Answers For [Recent Tests- VOL] - Keeping the fun in funfairs

A 13Fun is becoming a tricky issue for ride designers, in order to increase excitement, they have been ramping up the accelerations to create the most dizzying forces possible. But getting it right is far from easy. Err on the side of caution and people won't bother with a second ride. Go too far, however, and they may not be able to. Experts realize we are now at the limited of how much acceleration a human body can take, and designers are finding it hard to think up ways of keeping the public coming back for more. The problem is that true innovation has been lacking for a while, and fairground rides have become more about survival than actual enjoyment. So if our thrill-seeking bodies can rally take no more, what's going to keep dragging us back to amusement parks? Creating something new and exciting, yet safe, is going to take some careful thought.

B When the Disney Corporation asked German designer Walter Stengel to design a giant loop ride for them in the 1970, he went to NASA, the aeronautics and space foundation, to discover the effects of sustained acceleration on the pilots. NASA's research suggests that the maximum level we can endure is 9 g, g being the standard unit of acceleration due to gravity. Go much beyond that and pilots pass out. Go further still and they suffer serious internal damage. 1So Stengel decided that the maximum vertical acceleration for the public should be 6, and then only for a second or so. What's more, he put firm restrictions on the rate at which acceleration can increase- you'll never go down a 45 degree ramp into a tight circular loop, for instance.

C But stricter safety limits only intensify the need to search for novel ways to thrill customers. Part of the problem is that no matter how exciting an attraction is after a few goes the passengers will have some idea of what to expect. 2The next stage in designing rides, however could throw predictability out of the window. This step has already been taken in the most recent waltzer's, or tea-cup rides. Ride a waltzer and you sit in a car that spins on its own axis. The car is on a huge platform that also rotates. In the past you could take comfort from the fact that the spin was tightly controlled by gears that turned your car at a rate determined by the rotation speed of the whole ride. 7But the latest generation of waltzer cars spin freely, at a rate determined by the weight and position of the people in them. 2So you never have the same experience twice. "People seem to like these "chaotic rides", says Stenge.

D Although seemingly a passport to endless thrills chaos does have one rather obvious drawback it's unpredictable. 3Despite complex calculations, designers can never be completely sure that something odd won't happen, especially since freely turning systems occasionally hit a resonance frequency. For example, if pushed at a particular frequency, a child on a swing would go over the top of the swing's frame. Similarly, 8if you drive a revolving waltzer car at its resonance frequency it could speed up uncontrollably. This could be very hazardous, according to Stengel. 3If a ride is subjected to unforeseen stresses, no one can guarantee that it will be able to cope.

E 12No one even knows what the safe limits of rotational force are, let alone its effect on the human body. Stengel has worked with the German Air Force, rotating volunteers head over heels while also making them cartwheel or pirouette like a ballet dancer. It emerged that 9if the pilots were turned on all three axes simultaneously, they became so nauseous they almost blacked out, and when they got off they couldn't walk. But what Stengel found particularly puzzling was that 4-10they also developed headaches and other problems about two days later. 4Since these effects aren't understood, he ties to limit how people on his rides are rotated. We want to provide fun, not pain.

F With that goal in mind, Stengel feels that flinging people around in ever more chaotic machines is no longer the way forward. 5He believes that the sequence of accelerations, not their size, is what counts and that the way to make rides more fun is to put people through a carefully designed succession of relatively small accelerations. Other experts in this field agree, and 14it seems likely that designers could formulate profiles even for existing attractions that would lead to higher amusement value. Recent experiments testing the tolerances of Dutch military pilots to a range of accelerations have shown that tumbling around in machines doesn't have to be unpleasant. 5When the force is kept low, the subjects actually enjoy the experience.

G 6The fun seems to come from the unforeseen, particularly when 11an effect called the Coriolis illusion comes into play. 6-11This is an agreeable tumbling feeling which occurs, for example, 6when the head is suddenly tilted while the subject is spinning with eyes closed. It appears that a roll which includes, for instance, an unexpected change of acceleration from a small negative g (a feeling of weightlessness) to a small positive g (a slight crushing sensation) has an extraordinary effect on people. If the theories of Stengel and other experts really do work, fairground fun might one day be measured in smiles, not screams.