A turnbuckle, stretching screw or bottlescrew is a device for adjusting the tension or length of

rope A rope is a group of yarns, plies, fibres, or strands that are twisted or braided together into a larger and stronger form. Ropes have tensile strength and so can be used for dragging and lifting. Rope is thicker and stronger than similarl ...

cable Cable may refer to: Mechanical * Nautical cable, an assembly of three or more ropes woven against the weave of the ropes, rendering it virtually waterproof * Wire rope, a type of rope that consists of several strands of metal wire laid into a hel ...

tie rod A tie rod or tie bar (also known as a hanger rod if vertical) is a slender structural unit used as a tie and (in most applications) capable of carrying tensile loads only. It is any rod or bar-shaped structural member designed to prevent the separa ...

s, and other tensioning systems. It normally consists of two threaded eye bolts, one

screw A screw and a bolt (see '' Differentiation between bolt and screw'' below) are similar types of fastener typically made of metal and characterized by a helical ridge, called a ''male thread'' (external thread). Screws and bolts are used to ...

ed into each end of a small metal frame, one with a left-hand thread and the other with a right-hand thread. The

tension Tension may refer to: Science * Psychological stress * Tension (physics), a force related to the stretching of an object (the opposite of compression) * Tension (geology), a stress which stretches rocks in two opposite directions * Voltage or el ...

can be adjusted by rotating the frame, which causes both eye bolts to be screwed in or out simultaneously, without twisting the eye bolts or attached cables.

Uses

Turnbuckles are most commonly used in applications which require a great deal of

; they can range in mass from about ten

gram The gram (originally gramme; SI unit symbol g) is a unit of mass in the International System of Units (SI) equal to one one thousandth of a kilogram. Originally defined as of 1795 as "the absolute weight of a volume of pure water equal to th ...

s for thin cable used in a garden

fence A fence is a structure that encloses an area, typically outdoors, and is usually constructed from posts that are connected by boards, wire, rails or netting. A fence differs from a wall in not having a solid foundation along its whole length. ...

, to thousands of

kilogram The kilogram (also kilogramme) is the unit of mass in the International System of Units (SI), having the unit symbol kg. It is a widely used measure in science, engineering and commerce worldwide, and is often simply called a kilo colloquially. ...

s for structural elements in buildings and

suspension bridge A suspension bridge is a type of bridge in which the deck is hung below suspension cables on vertical suspenders. The first modern examples of this type of bridge were built in the early 1800s. Simple suspension bridges, which lack vertical ...

Aircraft

Turnbuckles have been used in aircraft construction, especially during the early years of aviation. Historically, biplanes might use turnbuckles to adjust the tension on structural wires bracing their wings. Turnbuckles are also widely used on flexible cables in flight control systems. In both cases they are secured with

lockwire Safety wire or locking-wire is a type of '' positive locking device'' that prevents fasteners from falling out due to vibration and other forces. The presence of safety wiring may also serve to indicate that the fasteners have been properly tigh ...

or specifically designed wire clips to prevent them from turning and losing tension due to vibration.

Shipping

Turnbuckles are used for tensioning a ship's

rigging Rigging comprises the system of ropes, cables and chains, which support a sailing ship or sail boat's masts—''standing rigging'', including shrouds and stays—and which adjust the position of the vessel's sails and spars to which they ar ...

and

lashing Lash or Lashing may refer to: * Eyelash * Whiplash (disambiguation) * Lashing (ropework), a form of connecting solid objects tightly using rope or cord * Flagellation, a form of torture or punishment involving a whip * Backlash (engineering), clea ...

s. This device is also known as a bottlescrew in this context.

Sports

Turnbuckles find common use to tension the ropes in

professional A professional is a member of a profession or any person who works in a specified professional activity. The term also describes the standards of education and training that prepare members of the profession with the particular knowledge and sk ...

wrestling ring A wrestling ring is the stage on which a professional wrestling match usually occurs. It is similarly constructed to a boxing ring and is traditionally square-shaped. Configuration and construction The configuration and construction of the tra ...

s and

boxing ring A boxing ring, often referred to simply as a ring or the squared circle, is the space in which a boxing match occurs. A modern ring consists of a square raised platform with a post at each corner. Four ropes are attached to the posts and pulled ...

s, where they serve as the attachment between the ring ropes and ring posts. Rather than the usual bare metal, here the turnbuckles are covered with padding in order to protect participants and staff. Turnbuckles even play a part in professional wrestling where they are often dramatically used by participants as part of their offensive moveset.

Entertainment industry

Turnbuckles are used in nearly all rigging performed in the entertainment industry, including

theatre Theatre or theater is a collaborative form of performing art that uses live performers, usually actors or actresses, to present the experience of a real or imagined event before a live audience in a specific place, often a stage. The perfor ...

film A film also called a movie, motion picture, moving picture, picture, photoplay or (slang) flick is a work of visual art that simulates experiences and otherwise communicates ideas, stories, perceptions, feelings, beauty, or atmospher ...

, and live concert performances. In entertainment

, turnbuckles are more commonly used to make small adjustments in line lengths. This is generally to make a flown unit sit parallel to the stage. Another way a turnbuckle could prove helpful is with making very minor height or angle adjustments.

Pipe systems

Turnbuckles are used in piping systems as a way to provide minor adjustments for field inconsistencies. This also allows for a minimum amount of resistance when transferring the load to the support components.

Orthopaedics

A type of splint is used for upper limb to produce gradual stretching over contracted joint by its turn buckle mechanism. Used to treat stiff elbow and Volkmann Ischemic Contracture.

Gallery

File:Turnbuckles.jpg , Turnbuckles – lower quality aluminum bolt and hook beside higher quality cast stainless steel File:Bochum - Günnigfelder Straße - Zeche Hannover - Schacht 1 in 10 ies.jpg , Turnbuckle used in building support File:Turnbuckle James Craig.JPG , Turnbuckle support for the main topmast fore stay of a sailing ship File:Wrestling Turnbuckles (WWE) jjron 10.11.2007.jpg , Padded turnbuckles in a wrestling ring connecting ring ropes to post File:Turnbuckles on a support for a jetty 3.jpg , Turnbuckles on a support for a boat jetty

References

External links

* {{Commons category-inline, Turnbuckles Hardware (mechanical) Sailing rigs and rigging