Bungee cords equipped with metal hooks A bungee cord (sometimes spelled bungie; also known as a shock cord or an ocky strap) is an

elastic Elastic is a word often used to describe or identify certain types of elastomer, Elastic (notion), elastic used in garments or stretch fabric, stretchable fabrics. Elastic may also refer to: Alternative name * Rubber band, ring-shaped band of rub ...

cord composed of one or more elastic strands forming a core, usually covered in a woven cotton or

polypropylene Polypropylene (PP), also known as polypropene, is a thermoplastic polymer used in a wide variety of applications. It is produced via chain-growth polymerization from the monomer Propene, propylene. Polypropylene belongs to the group of polyolefin ...

sheath. The sheath does not materially extend elastically, but it is braided with its strands spiraling around the core so that a longitudinal pull causes it to squeeze the core, transmitting the core's elastic compression to the longitudinal extension of the sheath and cord. Specialized bungees, such as some used in bungee jumping, may be made entirely of elastic strands.

Uses

upA child on a bungee cord device in Moscow, Russia Bungee cords have been used to provide a lightweight suspension for aircraft undercarriages from before

World War I World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...

, and are still used on many small homebuilt aircraft where weight remains critical. Bungee cords were also used in

parachuting Parachuting and skydiving are methods of descending from a high point in an atmosphere to the ground or ocean surface with the aid of gravity, involving the control of speed during the descent using a parachute or multiple parachutes. For hu ...

to assist in opening the old-style parachute container after the ripcord was pulled. Today, bungee cords are most often used to secure objects without tying

knot A knot is an intentional complication in Rope, cordage which may be practical or decorative, or both. Practical knots are classified by function, including List of hitch knots, hitches, List of bend knots, bends, List of loop knots, loop knots, ...

s and to absorb shock. Inexpensive bungee cords, with metal or plastic hooks on each end, are marketed as a general utility item. In Australia, this form is known as an octopus, or "occy", strap, or as a jockey strap. These can be an individual strap, or a set of four hooked straps held together by a metal ring allowing the occy strap to secure items around various tie points, for example a suitcase to a car roof rack. Extensions of the concept are available as a coarse net of bungee cords with metal or plastic hooks around the periphery, for securing irregularly shaped loads of luggage and cargo on the backs of

pickup truck A pickup truck or pickup is a Truck_classification#Table_of_US_GVWR_classifications, light or medium duty truck that has an enclosed cabin (truck), cabin, and a back end made up of a cargo bed that is enclosed by three low walls with no roof (th ...

s, roofs of cars, and so on. Bungee cords have also been used to make bungee chairs and for other purposes.

Etymology

The origin of the name "bungee", "bungie" or "bungy" is uncertain. The

Oxford English Dictionary The ''Oxford English Dictionary'' (''OED'') is the principal historical dictionary of the English language, published by Oxford University Press (OUP), a University of Oxford publishing house. The dictionary, which published its first editio ...

records the use of the phrase in 1938 for launching of gliders using an elasticated cord.

Hazards

Bungee cords are a major source of eye injury, and some doctors suggest not using them.

References

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