Rock Star: Fairbanks-Morse Z Rock Crusher

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by J.O. Parker
Fred tosses a large limestone rock into the rock crusher during a demonstration at the 2018 Midwest Old Threshers Reunion.


The antique rock crusher at the Midwest Old Threshers Reunion has been a people pleaser for 40 years, drawing steady crowds to watch and learn as the machine clanks and churns, turning limestone boulders into gravel.

With several demonstrations held daily during the annual reunion, which takes place in Mount Pleasant, Iowa, over a five-day stretch ending on Labor Day, volunteers Fred Fleming and Mike Dietze work like a well-oiled machine, tossing limestone into the rock crusher.

The two men, both from the Lincoln, Nebraska, area, have been attending the reunion since 1982. They typically arrive at the reunion grounds about a week early to help set up the stationary gas engine area. Part of that involves helping other volunteers haul rock from a nearby quarry to use in the crusher demonstrations.

Adding a crusher to the display

Built by Wheeling Mold & Foundry Co., Wheeling, West Virginia, Mt. Pleasant’s rock crusher was donated to the Old Threshers association in the 1970s. The Wheeling firm was established prior to 1900; the crusher was likely built between 1910-1930. At some point, one of the crusher’s flywheels was replaced with one from Universal Crusher Co., Cedar Rapids, Iowa.

In 1977, stationary gas engine collector Louis Tuller, Mount Pleasant, and his son, Barry, now of Stevensville, Michigan, first demonstrated the crusher belted to their 7hp Hercules engine.

The crusher was a good fit for the reunion. Once commonplace on the farm, crushers were used to pulverize limestone, which was then applied to the fields to adjust soil acidity. Crushers were also used to supplement farm income, processing rock for use in making concrete and road construction.


The Tullers are familiar names at the reunion. Barry, who grew up in Mount Pleasant and graduated from high school in 1977, was taken to his first reunion as an infant. He’s missed only one show since. “We got our first gas engines in 1974 and have exhibited every year since,” he says. Louis served on the Old Threshers Board of Directors from 1978 through 2014, and Barry served as gas engine area coordinator during that time.

Fairbanks-Morse Model Z: Farm workhorse

The rock crusher was an instant hit with reunion attendees. Hoping to enhance the display, the Tullers began looking for an engine to pair with the crusher for a permanent display.

The two had a conversation with Milo Matthews (since deceased), an original member of the Old Threshers Board of Directors. “He offered a 1920 Fairbanks Morse & Co. 10hp Model Z for the display,” Barry says.


Based in Beloit, Wisconsin, Fairbanks-Morse was the largest producer of flywheel gas engines in the U.S., with earliest examples dating to the 1890s and continuing until at least the 1970s. The Z line featured volume governing for extra smooth operation. Production of the 10hp Z began in 1916. By the mid-1920s, 400,000 Model Z engines had been built.

The 10hp Model Z powering the Old Threshers rock crusher is typical of engines once used on the farm to pump water, shell and grind corn, and run elevators and hay presses. Well-built and reliable, the engines were priced right and the company maintained an efficient distribution network.

Today, the Model Z remains popular among collectors. “Many Fairbanks-Morse “Z” line engines have throttling governors, this one included,” Barry adds. “A butterfly valve connected to the governor controls the air/fuel mixture to the engine. The engine is a typical 4-cycle, so it fires once for every two revolutions of the flywheels. The throttling governor is similar to that used on cars that use carburetors.”

Visitors don’t often see the “behind-the-scenes” work that goes into producing a show. Here, volunteers from the Midwest Old Threshers Reunion meet a week before the show to gather limestone at a rock quarry near Mount Pleasant for use in rock-crushing demonstrations.
Photo courtesy Stuart Seedorff

In the summer of 1978, Barry and his dad hauled the engine from Milo’s farm to the Old Threshers grounds and began work on combining the unit with the crusher. “To accommodate the crusher, a steel platform was fabricated and welded by Lloyd Widmer (another early member of Old Threshers board) to the Fairbanks-Morse cart,” Barry says. “We had a cooling tank made for the engine and found a pump to circulate the water. The engine was cleaned, made functional and the whole outfit was painted.” The rock crusher and Fairbanks-Morse engine were demonstrated multiple times a day at the 1978 reunion.

Comedy pulls in crowds

Mike and Fred got involved with the rock crusher demonstration in about 1990. “It’s the people I enjoy being around,” Mike says. “I don’t want to watch the parade. I’m the guy who wants to be in the parade.”

A few years back, Fred (known at Mount Pleasant as “Stoney”) and Mike (“the Crusher”) dressed in old-time black-and-white prisoner uniforms and took part in a skit. With the aid of the show’s North Village sheriff and deputies, the two convicts boarded the steam train at the station and were taken to the North Village, where they were marched to the rock crusher in the gas engine area.

“We (each) had a pair of handcuffs that were held together with twist ties,” Fred recalls. “The sheriff would blast our handcuffs with a shotgun, we’d pull our hands apart, start the rock crusher and go to work.”

On occasion, the duo would try to “escape” during the skit, often taking a hostage from the audience of onlookers. “It was fun,” Fred says. “After that, they (the sheriff and deputies) would march us to the jail in the North Village, where we’d take part in a jail break and bank robbery skit with the North Village Gang.”

The two men took part in the skit for nearly a dozen years before they retired from show business. “Mike and I got too old to keep doing the skit,” Fred says. “We were supposed to get shot and fall down, but that hurt too much.”

To this day, even without the daily convict skit, the duo continues to entertain large crowds with daily demonstrations of the rock crusher and visit with those who want to learn more about stationary gas engines and how they changed the face of farming and industry.

“We enjoy a lot of camaraderie,” adds Carl Thompson, director of the Mount Pleasant gas engine area.


Making hard work easier

The rock crusher was the first big display the Tullers got involved with in the gas engine area. Later they helped with the Farm Powerhouse, Threshing with a Gas Engine, Fairbanks Morse Diesel Generator (Museum A), Gas Engine Woodshop, Large Engines (including a 35hp Olin and 15hp Reid), and the Marvin Mill (Museum B).

All were important projects at a show that puts a priority on working displays. “It shows how simple machines like the crusher made work much easier,” Barry says said. “It has always been a popular exhibit; people ask to see it run.”

None of it would be possible without the small army of volunteers who bring their engines and donate their time to make it all happen. “I really enjoy the gas engine hobby, getting to show and talk engines,” Barry adds. “But the Mount Pleasant show is really a reunion, and it is great to get together with family and friends and enjoy the week. I grew up coming to the show, and now my kids have done the same. It is a special show and we look forward to it every year.” FC

Freelance writer J.O. Parker has extensive experience as a community newspaper editor and photographer. He enjoys telling people’s stories through photographs and words, attending steam engine shows and antique collecting with his wife, Debbie. Email him at

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