Guy-wire in the context of "Earth anchor"

A guyed mast is a tall thin vertical structure 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 to stand unsupported or bear loads. It requires guy lines to stay upright and to resist lateral (shear) forces such as wind loads. 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 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 guys. Most derricks have at least two components, either a guyed mast or self-supporting tower, and a boom hinged at its base to provide articulation, as in a stiffleg derrick. The most basic type of derrick is controlled by three or four lines connected to the top of the mast, which allow it to both move laterally and cant up and down. To lift a load, a separate line runs up and over the mast with a hook on its free end, as with a crane.

Derricks are especially useful for high-rise rigging, jobs that cover a long period of time, or jobs when the impact to street or pedestrian traffic is a concern. Forms of derricks are commonly found aboard ships and at docking facilities. Large derricks mounted on dedicated vessels are known as floating derricks and shearlegs.

A gin pole is a pivoting 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 lies above the object to be lifted. The pole (also known as a mast, boom, or spar) is secured with three or more guys. These are manipulated to move the load laterally, with up and down controlled by the pulley or block. In tower construction, a gin pole can also be “jumped” up the completed sections of a tower to lift the higher sections into place.