A guyed mast is a tall thin vertical

structure A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as ...

that depends on guy lines (diagonal tensioned cables attached to the ground or a base) for stability. The mast itself has the compressive strength to support its own weight, but does not have the

shear strength In engineering, shear strength is the strength of a material or component against the type of yield or structural failure when the material or component fails in shear. A shear load is a force that tends to produce a sliding failure on a mater ...

to stand unsupported or bear loads. It requires guy lines to stay upright and to resist lateral (shear) forces such as

wind load Wind engineering is a subset of mechanical engineering, structural engineering, meteorology, and applied physics that analyzes the effects of wind in the natural and the built environment and studies the possible damage, inconvenience or benefit ...

s. Examples include masts on sailing vessels, towers for telecommunications, meteorology, and masts on cranes, power shovels, draglines, and derricks, starting with the simple

gin pole A gin pole is a pivoting guyed_mast, mast supported by one or more guy-wires that uses a pulley or block and tackle mounted on its upper end to lift loads. The lower end is braced or set in a shallow hole and positioned so the upper end lie ...

Applications

The principal applications of guyed masts are the masts of sailing vessels, guyed towers, and as the main tower of heavy equipment such as cranes,

power shovel A power shovel, also known as a motor shovel, stripping shovel, front shovel, mining shovel or rope shovel, is a bucket-equipped machine usually powered by steam, diesel fuel, gasoline or electricity and used for digging and loading earth or frag ...

dragline A dragline excavator is a heavy-duty excavator used in civil engineering and surface mining. It was invented in 1904, and presented an immediate challenge to the steam shovel and its diesel and electric powered descendant, the power shovel. ...

s, and

derrick A derrick is a lifting device composed at minimum of one guyed mast, as in a gin pole, which may be articulated over a load by adjusting its Guy-wire, guys. Most derricks have at least two components, either a guyed mast or self-supporting tower ...

s, the simplest of which is the

. Guyed masts are frequently used for

radio masts and towers Radio masts and towers are typically tall structures designed to support antenna (radio), antennas for telecommunications and broadcasting, including television. There are two main types: guyed and self-supporting structures. They are among the ...

. The mast can either support radio antennas (for VHF,

UHF Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter ...

and other microwave bands) mounted at its top, or the entire structure itself can function as a

mast radiator A mast radiator (or radiating tower) is a radio mast or tower in which the metal structure itself is energized and functions as an antenna. This design, first used widely in the 1930s, is commonly used for transmitting antennas operating at l ...

antenna (for

VLF Very low frequency or VLF is the ITU designation for radio frequencies (RF) in the range of 3–30 kHz, corresponding to wavelengths from 100 to 10 km, respectively. The band is also known as the myriameter band or myriameter wave ...

, LF, MF). In the latter case, the mast needs to be insulated from the ground. Guyed radio masts are typically tall enough that they require several sets of guy lines, 2 to 4, attached at different heights on the mast, to prevent them from buckling. An exception to multiple guys was the

Blaw-Knox tower The Blaw-Knox company was an American 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 Un ...

, widely used during the 1930s, whose distinctive wide diamond ( rhomboidal) shape gave it the shear strength that it only required one set of guys. Guyed masts are sometimes also used for measurement towers, to collect meteorological measurements at certain heights above ground level. Sometimes they are used as pylons (transmission towers), although their usage in agricultural areas is problematic because anchor foundations handicap ploughing. The tallest guyed tower is currently the KRDK-TV mast in

Traill County, North Dakota Traill County is a County (United States), county in the U.S. state of North Dakota. As of the 2020 United States census, 2020 census, the population at 7,997, and was estimated to be 7,989 in 2024. The county seat is Hillsboro, North Dakota, H ...

, USA. The mast on heavy equipment such as a crane is its main supporting tower, typically of trussed steel construction. Wire rope guys typically led back to the crane's base stabilize it and support its ability to bear significant shear loads while lifting. File:Schema-greement-TETE.png, A sailboat's mast is supported by shrouds and stays - nautical equivalents of guy wires File:Jauerling - Sender (1).JPG, The Sendeturm Jauerling is a partially guyed 141 meter tower built in 1958, consisting of a 35-metre-high free-standing steel framework tower, which carries a 106 meter guyed steel tube mast on the top File:Trispastos scheme.svg, The '' Trispastos'' ("three-pulley-crane") is a simple guyed mast form of crane that dates to Greco-Roman times

Partially guyed tower

A partially guyed tower is a tower structure which consists of a free-standing base, in most cases of concrete or of lattice steel, with a guyed mast on the top. The anchor base of the guyed mast can be on the top of the tower or on the ground.

Use

Partially guyed towers are typically used when a very high tower for FM and TV transmission is required, while also carrying antennas for directional radio services at a much lower height. In such cases the antennas for directional radio services are mounted on the top of the free-standing part of the tower, while the guyed mast on its top carry the FM and TV antennas. They can be also used in order to upgrade small stable towers (like watertowers) with a long antenna mast for FM and TV broadcasting. However their use is rare, and they exist chiefly in certain European countries. Note that

s which stand atop an antenna tuning hut ( helix building) are not considered partially guyed towers, because the hut is much smaller than the mast radiator. Such constructions include the Mühlacker radio transmitter and the Ismaning radio transmitter.

Anchor placements

Partially guyed towers can be divided into two types, depending on the placement of the guy anchors.

Atop the free-standing tower

Guyed masts on skyscrapers or wider towers are often guyed on the roof of the free-standing basement structure. In such cases, there is no major constructive difference of the guyed mast to a guyed mast on plain ground, and the construction of the free-standing basement tower does not differ much from a tower of the same height without a mast. The guyed mast of such constructions is usually of lesser height than basement tower.

On the ground

Partially guyed towers in which at least one basement of the guy anchors is on the ground are more rare. The placement of guy basements across a broader geometric base allows for a mast much taller than the free-standing basement tower, and the integration of tower and mast should be considered in all facets of construction and maintenance.

Gallery

File:KBRC antenna tower guy wires.JPG, 200 foot (61 m) radio mast of an AM radio station in

Mount Vernon, Washington Mount Vernon is the county seat of and the most populous city in Skagit County, Washington, United States. A central location in the Skagit River Valley, the city is located south of the U.S.–Canada border and north of Seattle. The popul ...

, USA, supported by three sets of 120° guy lines File:Guyed mast cable.JPG, Mast guy line File:Guyed mast anchor.JPG, Guyed mast guy line anchor File:North hessary building.jpg, Guyed mast transmitter building File:Brown Road Tower.jpg, A guyed FM and TV radio mast in Christmas, FL. It is tall.

References

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