Willis Tower

The Willis Tower ( until July 2009 Sears Tower ) is the tallest building in the city of Chicago, at the same time also currently the second tallest skyscraper in the United States and the tenth tallest building in the world. The building is located in the Chicago Loop on South Wacker Drive, corner of Adams Street. The address is 233 South Wacker Drive, Chicago, IL 60606th

  • 2.1 Description
  • 2.2 Skydeck viewing platform
  • 2.3 glass balconies
  • 4.1 Temporal Data
  • 4.2 Specifications
  • 4.3 Miscellaneous

History

Construction and opening

The on behalf of the American retail group Sears ( Sears Roebuck and Co.) from 1970 built the Sears Tower (since 2009: Willis Tower ) was opened after a four -year construction period in 1974 in Chicago. In charge of the construction project and the subsequent management was Cushman & Wakefield. With a height of 442 meters (total height with antenna 527 meters, 108 floors) he was after its completion the tallest building in the world, prompting the World Trade Center (417 meters) in New York 's tallest skyscraper from. The company Sears, whose headquarters is located in Chicago and that was in the days of the opening of the tower, the largest retailer in the world with 350,000 employees brought into the building under its corporate headquarters.

Height records

In 1998, the Petronas Towers in Kuala Lumpur complaint ( a total of 452 meters, roof 378 meters, the highest floor at 375 meters) the title of the tallest building in itself, however, was disputed in the wake violently about the crucial dimensions, in particular whether the total height including antennas, the roof height, the height of the top floor or the structure height shall prevail. However, the skyscraper in Chicago had to have the highest roof. Until 2000 the building but not held the record for the highest total height. This track was still wearing the north tower of New York's World Trade Center ( 526.7 meters), as well as the highest usable floor, but which was higher with 413 meters only a few centimeters. Only when one of the antennas on the building in June 2000 to 527 meters ( previously 520 meters) was increased, it became the tallest building in the whole world.

In 2004, he lost the title of the highest roof and the top floor of the Taipei 101 ( total 508 meters; roof 448 meters). However, the Sears Tower remained with a total height of 527 meters up to the top of the mast, the tallest building in the whole world. Only when the Burj Khalifa at its official opening in January 2010 took over all records (total height 830 meters, structural and official altitude 828 meters) the tower lost even this record. Today, the Willis Tower is still one of the highest non -guyed structures in the world and the second tallest freestanding structure in the United States. After the completion of some higher buildings in Asia it still remained the title of highest skyscraper in North America or to the Americas. After May 2013, the One World Trade Center in New York had reached its final height of 541 meters, he was replaced as the tallest building in the United States after 39 years. The One World Trade Center surpasses him in both the architectural ( official ) level as well as in the overall height by its spire towering above the antennas of the Willis Tower, the roof of One World Trade Center with 417 meters is slightly lower. The Willis Tower remains the tallest building in Chicago.

Renaming

On 16 July 2009 the former Sears Tower was renamed Willis Tower after the London Insurance Group Willis Group Holdings leased approximately 13,000 square feet of office space in the building and the naming rights bought the skyscraper. A spokeswoman for the Sears Group, the rights to the name had secured from 1973 to 2003 and by 1992 it had its head office, called the name change " sad ". After the exodus 1992 Sears took no more rooms in the Sears Tower, but even after 2003, the tower remained officially named Sears Tower. In the U.S. the name change came surveys of the Chicago Tribune According to rejection. This was due mainly to the fact that the building since its completion in 1974 - so for a period of more than three decades - the name Sears Tower was wearing and this name therefore had a fixed reference both to the tower and for the city of Chicago. In common parlance, the tower is therefore common in the U.S. public still called Sears Tower.

Architecture

Description

The Willis Tower consists of nine square columns in a 3 × 3 arrangement, which terminate at different heights. Up to a height of 200 meters ( 49th floor ) of the nine tubes form a big square, from there, two of them end up on opposite corners. From the top line of the 200 meters to a height of about 260 meters ( 65th floor) the tower consists of seven tubes, then end in 260 meters height, the other two tubes at the corners. From 260 meters up to 360 meters ( 89th floor) lead five tubes in a cross-shaped cross-section, where then end three of the five tubes. Up to 442 meters ( 108 floor) go only two of the nine tubes, namely the central tube and another at the edge. Due to its unique design the Willis Tower from different perspectives offers so many different views like no other building. The load-bearing elements of the building are almost exclusively made ​​of steel. This design is now used less frequently (most new buildings consist the main elements of steel and concrete ). The Willis Tower is still the tallest building of this type.

