Sears Tower

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Sears Tower
Sears Tower was the world's tallest building from 1973 to 1998.*
Preceded by	World Trade Center
Surpassed by	Petronas Twin Towers
Information
Location	Chicago, Illinois, USA
Status	Complete
Constructed	1970-1973
Height
Antenna/Spire	1,730 ft (527 m)
Roof	1,451 ft (442 m)[1]
Technical details
Floor count	108[2]
Floor area	4.56 million sq ft. (3.81 million sq ft. rentable) 418,064 m² (353,961 m² rentable)[3]
Elevator count	104, with 16 double-decker elevators
Companies
Architect	Skidmore, Owings and Merrill
*Fully habitable, self-supported, from main entrance to highest structural or architectural top; see the list of tallest buildings in the world for other listings.

The Sears Tower is a skyscraper in Chicago, Illinois. It has been the tallest building in the United States since 1973, surpassing the World Trade Center, which itself had surpassed the Empire State Building only a year earlier. Commissioned by Sears, Roebuck and Company, it was designed by chief architect Bruce Graham and structural engineer Fazlur Khan of Skidmore, Owings and Merrill.

Construction commenced in August 1970 and the building reached its originally anticipated maximum height on May 3, 1973. When completed, the Sears Tower had overtaken the roof of the World Trade Center in New York City as the world's tallest building. The tower has 108 stories as counted by standard methods, though the building owners count the main roof as 109 and the mechanical penthouse roof as 110. The distance to the roof is 1,451 feet (442 m), measured from the east entrance.^[4]

In February 1982, two television antennas were added to the structure, increasing its total height to 1,705 feet (520 m). The western antenna was later extended to 1,730 feet (527 m)^[5] on June 5, 2000 to improve reception of local NBC station WMAQ-TV.

Black bands appear on the tower around the 29th–32nd, 64th–65th, 88th–89th, and 104th–109th floors. These are louvers which allow ventilation for service equipment and obscure the structure's belt trusses which Sears Roebuck did not want to be visible as on the John Hancock Center.

The building's official address is 233 South Wacker Drive, Chicago, Illinois 60606.

On August 12, 2007, the Burj Dubai in Dubai, United Arab Emirates was reported by its developers to have surpassed the Sears Tower in all height categories.^[6]

[edit] History

[edit] Planning and construction

In 1969, Sears, Roebuck & Co. was the largest retailer in the world, with about 350,000 employees.^{[citation needed]} Sears executives decided to consolidate the thousands of employees in offices distributed throughout the Chicago area into one building on the western edge of Chicago's Loop. With immediate space demands of 3 million square feet (279,000 m²), 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 largest office buildings in the world.^{[citation needed]}

Sears executives decided early on that the space they would immediately occupy should be efficiently designed to house the small army that was their Merchandise Group. However, floor space for 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, and to have a higher window-space to floor-space ratio, to be more attractive and marketable to these prospective lessees. Smaller floor sizes necessitated a taller structure. Skidmore architects proposed a tower which would have large 55,000-square-foot (5,000 m²) 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 distinctive, husky-shouldered look.

View of Soldier Field from the Sears Tower Sky Deck

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 rather by a limit 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 antennas 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 completed in May 1973. Construction costs totaled approximately $150 million USD at the time,^[7] which would be equivalent to roughly $950 million USD in 2005. For comparison, Taipei's Taipei 101, built in 2004, cost around the equivalent of US$1.64 billion in 2005 dollars.

[edit] Post-opening

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. The fortunes of Sears & Roebuck declined in the 1970s as the company lost market share and its management grew ever more cautious.^[8] The Sears Tower itself was not the draw Sears hoped it would be. The tower stood half-vacant for a decade as more office space was erected in Chicago in the 1980s. The company was eventually obliged to take out a mortgage on its signature building. Sears began moving its offices out of the Sears Tower in 1993 and had completely vacated the building by 1995, moving to a new office campus in Hoffman Estates, Illinois.

Sears Tower has gone through several owners in the years since but Sears has retained the naming rights for the building. It is now a multi-tenant office building with more than 100 different companies in residence, including major law firms, insurance companies and financial services firms.

[edit] The Skydeck

The Sears Tower Skydeck observation deck opened on June 22, 1974 and is located on the 103rd floor of the tower. It is 1,353 feet (412 m) above ground and is one of the most famous tourist attractions in Chicago. Tourists can experience how the building sways on a windy day. They can see far over the plains of Illinois and across Lake Michigan to Indiana, Michigan and Wisconsin on a clear day. It takes about 45 seconds to soar to the top in either of two special elevators. The Sears Tower Skydeck competes with the John Hancock Center's observation floor a mile and a half away, which is 323 feet (98 m) lower. 1.3 million tourists visit the Skydeck annually.

A second Skydeck on the 99th floor is used when the 103rd floor is closed.

The tourist entrance can be found on the south side of the building along Jackson Boulevard.

