Tower

For other uses, see Tower (disambiguation).

CN Tower (the world's tallest completed freestanding structure) in Toronto, Ontario, Canada.

The Sears Tower, in Chicago, Illinois.

The Eiffel Tower in Paris.

The TV Tower in Prague.

El Faro towers in Buenos Aires, Argentina one of the tallest towers in the city

Shukhov Tower in Moscow, Russia. Currently under threat of demolition.

Towers are thytdickhuman-made structures that are always taller than they are wide, usually by a significant margin. Towers are generally built to take advantage of their height, and can stand alone or as part of a larger structure.

History

Towers have been used by mankind since prehistoric times. Some of the earliest surviving examples are the broch structures in northern Scotland, which are conical towerhouses. The Chinese used towers as integrated elements of the Great Wall of China as early as about 210 BC. These and later examples from Phoenician and Roman cultures emphasised the use of a tower in fortification and sentinel roles. For example, watchtower elements are found at Mogador from the first millennium BC, derived from Phoenician or Carthaginian origins, while the Romans utilised octagonal towers as elements of Diocletian's Palace in Croatia, which monument dates to approximately 300 AD.

A noted incomplete tower is the Hassan Tower in Morocco, where work was abandoned in 1199 AD, and the tower stands today as a monument in its incomplete state. Another well known tower is the Leaning Tower of Pisa in Pisa, Italy built from 1173 until 1372. The Himalayan Towers are stone towers located chiefly in Tibet built approximately 14th to 15th century.

Some old towers in the United States are the Milwaukee City Hall, built in 1895 in Milwaukee, Wisconsin and the Woolworth Building, completed in 1913 in New York City. In Chicago, the Solidarity Tower of the historic Gateway Theatre is a replica of the main tower of the Royal Castle in Warsaw.

Etymology

Old English torr is from Latin turris via Old French tor. The Latin term together with Greek τύρσις was loaned from a pre-Indo-European Mediterranean language, connected with the Illyrian toponym Βου-δοργίς. With the Lydian toponyms Τύρρα, Τύρσα, it has been connected with the ethnonym Τυρρήνιοι as well as with Tusci (from *Turs-ci), the Greek and Latin names for the Etruscans (Kretschmer Glotta 22, 110ff.)

Functions of towers

Skyscrapers

A modern type of tower, the skyscraper, uses less ground space as a ratio of total building interior square footage. Skyscrapers are often not classified as towers, although most have the same design and structure of towers. In the United Kingdom, tall domestic buildings are referred to as tower blocks. In the United States, the World Trade Center had the nickname the Twin Towers, a name shared with the Petronas Twin Towers in Kuala Lumpur.

Strategic advantages

The tower throughout history has provided its users with an advantage in surveying defensive positions and obtaining a better view of the surrounding areas, including battlefields. They were installed on defensive walls or rolled near a target, see siege tower. Presently, strategic-use towers can be found at prisons or military camps.

Potential energy

By using gravity to move objects or substances downward, a tower can be used to store items or liquids like a storage silo or a water tower, or aim an object into the earth such as a drilling tower. Ski-jump ramps use the same idea, and in the absence of a natural mountain slope or hill, can be human-made.

Communication enhancement

In history, simple towers like lighthouses, bell towers, clock towers, signal towers and minarets were used to communicate information over greater distances. In more recent years, radio masts and cell phone towers facilitate communication by expanding the range of the transmitter. The CN Tower in Toronto, Canada was built as a communications tower, with the capability to act as both a transmitter and repeater. Its design also incorporated features to make it a tourist attraction, including the world's highest observation deck at 147 stories.

Transportation support

Towers can also be used to support bridges, and can reach heights that rival some of the tallest buildings above-water. Their use is most prevalent in suspension bridges and cable-stayed bridges. The use of the pylon, a simple tower structure, has also helped to build railroad bridges, mass-transit systems, and harbors.

Other towers

• To access tall or high objects: launch tower, service tower, supply tower, scaffold, tower wagon
• To access atmospheric conditions aloft: wind turbine, meteorological measurement tower, tower telescope, solar power station
• To take advantage of the temperature gradient inherent in a height differential: cooling tower, chimney
• To protect from exposure: BREN Tower
• For industrial production: shot tower
• To drop objects: drop tower, bomb tower, diving platform
• To test height-intensive applications: elevator test tower
• To improve structural integrity: thyristor tower
• To mimic towers or provide height for training purposes: fire tower, parachute tower
• As art: Shukhov Tower
• For recreation: rock climbing tower
• As a symbol: Tower of Babel, The Tower (Tarot card), church tower

The term "tower" is also sometimes used to refer to firefighting equipment with an extremely tall ladder designed for use in firefighting/rescue operations involving high-rise buildings.

See also

• Additionally guyed tower
• Bell tower
• Campanile
• Inclined towers
• List of towers
• Partially guyed tower
• Turret
• Watchtower
• World's tallest structures
• World Federation of Great Towers
• Federal Communications Commission re FCC Broadcasting Tower Database (USA)

Notes

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