User:Scott Oglesby/Willis Tower

Willis Tower, formerly named Sears Tower, is a 108-story 1450 ft skyscraper in Chicago, Illinois. At the time of its completion in 1973 it was the tallest building in the world, surpassing the World Trade Center towers in New York. Currently, Willis Tower is the tallest building in the United States and the fifth-tallest freestanding structure in the world.

Although Sears' naming rights expired in 2003, the building continued to be called Sears Tower for several years. However, in March 2009 London-based insurance broker Willis Group Holdings, Ltd., agreed to lease a portion of the building and obtained the building's naming rights as part of the agreement. On July 16, 2009, at 10:00 am Central Time, the building was officially renamed Willis Tower.

Planning and construction
In 1969, Sears, Roebuck & Co. was the largest retailer in the world, with approximately 350,000 employees. 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 predictions and plans for future growth necessitating even more space, Sears commissioned architects Skidmore, Owings and Merrill to produce a structure that would be one of the largest office buildings in the world. Their team of architect Bruce Graham and structural engineer Fazlur Khan designed the building as nine square "tubes"—each essentially a separate building—clustered in a 3x3 matrix. All nine tubes would rise up to the 50th floor of the building. At the 50th floor, the northwest and southeast tubes end, and the remaining seven continue up. At the 66th floor, the northeast and the southwest tubes end. At the 90th floor, the north, east, and south tubes end. The remaining west and center tubes continue up to the 108th floor.

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. But 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 high window-space to floor-space ratio, to be 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.

As Sears continued to offer optimistic projections for 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 was 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, 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$1.76 billion in 2005 dollars.

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.

In February 1982, two television antennas were added to the structure, increasing its total height to 1707 ft. The western antenna was later extended to 1730 ft on June 5, 2000 to improve reception of local NBC station WMAQ-TV.

Post-opening
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. 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.

By 1990, Keck, Mahin & Cate, a law firm, considered moving out of its space in the Sears Tower and moving into a potential new development, which would become 77 West Wacker Drive. Brokers who were familiar with the lease negotiations stated that Sears was trying to keep Keck, Mahin & Cate in the building. Keck, Mahin & Cate decided to move into 77 West Wacker, and the Prime Group, developer of 77 West Wacker, finalized the development of the facility. During the time that Keck, Mahin & Cate was scheduled to move out of the Sears Tower, Sears planned to move its offices to its merchandise group facilities in Hoffman Estates, Illinois. Sears began moving its offices out of the Sears Tower in 1992.

In 1994 Sears sold the building to Boston-based AEW Capital Management with financing from MetLife. At the time it was one third vacant. By 1995 Sears had completely vacated the building, moving to a new office campus in Hoffman Estates.

In 1997 Toronto-based TrizecHahn Corp (the owner at the time of the CN Tower) purchased the building for $110 million, and assumption of $4 million in liabilities, and a $734 million mortgage.

In 2003 Trizec surrendered the building to lender MetLife.

In 2004 Metlife sold it to a group of investors that includes New York investors Joseph Chetrit, Joseph Moinian, Lloyd Goldman, Joseph Cayre and Jeffrey Feil and Skokie-based American Landmark Properties. The quoted price was $840 million with $825 million held in a mortgage.

Future plans
In February 2009 the owners announced they are considering a plan to paint the structure silver. The paint would "rebrand" the building and highlight its advances in energy efficiency. The estimated cost is $50 million.

Since 2007 the building owners have been considering building a hotel adjacent to the building on the north side of Jackson between Wacker and Franklin on the site of a plaza that is the entrance to tower's observation deck. The tower's parking garage is beneath the plaza. Building owners say the second building was considered in the original design. City zoning does not permit construction of such a tall tower there.

Terrorist plot
In 2006, seven men were arrested by US authorities and charged with plotting to destroy the tower. The case originally went to court in October of 2007; after three trials, five of the suspects were convicted and two were acquitted. The alleged leader of the group, Narseal Batiste, was sentenced to 13 1/2 years in prison in November 2009.

The Skydeck


Skydeck Chicago at Willis Tower opened as The Sears Tower Skydeck observation deck on June 22, 1974. It 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 60 seconds to soar to the top in either of two special, Schindler Group elevators. The 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.

In January 2009, the Skydeck began a major renovation including the installation of glass balconies extending approximately four feet over Wacker Drive from the 103rd floor. The all-glass boxes allow visitors to look through the floor to the street 1353 ft below. The boxes, which can bear five tons of weight (about 4.5 metric tonnes), opened to the public on July 2, 2009.

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.

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.

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

Height
Sears Tower remains the tallest building in the Americas. With a pinnacle height of 1730 feet (527 m), it is the second tallest freestanding structure in the Americas, as it is 86 feet (26 m) shorter than Toronto's CN Tower, and is the only other freestanding structure in the Americas to exceed 1640 feet (500 m) in height. As of August 2009, Willis Tower is the fifth tallest freestanding structure in the world (by pinnacle height), after the Burj Dubai, the Guangzhou TV & Sightseeing Tower, the CN Tower and the Ostankino Tower.

