The reverse bungee (or catapult bungee, or Ejector Seat) is a modern type of fairground ride introduced by S & D Leisure in 1999 as a slightly more controlled, inverted version of the bungee jump.
The ride consists of two telescopic gantry towers mounted on a semi trailer, feeding two elastic ropes down to a two person passenger car constructed from an open sphere of tubular steel. The passenger car is secured to the trailer with an electro-magnetic latch as the elastic ropes are stretched. When the electromagnet is turned off, the passenger car is catapulted vertically with an acceleration of 4.8 g, reaching a maximum altitude of 55 metres (180 ft).
The passenger sphere is free to rotate between the two ropes, giving the riders a thoroughly chaotic and disorienting ride. After several bounces, the ropes are relaxed and the passengers are lowered back to the launch position.
The Bournemouth incident :
http://archive.bournemouthecho.co.uk/2004/7/15/65207.html