From the beginning of time, humans have adapted to their environment. As part of that adaptation, creative thinkers employed natural power in the form of wind and water. But these sources of nature’s blessings have limitations. Wind is not constant and water is not always available. And neither natural resource could provide power to till the land for food production.
As a supplement, beasts of burden — most commonly horses and oxen — were harnessed. These wonderful animals were also utilized for purposes other than working the land. It’s estimated that horses were used to generate rotary power well over 300 years ago.
In about 1840, horse sweep powers began to be developed. A large iron gearbox was mounted on a rotating frame. Sweep arms were attached at the top of the gearbox. Varying numbers of horses were hitched to the arms and walked in circles to turn a vertical axle in the gearbox. A series of gears under the frame of the gearbox drove the horizontal output shaft. A pulley at the end of the output shaft transferred the resulting power to implements.

In a gristmill, the sweep power was often connected to one of the burrs in the gearbox. When the horses walked in a circle, it turned the burrs, grinding the grain. Operating this form of gristmill required caution. The person feeding the mill hopper had to step over the sweep arms when they were moving.
Oddly enough, horses were the only animals considered as a power source for the sweep power. Oxen were a popular farm traction animal. They are lower maintenance than horses and provided food when no longer used for draft purposes. However, they were thought to get dizzy from walking in circles.
Manufacturers added power
Homemade horse sweep powers set the course for commercially manufactured units. According to C.H. Wendel in Encyclopedia of American Farm Implements & Antiques, numerous styles appeared and many were built under license from their respective patentees. Especially before 1910, he notes, many threshing machine manufacturers also offered sweep powers.

In most cases, the thresher manufacturer built the sweep power using designs perfected by others. The Dingee-Woodbury power, for instance, was built and sold in large numbers by J.I. Case Threshing Machine Co. as well as by Advance Thresher Co., Belleville (Illinios) Machine Works, C. Aultman & Co., Geiser Mfg. Co., Harrison Machine Works, M. Rumely Co., Minneapolis Threshing Machine Co., Minnesota Thresher Mfg. Co., Northwest Thresher Co. and Russell & Co.
In the late 1800s, Dingee-Woodbury sweep powers were among the larger manufactured powers. The Westinghouse Co. offered horse lever (sweep) powers in its 1886 catalog in two sizes: the No. 1 for use with 10 or 12 horses and the No. 2 for use with four or six horses. The 1908 Sears, Roebuck & Co. catalog also included horse sweep powers.

In 1915, Wendel notes, more than 30 companies produced sweep powers, and another dozen built tread (or railway) powers. By the 1930s, only a half-dozen companies still offered sweep powers. After the end of World War II, the sweep power era had ended.
Bringing a home-built sweep power back to life
Metal worker/machinist Ammon Weaver Jr., now of Spencer, Tennessee, known for building treadmills powered by horses, developed his own horse sweep power. Through those applications, Ammon demonstrated how draft horses paid their own rent and then some.
Ammon’s horse sweep power found an appreciative audience. “Ammon brought a horse treadmill to Horse Progress Days at Mount Hope, Ohio, for demonstration purposes,” recalls Henry Raber, Baltic, Ohio. “We encouraged him to do the same with his sweep but it never worked out. When Ammon moved out of the area, he no longer had use for it. He offered the sweep to us, providing we moved it.”

The men built a trailer to use in transporting the sweep. Once onsite, the axles are removed so the unit sits on the ground. The gearbox and sweep are secured with four 10-by-10-inch oak beams measuring 12 feet in length. The beams are secured with stakes driven in the ground. “There’s lots of pressure on the center unit when the horses are walking,” Henry says.
The next step was a complete overhaul. The sweep’s rotted wooden arms were replaced with metal pieces. Made from 4-inch square steel tubes, the new arms are 18 feet long. Cables were connected from the gearbox to each arm and between the arms. Turnbuckles serve as tighteners on the connecting cables, stabilizing the arms. Henry estimated the replacement arms and cables added 1,000 pounds to the sweep’s weight.

“The gearbox consists of three gears that are stacked,” he says. “The smallest gear sits on top and progresses to the third gear, the largest one, on the bottom. The series of gears drive the horizontal shaft. The pulley on the shaft’s end turns at 500rpm.”
Practice makes perfect
Prior to setting up for the first demonstration, the group held practice sessions. Four owners — Wayne Raber and Andy Hershberger, both of Baltic, and Sam Miller and Daniel Miller, both from Millersburg — brought one team each for a total of eight Belgians. “Each horse was hitched to a single tree that was hooked to the beam,” Henry says. “A long rope connecting the horses enables them to pull together.”

Even though a man walked alongside each horse, it was difficult to get the horses to walk together. “Each horse wanted to walk at different speeds,” Henry says. “And then it was hard to get all the horses to stop at the same time. After the first practice, I wasn’t sure it was going to work.”
But once the horses became accustomed to the new operation, they worked well together. “After the fourth practice, we simply said, ‘giddy up’ and off they went,” Henry says. “If a single horse were to be replaced, the new horse adapted easily.” For safety purposes, a loose rope connected the bit to the point where the singletree was hooked at the arm in front of the horse. “With large crowds observing,” he adds, “we did not want a horse to break away if it got scared.”
The sawmill is owned by organizers of Daughty Valley Steam Days, an annual event held near Charm, Ohio. Those assisting with the sawmill included Andy Miller, Roman Miller, Andy Raber and Roy Raber, all of Baltic.
Rest for horses and volunteers
The first demonstration, at the 2021 Horse Progress Days in Mount Hope, was considered a success. Fifteen men were involved, including those who operated the sawmill powered by the sweep. “We were pleased with the large crowds that gathered for each exhibition during the two-day event,” Henry says.

The volunteers took breaks about every 30 minutes. “We simply said ‘whoa’ and the horses generally stopped,” he says. “The horses were kept in place during the rest time. After a period during the day, we took the horses out of the sweep to feed and water them.”
All involved were pleased with the outcome. “The most rewarding part was the many nice comments we received,” Henry says. “Hopefully we can repeat the demonstration at future events.” FC
Freelance writer Fred Hendricks of Mansfield, Ohio, covers a vast array of subjects relating to agriculture. Email Fred at fwhendricks@gmail.com.