Some loyal readers will know that, alongside my research on commercial high-rise construction, I’ve very happily gone down a rabbit hole the last few years chasing the history of the city’s grain elevators–Chicago’s “other” skyscrapers. That’s a comparison that was made by many at the time–Inland Architect said in 1896 that “the first sky-scraper was a grain elevator,” and when the Montauk was built in 1882, at 130 feet it was shorter than seven of the grain elevators that lined the River at the time.
That history is, I hope, going to be the subject of a published paper sometime next year–the city’s elevators were instrumental in its role as a financial center, and even though there are only a handful of structures left–and none from before 1900–their influence can be seen in Buckingham Fountain, IIT, Wacker Drive, and the U.S. Supreme Court…it’s a doozy of a story.
But they also impacted building as a whole, pioneering technologies that were adapted by commercial skyscraper architects once they’d proven themselves. Mechanical transport, temperature monitoring, and pile foundations all saw proving grounds in grain elevators, sometimes decades before their application in buildings for people.
One of the most influential pieces of technology transfer came from Chicago engineer John S. Metcalf, who constructed one of the first concrete grain silos in Indianapolis, and who was commissioned by the Santa Fe Railroad in 1906 to build silos and an elevator for their freight yard at Damen Ave. and the Chicago River. Like most elevators, this one was designed to buffer the flow of grain from points west, arriving by rail, by providing storage and a docking facility for lake barges that could carry the grain to points east. Its location, two miles upstream from downtown, speaks to the congestion that was plaguing the River by this point, but it also illustrates the position of Chicago as place of exchange and transfer–the Santa Fe was one of over 100 elevators built before the Depression that allowed the city to absorb the influx of corn, wheat, and other grains from the midwest and Plains states.
Metcalf’s innovation was to apply a new material–reinforced concrete–to the problem of grain storage. Concrete was fireproof, a big improvement over the timber elevators that had been constructed throughout the 19th century, but one that required skilled carpentry to build the cylindrical formwork needed to build silos that could, by incorporating hoops of reinforcing steel, resist the fluid pressure of a hundred or so feet worth of vertically piled grain. In 1904 and 1905, Metcalf patented a system of moving formwork that used donut-shaped forms, about four feet tall, to pour one day’s worth of concrete at a time. The next morning, after a pour had cured to a working strength, laborers would crank the forms up another four feet, using steel rods embedded in the concrete as rails to support the forms and their attendant scaffolding platforms, and to assure that they rose truly vertically. Scientific American referred to Metcalf’s innovation as ‘quite as simple as it is ingenious,’ as it reduced costs for concrete construction below those for steel.
Metcalf built thirty-five silos out of concrete for Santa Fe in 1906, paired with a head house constructed of timber that housed the elevating machinery and the ‘marine legs’ that could take grain up, or discharge it, into waiting barges. In 1932, the wooden head house burned, but the concrete bins were unharmed by the fire and the railroad commissioned Metcalf to rebuild the head house in concrete. Both of these structures–the original 1906 bins and the rebuilt 1932 head house–are extant but in ruins, abandoned by the railroad in the 1970s and taken over since by the State of Illinois. Given the importance of slip-form construction to concrete high rises, Metcalf deserves more credit than he’s ever had as the inventor of this system. He also, along with engineer Jason MacDonald, also of Chicago, deserves recognition for building an astonishing number of slip-formed concrete elevators throughout the United States and Canada, and for revolutionizing the type; after Santa Fe, all grain elevator construction in Chicago, and most of it throughout the midwest, switched from timber to concrete.
The Santa Fe is one of just four pre-WWI elevators left standing in Chicago–in addition there are two along the Calumet River and one (threatened) in the West Loop. Metcalf’s pioneering bins are the most visible of these, though, as they can be seen from the Stevenson Expressway and the Orange Line CTA. They deserve some sort of landmark designation as one of the last links to the most important trade in the city, and for their own quiet beauty–the end elevation of the 1906 bins is, frankly, something a lot of architects would be happy with today.