The Watford Corn Sheller

Canadian-built corn sheller showcases several unique features, including wood frame construction and an unusual flywheel configuration.

Watford sheller

The Watford sheller.

Photo by Dutch deHaan

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While attending the annual Portland, Indiana, engine show several years ago, I visited with a fellow corn sheller enthusiast. This gentleman was a very serious corn sheller collector and quite the resource. He suggested that I take a look at a one-hole sheller he had brought along as a candidate for future restoration. While it appeared mechanically complete, it did have some serious structural problems. I asked him just who made such an unusual machine, and he replied, “It’s a Watford!”

The Watford was unlike any sheller I had seen. The input power was designed to be a one-man crank input. That was where all the similarities to common corn shellers of the period came to an abrupt end.

First, a bit of background on the famous inventor and businessman, Thomas Doherty. Born in 1843 in Lanark County, Canada West, Thomas was the youngest child of James and Rachel (Garrett) Doherty. His formal education ended in 1857. He married in 1864 and spent the next several years running the family farm.

Doherty showed inherent mechanical aptitude early. He started with a small machinery repair shop on the farm. He also became an accomplished thresherman and mastered the internal workings of the machine. In 1875, enticed by free land, he moved his family to Watford, Ontario, Canada, where he intended to establish a business.

Watford was first settled in 1851 at what was known as Brown’s Corners, a stagecoach stop between the village of Warwick and Brooke Township. The Great Western Railway, built in 1856, caused the settlement to be relocated near the tracks in its present location. It was incorporated as the village of Watford in 1873.

Doherty founded Watford Agricultural Implement Works (WAIW) in Watford in 1875. The business provided a large and diverse line of products and a repair service. WAIW grew significantly over the next five years. With continued growth, in 1882 Doherty took on a partner.

Doherty’s diverse passions led him to many business ventures, including extremely ornate stoves, automobiles, engines and boilers. He also was a pioneer in the steel refining process now referred to as decarburization. In 1881, he founded Doherty Mfg. Co. in the neighboring community of Sarnia. By 1913, his plant was producing more than 3,000 stoves a year. Doherty became heavily involved in civic matters before his sudden death in 1916.

Designed with unusual features

The sheller named for Doherty’s adopted hometown had several unique features, including wood frame construction, an unusual flywheel configuration, an incorporated inlet casting, a spring sheller process and primary and secondary discharge.

The frame mimics construction typical of the period. Utilizing 1-3/4-by-2-1/4-inch oak stock, the Watford’s frame consists of four upright legs, two horizontal feet and four horizontal cross-members. Mortise and tenon joints provide a solid rectangular frame. Flat poplar wooden panels are fitted into rabbets in the frame. The top is easily removed for spring adjustment and simple cleaning.

This Watford sheller does not utilize a standard single large flywheel. Instead, it incorporates two small identical flywheels of approximately 16 inches in diameter to store inertia for the shelling process. These flywheels were engineered to provide approximately the same inertia storage of the typical large, single, cast-iron flywheel and are fitted to a high-speed shaft.

One advantage of the smaller flywheels was that, although two were used, they were smaller in diameter and posed far less physical imbalance in the overall machine. The flywheels were made with a flat outer surface. That allowed for a small drive belt from a hit-and-miss engine to run directly on the flywheel’s outer surface, powering the sheller. The smaller flywheels essentially distributed their weight evenly across the sheller, thus, the machine was less likely to fall and break. They also were less of a physical danger to the operator because of their smaller size.

Deviating from the ordinary

Another unusual feature of this sheller was its large cast iron inlet casting. Although small in comparison to other traditional shellers (such as those built by John Deere and International Harvester), this convenient inlet casting would allow a number of ears to be placed in a queue for shelling. Since the casting was incorporated into the sheller, it was far less likely to be damaged because of the unit’s smaller overall footprint.

While the Watford is a “spring sheller,” it does not follow the traditional design standard of the vast majority of early freestanding shellers. A hand-crank provides the power input to the low-speed shaft. The two main parallel shafts (high and low speed) were fitted with the standard straight and beveled runners rotating at different speeds and directions to perform the actual “shelling.”

However, in this sheller, Doherty provided the actual “spring force” on the rag iron by utilizing a coil spring. One end of the spring was connected to the sheller frame while the free end was attached to the rag iron. This was possible since the rag iron casting incorporated a lever arm providing a pivot point to transfer the spring force to the shelling process. Since this spring is internal to the sheller (and which would be adjusted from below the top surface), it allows the top of the sheller to be clear of any obstructions. 

Oscillation by eccentric

This Watford did not separate the corn from the cobs by employing the most common, large-curved-cob raking system to discharge cobs through a side outlet casting. Instead, this sheller discharged internally both cobs and shelled corn directly downward, beneath the spring-biased rag iron onto an inclined oscillating tray. Oscillation was provided by an eccentric on one of the flywheels through a lever arm that yields about a 1-inch plus-and-minus horizontal movement of the tray.

Simple wood-on-wood sliding surfaces formed the “bearings.” Below the rag iron, this tray has a rectangular window cut into it. The window is laced with thin, taut wires about 1/2 inch apart, which allow only shelled corn to pass directly through and then pass the cobs on down the slope to discharge through a side opening in the wooden structure. 

These wires need to be taut. Large nails (approximately 16d) were cut to about 1/2 inch in length and a small hole drilled through the body of the nail directly below the head. Holes were drilled along the edges of the shaker tray for these shortened nails. They were tightly fitted, which allowed the wires to be passed through them and then turned with pliers to created permanent tension.

Efficient, compact sheller

The number of creative design concepts employed by Doherty make the Watford unique. These simplified the shelling process, minimized larger castings, provided better balance and yielded an efficient and compact sheller. Doherty’s efforts with this design showed a solid departure from typical spring shellers of the period. FC


Grateful acknowledgement is given to the Lambton County Archives, Ontario, Canada, which provided information for this article.

With a background in steel industry automation, Dutch deHaan also has 20 years’ experience as a restorer of antique farm machinery. He currently resides in Evansville, Indiana. Contact him at: totalconceptengineering@gmail.com.