turn, power to the inside wheels was interrupted, and the outside wheels didn't have enough traction to pull the load through the entire turn.