YouTube Twitter Facebook YouTube Twitter Facebook







about bill

Roller coaster

May 30, 2000

A public radio commentary

I have great faith in my fellow engineers, but there is one piece of technology used by three hundred million people, which I'm never going to try. It's a roller coaster.

They terrify me, although engineers design them to be so safe that insurance companies worry more about sprained ankles from Merry-go-rounds. The engineer's goal is to use gravity and acceleration to confuse, and apparently delight, a rider.

The main thrill is the g-forces - the changes in weight from acceleration. When the cars take off a rider feels about two and a half gees, nearly what the astronauts feel when the space shuttle launches. By understanding these g-forces, engineers have been able to enhance riders' thrills, and prevent their deaths. An early coaster called the "Flip-Flap" had the first loop-the-loop, which is a complete circle that turns riders upside down. Its designers understood g-forces so poorly that as the cars went around the loop they exerted twelve gees on the riders. Fighter jet pilots black out usually at ten gees. This coaster occasionally snapped riders' necks. Today's engineers use computers to calculate the forces on every section of the track.

It isn't, though, only technical skill that makes a good roller coaster. Knowing some psychology also helps. Designers have learned over the years that it's best to have a slow ascent on the first hill, then dangle people at the top before the great plunge. On that plunge, engineers try to make cars go as straight down as possible and appear to curl underneath, giving riders the impression that they're about to jump off the track. A good roller coaster engineer also makes use of the supporting structure. Sending a car close to a column gives the impression of speed, and a classic coaster trick is the "fine del cap" - Latin for "end of the head." By this they mean shooting the cars toward a horizontal beam, then ducking just at the last moment.

With these principles in mind, here are tips on how to make your ride more scary, and I gather, more fun. The front car feels fastest. Close your eyes briefly during the ride it will help confuse you. Also look backward to get dizzy. Lift you feet as the car crests a hill - you'll feel weightless. And ride after a rain because the tracks are slippery and the coaster is faster.

And another tip is to keep coming back, because they're always improving the rides. For example, some new coasters no longer start on a hill, instead they are driven by motors used to power rockets. With these motors, roller coasters blast off with accelerations of 4.5 gees. Myself, I'll be on the ground, holding cotton candy, and feeling only one gee.

Copyright 2000 William S. Hammack Enterprises