Reaching For the Sky
When the actual construction began workers dug out about 180,000 cubic yards of dirt and materials and created a hole that was 100 feet deep. Two hundred watertight chambers called “caissons” were built to serve as the foundation of the building. The first of the steel was placed on June 7, 1971, with the first nut set into place and tightened by Gordon M. Metcalf, chairman of the board at Sears and Arthur M. Wood, president of Sears. All of the steel used came from U.S Steel Corporation. It was delivered to the site in premade 15 x 25 foot sections known as “Christmas trees” (Doherty 20). These premade sections enabled the steel to be bolted into place quickly and efficiently. All of the nine tubes together used about 76,000 tons of steel. That was enough steel to make 50,000 cars (Doherty 22)! Construction of the Sears Tower went quickly. Workers completed about two floors each week. Even though progress was fast, workers encountered new challenges as they worked on the higher floors. In addition to workers having to work one thousand feet in the air, it was very difficult to get the workers down to the ground for their breaks and times to eat. This problem was solved by adding mobile catering kitchens on the 33rd and 66th floors. Another major challenge for the builders was the wind. The wind blew so hard sometimes, that the workers could not work on the upper levels of the building. “The wind was the only thing that ever stopped construction work on Sears Tower” (Doherty 25). In March, 1972, the framework was halfway complete. “It would not be long before Chicago could boast a skyscraper that reached heights never before reached by human engineering” (Doherty 25).
As work continued on the upper floors, workers started putting the sheets of aluminum and windows on the lower levels of the tower. The architects chose aluminum instead of the more traditional stone so the tower would look “as modern as its design” (Doherty 27). Aluminum also provided more efficiency and durability with less weight. However, this choice created a problem for the designers. Aluminum would become discolored from the pollution in the city. In order to solve this problem, the sheets of aluminum were anodized. This means that an electrical current was run through the aluminum in order to fuse a special coating material to it. The designers chose a dark color coating to hide the effects of city pollution. Once the aluminum covering was in place, workers added the 16,000 bronze tinted windows. On the floors with cross bracing, slotted covers were installed instead of windows. This gave the exterior a more distinctive look.
On May 3, 1973, the last beam was put into place on top of the Sears Tower. The beam was signed by 12,000 construction workers, Sears’ employees and other Chicagoans. Finally the completed tower was topped with two radio and broadcast antennas. The Sears Tower was the tallest building in the Western Hemisphere, and reached 1,729 feet (including the antennae) into the sky.
In spite of the fact that the architects and structural engineers solved the many challenges in building the world’s tallest building, the leadership of Sears did not foresee even greater problems they would face after the building’s completion. New competitors such as Wal-Mart and K-Mart took away much of Sears’ business. Because it was so large, Sears could not adapt fast enough to the changing marketplace. “In 1988, Sears Roebuck and Company moved out of the building, but the Sears Tower name remained the same. It was renamed Willis Tower in 2009, after the Willis Group Holdings, the global insurance broker who calls the Tower its Midwest home” (www.willistower.com).
When the actual construction began workers dug out about 180,000 cubic yards of dirt and materials and created a hole that was 100 feet deep. Two hundred watertight chambers called “caissons” were built to serve as the foundation of the building. The first of the steel was placed on June 7, 1971, with the first nut set into place and tightened by Gordon M. Metcalf, chairman of the board at Sears and Arthur M. Wood, president of Sears. All of the steel used came from U.S Steel Corporation. It was delivered to the site in premade 15 x 25 foot sections known as “Christmas trees” (Doherty 20). These premade sections enabled the steel to be bolted into place quickly and efficiently. All of the nine tubes together used about 76,000 tons of steel. That was enough steel to make 50,000 cars (Doherty 22)! Construction of the Sears Tower went quickly. Workers completed about two floors each week. Even though progress was fast, workers encountered new challenges as they worked on the higher floors. In addition to workers having to work one thousand feet in the air, it was very difficult to get the workers down to the ground for their breaks and times to eat. This problem was solved by adding mobile catering kitchens on the 33rd and 66th floors. Another major challenge for the builders was the wind. The wind blew so hard sometimes, that the workers could not work on the upper levels of the building. “The wind was the only thing that ever stopped construction work on Sears Tower” (Doherty 25). In March, 1972, the framework was halfway complete. “It would not be long before Chicago could boast a skyscraper that reached heights never before reached by human engineering” (Doherty 25).
As work continued on the upper floors, workers started putting the sheets of aluminum and windows on the lower levels of the tower. The architects chose aluminum instead of the more traditional stone so the tower would look “as modern as its design” (Doherty 27). Aluminum also provided more efficiency and durability with less weight. However, this choice created a problem for the designers. Aluminum would become discolored from the pollution in the city. In order to solve this problem, the sheets of aluminum were anodized. This means that an electrical current was run through the aluminum in order to fuse a special coating material to it. The designers chose a dark color coating to hide the effects of city pollution. Once the aluminum covering was in place, workers added the 16,000 bronze tinted windows. On the floors with cross bracing, slotted covers were installed instead of windows. This gave the exterior a more distinctive look.
On May 3, 1973, the last beam was put into place on top of the Sears Tower. The beam was signed by 12,000 construction workers, Sears’ employees and other Chicagoans. Finally the completed tower was topped with two radio and broadcast antennas. The Sears Tower was the tallest building in the Western Hemisphere, and reached 1,729 feet (including the antennae) into the sky.
In spite of the fact that the architects and structural engineers solved the many challenges in building the world’s tallest building, the leadership of Sears did not foresee even greater problems they would face after the building’s completion. New competitors such as Wal-Mart and K-Mart took away much of Sears’ business. Because it was so large, Sears could not adapt fast enough to the changing marketplace. “In 1988, Sears Roebuck and Company moved out of the building, but the Sears Tower name remained the same. It was renamed Willis Tower in 2009, after the Willis Group Holdings, the global insurance broker who calls the Tower its Midwest home” (www.willistower.com).