Radio masts and towers - AbsoluteAstronomy.com

Radio masts and towers are, typically, tall structures designed to support antenna

Antenna (radio)

An antenna is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver...

s (also known as aerials) for telecommunication

Telecommunication

Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...

s and broadcasting

Broadcasting

Broadcasting is the distribution of audio and video content to a dispersed audience via any audio visual medium. Receiving parties may include the general public or a relatively large subset of thereof...

, including television

Television

Television is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...

. They are among the tallest man-made structures. Similar structures include electricity pylon

Electricity pylon

A transmission tower is a tall structure, usually a steel lattice tower, used to support an overhead power line. They are used in high-voltage AC and DC systems, and come in a wide variety of shapes and sizes...

s and towers for wind turbine

Wind turbine

A wind turbine is a device that converts kinetic energy from the wind into mechanical energy. If the mechanical energy is used to produce electricity, the device may be called a wind generator or wind charger. If the mechanical energy is used to drive machinery, such as for grinding grain or...

s.

Masts are sometimes named after the broadcasting organisations that use them, or after a nearby city or town.

The Warsaw Radio Mast

Warsaw radio mast

The Warsaw radio mast was the world's tallest structure until its collapse on 8 August 1991. It is the second tallest land-based structure ever built, being surpassed as tallest by the Burj Khalifa, completed in 2010....

was the world's tallest supported structure on land, but it collapsed on August 8, 1991, leaving the KVLY/KTHI-TV mast as the tallest.

In the case of a mast radiator

Mast radiator

A mast radiator is a radio mast or tower in which the whole structure itself functions as an antenna. This design is commonly used for transmitting antennas operating at low frequencies, in the VLF, LF and MF ranges, in particular those used for AM broadcasting. The metal mast is electrically...

or radiating tower, the whole mast or tower is itself the transmitting antenna.

Mast or tower?

The terms "mast" and "tower" are often used interchangeably. However, in structural engineering terms, a tower is a self-supporting or cantilever

Cantilever

A cantilever is a beam anchored at only one end. The beam carries the load to the support where it is resisted by moment and shear stress. Cantilever construction allows for overhanging structures without external bracing. Cantilevers can also be constructed with trusses or slabs.This is in...

ed structure, while a mast is held up by stays or guys

Guy-wire

A guy-wire or guy-rope, also known as simply a guy, is a tensioned cable designed to add stability to structures . One end of the cable is attached to the structure, and the other is anchored to the ground at a distance from the structure's base...

. 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 tower

Additionally guyed tower

An additionally guyed tower is a free-standing tower, which is also additionally guyed.An additional guying can be temporarily or permanently. Temporarily additional guying is used when work on static relevant parts of the tower is done....

s. For example:

The Gerbrandy tower
Gerbrandy Tower
The Gerbrandy Tower is a tower which was built in 1961 in the Netherlands.-Description:It is situated in IJsselstein. The Gerbrandy Tower is used for directional radio services and for FM- and TV-broadcasting. The Gerbrandy Tower consists of a concrete tower with a height of 100 meters on which a...

consists of a self-supporting tower with a guyed mast on top.
The few remaining Blaw-Knox tower
Blaw-Knox Tower
The Blaw-Knox company was a manufacturer of steel structures and construction equipment based in Pittsburgh, Pennsylvania. The company is today best known for its radio towers, most of which were constructed during the 1930s in the United States...

s do the opposite: they have a guyed lower section surmounted by a freestanding part.
Zendstation Smilde
Zendstation Smilde
Zendstation Smilde is a tall, guyed structure similar to the Gerbrandy Tower, built in Hoogersmilde, the Netherlands in 1959 for directional radio services and TV and FM-transmissions. It consists of an 80 metre high reinforced concrete tower and had until a fire accident on July 15, 2011, a guyed...

, a tall tower with a guyed mast on top (guys go to ground)
Torre de Collserola
Torre de Collserola
Torre de Collserola is a uniquely designed tower located on the Tibidabo hill in the Serra de Collserola, in Barcelona, Catalonia, Spain. It was designed by architect Sir Norman Foster, and built in 1991 for the 1992 Summer Olympics. It features a pod for floor space like many towers but uses...

, a guyed tower with a guyed mast on top (tower portion is not free-standing)

Steel lattice

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.

When built as a stayed mast, usually the whole mast is parallel-sided. One exception is the Blaw-Knox

Blaw-Knox Tower

The Blaw-Knox company was a manufacturer of steel structures and construction equipment based in Pittsburgh, Pennsylvania. The company is today best known for its radio towers, most of which were constructed during the 1930s in the United States...

type.

