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Photo courtesy of Randy Stancik

Stepping Out onto Chicago's 1300-Foot-High Glass Ledge

Original image
Photo courtesy of Randy Stancik

The first step out of Chicago’s Willis Tower Skydeck and onto The Ledge is a doozy, even if you’re not afraid of heights. That's because the boxes extend 4.3 feet from the skyscraper’s facade, 103 floors—that’s 1353 feet, or 6960 deep dish pizzas—above Wacker Drive. And did I mention they're made of glass? Incredibly clear glass, offering unobstructed views up, out, and down … if you can muster up the nerve to look at your feet, which can even be hard for Ledge veterans to do. "I’ve been on this a thousand times, and my damn knees buckle every time I’m out there," Randy Stancik, general manager of the Willis Tower, tells mental_floss. "It is not a natural feeling."


Skydeck has been around since 1974, just a year after the Willis (which was known as the Sears Tower until 2009) opened its doors. But by the 2000s, tourism to the Skydeck had leveled off; about a million people were visiting each year. Stancik was hired from Chicago’s John Hancock tower to revitalize the Skydeck in an $8 million renovation that included revamping a downstairs section into an interactive area that features Chicago history, architecture, sports, music, and pop culture.

Stancik and the architects at Skidmore, Owings & Merrill (who also designed the tower) explored a number of ideas for Skydeck, including having some screened-in areas that would create wind gusts naturally. “I was telling the engineer what I really wanted to do was get people right to the windows,” he says. He was inspired by the scene in Ferris Bueller’s Day Off where the titular character and his friends stood in the Skydeck, foreheads pressed to the glass, trying to catch a glimpse of what was below them. “The architects said, ‘What if we build a glass walkout?’”

Stancik didn’t need convincing, but he did wonder if it could be done. “The truth is, [people] build so much with architectural glass that it was time to do it,” he says. There were engineering challenges beyond just building an enclosed glass box strong enough for people to walk on, though—the boxes would need to retract in order for the building’s windows to be cleaned. “We were going to have rigs that went around them,” he says, “but it defeated the purpose if you have something going underneath it.”

Engineering the four glass balconies—10 feet tall, 10 feet wide, and 4.3 feet deep—took a year. They’re each constructed of three pieces of laminated, low-iron glass, each half an inch thick, weighing a total of 1500 pounds, with structural interlayers of DuPont SentryGlas, each 0.060 inches thick, in between; the interlayers are five times tougher and 100 times stiffer than traditional interlayers. A top protective layer protects the glass from getting scratched and is replaced every 6 to 9 months. Each box hangs from a nearly-invisible steel frame. “The Ledge can hold more human weight than we could ever put on it—5 tons,” Stancik says. The glass and steel balconies were designed by Halcrow Yolles and installed by Chicago-based MTH Industries. And yes, they retract: Creating the motors to pull them flush and then into the building on rails took two months alone.


The Ledge opened in July 2009; these days, between 1.5 and 1.6 million people visit each year. When the weather cooperates, visitors to the Skydeck can see 50 miles, including Chicago landmarks like the Field Museum, the Shedd Aquarium, and Millennium Park, 17 miles of uninterrupted park land, and the Metropolitan Correctional Center, Chicago, where inmates play volleyball during their exercise time. (Last year, two inmates escaped from that prison using bedsheets they had tied together.) In the distance, the shores of Michigan and Indiana are also visible. And that's all before they even step out onto The Ledge on the Tower's west side.

"Not everybody can come into a skyscraper, let alone the second tallest one in the U.S.," Stancik says. (The 1450-foot, 110-story building was dethroned just this year by New York City’s One World Trade Center.) "We never take the views for granted. It’s a great place to start your trip to Chicago, to get your bearings."


It’s a cold, wet day in mid-September when my friend and I visit the Willis Tower. From the street, the balconies that comprise The Ledge are just specks—you can hardly see them. After an ear-popping elevator ride, we find ourselves on the 103rd floor. Earlier, cloud cover had obstructed the view, but the foggy weather has dissipated by the time we get there, and it’s easy to tell, even from my spot inside the building, that you can see all the way down to the street.

Erin McCarthy

Even though I know, logically, that The Ledge can support 5 tons, it’s hard for me to think about walking out there, because I’m afraid of heights. I try not to let that fear stop me from having cool experiences, though, and I am currently cursing myself for that attitude. “Oh god,” I mutter, as I watch Stancik walk onto The Ledge, expecting me to follow him. “Oh god, oh god, oh god.”

“You have to walk out of a perfectly fine skyscraper and trust that we knew what we were doing,” Stancik says. “We really wanted people to think about taking that step or two.”

Believe me, I’m thinking about it. What’s comforting—if you can call it that—is that The Ledge is designed to be an experience I can control: It’s two steps on and two steps off. I can take my time going out, and come back in as quickly as I want. “If somebody’s here against their will, they don’t have to go out there,” Stancik had told me earlier. “We don’t want to force anybody. Lots of people—you’ll see it—they step out, smile for the camera and get out of there. They don’t look down.”

There is an area for people who don’t want to walk out on The Ledge, but I’m determined not to use it—and determined to look down, fear of heights be damned. So, with a death grip on the table where The Ledge’s official photographer is set up, I slowly inch out onto the glass.

Apparently, I’m not going fast enough. “I kind of want to push her!” my friend jokes.

“Oh, no,” Stancik says. “Don’t do that.”

