How This Chicago Skyscraper Barely Touches the Ground

The very first sky­scraper went up in 1885 in Chica­go. It’s only nat­ur­al that such a brazen­ly ambi­tious form of build­ing would spring forth (or rather, up) from not just the Unit­ed States of Amer­i­ca, but from that most aes­thet­i­cal­ly Amer­i­can of all metrop­o­lis­es. And though near­ly every world city now has high-ris­es on its sky­line (some of them only grudg­ing­ly tol­er­at­ed) the art of the sky­scraper has con­tin­ued to advance in the cap­i­tal of the Mid­west. Take 150 North River­side, fea­tured in the video above from Chica­go-based archi­tec­ture Youtu­ber Stew­art Hicks. Since its com­ple­tion in 2017, that 54-sto­ry tow­er has not just received crit­i­cal acclaim, but also the awe of onlook­ers to whom it seems like it should­n’t be able to stand at all.

“At its base, it’s almost like the tow­er’s been eat­en away, leav­ing its core behind,” Hicks says of its unusu­al shape. “You might think that this would make the entire build­ing struc­tural­ly unsta­ble — and you’d be right, if this fea­ture was­n’t com­pen­sat­ed for in the design and con­struc­tion process.” The engi­neer­ing involves mak­ing the arms of the Y‑shaped low­er lev­els “entire­ly out of steel. These ele­ments pre­car­i­ous­ly spring out of the con­crete core and trans­fer all of the loads of the out­side floors above. The forces are so great, these steel mem­bers are the largest I‑beams ever made,” spe­cial­ly designed and man­u­fac­tured for this project.

On the oth­er end sits a “tuned mass damper, which, fun­da­men­tal­ly, is just a giant con­crete water tank at the top of the build­ing.” When wind blows against the tow­er, caus­ing it to bend slight­ly, the water slosh­es around in response. “But the water moves slow­er than the build­ing does, so its weight is back over the orig­i­nal cen­ter of grav­i­ty,” which keeps the struc­ture from bend­ing too far. Though I’ve nev­er vis­it­ed 150 North River­side, I’ve seen a sim­i­lar mech­a­nism at work at the top of Taipei 101, the Tai­wanese cap­i­tal’s star sky­scraper, whose own tuned mass damper — enor­mous, spher­i­cal, and pen­du­lum-like — has become a favorite pho­to spot among tourists.

Hicks’ video also brought back an even ear­li­er mem­o­ry: that of Rainier Tow­er, a nine­teen-sev­en­ties office build­ing in Seat­tle whose taper­ing base impressed me in child­hood. Archi­tect Minoru Yamasa­ki (design­er, ear­li­er that decade, of the World Trade Cen­ter) used it in order “to main­tain as much free space at the base as pos­si­ble,” though it does tend to chan­nel winds with a Chica­go-like inten­si­ty. As for 150 North River­side, its per­ilous­ly tiny-look­ing foot­print result­ed from its lot, which offered a mere 35-foot-wide build­able space hemmed in by train tracks on one side and the Chica­go Riv­er on the oth­er. 150 North River­side stands, desir­ably, at the con­flu­ence of the river’s north and south branch­es — but also at the con­flu­ence of archi­tec­tur­al inge­nu­ity and the Chicagoan mon­ey­mak­ing spir­it.

Relat­ed con­tent:

How a 1930s Archi­tec­tur­al Mas­ter­piece Har­ness­es the Sun to Keep Warm in the Win­ter & Cool in the Sum­mer

Why the Lean­ing Tow­er of Pisa Still Hasn’t Fall­en Over, Even After 650 Years

The Sto­ry of the Flat­iron Build­ing, “New York’s Strangest Tow­er”

Good­bye to the Nak­a­gin Cap­sule Tow­er, Tokyo’s Strangest and Most Utopi­an Apart­ment Build­ing

Amaz­ing Aer­i­al Pho­tographs of Great Amer­i­can Cities Cir­ca 1906

10-Sto­ry High Mur­al of Mud­dy Waters Goes Up in Chica­go

Based in Seoul, Col­in Marshall writes and broad­casts on cities, lan­guage, and cul­ture. His projects include the Sub­stack newslet­ter Books on Cities, the book The State­less City: a Walk through 21st-Cen­tu­ry Los Ange­les and the video series The City in Cin­e­ma. Fol­low him on Twit­ter at @colinmarshall or on Face­book.