When built as a tower, the structure may be parallel-sided or taper over part or all of its height. When constructed of several sections which taper exponentially with height, in the manner of the Eiffel Tower

Eiffel Tower

The Eiffel Tower is a puddle iron lattice tower located on the Champ de Mars in Paris. Built in 1889, it has become both a global icon of France and one of the most recognizable structures in the world...

, the tower is said to be an Eiffelized one. The Crystal Palace tower in London

London

London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...

is an example.

Tubular steel

Guyed masts are sometimes also constructed out of steel tubes. This construction type has the advantage that cables and other components can be protected from weather inside the tube and the structure may look more clean.
These masts are mainly used for FM-/TV-broadcasting, but sometimes also as mast radiator. The big mast of Mühlacker transmitting station is a good example of this.
A disadvantage of this mast type is that it is much more affected by winds than masts with open bodies. Several tubular guyed masts have collapsed. In the UK, the Emley Moor and Waltham

Waltham transmitting station

The Waltham transmitting station is a broadcasting and telecommunications facilityat Waltham-on-the-Wolds, 5 miles north-east of Melton Mowbray. It sits inside the Waltham civil parish near Stonesby, in the district of Melton, Leicestershire, UK. It has a guyed steel tubular mast...

TV stations masts collapsed in the 1960s. In Germany the Bielstein transmitter

Sender Bielstein

The Sender Bielstein is an FM- and TV-broadcasting facility on the 393 metre high Bielstein mountain in the Forest of Teutoburg, North Rhine-Westphalia, Germany. Bielstein transmitter, which is property of WDR and used for transmitting its programmes was established in 1951. It used until 1954 a...

collapsed in 1985.
Tubular masts were not built in all countries. In Germany, France, UK, Czech, Slovakia and the former Soviet Union, many tubular guyed masts were built, while there are nearly none in Poland or North America.

In several cities in Russia and Ukraine several tubular guyed masts with crossbars running from the mast structure to the guys were built in the 1960's. All these masts are exclusively used for FM and TV transmission and, except for the mast in Vinnytsia

TV Tower Vinnytsia

The TV Tower Vinnytsia is a 354 metre high guyed steel tube mast used for FM- and TV-transmission, located in Ukraine. A special feature of its structure are three crossbars arranged in 120 degree angles in two levels, running from its structure to the guys.TV Tower Vinnytsia is not the only...

, are between 150 and 200 metres tall.
The crossbars of these masts are equipped with a gangway that holds smaller antennas, though their main purpose is oscillation damping.

Reinforced concrete

Reinforced concrete towers are relatively expensive to build but provide a high degree of mechanical rigidity in strong winds. This can be important when antennas with narrow beamwidths are used, such as those used for microwave point-to-point links, and when the structure is to be occupied by people.

In the 1950s, AT&T built numerous concrete towers, more resembling silos than towers, for its first transcontinental microwave route. Many are still in use today.

In Germany

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

and the Netherlands

Netherlands

The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

most towers constructed for point-to-point microwave links are built of reinforced concrete

Reinforced concrete

Reinforced concrete is concrete in which reinforcement bars , reinforcement grids, plates or fibers have been incorporated to strengthen the concrete in tension. It was invented by French gardener Joseph Monier in 1849 and patented in 1867. The term Ferro Concrete refers only to concrete that is...

, while in the UK

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

most are lattice tower

Lattice tower

A lattice tower or truss tower is a freestanding framework tower. They can be used as electricity pylons especially for voltages above 100 kilovolts, as a radio tower or as an observation tower....

s.

Concrete towers can form prestigious landmarks, such as the CN Tower

CN Tower

The CN Tower is a communications and observation tower in Downtown Toronto, Ontario, Canada. Standing tall, it was completed in 1976, becoming the world's tallest free-standing structure and world's tallest tower at the time. It held both records for 34 years until the completion of the Burj...

in Toronto

Toronto

Toronto is the provincial capital of Ontario and the largest city in Canada. It is located in Southern Ontario on the northwestern shore of Lake Ontario. A relatively modern city, Toronto's history dates back to the late-18th century, when its land was first purchased by the British monarchy from...

. As well as accommodating technical staff, these buildings may have public areas such as observation decks or restaurants.

The Stuttgart TV tower

Fernsehturm Stuttgart

The Fernsehturm Stuttgart is the world's first TV tower built from concrete ....

was the first tower in the world to be built in reinforced concrete. It was designed in 1956 by the local civil engineer Fritz Leonhardt

Fritz Leonhardt

Fritz Leonhardt was a German structural engineer who made major contributions to 20th century bridge engineering, especially in the development of cable-stayed bridges...

