The First Fruit Of A New Age
THE STRUCTURE IN THIS PICTURE MAY NOT LOOK LIKE the pinnacle of architectural beauty to you, but in 1920 the French architect Le Corbusier declared it and its brethren “the magnificent FIRST FRUITS of the new age.” By that year he and his fellow modernists would have had a field day in the American Midwest, where the innovative new buildings, concrete grain elevators—clusters of tall grain-storage cylinders ringed by complicated conveyor mechanisms that moved enormous tonnages of wheat in and out—were springing up apace with the expansion of wheat farming across the Plains. This particular silo, standing as tall as a 12-story building in St. Louis Park, at the intersection of routes 7 and 100 on the outskirts of Minneapolis, is the very first of the first fruit. It was built in 1899 and 1900 as an experiment, the nation’s earliest grain silo constructed entirely of reinforced concrete. It not only revolutionized grain-elevator design but also helped modernize the entire American system of storing and shipping wheat.
In the decades before it was built, America’s flour mills were suffering from a shortage of sort—not because the nation’s farmers weren’t growing enough grain but because they lacked adequate facilities to store what they grew. Mills can operate all year long, but the harvest time for wheat lasts only a few weeks. Up through the mid-18 70s most Western farmers packed their annual harvest into sacks to sell in nearby towns, a slow and costly process. If a farmer couldn’t find any customers, he had to take the wheat back home and either store it himself or dispose of it. As a result, many farmers grew only what they thought they could sell right away.
They were rescued from their plight by a businessman named Frank Peavey. Born in Maine in 1850, Peavey moved West when he was 15 and eventually settled in Sioux City, Iowa, where he ran a successful farm-implement business. Recognizing the difficulty farmers had selling their harvests, he began accepting wheat as payment, and by 1874 he had established a company to buy, store, and sell the crop. He built his first wooden grain elevator that year. It held a relatively small 6,000 bushels and was powered by a horse hitched to a pole that turned an axle to lift buckets of grain to the top. Peavey was pleased with this initial foray into grain storage, and the next year he began work on what would become the first-ever grain-storage network. He started building hundreds of wooden grain elevators along railroads that ran through farming areas to store the wheat he bought there, and he erected large storage terminals near mills in cities. When the mills started to run low, he would ship carloads of wheat from the country elevators to the terminal elevators, maintaining a continuous supply all year.
The new storage and shipping system was an instant success. Working in bulk substantially reduced costs, farmers had a single buyer close to their farms, and millers were happy to contract for a year-round supply of wheat. But the elevators themselves left much to be desired. They were highly susceptible to fire, especially from lightning strikes; dust would build up to levels where a single spark could set off an explosion. Peavey learned this the hard way. The St. Anthony terminal elevator in Minneapolis, which he built in 1886, was the largest grain elevator in the Northwest. Within a year the wooden structure had burned to the ground, taking more than a million bushels of wheat with it.
With fire-insurance costs skyrocketing, Peavey joined the search for a solution. In the mid-1890s, after moving his headquarters to Minneapolis to be nearer to his principal customers, he began consulting with a local building contractor, Charles F. Haglin, about constructing a new kind of fireresistant silo. They turned to a little-tried material, reinforced concrete—concrete poured over metal rods to bolster its strength. Haglin, who had been trained as an architect, felt confident that concrete silos would be stable and fire-resistant, but his thinking ran counter to the prevalent opinion of the time. Most builders and engineers believed that since concrete was less flexible than wood, it would crack or explode under the pressure exerted by thousands or bushels of grain. At best, they argued, the wheat in concrete tanks would become moldy.
Nevertheless, Peavey decided to back Haglin in putting up a single cylindrical reinforced-concrete silo. Haglin chose the shape for its unmatched structural stability and resistance to outward pressure from the grain. The silo would be 125 feet tall and have an internal diameter of 20 feet and a capacity of 30,000 bushels. Its wall would taper in thickness from 15 inches at the base to 8 inches at the top. The crew broke ground in the summer of 1899, laying a foundation of timber pilings.
