At the time the Sears Tower was constructed in 1974, it was the world’s tallest building, eclipsing New York’s twin-towered World Trade Center by 25 meter. It would keep the title of tallest building in the world until the Petronas twin towers in Kuala Lumpur, Malaysia were constructed in 1997. In 2009 incoming tenant Willis Group Holdings, an insurance brokerage firm based in London, changed the building’s name to Willis Tower.
The building consists of nine framed tubes which are actually nine skyscrapers on themselves taken together into one building. Originally, the plan included no less than 15 tubes, but when the planned hotel was taken out of the project, only nine tubes were used in the final designs. The nine tubes all reach forty-nine stories. At that point, two tubes end. The other rose up to the sixty-fifth floor. From the sixty-sixth to the ninetieth floor, the tower has the shape of a crucifix. Two tubes, creating a rectangular, reach the full height of 442 meter. The result is an interesting tower which looks different from all angles. The construction, designed by Fazlur Kahn, has other advantages: the construction with separate tubes provides lateral strengths to withstand the strong Chicago wind loads, as each tube only needs to take a part of the pressure.
The exterior is sheathed in black aluminum and bronze-tinted glass. Black bands appear around the building at the 30th–31st, 48th–49th, 64th–65th, and 106th–108th floors, at which points louvers clad the areas devoted to mechanical operations of the building. In the lobby is a major work by the American sculptor Alexander Calder, an enormous motorized mural named Universe, which he called a “wall mobile.”
Willis Tower is the perfect way to capture the stunning panoramic views of Chicago and its hundreds of neighborhoods and suburbs stretching for miles. You can see the whole sprawling metropolis and miles out into each direction from atop the Skydeck Chicago at Willis Tower. You can experience how the building sways on a windy day and can also see far over the plains of Illinois and across Lake Michigan to Indiana, Michigan and Wisconsin on a clear day.
Elevators take tourists to the top in about 60 seconds and allow feeling the pressure change as they rise up. Some 1.3 million tourists visit the Skydeck annually. In January 2009, the Willis Tower owners began a major renovation of the Skydeck to include the installation of retractable glass balconies, extending approximately four feet over Wacker Drive from the 103rd floor. The all-glass boxes allow visitors look 1,353 feet down. Remember, this is a 360-degree observatory, meaning there’s no direction from which you can’t see!
Visit to Sears Tower is included in our bus tour to Chicago!