Fibreglass

Fibreglass poles are occasionally used for low-power non-directional beacons or medium-wave broadcast transmitters.

Wood

There are fewer wooden towers now than in the past. Many were built in the UK during World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

because of a shortage of steel. In Germany before World War II wooden towers were used at nearly all medium-wave transmission sites, but all of these towers have since been demolished, except for the Gliwice Radio Tower

Gliwice Radio Tower

The Gliwice Radio Tower is a transmission tower in the Szobiszowice district of Gliwice, Upper Silesia, Poland.-Structure:It is an high construction of impregnated larch wood framework and bronze connectors. The tower was nicknamed "the Silesian Eiffel Tower" by the local population, although the...

.

Ferryside Relay

Ferryside Relay

Ferryside Relay is a small TV relay in the village of Ferryside, Carmarthenshire, Wales . Ferryside Relay is one of the few broadcasting transmitters using a wooden pole as aerial tower.- Digital switchover :...

is an example of a TV relay transmitter using a wooden pole.

Poles

Shorter masts may consist of a self-supporting or guyed wooden pole, similar to a telegraph pole. Sometimes self-supporting tubular galvanized steel poles are used: these may be termed monopole

Monopole

Monopole may refer to:*Magnetic monopole, or Dirac monopole, a hypothetical particle that may be loosely described as a magnet with only one pole, or related concepts in physics and mathematics:...

Buildings

In some cases, it is possible to install transmitting antennas on the roofs of tall buildings. In North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

, for instance, there are transmitting antennas on the Empire State Building

Empire State Building

The Empire State Building is a 102-story landmark skyscraper and American cultural icon in New York City at the intersection of Fifth Avenue and West 34th Street. It has a roof height of 1,250 feet , and with its antenna spire included, it stands a total of 1,454 ft high. Its name is derived...

, the Willis Tower ,and formerly on the World Trade Center

World Trade Center

The original World Trade Center was a complex with seven buildings featuring landmark twin towers in Lower Manhattan, New York City, United States. The complex opened on April 4, 1973, and was destroyed in 2001 during the September 11 attacks. The site is currently being rebuilt with five new...

towers. When the buildings collapsed, several local TV and radio stations were knocked off the air until backup transmitters could be put into service. Such facilities also exist in Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

, particularly for portable radio services and low-power FM

Frequency modulation

In telecommunications and signal processing, frequency modulation conveys information over a carrier wave by varying its instantaneous frequency. This contrasts with amplitude modulation, in which the amplitude of the carrier is varied while its frequency remains constant...

radio stations. In London

London

, the BBC

BBC

The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff...

erected in 1936 a mast for broadcasting early television on one of the towers of a Victorian building, the Alexandra Palace

Alexandra Palace

Alexandra Palace is a building in North London, England. It stands in Alexandra Park, in an area between Hornsey, Muswell Hill and Wood Green...

. It is still in use.

Disguised cell-sites

Many people view bare cellphone towers as ugly and an intrusion into their neighbourhoods. Even though people increasingly depend upon cellular communications, they are opposed to the bare towers spoiling otherwise scenic views. Many companies offer to 'hide' cellphone towers in, or as, trees, church towers, flag poles, water tanks and other features. There are many providers that offer these services as part of the normal tower installation and maintenance service. These are generally called "stealth towers" or "stealth installations", or simply concealed cell sites.

The level of detail and realism achieved by disguised cellphone towers is remarkably high; for example, such towers disguised as trees are nearly indistinguishable from the real thing, even for local wildlife (who additionally benefit from the artificial flora). Such towers can be placed unobtrusively in national parks and other such protected places, such as towers disguised as cacti

Cactus

A cactus is a member of the plant family Cactaceae. Their distinctive appearance is a result of adaptations to conserve water in dry and/or hot environments. In most species, the stem has evolved to become photosynthetic and succulent, while the leaves have evolved into spines...

in Coronado National Forest

Coronado National Forest

The Coronado National Forest includes an area of about 1.78 million acres spread throughout mountain ranges in southeastern Arizona and southwestern New Mexico....

.

Even when disguised, however, such towers can create controversy; a tower doubling as a flagpole attracted controversy in 2004 in relation to the U.S. Presidential campaign of that year, and highlighted the sentiment that such disguises serve more to allow the installation of such towers in subterfuge away from public scrutiny rather than to serve towards the beautification of the landscape.