At 1,482.6 feet (451.9 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).

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. In 2008, the Shanghai World Financial Center claimed the records of tallest building by roof and highest occupied floor.



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.

When completed, 1 World Trade Center in New York City is expected to surpass Willis Tower through its structural and pinnacle heights, but not by roof or highest occupied floor. Burj Dubai, currently topped out but still under construction in Dubai, has laid claim (by a significant margin) to all height records, surpassing the Sears Tower, the CN Tower, 1 World Trade Center, Taipei 101 and Shanghai World Financial Center in every category. The Chicago Spire, which has a planned height of 610 m (2,000 ft) is expected to lay claim to all categories of height records in the Americas upon completion, but its construction is currently on hold due to financial difficulties.

Until 2000, the Sears Tower did not hold the record for the tallest building by pinnacle height. From 1969-1978, this record was held by the John Hancock Center, whose antenna reached a height of 1,500 ft (457.2 m), or 49 ft (14.8 m) taller than the Sears Tower's original height of 1,451 ft (442 m). In 1978, One World Trade Center became taller by pinnacle height due to the addition of a 359 ft (109.3 m) antenna, which brought its total height to 1,727 ft (526.8 m). In 1982, two antennas were installed on top of the Sears Tower which brought its total height to 1,707 ft (520.3 m), making it taller than the John Hancock Center but not One World Trade Center. However, the extension of the Sears Tower's western antenna in June 2000 to 1,730 feet (527 m) allowed it to just barely claim the title of tallest building by pinnacle height.

Naming rights
Although Sears sold the Tower in 1994 and had completely vacated it by 1995, Sears retained the naming rights to the building through 2003. The new owners were rebuffed in renaming deals with CDW Corp in 2005 and the U.S. Olympic Committee in 2008. London-based insurance broker Willis Group Holdings, Ltd. leased more than 140,000 square feet of space on three floors in 2009. A Willis spokesman said the naming rights were obtained as part of the negotiations at no cost to Willis. The building was renamed Willis Tower on July 16, 2009. The naming rights are valid for 15 years so it is possible that the building’s name could change again in 2024. The Chicago Tribune joked that the building’s new name reminds them of the oft-repeated "What you talkin' 'bout, Willis?" catchphrase from the 1980s American television sitcom Diff'rent Strokes. According to a July 16, 2009 CNN article, some Chicago area residents were reluctant to accept the Willis Tower name.

Film and television
The building has appeared in numerous films and television shows set in Chicago such as Ferris Bueller's Day Off, where Ferris and company watch the streets of Chicago from the observation deck. 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. The building is also featured in History Channel's Life After People, in which it and other human-made land marks suffer from neglect without humans around, and it collapses two hundred years after people are gone. 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. Also, in an episode of Kenan and Kel, Kenan Rockmore and Kel Kimble decide to climb to the top of the Sears Tower, so that Kenan can declare his love for a girl.

On May 25, 1981, Dan Goodwin, wearing a homemade Spider-Man suit while using suction cups, camming devices, and sky hooks, and despite several attempts by the Chicago Fire Department to stop him, made the first successful outside ascent of Sears Tower. Goodwin was arrested at the top after the seven hour climb and charged with trespassing. Goodwin stated the reason he made the climb was to call attention to shortcomings in high-rise rescue and firefighting techniques. After a lengthy interrogation by Chicago's District Attorney and Fire Commissioner, Goodwin was released.

Figures and statistics

 * The top of Willis Tower is the highest point in Illinois. The tip of its highest antenna is 1,730 feet (527.3 m) above street level or 2,325 feet (708 m) above sea level, its roof is 1,450 feet and 7 inches (442.1 m) above street level or 2,046 feet (623 m) above sea level, the 103rd floor observation deck (The Sky deck) is 1,353 feet (412 m) above street level or 1,948 feet (593 m) above sea level, the Franklin Street 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.
 * The design for Willis 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). Willis 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.
 * The restrooms on the 103rd floor 1,353 feet (412 meters) above street level are the highest in the western hemisphere.

Broadcasting
Many broadcast station transmitters are located at the top of Willis Tower. Each list is ranked by height from the top down. Stations at the same height on the same mast indicate the use of a diplexer into the same shared antenna. Due to its extreme height, FM stations (all class B) are very limited in power output.

Radio stations
Also WB(Weather band)/WX (aka. NOAA Weather Radio) transmit off the top of the Willis Tower on frequency 162.550 MHz (Channel 7) known as KWO39. Also equipped with SAME (Specific Area Message Encoding) for text alerts and hazardous weather alarm on weather radios. For weather radio station listing, please visit http://www.nws.noaa.gov/nwr/ for more information.