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Chicago’s Famous Steel ‘Bean’

This post is part of our Weekend Notes series. Take a breather to get inspired by the power of steel and enjoy your weekend. 

It’s hard to imagine how a giant steel bean might bend time and space. But that’s exactly what world-renowned artist Anish Kapoor had in mind when he created Cloud Gate.

Cloud Gate – more affectionately called “The Bean” by its millions of visitors – is one of those rare art pieces that looks like it coalesced into Chicago’s Millennium Park from some higher spatial dimension.

While its origin may be decidedly more mundane, the process of how it came to be is nothing short of extraordinary. Though it looks as if it was forged effortlessly out of one giant chunk of material, the piece is actually made up of 168 stainless steel plates all seamlessly welded together and polished to a mirror finish. It measures 33 x 66 x 42 feet and weighs 110 tons.

On the inside, the structure is held up by an unseen super-structure of two large o-shaped steel rings and a pipe truss system. The elliptical outside famously distorts the clouds and Chicago’s skyline, elongating the scenery as well as the reflection of the viewer.

Viewers can also enter the ‘omphalos,’ or navel of the sculpture from under a 12-foot arch. The navel’s apex is 27-feet off the ground and the concave structure of the space serves to distort light and reflections even further into a swirling mess of skewed perspective. 

These elaborate effects were the result of over five years of painstaking attention-to-detail, long hours and on-the-spot innovation by Chicago firm MTH and Oakland’s Performance Structures Inc. (PSI).

PSI often had to improvise in order to maintain Kapoor’s original specs. While plasma cutting the ¼ – 3/8-inch plates proved to be fairly easy, the very specific curvature requirements for each piece caused a unique issue. To solve this problem, the team assembled a three dimensional roller device similar to a fender maker that curved the pieces to within a hundredth of an inch of the desired measure. Then they used flux-core welds to attach the pieces to metal rib-frames, which served to protect the plates from warping en route to Chicago.

After they completed, the difficult task of welding the huge, delicate stainless plates on-site in Chicago fell to MTH. They later said this project was one of the most technically difficult jobs they would ever do. Whether it was welding or polishing, the MTH workers were in full gear in 90-degree weather trying to flawlessly weld, grind or polish some of the most fragile metal they’d ever worked with.

Their hard work paid off, as Cloud Gate is considered one of the world’s most admired and recognizable public art displays. Inspired by the texture and movement of liquid mercury, Kapoor simply sought to create a space in which real and abstract met. Instead, with some help, he’s created a work that will continue to humble visitors for generations.

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