Without warning, in August 1999 French urban climber Alain "Spiderman" Robert, using only his bare hands and feet scaled the building's exterior glass and steel wall all the way to the top. A thick fog settled in near the end of his climb, making the last 20 floors of the building's glass and steel slippery.^[9]

[edit] Gallery

Sears Tower as seen from John Hancock Center observation deck

900 North Michigan, Park Tower, the John Hancock Center, and Water Tower Place (L-R) as seen from the Sears Tower observation deck

Westward view from Sears Tower

[edit] Height

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Height comparison with other tall buildings.

At 1,483 feet (452 m) 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 1998. Not everyone agreed, and in the ensuing controversy four different categories of "tallest building" were created. Of these, Petronas was the tallest in one category (height to top of architectural elements, meaning spires but not antennas). However, before the addition of the Sears Tower's own two antennas in 1982, One World Trade Center was taller by height to top of its 360-foot (110 m) antenna (added in 1978 to its previous 1368-foot (417 m) height).

Taipei 101 in Taiwan claimed the record in three of the four categories in 2004 to become generally recognized as the tallest building in the world. Taipei 101 surpassed the Petronas Twin Towers in spire height and the Sears Tower in roof height; it also claimed the record for highest occupied floor. The Sears Tower retained one record: its antenna exceeded the Taipei 101's spire in height.

The Sears Tower remained the tallest office building in North America, and retains the world record when measuring from sidewalk level of the main entrance to the top of the antenna. It is however the second tallest free standing structure or tower in North America measuring 85 feet shorter than Toronto's CN Tower. When completed, the Freedom Tower in New York City is expected to surpass the Sears Tower through its structural but not occupied peak.^{[citation needed]} Burj Dubai, currently under construction in Dubai, is expected to claim all height records, surpassing the Sears Tower, Taipei 101 and the CN Tower, when it opens in 2009. The Chicago Spire now under construction is expected to lay claim to most height records for North American structures the following year.^{[citation needed]}

[edit] Cultural depictions

Sears Tower as viewed from Chinatown

[edit] Film and television

The Sears Tower appears in numerous films and television shows set in Chicago such as Ferris Bueller's Day Off, Ferris and company watch the streets of Chicago from the observation deck.^[10] The television show Late Night with Conan O'Brien introduced a character called The Sears Tower Dressed In Sears Clothing when the show visited Chicago in 2006.^[11] The building is also featured in History Channel's Life After People, in which the Sears Tower and other man made land marks suffer from neglect without humans around and collapses two hundred years after people are gone.^[12] In an episode of the television series, Monk, Adrian Monk tries to conquer his fear of heights by imagining that he is on top of the Sears Tower. The tower is seen in the PC game Command and Conquer: Red Alert 2^[13] and the Rampage series of video games. The tower is also featured in SimCity PC games, as well as Namco's Ace Combat 5 The Unsung War.

[edit] Position in Chicago's skyline

[edit] Figures and statistics

Sears Tower viewed from S Wacker Dr.

• The top of the Sears Tower is the highest point in Illinois. The tip of its highest antenna is 1,730 feet (527.3 m) or 2,325 feet (708 m) above sea level, its roof is 1,451 feet (442.3 m) above street level or 2,046 feet (623 m) above sea level, the 103rd floor observation deck (The Sky deck) is 412 m (1,353 ft) above street level or 1,948 feet (593 m) above sea level, the Wacker Drive main entrance is 595 feet (181 m) above sea level. (The highest natural point in Illinois is the Charles Mound, at 1,235 feet (376 m) above sea level.)
• The building leans about 4 inches (10 cm) from vertical due to its slightly asymmetrical design, placing unequal loads on its foundation. This can occasionally be felt.
• The antennas atop the Sears Tower are struck by lightning an average of 650-675 times per year.^{[citation needed]}
• The design for the Sears Tower incorporates nine steel-unit square tubes in a 3 tube by 3 tube arrangement, with each tube having the footprint of 75 x 75 feet (22 x 22 m). The Sears Tower was the first building for which this design was used. The design allows future growth of extra height to the tower if wanted or needed. ^[14]
• The restrooms on the 103rd floor sky deck 1,353 feet (412 m) above street level are the highest in the world.

[edit] References

[edit] See also

Wikimedia Commons has media related to:

Sears Tower

• Sears Merchandise Building Tower - original Sears Tower
• Sears, Roebuck and Company Administration Building
• Chicago architecture
• List of tallest buildings by U.S. state
• List of tallest buildings in the United States
• List of tallest buildings in Chicago
• List of towers
• World's tallest structures
• List of tallest freestanding structures in the world
• WLS-TV

Skyline perspective

[edit] External links

• Official Sears Tower website
• Sears Tower on Emporis
• Sears Tower Facts, Graphs and Pictures
• Sears Tower Skydeck website
• SkyscraperPage diagram of Sears Tower
• Google 3D Model
• Sears Tower Cam
• Sears Tower in the Structurae database

• Sears Tower is at coordinates 41°52′44″N 87°38′09″W / 41.8789, -87.6358 (Sears Tower)Coordinates: 41°52′44″N 87°38′09″W / 41.8789, -87.6358 (Sears Tower)

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