Disguised cell sites sometimes can be introduced into environments that require a low-impact visual outcome, by being made to look like trees, chimneys or other common structures.

Mast radiators

A mast radiator is a radio tower or mast in which the whole structure works as an antenna. It is used frequently as a transmitting antenna for long or medium wave broadcasting.

Structurally, the only difference is that a mast radiator may be supported on an insulator at its base. In the case of a tower, there will be one insulator supporting each leg.

Telescopic, pump-up and tiltover towers

A special form of the radio tower is the telescopic mast. These can be erected very quickly. Telescopic masts are used predominantly in setting up temporary radio links for reporting on major news events, and for temporary communications in emergencies. They are also used in tactical military networks. They can save money by needing to withstand high winds only when raised, and as such are widely used in amateur radio

Amateur radio

Amateur radio is the use of designated radio frequency spectrum for purposes of private recreation, non-commercial exchange of messages, wireless experimentation, self-training, and emergency communication...

.

Telescopic masts consist of two or more concentric sections and come in two principal types:

Pump-up masts are often used on vehicles, and are raised to their full height pneumatically or hydraulically. They are usually only strong enough to support fairly small antennas.
Telescopic lattice masts are raised by means of a winch, which may be powered by hand or an electric motor. These tend to cater for greater heights and loads than the pump-up type. When retracted, the whole assembly can sometimes be lowered to a horizontal position by means of a second tiltover winch. This enables antennas to be fitted and adjusted at ground level before winching the mast up.

Balloons and kites

A tethered balloon

Balloon

A balloon is an inflatable flexible bag filled with a gas, such as helium, hydrogen, nitrous oxide, oxygen, or air. Modern balloons can be made from materials such as rubber, latex, polychloroprene, or a nylon fabric, while some early balloons were made of dried animal bladders, such as the pig...

or a kite can serve as a temporary support. It can carry an antenna or a wire (for VLF, LW or MW) up to an appropriate height. Such an arrangement is used occasionally by military agencies or radio amateurs. The American broadcasters TV Martí

TV Martí

TV Martí was created by the US government to provide news and current affairs programming to Cuba. It is named after Cuban independence leader José Martí, and is the television equivalent to Radio Marti.-History:...

broadcast a television program to Cuba

Cuba

The Republic of Cuba is an island nation in the Caribbean. The nation of Cuba consists of the main island of Cuba, the Isla de la Juventud, and several archipelagos. Havana is the largest city in Cuba and the country's capital. Santiago de Cuba is the second largest city...

by means of such a balloon.

Other special structures

For two VLF

Very low frequency

225px|thumb|right|A VLF receiving antenna at [[Palmer Station]], Antarctica, operated by Stanford UniversityVery low frequency or VLF refers to radio frequencies in the range of 3 kHz to 30 kHz. Since there is not much bandwidth in this band of the radio spectrum, only the very simplest signals...

transmitters wire antennas spun across deep valleys are used. The wires are supported by small masts or towers or rock anchors. See List of spans: Antenna spans across valleys. The same technique was also used at Criggion radio station.

For ELF transmitters ground dipole

Ground dipole

A Ground dipole, or Ground antenna, is a special type of antenna which consists of two electrodes positioned in the ground.Ground dipole antennas are usually used for transmitting and receiving on the ELF and VLF bands. The antenna consists of two electrodes, planted in the ground at some distance...

antennas are used. Such structures require no tall masts. They consist of two electrodes buried deep in the ground at least a few dozen kilometres apart. 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.

Economic and aesthetic considerations

The cost of a mast or tower is roughly proportional to the square of its height.
A guyed mast is cheaper to build than a self-supporting tower of equal height.
A guyed mast needs additional land to accommodate the guys, and is thus best suited to rural locations where land is relatively cheap. An unguyed tower will fit into a much smaller plot.
A steel lattice tower is cheaper to build than a concrete tower of equal height.
Two small towers may be less intrusive, visually, than one big one, especially if they look identical.
Towers look less ugly if they and the antennas mounted on them appear symmetrical.
Concrete towers can be built with aesthetic design - and they are, especially in Continental Europe. They are sometimes built in prominent places and include observation decks or restaurants.

Masts for HF/shortwave antennas

For transmissions in the shortwave

Shortwave

Shortwave radio refers to the upper MF and all of the HF portion of the radio spectrum, between 1,800–30,000 kHz. Shortwave radio received its name because the wavelengths in this band are shorter than 200 m which marked the original upper limit of the medium frequency band first used...

range, there is little to be gained by raising the antenna more than a few wavelength

Wavelength

In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...

s above ground level. Shortwave transmitters rarely use masts taller than about 100 metres.

