Tower

tallest tower in the world

A tower is a tall

guy-wires

and are therefore, along with tall buildings, self-supporting structures.

Towers are specifically distinguished from

telecommunication

purposes. A tower can stand alone or be supported by adjacent buildings, or it may be a feature on top of a larger structure or building.

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

Etruscans

(Kretschmer Glotta 22, 110ff.)

History

Towers have been used by humankind since prehistoric times. The oldest known may be the circular stone tower in walls of

Babylonian architecture

.

Some of the earliest surviving examples are the

castles

.

Other well known towers include the

Himalayan Towers are stone towers located chiefly in Tibet

built approximately 14th to 15th century. [2]

Mechanics

Up to a certain height, a tower can be made with the supporting structure with parallel sides. However, above a certain height, the compressive load of the material is exceeded, and the tower will fail. This can be avoided if the tower's support structure tapers up the building.

A second limit is that of buckling—the structure requires sufficient stiffness to avoid breaking under the loads it faces, especially those due to winds. Many very tall towers have their support structures at the periphery of the building, which greatly increases the overall stiffness.

A third limit is dynamic; a tower is subject to varying winds, vortex shedding, seismic disturbances etc. These are often dealt with through a combination of simple strength and stiffness, as well as in some cases tuned mass dampers to damp out movements. Varying or tapering the outer aspect of the tower with height avoids vibrations due to vortex shedding occurring along the entire building simultaneously.

Functions

Although not correctly defined as towers, many modern

Petronas Twin Towers in Kuala Lumpur. In addition some of the structures listed below do not follow the strict criteria used at List of tallest towers

.

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 constructed on

defensive walls, or rolled near a target (see siege tower

). Today, strategic-use towers are still used at prisons, military camps, and defensive perimeters.

Potential energy

By using gravity to move objects or substances downward, a tower can be used to store items or liquids like 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

Toronto, Ontario

, Canada was built as a communications tower, with the capability to act as both a transmitter and repeater.

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.

Control towers

are used to give visibility to help direct aviation traffic.

Other

To access tall or high objects:
tower crane
To access atmospheric conditions aloft:
tower telescope, solar power
station

To lift high tension cables for electrical power distribution transmission tower
To take advantage of the temperature gradient inherent in a height differential: cooling tower
To expel and disperse potentially harmful gases and particulates into the atmosphere: chimney
To protect from exposure:
lightning rod tower
For industrial production: shot tower
For surveying: Survey tower
To drop objects: Drop tube (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:
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.

Gallery

The Galata Tower, also called Christea Turris (the Tower of Christ in Latin), was built in 1348 A.D. by the Genoese colony in Constantinople.
Typical modern water tower in Carmel, Indiana, United States
Näsinneula, an observation tower in Tampere, Finland, at night
Watchtower in the Israeli West Bank barrier
The only bridge being a member of the World Federation of Great Towers: Most SNP, Bratislava, Slovakia
Medieval military towers from Ingushetia, Caucasus Mountains
Lifeguard tower, Asprovalta (Greece)
The towers of wind turbines support the rotors.
White Tower (Brixen)-Italy built in 1591
Some of the Towers of Pavia, 11th-13th century
The Aulanko Tower at the Aulanko Nature Reserve in Hämeenlinna, Finland
Rassef Islamic tower, Almussafes

References

^ Map, The Megalithic Portal and Megalith. "Diocletian's Palace". The Megalithic Portal.
^ Dana Thomas, "Towers to the Heavens", Newsweek, 2003-11-15

External links

[1] Map, The Megalithic Portal and Megalith. "Diocletian's Palace". The Megalithic Portal.

[2] Dana Thomas, "Towers to the Heavens", Newsweek, 2003-11-15

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