Mansfield Roller Mill: A Historic Indiana Landmark of Early Industrial Milling
Ross Plotkin, Interpretive Naturalist at the Historic Mansfield Roller Mill under the Indiana Department of Natural Resources, says, “This really gives us a beautiful snapshot of what milling was like at the end of the 1800s, a critical point in American history. It was sort of the final full-on into industrialization that the country went. This really shows on a local level what that industrialization was really like. I think most people think of big steel mills, giant factories in big cities. Indiana was industrialized very much on a small town basis first.”
Jacob Rohm, a successful local miller, purchased this parcel of land in 1875. He quickly tore down an older, less efficient mill built in 1819.
“The first mill that was here in 1819 utilized a tub wheel. That's a sideways water wheel, and immediately on top of that were the stones. It was a very labor intensive job. You had to shovel and carry everything in a bag over your shoulder. A day's worth of grinding here would have probably been several weeks worth of grinding in that old mill,” explains Plotkin.
Rohm saw its success through efficiency as he built his new mill on the banks of Raccoon Creek.
“Jacob Rohm, who owned several other steam-powered mills, saw this as an opportunity to basically get a free power source for his mill, which meant that he could take risks that he couldn't at his steam-powered mills. There was a significant amount of new technologies and ideas that had flooded into the milling industry and market. Jacob Rohm saw those, and he wanted this to be a proving ground, at least for himself,” Plotkin states.
How Water Power and Roller Technology Changed Milling
Rohm's first big change was to replace age-old stone grinders with precision steel rollers.
“We call it one of the first in Indiana. It was the first in this region, the Wabash Valley, to get rollers, which is the technology that's still being used today. Two big rollers, grain goes down, gets crushed, falls between them. With these rollers, you can actually very finely control the fineness and how fast it's going,” Plotkin explains. “With stones, you can't really push the stones much closer together than they're already set. If you do, it might start a fire or it will get a real nasty taste, or it's just going to be grinding it too close. With the metal rollers, you can actually run the grain through the same machine again and again to get a very even fine and high quality product.”
Rohm's mill needed more power than a traditional water wheel could offer, and so he installed an underwater turbine in 1886, which is still in place, and 138 years later, still functional.
“Turbines were often used in a lot of mills in the latter half of the 1800s, when they started becoming very viable. They started to replace water wheels, and the vertical turbines that you find at, say, a place like Spring Mill State Park at their mill,” says Plotkin.
“Out here is the mill pond that directs water off the creek. By using this gate here, we can get the water down into the turbines and get the mill turned on.”
Plotkin continues, “We control the water over the series of gates, and historically, you would have had about seven feet of water sitting on top of that turbine. That water then goes through holes in the side of the casing, and more or less pushes water pressure onto a spinning fan blade, and that's what creates the circular motion. This particular mill is all belt run. We've got one shaft that comes out of the turbine. From there we hook up all the belts and the belts spin each of the machines. It was running the four wheat rollers, 16 elevator banks, as well as probably about 15 to 20 other pieces of machinery just dedicated to processing wheat.”
But it wasn't just the modern equipment that made this mill superior. The design of the building played a large part too.
“The verticality of the mill gives the ability of the mill to go up. When someone comes in and dumps the grain, they're actually going to dump it in a drop chute that goes down to the basement. The elevators then will move it all the way up to the top of the building, and gravity can then work its way from there. Then you can arrange the flow of the mill so that as it goes through, it hits the most amount of machines that it needs in a single run, whereas otherwise you'd have to move everything on a horizontal plane, which would actually be much harder at the time,” explains Plotkin.
The mill changed hands several times over the years, but it had a surprisingly long life, only ceasing operations in 1967. In 1995, it was gifted to the Indiana DNR for historic preservation, and today it's open for tours, allowing the public to get a glimpse of what Indiana was like at a pivotal period in time.
“Most people don't really think about where their food comes from and what went into making it that way. Here at the mill, we very much are able to show you what processes have been there for a while, and you get to see how people piece that together and [what they] came up with,” concludes Plotkin.
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The above video is a clip from Journey Indiana from WTIU. You can watch more segments and full episodes at pbs.org/show/journey-indiana/