A gin pole is a pivoting mast supported by one or more

guy-wire A guy-wire, guy-line, guy-rope, down guy, or stay, also called simply a guy, is a tensioned cable designed to add stability to a freestanding structure. They are used commonly for ship masts, radio masts, wind turbines, utility poles, and ten ...

s that uses a

pulley Sheave without a rope A pulley is a wheel on an axle or shaft enabling a taut cable or belt passing over the wheel to move and change direction, or transfer power between itself and a shaft. A pulley may have a groove or grooves between flan ...

block and tackle A block and tackle or only tackle is a system of two or more pulleys with a rope or cable threaded between them, used to provide tension and lift heavy loads. The pulleys are assembled to form blocks and then blocks are paired so that one is ...

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.

Etymology

The gin pole is derived from a

gyn GYN may refer to: * Gyn, a lifting device on sailing ships * Guyanese Creole * Gynaecology Gynaecology or gynecology (see American and British English spelling differences) is the area of medicine concerned with conditions affecting the femal ...

, and considered a form of

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 ...

, called a standing derrick or pole derrick, distinguished from

sheers Shear legs, also known as sheers, shears, or sheer legs, are a form of two-legged lifting device. Shear legs may be permanent, formed of a solid A-frame and supports, as commonly seen on land and the floating sheerleg, or temporary, as aboard a ...

(or ''shear legs'') by having a single boom rather than a two-legged one.

Applications

In addition to being used as simple lifting devices in field operations such as construction, logging, loading and unloading boats, and emergency repairs, gin poles are well suited to raising loads above structures too tall to reach with a crane, such as placing an antenna on top of a tower/steeple, and to lift segments of a tower on top of one another during erection. When used to create a segmented tower, the gin pole can be detached, raised, and re-attached to the just-completed segment in order to lift the next. This process of ''jumping'' is repeated until the topmost portion of the tower is completed. They can also hold a person if strong enough (thus opening stage uses, such as in magic shows). Gin poles are mounted on trucks as a primitive form of mobile crane, used in combination with a typically front-mounted

winch A winch is a mechanical device that is used to pull in (wind up) or let out (wind out) or otherwise adjust the tension (physics), tension of a rope or wire rope (also called "cable" or "wire cable"). In its simplest form, it consists of a Bobb ...

for lifting and relocating loads, and in salvage operations in lieu of a more capable wrecker.

References

External links

Notes & drawings
Tools Cranes (machines) Lifting equipment {{architecture-stub