Now, finally, out on the glass, my hands off the photographer’s table, I take a deep breath and look down. From 1300 feet, the taxis look like Matchbox cars, the river a thin ribbon weaving through the city. Even the tops of other skyscrapers seem far away.

It’s dizzying. My knees are shaking, my stomach in knots, but there’s no denying that this is awesome. I take a photo and send it to my mom—who is also afraid of heights—with the message, "1300 feet up on a glass ledge!" "CRAZY !!!!!!!!!" she responds.

Erin McCarthy

In the other boxes, visitors seem more at ease than I am: A woman does a headstand, and a guy plops down in a corner to take a selfie. Meanwhile, it’s all I can do to get into the right spot for the Tower’s photographer to take a picture. “Take a big step back!” he tells me and my friend. I take a small one. “One more…” he urges. Finally, we’re in the right position; he snaps a photo.

Afterward, I step off the glass, back into the safety of the skyscraper, and announce "I did it!" to no one in particular. Stancik is smiling. He sees this kind of thing every day.

All images courtesy of Randy Stancik/Willis Tower unless otherwise noted.

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Honda Debuts a Rain-Proof Disaster Robot That Can Climb Ladders
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A new Honda robot could signal the future of disaster response technology. According to IEEE Spectrum, the Japanese company recently debuted a prototype for a cutting-edge disaster-response robot agile enough to climb ladders, ascend stairs, maneuver over pipes, and move through narrow spaces, among other capabilities.

Honda unveiled the prototype for the E2-DR at September’s IEEE/RSJ International Conference on Intelligent Robots and Systems in Vancouver. The slow-moving humanoid robot looks like a beginning skater stepping onto the ice for the first time, stepping cautiously up stairs and through small spaces, but the fact that it can navigate these kinds of obstacles is a feat. Scaling ladders and walking up and down stairs are usually no easy tasks for robots, and both are among the challenges featured in the annual DARPA Robotics Challenge obstacle course—which is infamous for making very, very expensive robots fall all over the place.

Designed to inspect, maintain, and provide disaster response in places like factories and power plants, the E2-DR is 5.5 feet tall, weighs around 187 pounds, and can run for about 90 minutes at a time. Crucially, it’s less than 10 inches thick back-to-front, allowing it to squeeze through small corridors laterally.

The robot can reverse its knees to allow it to keep them from bumping against stairs as it walks, and its hands can grip ladders and rails. It can also open doors and climb on all fours. It’s equipped with rangefinders, cameras, and 3D sensors so that it can be piloted remotely.

Because it’s designed to work in disaster zones (like within the Fukushima power plant) the robot has to be able to withstand water, debris, dust, and extreme temperatures. It’s already been able to climb up and down a ladder in the face of 1 inch-per-hour rain, according to Honda.

IEEE Spectrum notes that we haven’t seen it fall, and falling down is, despite how silly it looks in testing, an important thing to test before sending robots into the field. In unpredictable settings and rough terrain, it’s likely that a robot is going to misstep and fall down at some point, and it needs to be able to not just withstand the fall, but get itself back up.

The E2-DR is just a prototype, and Honda will continue to work on it for the foreseeable future. For now, though, it’s made an impressive start.

[h/t IEEE Spectrum]

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This Just In
Want to Become a Billionaire? Study Engineering
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If you want to get rich—really, really rich—chances are, you should get yourself an engineering degree. As The Telegraph reports, a new analysis from the UK firm Aaron Wallis Sales Recruitment finds that more of the top 100 richest people in the world (according to Forbes) studied engineering than any other major.

The survey found that 75 of the 100 richest people in the world got some kind of four-year degree (though others, like Bill Gates and Mark Zuckerberg, attended a university but dropped out before graduation). Out of those who graduated, 22 of those billionaires received engineering degrees, 16 received business degrees, and 11 received finance degrees.

However, the survey doesn't seem to distinguish between the wide range of studies that fall under the "engineering" umbrella. Building a bridge, after all, is a little different than electrical engineering or computing. Four of those 100 individuals studied computer science, but the company behind the survey cites Amazon's Jeff Bezos (who got a bachelor's degree in electrical engineering and computer science from Princeton) and Google's Larry Page (who studied computer engineering at the University of Michigan and computer science at Stanford) as engineers, not computer scientists, so the list might be a little misleading on that front. (And we're pretty sure Bezos wouldn't be quite so rich if he had stuck just to electrical engineering.)

Aaron Wallis Sales Recruitment is, obviously, a sales-focused company, so there's a sales-related angle to the survey. It found that for people who started out working at an organization they didn't found (as opposed to immediately starting their own company, a la Zuckerberg with Facebook), the most common first job was as a salesperson, followed by a stock trader. Investor George Soros was a traveling salesman for a toy and gift company, and Michael Dell sold newspaper subscriptions in high school before going on to found Dell. (Dell also worked as a maitre d’ in a Chinese restaurant.)

All these findings come with some caveats, naturally, so don't go out and change your major—or head back to college—just yet. Right now, Silicon Valley has created a high demand for engineers, and many of the world's richest people, including Bezos and Page, earned their money through the tech boom. It's plausible that in the future, a different kind of boom will make a different kind of background just as lucrative. 

But maybe don't hold your breath waiting for the kind of industry boom that makes creative writing the most valuable major of them all. You can be fairly certain that becoming an engineer will be lucrative for a while.

[h/t The Telegraph]


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