Bungee jumping (also spelled "Bungy" jumping)[1][2] is an activity that involves jumping from a tall structure while connected to a large elastic cord. The tall structure is usually a fixed object, such as a building, bridge or crane; but it is also possible to jump from a movable object, such as a hot-air-balloon or helicopter, that has the ability to hover above the ground. The thrill comes as much from the free-falling as from the rebounds.[3]
When the person jumps, the cord stretches and the jumper flies upwards again as the cord snaps back, and continues to oscillate up and down until all the energy is dissipated.
he word "bungee" (pronounced /ˈbʌndʒiː/) originates from West Country dialect, meaning "Anything thick and squat",as defined by James Jennings in his book "Observations of Some of the Dialects in The West of England" published 1825. Around 1930 the name became used for a rubber eraser. The word bungy, as used by A J Hackett, is "Kiwi slang for an Elastic Strap".[4] Cloth-covered rubber cords with hooks on the ends have been available for decades under the generic name bungy cords.
In the 1950s David Attenborough and a BBC film crew brought back footage of the "land divers" (known as "Naghol") of Pentecost Island in Vanuatu, young men who jumped from tall wooden platforms with vines tied to their ankles as a test of their courage and passage into manhood.[5] A similar practice, only with a much slower pace for falling, has been practised as the Danza de los Voladores de Papantla or the 'Papantla flyers' of central Mexico, a tradition dating back to the days of the Aztecs.
A tower 4,000 feet (1,200 m) high with a system to drop a “car” suspended by a cable of “best rubber” was proposed for the Chicago World Fair, 1892-1893. The car, seating two hundred people, would be shoved from a platform on the tower and then bounce to a stop. The designer engineer suggested that for safety the ground below “be covered with eight feet of feather bedding”. The proposal was declined by the Fair’s organizers.[6]
Bungee at Kawarau Bridge
The first modern bungee jumps were made on 1 April 1979 from the 250-foot (76 m) Clifton Suspension Bridge in Bristol, by David Kirke, Chris Baker, Simon Keeling, Tim Hunt and Alan Weston of the Oxford University Dangerous Sports Club.[7] The jumpers were arrested shortly after, but continued with jumps in the US from the Golden Gate and Royal Gorge bridges, (this last jump sponsored by and televised on the American program That's Incredible) spreading the concept worldwide. By 1982 they were jumping from mobile cranes and hot air balloons.
Commercial bungee jumping began with the New Zealander, A J Hackett, who made his first jump from Auckland's Greenhithe Bridge in 1986.[8] During the following years Hackett performed a number of jumps from bridges and other structures (including the Eiffel Tower), building public interest in the sport, and opening the world's first permanent commercial bungee site; the Kawarau Bridge Bungy at Queenstown in the South Island of New Zealand.[9] Hackett remains one of the largest commercial operators, with concerns in several countries.
Despite the inherent danger of jumping from a great height, several million successful jumps have taken place since 1980. This is attributable to bungee operators rigorously conforming to standards and guidelines governing jumps, such as double checking calculations and fittings for every jump. As with any sport, injuries can still occur (see below), and there have been fatalities. A relatively common mistake in fatality cases is to use a cord that is too long. The cord should be substantially shorter than the height of the jumping platform to allow it room to stretch. When the cord reaches its natural length the jumper either starts to slow down or keeps accelerating depending upon the speed of descent. One may not even start to slow until the cord has been stretched a significant amount, because the cord's resistance to distortion is zero at the natural length, and increases only gradually after, taking some time to even equal the jumper's weight. See also Potential energy for a discussion of the spring constant and the force required to distort bungee cords and other spring-like objects.
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