There’s nothing like the exhilarating magic of the gravity-defying loop-the-loops and scream-inducing roller coaster drops. The experience is pure adrenaline. Significant finesse and engineering expertise go into making the rides safe and enjoyable for you and all visitors at theme parks. So, what exactly is the science behind roller coaster physics and engineering?
The Classic Physics
Gravity was the driving force behind the world’s first roller coaster concepts. What were previously Russian ice slides in the 16th century and coal transport cars in 1800s Pennsylvania are now towering metal beasts in tropical theme parks. Every iteration of these classic thrills experimented with roller coasters’ core physics. Understanding their origins is essential to know how experts engineer coasters today.
Gravity
The classic chain lift that pulls cars up a clacking hill exists because those trains don’t have a power source, like a battery or engine. The cars rely on gravity from drops to provide constant downward force and send riders on their journey — along with help from velocity and Newton’s first law of motion.
Potential and Kinetic Energy
The lift serves another purpose. While the car ascends, it stores potential energy based on the other forces and stresses working alongside it. When the train drops down the hill, it becomes active kinetic energy. It helps the car’s weight maintain momentum as it flies down the track. Other forces try to diminish that energy, such as friction and air resistance, but engineers design coasters to be resilient against these factors.
Other roller coasters rely on magnetics and a catapult-launch lift to gather energy. Instead of relying on the chain lift to build potential energy, the magnets produce kinetic energy in those seconds.
G-Forces
The sinking, somewhat nauseous butterfly feeling in your gut going through loops and hills are G-forces at work. The design of the coaster changes how they act on the body. Sometimes, riders experience free fall, with no forces on them but gravity. In other instances, you’ll get air time — called negative G-force — for a feeling of weightlessness as you slightly pop up from your seat. These are the coasters around the world known for their intense G-forces:
- Flip Flap Railway at Sea Lion Park
- Tower of Terror in Gold Reef City
- Skyrush in Hersheypark
- Intimidator 305 at Kings Dominion
- Apollo’s Chariot at Busch Gardens Williamsburg
Inertia
Inertia is the force required to get an object to start moving. It’s important to distinguish that the rider’s inertia differs from the car’s. Calculating moments of inertia is a critical safety component for inversions because it keeps everyone in the cars without falling out during loops — even with restraints. Gravity and centripetal acceleration want to drop passengers into the air below you, but inertia keeps you intact.
The Engineering Considerations
Now it’s time to combine that physics know-how to engineer and build a roller coaster. After physics, engineers consider other aspects to brainstorm design:
- Train type, such as bobsled, inverted or floorless
- Material, whether wooden, steel or hybrid
- Track maps, such as wild mouse or terrain coasters
- How much area designers have for the track
- Use of technology to inform design, such as AI or virtual reality
- Number of inversions and what types, if any
- Rider demographics, such as weight and height
- Safety precautions, such as restraint type
- Lift type, such as chain or cable lift versus powered linear accelerators
Another consideration is the height of the drop. Hyper, giga, and strata coasters refer to rides that reach 200, 300, and 400 feet, respectively. As of 2023, only eight of these coasters exist in the world. One of them is Kingda Ka at Six Flags Great Adventure, a strata coaster that’s 456 feet tall. These masterworks of engineering are enough to tempt any student into entering mechanical, structural, or electrical engineering.
The Building Basics
After considering these factors, engineers get into the nitty-gritty. They dock up blueprints of the track layout, including where support beams and safety controls are. They review the shape of the inversions, such as making loops teardrop-shaped instead of circular, to maximize its physics and rider comfort.
Brakes are another essential component for fun and safety. Nobody wants to be hit by the previous car before you even leave the station. Trim brakes slow down the train, and block brakes halt it entirely. They’re embedded into the tracks. Other variants include fin brakes, which are on the cars and clamp onto the track to produce friction. Magnetic or skid brakes use magnets to force a train to slow down.
Finally, the engineering process ends with testing. Computers power everything in roller coasters, so engineers test simulations in software and build prototypes before breaking ground on the real deal. The information translates to manufacturers that work with engineers to lay concrete foundations, erect supports, reinforce with steel plating if necessary and construct the framework for track-laying.
The New Revolutions
Revolutions in roller coaster design happen in more ways than one — roller coaster fans have high expectations, pushing designers and engineers to be more creative. Engineers are putting inversions, revolutions, drops, and cart design to the test to create coaster formulas that continue to surprise riders.
Fourth-dimension coasters are a new feat of coaster engineering. An example of this can be found in Japan’s Eejanaika. The seats on this coaster rotate 360 degrees because of its unique four-rail design.
Formula Rossa in Abu Dhabi was inspired by the engineering of jet planes for its world-record-setting 150 mph launch. The hydraulic launcher continues to appear in other coaster designs.
Additionally, engineers are designing roller coasters to make them accessible for people with disabilities. Engineers work to share the fun in their creations by ensuring everyone enjoys them.
Engineering Coasters in the Right Direction
To become a roller coaster engineer, you don’t need specific design experience, but you will need to study engineering at a university and earn a degree. What you learn about physics and mechanical or structural engineering in college can translate to becoming the next big name in the coaster world. That foundational knowledge will help you forge a thrill ride that makes safety its top priority.
Opinions expressed by Sphero.com contributors are their own.
