From the pyramids of Egypt to the Twin Towers, we love tall buildings, Read about these architectural marvels that define the New York skyline.
BY the early 1900s, Manhattan was bursting at the seams with millions of new residents and 69 of the country’s biggest companies, like General Electric and U.S. Steel. There was nowhere to build but up.
Enter the skyscraper. Unlike traditional buildings, which are supported by their brick and concrete outer structure, skyscrapers are supported by a steel grid framework and interior steel- frame core.
Architects, influenced by Brooklyn Bridge builders John and Washington Roebling, began using steel-frame construction in their building designs.
Elisha Graves Otis’ passenger elevator had been in use since 1857. The seven-story Equitable Life Insurance Co. was the first office building in the city to use one.
In 1889, the 11-story Tower Building was New York’s first “skyscraper.” Next came the 18-story World Building, and in 1902, the 21-story Fuller Building, or Flatiron, named for its triangular shape.
In 1907, the Singer Building was the world’s tallest, at 47 stories high. Next came the Metropolitan Life Insurance Co.
In 1910, property on Wall Street was selling at $25,000 a foot.
The skyscraper frenzy was on.
With their central core and steel-frame construction, skyscrapers defy the pull of gravity.
Their steel beams are lighter and stronger than traditional stone masonry or iron.
Skyscrapers have steel grids that are attached vertically, horizontally and even sometimes diagonally for complete support. These three-dimensional grids are the key to the building’s strength. Once the steel structure is in place, the entire thing is covered in concrete, steel or even glass – very strong indeed.
In addition to the vertical pull of gravity, the buildings must also contend with the horizontal force of the wind. Most skyscrapers can sway several feet in either direction. The horizontal and vertical grids are tightened so that they function like a steel pole. Super structures like the Empire State and Chrysler buildings have additional core structures throughout their centers, particularly around the elevator shafts.
The World Trade Center Towers were engineering marvels and the world’s tallest buildings, at 110 stories. Until their construction, the 102-story Empire State Building, erected in 1930, had been the tallest. Excavation for the Twin Towers started in 1966. The chief architect was Minoru Yamasaki.
The Twin Towers featured innovative tubes, built where the steel support columns would normally be, on the outside of the building and at the core.
Each tower was a box inside a box. The columns were covered in aluminum, giving the buildings their silvery color.
Ironically, Yamasaki was afraid of heights. He included 22-inch windows to make the buildings feel more secure.
The Towers were tall, stable and a distinct departure from the pyramid design of most New York skyscrapers.
The World Trade Center complex opened on April 4, 1973, and The Towers quickly became New York icons. Sadly, they were destroyed by terrorists on Sept. 11, 2001.
More than just skyscrapers, The Towers were symbols of architectural innovation and commercial success. Architect Yamasaki said of them, “The World Trade Center buildings in New York had a bigger purpose than just to provide room for tenants. The World Trade Center is a living symbol of man’s dedication to world peace … his belief in the cooperation of men, and, through cooperation, his ability to find greatness.”
Source: howstuffworks.com
Today’s lesson fulfills the following New York standards: ELA: 1c, 3c, 3d, 5a.
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New York Post activities
Make a list of your favorite tall buildings in the city. Use the Internet or encyclopedia to learn more about them.
Look at a picture of the New York City skyline and name the distinctive buildings.
Visit http://www.howstuffworks.com to learn more about skyscrapers.