To raise the tower, Haglin adapted a device called the slip form, which today is a mainstay of concrete construction. A slip form is a mold that can be jacked up to hold successive layers of concrete. Haglin’s prototype consisted of two wooden tubes a few feet high, one to form the inside boundary and a second to frame the outside. Workers set the two tubes, one inside the other, atop the foundation and, after inserting the brass reinforcing rods that would rise the height of the tower, braced the tubes with steel hoops and poured concrete between them. Once the concrete had cured, the workers unbraced the forms, lifted them up to rest on the top of the existing tower, rebraced them, and poured another layer of concrete directly on top of the first. Growing tier by tier, the silo reached a height of 68 feet in the fall of 1899, at which point Peavey and Haglin decided to stop construction for an initial test to allay fears about the quality of grain stored in concrete. Freight cars brought bulk wheat to a siding, and the grain was shoveled into buckets, hoisted by rope to the top, and hand-dumped into the silo. It remained there through the winter to be tested for quality the following spring.
In the meantime, during the winter of 1900 Haglin accompanied Peavey’s son-in-law, Frank T. Heffelfinger, on a trip to Europe to investigate rumors that concrete silos were being used for grain storage there (and to look into the possibility of expanding their grain business to Russia). They found some small square bins of steel and concrete, but none in the shape of a cylinder, and they concluded that their design was better. They were also relieved to learn that grain kept perfectly well in the European concrete bins.
As the travelers made their way home in the spring of 1900, preparations were under way to draw the wheat from the experimental silo. On the appointed day a group of observers gathered to witness the test, but most of them kept their distance, in case emptying the silo created a vacuum that caused it to collapse, as many predicted. Haglin, however, stood confidently next to the tank while the release lever was pulled. The stored wheat poured out by gravity and coursed down a ramp into an 8-foot-deep concrete-lined pit. The structure showed neither cracks nor any other signs of weakening, and the wheat was in perfect condition. The concrete silo had provided superior insulated dry storage throughout the harsh winter months and had remained impervious to the rodents and insects that commonly infested wooden silos. Peavey and Haglin soon set about finishing the tower, which eventually reached 125 feet.
Flush with success, Peavey embarked on another ambitious project, building the country’s first multi-silo concrete grain elevator, in Duluth. Loath to change a successful formula, he awarded the construction contract to Haglin, who envisioned 50 reinforced-concrete silos. Thirty of them would stand 110 feet tall and 33 feet across, holding 75,000 bushels each, while the other 20, which fit in the spaces between them, would hold 55,000 bushels each. When the elevator was completed, in January 1902, the Minneapolis Journal proclaimed it “the first concrete grain elevator in the Western Hemisphere and the largest in the world.”
As such, it set the standard for concrete terminal elevator design and operation. When railroad cars bearing grain from the farmlands pulled up, workmen shoveled the grain into a hopper that funneled it onto a conveyor belt. The belt took the grain to the leg, a device that carried buckets up the elevator, pulled by a chain attached to pulleys. The grain poured into the buckets, and when it reached the top, it emptied through a funnel onto a scale, was weighed, and traveled out over the silos on another conveyor belt to be dumped into its designated bin. Outbound grain flowed by gravity through a spout at the bottom of the silo onto a conveyor belt for final weighing and release into freight cars, trucks, or barges waiting at the shipping dock.
Within a few years, Peavey and Haglin had made large wooden grain elevators obsolete, though smaller ones, usually covered with galvanized steel, continue to serve individual towns to this day. Reinforced concrete proved to be the most economical and efficient material for the huge elevators that were erected in grain-processing centers, and it remains the norm today throughout the world, despite many improvements in the accompanying machinery. The Kalama Export Company in Kalama, Washington, recently built a 2-million-bushel-capacity addition to an already 2.3-million-bushel elevator. It handles corn and wheat for export to the growing Asian marketplace with a unique system in which arriving freight cars are weighed, unloaded, and then weighed again to determine the net weight of the grain removed. Other industries have taken up Peavey and Haglin’s idea too. Many concrete silos today store materials like cement and concrete mix.
Unlike their wooden forebears, concrete elevators are surprisingly durable. Changes in shipping and storage patterns can force granaries to shut down silos, as happened in Buffalo when the St. Lawrence Seaway opened in 1959, but the buildings themselves continue to stand. Often it would cost more to demolish them than it did to build them in the first place. The grandfather of them all, the first silo built by Peavey and Haglin in Minneapolis, survives after more than a century, with only the rotting timber pilings in its foundation replaced in 1970 by steel-reinforced concrete. And it’s likely to be around for many years more, having been added to the National Register of Historic Places in 1978. After serving its purpose and proving Peavey and Haglin’s experimental theory, however, it was never used for storage again. It now bears the logo of a local cookware manufacturer, visible from the nearby highways. It’s a billboard that betrays no hint of the revolutionary role it once played.