Sears Tower

The Sears Tower is a skyscraper in Chicago, Illinois. Commissioned by Sears, Roebuck and Company, it was designed by chief architect Bruce Graham and structural Engineer Fazlur Khan of Skidmore, Owings, & Merrill. Construction commenced in August 1970, and reached its maximum height on May 4 1973. When completed, the Sears Tower had overtaken the twin towers of the World Trade Center in New York City as the world's tallest building. It is normally said to have 110 stories but by some measures has 108. The height of the roof is 1,450 feet (442 m) measured from the main entrance, or 1,454 feet (443 m) measured from the side entrance (both figures are seen in reference books but the Council on Tall Buildings and Urban Habitat uses main-entrance heights). The total height of the structure including the two television antennas on top added in February 1982 was 1,707 feet (520 m), the western antenna was later extended to 1,729 feet (527 m) on June 5, 2000 to outstrip the World Trade Center antenna.

Contents

1 History 2 The Skydeck 3 Which is tallest? 4 See also 5 External links

History

In 1969, Sears, Roebuck was, by far, the largest retailer in the world, with a total three hundred and fifty thousand employees. Sears executives decided to consolidate the thousands of employees scattered throughout office buildings in the Chicagoland area into one building in Chicago's west Loop. With immediate space demands of three million square feet, or about seventy one-acre (city-block sized) floors, and with predictions and plans for future growth necessitating even more space than that, architects for Skidmore knew that the building would be one of the tallest in the city and certainly one of the largest office buildings in the world.

Sears executives decided early on that the space they would immediately occupy should be as efficiently designed to house the small army that was their Merchandise Group. However, future growth would be rented out to smaller firms and businesses until Sears could retake it. Therefore, the floor sizes would need to be smaller with more window space, to be more marketable to these prospective lessees. Smaller floor sizes necessitated a taller structure. Skidmore architects proposed a tower which would have large, fifty-five thousand square foot floors in the lower part of the building, and would gradually taper the area of the floors down in a series of setbacks, which would give the Sears Tower its disctinctive, husky shouldered look.

As Sears continued to offer optimistic projections for future growth, the tower's proposed height soared into the low hundreds of floors and surpassed the height of New York's unfinished World Trade Center to become the world's tallest building. Restricted in height not by physical limitation or imagination but by an artificial ceiling imposed by the Federal Aviation Administration to protect air traffic, the Sears Tower would be financed completely out of Sears' deep pockets, and topped with two antennae to permit local television and radio broadcasts. Sears and the City of Chicago approved the design, and the first steel was put in place in April 1971. The structure was complete in May of 1973.

However, Sears' optimistic growth projections never came to pass. Competition from its traditional rivals (like Montgomery Ward) continued, only to be surpassed in strength by other retailing giants, like Kmart, Kohl's and Wal-Mart. Sears, Roebuck deteriorated as market share slipped away and management grew paranoid and introverted through the 1970s. The Sears Tower was not the draw Sears hoped it would be to potential lessees, and stood half vacant for a decade as an orgy of construction dumped millions of access square feet of office space into the Loop in the 1980s. Finally, Sears was forced to take out a mortgage on their headquarters building. Sears began moving its offices out of the the Sears Tower in 1993 and had completely moved out by 1995, moving to a new office campus in Hoffman Estates, Illinois.

There have been several owners of the Sears Tower since then. The newest owners purchased the tower in March 2004 and are rumored to have plans to rename the building.

Now considered one of the finest locations for business in Chicago, the Sears Tower is now a multi-tenant office building with more than 100 different companies doing business there, including major law firms, insurance companies and financial services firms.

Without warning, in August 1999, French urban climber, Alain "Spiderman" Robert, using only his bare hands and feet and with no safety devices of any kind, scaled the building's exterior glass and steel wall all the way to the top (even in the face of a thick fog which settled in near the end of his climb, making the last 20 floors of the building slippery).

The Sears Tower is located at 233 South Wacker Drive, Chicago. The tourist entrance can be found on the south side of the building on Jackson Boulevard.

The Skydeck

The Sears Tower Skydeck observation deck on the 103rd floor of the tower is 1,353 feet above ground and is a famous tourist attraction. The tourists can experience how the building sways on a windy day. They can see far over the great plain of Illinois and across Lake Michigan on a clear day. The Sears Tower Skydeck competes with the John Hancock Center's observation floor across town, which is about 250 feet lower.

Which is tallest?

At 452 m (1,483 feet) tall, including decorative spires, the Petronas Twin Towers in Kuala Lumpur, Malaysia, laid claim to replacing the Sears Tower as the tallest building in the world in 1997. In the ensuing controversy four different categories were created with the Petronas only taking one of these, however, the re-definition has done little to help. With the arrival of another rule bender, the Taipei 101, the Petronas towers were surpassed in spire height and for the first time the Sears was surpassed in roof height, but the Sears antenna is still taller than the Taipei spire.

The Sears Tower is the tallest office building in the United States and it retains the world record when measuring the height from the sidewalk level of the main entrance to the top of antenna. When completed, the Freedom Tower in New York City may exceed the Sears Tower through its structural, but not occupied peak.

Sears Tower was unseated for having the highest roof of any building in the world and the highest habitable floor in the world by Taipei 101 in 2004. In side by side comparisons the Sears Tower still looks the tallest however, and the measurement rules are controversial.

Buildings are planned that would clearly surpass the Sears Tower in all height categories.

See also

• 50 Tallest buildings in the U.S.
• Tallest Buildings in Chicago
• List of towers
• World's tallest structures

External links

• Structurae: Sears Tower (http://www.structurae.de/en/structures/data/s0000065/index.cfm)
• Official Sears Tower website (http://www.thesearstower.com/)

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