Communications tower

Radio masts and towers are, typically, tall structures designed to support antennas (also known as aerials) for telecommunications and broadcasting, including television. There are two main types: guyed and self supporting structures. They are among the tallest man-made structures.

Masts are often named after the broadcasting organizations that originally built them or currently use them.

In the case of a mast radiator or radiating tower, the whole mast or tower is itself the transmitting antenna.

The terms "mast" and "tower" are often used interchangeably. However, in structural engineering terms, a tower is a self-supporting or cantilevered structure, while a mast is held up by stays or guys. Broadcast engineers in the UK use the same terminology. In US broadcast engineering, a tower is an antenna structure attached to the ground, whereas a mast is a vertical antenna support mounted on some other structure (which itself may be a tower, a building, or a vehicle). Masts (to use the civil engineering terminology) tend to be cheaper to build but require an extended area surrounding them to accommodate the guy wires. Towers are more commonly used in cities where land is in short supply.

There are a few borderline designs that are partly free-standing and partly guyed, called additionally guyed towers. For example:

Experimental radio broadcasting began in 1905, and commercial radio broke through in the 1920s.

Until August 8, 1991, the Warsaw radio mast was the world's tallest supported structure on land; its collapse left the KVLY/KTHI-TV mast as the tallest. There are over 50 radio structures in the United States that are 600 m (1968.5 ft) or taller.

The steel lattice is the most widespread form of construction. It provides great strength, low weight and wind resistance, and economy in the use of materials. Lattices of triangular cross-section are most common, and square lattices are also widely used. Guyed masts are often used; the supporting guy lines carry lateral forces such as wind loads, allowing the mast to be very narrow and simply constructed.

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