The entire building is clad in black aluminum. The facade consists of around 16,100 windows.

The floors 29-32, 64-65, 88-89 and 104-108 can not be used as office space, etc., these are ( visible on the facade (dark, without glass windows ) ) to the operational missiles where technical installations such as elevator motors, electrical switching stations and air conditioning systems are housed. Since the top floors are operating projectiles, the highest usable floor lies ( the 103 ) whereas the highest floor ( the 108th ) is only at a height of 412.7 meters to 436 meters.

There is a 2 storey high building, in which, among other things, a cleaning robot is placed on the window between the two antennas on the flat roof. If you add this, but still the official height is not more to be counted build with, would the Willis Tower 110 floors. This number of floors is contrary to the official Storey called by some sources.

In the lobby there is the sculpture of The Universe by Alexander Calder.

Visitor platform Skydeck

Of the 412 meter high viewing platform on the 103rd floor ( Skydeck ) you can look towards entry on some days up to 80 kilometers in four different states. Two lifts take this the visitor with around 8 m / s ( 28.8 km / h, 480 meters per minute) in 45 seconds on the Skydeck; they are among the fastest in the world. In the 99th floor there is an alternative view floor when that is closed in the 103rd floor.

Glass balconies

After the company took over the Willis Tower in summer 2009, a new attraction opened at the 412 -meter high observation deck on the 103rd floor. It was on the west side of the building facade where the wall as opposed to the other sides perpendicular goes straight down to the ground, three closed glass balconies mounted. These allow visitors to stand on a glass plate attached to only one side of the tower facade and otherwise is free, and thus to look through the glass floor 412 meters in depth. Since the collapse of the south tower of the World Trade Center in New York in September 2001, the observation deck was 420 feet high, the observation floor of the Willis Tower 412 meters above sea level is the highest viewing platform in the U.S.. There are currently no building in North America except the Willis Tower, which is still home to one floor at this height.

Use

The tower is predominantly an office building with approximately 350,000 sqm of office space. Tenants include in addition to the Willis Group ( use of approximately 13,000 sqm of office space ), among others, companies such Backstop Solutions, UniCare Life & Health Insurance Company, TradeStation Securities, TRU Office Advisors, Tressler LLP Lawyers and United Airlines. The latter had moved into the building in late 2010 after the merger with Continental Airlines in 2012 and there established the operating center. United was in 2010 with the use of nearly 20 % of the total office space to approximately 60,000 m² of largest tenant in the building. The state in June 2012 demonstrated the airline based in Chicago 12 floors of the Willis Tower, where they employed approximately 4,000 employees, and planned by the end of 2012 other employees in the building too embarrassed to give up other office locations in Chicago. The state in 2013 worked on 16 floors and 75,000 m² more than 4,000 United employees in the building, which acts as a factory and headquarters of United Airlines. A re-naming, for example, in United Tower, was excluded from sides of the building operator in 2012.

Data collection

Temporal data

  • Foundation stone laid: August 1970
  • Topping: May 1973
  • Opening: May 1974
  • Antenna Installation: February 1982

Specifications

  • Roof height: 442.3 m
  • Highest Floor: 436 m
  • Highest usable floor: 412.7 m to
  • Western antenna: 527.3 meters
  • Eastern antenna: 520 m
  • View Floor: 103rd floor ( to 412.7 m)
  • Elevators: 104
  • Elevator speed: 480 meters per minute
  • Levels: 108
  • Underground floors: 3
  • Total weight: about 220,000 t

Miscellaneous

  • The antenna tip of the Willis Tower is the highest point in the U.S. state of Illinois. The antenna peak is 527.3 meters above street level in Chicago and 708 meters above sea level. The roof is 442.3 meters above street level and 623 meters above sea level, the view platform ( Sky Deck ) on the 103rd floor is 412 meters above street level and 593 meters above sea level. The main entrance of the building and thus the street level of Chicago is located 181 meters above sea level. The highest natural point in Illinois is Charles Mound, one from sea level measured from 376 meters high hill.
  • The building deviates about 10 inches from the vertical from, caused by his slightly asymmetrical design, which has a non-uniform loading of the foundation result.
Architectural style International Style (architecture) Bruce Graham Fazlur Khan Skidmore, Owings & Merrill Sears Holdings Corporation Aluminium Chicago Sun-Times
720420
de