Flights of fancy in Chicago

Structural brilliance

The view looking down through the glass floor toward South Wacker Drive is just what you’d expect if you were balanced on top of 6,960 boxes of this city’s deep-dish pizza — or, as the exhibition at the Willis Tower also tells us, standing atop 313 Oprah Winfreys or 283 Barack Obamas.

That thought brings on its own sort of vertigo. The comfort is that those human towers would reach the top of the building itself, while this particular perch is a bit lower, on the 103rd floor: fewer pizzas, media stars and presidents would be required.

Not much help. Stand on the Ledge, as it is called, on the tower’s Skydeck and look down on rooftops and traffic helicopters, and leftward toward the haze over the lake, and outward along the city’s grid stretching toward the South Side. Despite the reassuring rivets in the 681 kg glass panels, the calm stillness of the air at the Windy City’s pinnacle and the security of a 10,000-pound weight capacity for each of the four 4.3-feet, or 1.3-metre deep glass boxes that protrude past the sheer edge of the Western Hemisphere’s tallest building — despite all that, you still feel twinges of queasiness.

If the Deity had wanted us to see straight down as far as we can see straight up, he would certainly not have come up with these glass extensions, which were added to the Skydeck in 2009. It is comforting to know that they were designed by the building’s original architects, Skidmore, Owings and Merrill, and mounted on tracks that allow them to be pulled inside for cleaning and maintenance. But any reassurance is undercut by the elimination of nearly all visible support; you walk within them, 1,353 feet above South Wacker Drive, surrounded by open air and unbounded space.

It’s a weird sensation. The structural use of steel made the Chicago skyscraper and its epigones possible at the turn of the 20th century. Later glass-clad frames seem to almost magically dissolve the signs of massive support that we expect when confronted with buildings of such height. But the playful formality of the glass skyscraper is very different when you stand within a transparent structure in which there is no structural steel evident, either above or below. Here wit turns to mischief; it’s a tease made by technology.

But there’s also an exhilaration that you don’t get from a visit to a distant relative of the Ledge: the Grand Canyon Skywalk. That attraction opened two years before these Chicago extensions and promised to be far more spectacular: a transparent-floored observation deck stretching outward 70 feet from the canyon’s rim and suspended 4,000 feet above the Colorado River.

It was built on land owned by the Hualapai Indians, who had great hopes that, along with bellicose helicopter rides into the canyon and quaint displays of folk culture, the Skywalk would guarantee the tribe a rosy economic future. I visited the Skywalk soon after its opening and was astounded not at seeing Nature’s expansive dimensions open at my feet, but at the sheer irrelevance of the enterprise. The expense, hype and setting couldn’t match Nature’s own spectacle at the main part of the canyon, run by the National Park Service — an immensity that makes all human enterprise seem like petty gimcrackery.

The Skywalk has recently come under the shadow of various legal squabbles between the tribe and the developer, but there also may be something inherently flawed in the concept. It might be that apart from such unusual activities as a space walk or a sky dive the natural world presents itself to us with as much power when seen horizontally as vertically. We don’t need vertigo to get the point.

But with the Ledge something is sensed that you can’t really get from walking around the Skydeck with its panoramic vistas of Chicago and its labelled guides to landmarks. I don’t recall that sensation from the observation deck of the old World Trade Center years ago either. When you look out through a window at the metropolis laid out before you, the city becomes a map, allowing you to make some sense of its immensity; this is the way pilots must feel as they guide their planes into urban airports. Window vistas on the world are beautiful but not powerfully unsettling or overwhelming. They help make sense of the world, not disrupt it.

Pull the rug out, though — or rather, pull out the solid floor, all suggestions of support, and stand on layers of glass — and something else happens. You become a vulnerable observer. You look at the city and its expanse, but you can’t settle into complacency or reflective mapping. You end up feeling, along with the amazement, an all-too-human unsteadiness. You are part of that city of course, and are even relying on its technological achievements by standing in this elevated spot. But you also recognise just how unusual and vulnerable those advances are. The city might attempt to transcend the human, but it also readily reflects it. Spend a minute on the glass Ledge, and you feel that in your bones.

In fact, when you visit the Ledge (which 1.5 million visitors do every year), you also find yourself in a series of exhibitions celebrating the city itself. We learn about the entertainers born in or closely connected to Chicagoland (as it is cutely called): Raquel Welch, Harrison Ford, Walt Disney, Hugh Hefner. Or about political figures: Hillary Rodham Clinton, Donald H Rumsfeld, Ronald Reagan, the Rev Jesse Jackson. Or writers: Ernest Hemingway, L Frank Baum, David Mamet (with Saul Bellow strangely omitted). Or musicians: Muddy Waters, Benny Goodman, Louis Armstrong. There is George Ferris, who invented his amusement-park ride for the 1893 World’s Fair here, and department-store magnates like Marshall Field and A Montgomery Ward. O’Hare Airport, we learn, was once called Orchard Place, which is why the initials for Chicago’s major hub are still ORD.

We learn that this very tower was conceived in 1969 when Sears Roebuck & Co was the largest retailer in the world, with about 3,50,000 employees. Once known as the Sears Tower, the building is celebrated in statistics that appear throughout the displays: it contains 25,000 miles of electrical cable, 43,000 miles of telephone cables, 16,100 windows, 2 billion cubic feet, or 56 million cubic metres of concrete, 104 elevator cars. It remained the Sears Tower until 2009, long after the company had sold it and moved out; it was renamed after the Willis Group, a London-based insurance broker, leased part of the building and obtained naming rights.

Now it is a monument to Chicago’s great retailing past and a witness to its passing. But when you stand on the Ledge, the entire urban fabric seems both marvellously permanent and permeated with vulnerabilities, an imposing achievement and a transitory exercise. Do you want to sense both the power and fragility of human civilisation? Walk on the Ledge.

International Herald Tribune