Access for riggers

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

Ladder

A ladder is a vertical or inclined set of rungs or steps. There are two types: rigid ladders that can be leaned against a vertical surface such as a wall, and rope ladders that are hung from the top. The vertical members of a rigid ladder are called stringers or stiles . Rigid ladders are usually...

. Larger structures, which tend to require more frequent maintenance, may have stairs and sometimes a lift, also called a service elevator.

Aircraft warning features

Tall structures in excess of certain legislated heights are often equipped with aircraft warning lamps

Aircraft warning lights

Aircraft warning lights are high-intensity lighting devices that are attached to tall structures and are used as collision avoidance measures. Such devices make structures more visible to passing aircraft and are usually used at night, although they may be used during the day as well...

, 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

Light-emitting diode

A light-emitting diode is a semiconductor light source. LEDs are used as indicator lamps in many devices and are increasingly used for other lighting...

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.

Light pollution and nuisance lighting

In some countries where light pollution

Light pollution

Light pollution, also known as photopollution or luminous pollution, is excessive or obtrusive artificial light.The International Dark-Sky Association defines light pollution as:...

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 1996 Telecommunications Act allows local jurisdictions to set maximum heights for towers, such as limiting tower height to below 200 feet and therefore not requiring aircraft illumination under U.S. Federal Communications Commission

Federal Communications Commission

The Federal Communications Commission is an independent agency of the United States government, created, Congressional statute , and with the majority of its commissioners appointed by the current President. The FCC works towards six goals in the areas of broadband, competition, the spectrum, the...

(FCC) rules. The limit is more commonly set to 190 or 180 feet to allow for masts extending above the tower.

Wind-induced oscillations

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

VLF transmitter DHO38

The VLF transmitter DHO38 is a VLF transmitter used by the German Navy near Rhauderfehn, Saterland, Germany. It is used to transmit coded orders to submarines of the German Navy and navies of other NATO countries....

in Saterland

Saterland

Saterland is a municipality in the district of Cloppenburg, in Lower Saxony, Germany. It is situated between the cities of Leer, Cloppenburg, and Oldenburg...

. There are also constructions, which consist of a free-standing tower (usually from reinforced concrete

Reinforced concrete

), onto which a guyed radio mast is installed. The best known such construction is the Gerbrandy Tower

Gerbrandy Tower

The Gerbrandy Tower is a tower which was built in 1961 in the Netherlands.-Description:It is situated in IJsselstein. The Gerbrandy Tower is used for directional radio services and for FM- and TV-broadcasting. The Gerbrandy Tower consists of a concrete tower with a height of 100 meters on which a...

in Lopik

Lopik

Lopik is a municipality and a town in the Netherlands, in the province of Utrecht.In the Netherlands, 'Lopik' is often used as a reference to the broadcasting facilities located in the eastern part of the municipality and in neighbouring IJsselstein...

(the Netherlands

Netherlands

). Further towers of this building method can be found near Smilde

Zendstation Smilde

Zendstation Smilde is a tall, guyed structure similar to the Gerbrandy Tower, built in Hoogersmilde, the Netherlands in 1959 for directional radio services and TV and FM-transmissions. It consists of an 80 metre high reinforced concrete tower and had until a fire accident on July 15, 2011, a guyed...

(the Netherlands) and Fernsehturm, Waldenburg, Baden-Württemberg

Waldenburg, Baden-Württemberg

Waldenburg is a hilltop town in south central Germany, eastwards of Heilbronn in the Hohenlohe of Baden-Württemberg. The town is the site of Waldenburg Castle and some hilltop churches...

, Germany

Germany

Hazard to birds

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.

Law

Since June 2010, 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.

Additional reading

Sreevidya, S., and Subramanian, N., Aesthetic Appraisal to Antenna Towers, Journal of Architectural Engineering, American Society of Civil Engineers, Vol. 9, No. 3, September 2003, pp. 102–108

External links

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.

Mast or tower?

Steel lattice

Tubular steel

Reinforced concrete

Fibreglass

Wood

Poles

Buildings

Disguised cell-sites

Mast radiators

Telescopic, pump-up and tiltover towers

Balloons and kites

Other special structures

Economic and aesthetic considerations

Masts for HF/shortwave antennas

Access for riggers

Aircraft warning features

Light pollution and nuisance lighting

Wind-induced oscillations

Hazard to birds

Law

See also

Additional reading

External links