Elevators, Free Fall and G-Forces

It's not the fall that kills you... it's the sudden stop at the end

Image Credit: Superman Tower Of Power ride at Six Flags Over Texas by Loadmaster (David R. Tribble) at wikipedia.org

Design a ride by adjusting the height versus time graph.

 The apparant weight of the rider arises from the ever present acceleration of gravity in combination with the acceleration of the elevator. If the elevator is stationary or moving with consant speed (i.e. not accelerating), the rider feels their normal weight. If the elevator accelerates upwards, the rider feels heavier and if the elevator accelerates downward the rider feels lighter. With a strong enough downward acceleration, the rider can experience effective weightlessness or even negative g forces (requiring seat belts or restraints to avoid head trauma!).

Basics: Easy Rider

Let's examine a safe, calm elevator ride. Set the height as high as it can go with the h slider, set the number of control points to the minumum (5) by clicking the -N button a few times. The first (left-most) control point represents the initial height of the elevator for this ride; drag it to the top. The last control point (the final elevator height) is always fixed at ground level, so that our passengers may exit the elevator. If you adjust the remaining points so all the control points end up along a straight line, Your graph should look like the figure below.

The g-force graph is flatlined at 1 g (normal gravity), which at first glance may make this the most boring elevator ride ever. However, this graph corresponds to an elevator descending at (nearly) constant speed which means the riders are entering and exiting a moving elevator! This is not safe. So, in order to at least make entering and exiting the elevator relatively safe, the initial and final velocities (displayed as Vi and Vf in the controls section) are at least close to zero. If the second control point and the second to last control point are adjusted, the following should be the result:

This ride has near zero initial and final velocity for safer rider loading and unloading. This should be a requirement for all rides you plan. The first and last control points set the initial and final height, while the second and second to last control points are used to fine tune the intiial and final velocities.

Thrills and Chills, but Please No Kills

Try making a more thrilling ride (more g's, please). You'll quickly discover that the more curved the height graph, the greater the g-forces. More control points (via +N) allows for more curving graphs.

Challenges:

 Remember your final ride design should have initial and final velocities near zero. Consider also that the curves can go above the maximum height and below zero height; aren't you glad we extended the structure above that maximum height and excavated a safety pit below? Don't forget to play the simulation so our virtual rider can enjoy the ride.