Daniel Stewart, ERS, for Zondits
Compressed air is often referred to as the “fourth utility” in commercial and industrial settings – joining water, electricity, and thermal fuels – because it has a wide variety of applications and is often essential to process and facility operation. Major advantages of compressed air as an energy source include high output-to-weight (and output-to-size) ratio of pneumatic actuators and tools, easy storage, and low maintenance for end-use devices. Pneumatic devices are also suitable for many environments and applications that their electronic counterparts are not. They can be used around combustible and energetic (i.e. explosive) materials, in damp environments or even totally submersed in water, and for rapid and repeating movements. These strengths are also the reason that compressed air is frequently used by amusement park engineers.
Let’s set the scene: It’s a beautiful August day and you have decided to go to Canobie Lake Park for an afternoon of fun. You have been waiting in line for the Yankee Cannonball for 30 minutes and you are finally next in line… But wait! Someone has installed a pesky gate to prevent you from preemptively entering the loading platform before the ride has come to a stop and the previous riders have exited the area. Well, that gate, and most others like it, is powered by compressed air. Similarly, the safety restraint that keeps you from flying out of your seat as you plummet down the ride’s 60-foot main drop is also activated by compressed air. Finally, the brakes at the end of the ride – you guessed it – are powered by compressed air.
All of these example applications could be achieved using electronic actuators, but compressed air has also enabled design engineers to create some pretty amazing rides. The Star Blaster, another Canobie Lake Park favorite, launches riders vertically using pneumatic pistons. The ride stores compressed air in large tanks within its trunk and releases it in a quick blast to propel its riders toward its 80-foot summit. Compressed air is also used as the ride’s primary braking system, gently cushioning the carriage as it returns to earth. The gusts of air emanating from the equipment also adds to the ride’s theme, somewhat emulating the sound of a rocket blasting the riders into space.
Compressed air is also responsible for propelling the Dodonpa coaster in Japan from 0–107 mph in 1.8 seconds with an acceleration of 2.7 G-forces (Gs), like a fighter plane being launched from an aircraft carrier. By comparison, a real space shuttle experiences approximately 3 Gs during its launch (though, admittedly, for a much longer period of time), and the fastest accelerating production car, the Porsche 918 Spyder, takes 2.2 seconds to go from 0–60 mph under a measly 1.3 Gs. By the way, aircraft catapults are also sometimes powered by compressed air!
Amusement park engineers also employ compressed air to create special effects in stationary, themed “dark rides” by creating wind, moving or tilting the rider seating platform, or controlling audio-animatronic figures and other props. It is true that compressed air is energy-intensive and therefore relatively expensive to generate, but sometimes there is just no substitute for the thrill of the ride!There are advantages in using compressed air as an energy source especially in an amusement park. Click To Tweet