When there is less land available, towers tend to be used because they can stand on their own. Steel lattice is inexpensive, strong, light and wind resistant. Lattices can be square or triangular, and their advantages make them commonly used on cell sites. From the transmitter building to the electrodes, overhead feeder lines run. These lines look like power lines of the 10 kV level, and are installed on similar pylons.
For transmissions in the shortwave range, there is little to be gained by raising the antenna more than a few wavelengths above ground level. Shortwave transmitters rarely use masts taller than about metres. Because masts, towers and the antennas mounted on them require maintenance, access to the whole of the structure is necessary.
Small structures are typically accessed with a ladder. Larger structures, which tend to require more frequent maintenance, may have stairs and sometimes a lift, also called a service elevator. Tall structures in excess of certain legislated heights are often equipped with aircraft warning lamps , usually red, to warn pilots of the structure's existence. In the past, ruggedized and under-run filament lamps were used to maximize the bulb life. Alternatively, neon lamps were used.
Nowadays such lamps tend to use LED arrays. Height requirements vary across states and countries, and may include additional rules such as requiring a white flashing strobe in the daytime and pulsating red fixtures at night.
Structures over a certain height may also be required to be painted with contrasting color schemes such as white and orange or white and red to make them more visible against the sky. In some countries where light pollution is a concern, tower heights may be restricted so as to reduce or eliminate the need for aircraft warning lights.
For example in the United States the Telecommunications Act allows local jurisdictions to set maximum heights for towers, such as limiting tower height to below feet and therefore not requiring aircraft illumination under U. The limit is more commonly set to or feet to allow for masts extending above the tower. One problem with radio masts is the danger of wind-induced oscillations.
This is particularly a concern with steel tube construction. One can reduce this by building cylindrical shock-mounts into the construction. One finds such shock-mounts, which look like cylinders thicker than the mast, for example, at the radio masts of DHO38 in Saterland.
There are also constructions, which consist of a free-standing tower usually from reinforced concrete , onto which a guyed radio mast is installed. The best known such construction is the Gerbrandy Tower in Lopik the Netherlands. Radio, television and cell towers have been documented to pose a hazard to birds. Reports have been issued documenting known bird fatalities and calling for research to find ways to minimize the hazard that communications towers can pose to birds.
Since June , Telecom operators in the USA can erect new telecom masts or towers as the government has lifted the moratorium, which was earlier placed on the issuance of permits for the construction of telecommunication towers. Wikimedia Foundation. List of catastrophic collapses of radio masts and towers — This is a list of catastrophic collapses of radio masts and towers. Arranged by dateMasts and towers can collapse as a result of natural disasters, such as storms and fires; from engineering defects; and from accidents or sabotage.
Here is a list… … Wikipedia. Telecommunications towers in the United Kingdom — The two major operators of radio masts and towers in the UK are Arqiva and National Grid Wireless according to Arqiva entry they have now merged. Antenna radio — Whip antenna on car … Wikipedia. New Zealand masts — and Towers range in size from short flagpoles to high radio transmitter antenna structures. Once in years a verticality check is suggested done by land surveyor. As gound under the towers settles unevenly the whole tower may change its centre of gravity.
This can be changed with correction rings. In case of steel constructions a anti-corrosion checek must be conducted, and any stained spots must be repaired. During u-bolts change and other metal on metal components as well we shall take under consideration electrochemical potential of used materials.
High difference here may lead to amazingly quick corrosion that may be dangerous for the structure rigidity. Main difference between towers and masts is comfort of use and amount of space needed for installation. There is an economy to consider as well. In general towers are more expensive than masts at the same height, but take up much more space. Some other factor is service cost. Masts need much more attention — frequent servicing is advised, guy wires tension must be regulated, u-bolts changed, and finally if something goes really bad — the chance is that mast will fall down.
Towers are less human dependent. Mast as a verb agriculture, forestry, ecology, of a population of plants :. A very tall iron-framed structure, usually painted red and white, on which microwave, radio, satellite, or other communication antennas are installed; mast. A similarly framed structure with a platform or enclosed area on top, used as a lookout for spotting fires, plane crashes, fugitives, etc. Tower as a verb obsolete, transitive :.
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