Sears Tower adds glass 'walk out' 1350 feet high
By Gizmag Team
July 14, 2009
If you're ever likely to suffer from Acrophobia (from the Greek: akron , meaning "peak, summit, edge" and phobos, "fear" and meaning an extreme or irrational fear of heights), then Sears Tower in Chicago is the place that'll surely bring it on. Standing at 1,450 feet and 110 stories, Sears Tower is the tallest building in North America and the third tallest building in the world. The building recently added a new attraction as part of an updated Skydeck Chicago experience. Christened “The Ledge”, it's a series of glass bays on the 103rd floor that offer visitors unobstructed views of Chicago – 1,353 feet straight down.
The Chicago office of Skidmore, Owings and Merrill (SOM), the building’s original designers, provided an innovative plan for this architectural and engineering achievement. SOM designed The Ledge so that the fully enclosed glass boxes rest between conveyer belts. The boxes retract into the building, allowing easy access for cleaning and maintenance. Extending from the tower’s west side, each box can accommodate four to five people at a time, with views over Wacker Drive and the Chicago River. “The Sears Tower set architectural and engineering standards when it was first built and now we were able to carefully craft new elements that expand the capabilities of the original design while retaining its integrity,” said Ross Wimer, design partner, SOM. “The Sears Tower has always been about innovation. For this new Skydeck experience, we have kept with that tradition. Cantilevering out from the side of America’s tallest building, the viewing platform will allow visitors to experience the incredible city of Chicago literally beneath their feet. This is a great addition to the Sears Tower and to Chicago,” added Bill Baker, structural engineer partner, SOM. The multi-media elevator gives visitors one of the fastest rides in the world up more than one hundred flights, while giving visitors points of reference for the heights they are ascending along their journey to the 103rd floor. Design and branding firm Hornall Anderson developed the visitor experience to showcase the tower’s story as both a Chicago and global icon. Combined with The Ledge, the Skydeck Chicago experience will provide visitors from all over the world an encompassing view of the building and the city. “The Skydeck attracts more than 1.3 million visitors annually who enjoy views of up to 50 miles and four states,” Stancik said. “Now, visitors will be taken on a ‘one stop Chicago’ journey from the building’s inception and role in Chicago, to the daring experience that awaits them on The Ledge. In a single trip up to 103, visitors see and learn about the best that Windy City has to offer.” MTH Industries, the Chicago-based 120-year-old glass and architectural metal contractor that installed Cloud Gate in Millennium Park, installed The Ledge’s glass panels. Each glass box is comprised of three layers of glass laminated into one seamless unit. The low-iron, clear glass is fully tempered and heat-soaked for durability. In addition, the motorized system that projects and retracts the boxes from the building utilizes steel LinearBeams. The Sears Tower Skydeck on the 103rd floor attracts more than 1.3 million visitors per year.