Eimco's Power-Horse Tractor

The last rein-drive tractor was built by Eimco Machinery Co., Salt Lake City.


| November 2006



Eimco Power Horse

Theo mowing with a dump rake pulled by his Power Horse tractor at a show in Belgrade, Mont.

Image courtesy Theo McAllister

One day several years ago, Theo McAllister spotted an unusual tractor operating a Fresno scraper, digging a basement near his Kanab, Utah, home. It was a small tractor, all four wheels were the same size … and the tractor was controlled by reins. "Down into the hole and back out the tractor and scraper worked, while an old gentleman operated them from the rim with long lines," Theo recalls, "like the tractor was a horse."

A memory surfaced for Theo, now 76. "In my teens, I saw a basement dug the same way but with a team of horses. I told my son Wesley, 'We've got to find one of those tractors. They'll be rare.'" That led the McAllisters to their first tractor show in Durango, Colo., in search of a Power-Horse tractor.

They didn't find a Power-Horse, but got hooked on old iron just the same. While the two scouted a Power-Horse, Theo researched this early four-wheel drive machine and its builders, a special part of Utah history dating to pioneer Mormon ranchers.

For three years the two collected old iron: 50 tractors and engines and a lot of parts joined their collection. They continued to run down leads on the Power-Horse, until they located the last (and hardest to find in good condition) part needed: a usable Power-Horse gearbox. Finally they could realize their dream of building a running Power-Horse.

New! A rein-drive tractor

In 1937, brothers Albert and Bond Bonham designed and built the Power-Horse A-20. Eimco Machinery Co., Salt Lake City, cast their rein-controlled four-wheel drive tractor. Weighing in at just 2,500 pounds, the Power-Horse used an Allis-Chalmers Model B engine. That year, Popular Mechanics ran a photo of the Power-Horse headlined: "Tractor Driven Like Dobbin Responds to Farmer's Reins."

During the Great Depression, the Power-Horse was a boon for small farmers in Utah, Idaho and Arizona who had already paid for their equipment and were reluctant to give up their horses or horse-drawn implements. If his horse died, the farmer was faced with buying another horse, which was expensive to maintain, or a new tractor, which was a huge investment. With the Power-Horse, however, the farmer could use mechanical power and his horse-drawn equipment.