Wild Rides

Roller coaster enthusiasts will flip head over heels—literally—for Maxx Force. The new attraction breaks records for the fastest inversion, or upside-down turn, and tallest double inversion in the world. It also has the fastest start of any coaster in North America, rocketing riders from 0 to 126 kilometers (78 miles) per hour in less than two seconds. “It’s intended to stick you to the back of your seat,” says Michael Reitz, a mechanical engineer at Six Flags.

Every roller coaster track has different loops, rolls, and drops. But despite coasters’ different designs, they all work on a similar principle. “What a roller coaster does is convert some sort of potential energy into kinetic energy,” says Jeff Rhoads. He’s a mechanical engineer who teaches a class on roller coaster dynamics at Purdue University in Indiana.

Roller coaster fans will truly flip head over heels for Maxx Force. The new coaster breaks several records. It has the fastest inversion (upside-down turn) and tallest double inversion in the world. It also has the fastest start of any coaster in North America. It rockets riders from 0 to 126 kilometers (78 miles) per hour in under two seconds. “It’s intended to stick you to the back of your seat,” says Michael Reitz, a mechanical engineer at Six Flags.

Every roller coaster track has different loops, rolls, and drops. The coasters may have different designs, but they all work on the same idea. “What a roller coaster does is convert some sort of potential energy into kinetic energy,” says Jeff Rhoads, a mechanical engineer at Purdue University in Indiana. He teaches a class on roller coaster dynamics.

With Maxx Force, potential energy is stored in tanks of compressed air (see How Maxx Force Works). The air is released in a powerful blast when the ride starts. It launches the coaster down the track, converting the stored energy into kinetic energy—the energy of motion. This differs from a traditional roller coaster, which has a chain that pulls it to the top of its first incline. As it rises, the roller coaster gains potential energy because of its height. The force of gravity then pulls the coaster down the track, converting its stored energy into kinetic energy.

Once Maxx Force launches, its energy gets converted back and forth from potential to kinetic as it moves up and down and through inversions. Some energy is lost to drag, a slowing force caused by air molecules pushing against the coaster as it moves. The force of friction also slows down the cars as their wheels rub against the track. But Maxx Force’s initial launch blast is more than enough to rocket the ride all the way to the end of the course.

Maxx Force stores potential energy in tanks of compressed air (see How Maxx Force Works). The air is released in a powerful blast when the ride starts. It shoots the coaster down the track. That converts the stored energy into kinetic energy—the energy of motion. A traditional roller coaster is different. A chain pulls it to the top of its first ramp. The roller coaster gains potential energy as it gets higher. Then the force of gravity pulls the coaster down the track. That converts its stored energy into kinetic energy.

After Maxx Force takes off, it moves up and down and through inversions. That converts its energy back and forth from potential to kinetic. Some energy is lost to drag. This slowing force is caused by air molecules pushing against the moving coaster. The force of friction also slows down the cars. That happens when their wheels rub against the track. But Maxx Force’s takeoff blast is more than enough. It rockets the ride all the way to the end of the course.    

Wonder Woman Lasso of Truth is a record-breaking attraction with a twist. At 17 stories, it’s the world’s tallest pendulum ride. People sit around the outside of a disc attached to a long arm. Motors raise the arm high up and then let it drop. The pendulum swings to the other side, rising until it pauses in midair. At that moment, it has zero speed. “Basically, all of the energy is potential energy then,” says Rhoads. But “as you swing down, you’re going to pick up speed.”

On its own, a pendulum continues swinging to almost the same height each time because of inertia. That’s the tendency of an object to keep moving unless acted on by an outside force. A little height is lost to drag and friction. But on the ride, motors boost the pendulum higher as it sways. At the peak of each swing, “it has more potential energy than it did the last time because it’s higher,” says Reitz. Riders sweep through the bottom of the arc—the point with the greatest kinetic energy—at speeds of up to 121 km (75 mi) per hour.

As the disc swings, it simultaneously spins riders in counterclockwise circles. Each time a rider passes through the same point in the swing, he or she is in a different position on the disc. “It’s a very cool sensation,” says Reitz. “It’s almost as if you’re moving back and forth in a wave motion.”

Wonder Woman Lasso of Truth is a record-breaking ride with a twist. It’s the world’s tallest pendulum ride, at 17 stories high. A disc is attached to a long arm. People sit around the outside of the disc. Motors raise the arm high up and then let it drop. The pendulum swings to the other side. It rises until it pauses in midair. At that moment, it has zero speed. “Basically, all of the energy is potential energy then,” says Rhoads. But “as you swing down, you’re going to pick up speed.”

On its own, a pendulum keeps swinging to almost the same height each time. That’s because inertia keeps an object moving unless an outside force acts on it. A little height is lost to drag and friction. But as this ride swings, motors boost the pendulum higher. At the top of each swing, “it has more potential energy than it did the last time because it’s higher,” says Reitz. The bottom of the swing is the point with the greatest kinetic energy. Riders sweep through this point at speeds up to 121 km (75 mi) per hour.

The disc doesn’t just swing. It also spins riders in counterclockwise circles. A rider passes through the same point in the swing over and over. Each time, he or she is in a different position on the disc. “It’s a very cool sensation,” says Reitz. “It’s almost as if you’re moving back and forth in a wave motion.”  

This seven-story ride began turning riders topsy-turvy last year. They strap into a row of seats along the bottom of a giant frame. It’s attached to pivots that allow it to rotate inside an even bigger frame, which rotates inside a third gigantic frame. Each frame has its own axis of rotation, or line around which it turns, says Reitz. “You can be spinning in multiple axes at any given moment.”

The ride was inspired by a gyroscope—a device with a wheel mounted inside larger wheels that can spin freely. Gyroscopes detect orientation in planes, ships, and even smartphones. The inner wheel of a real gyroscope spins in a fixed position, even when the device is tilted. Designers decided that wasn’t wild enough for the new ride.

Motors turn the nested frames at the points where they connect, so riders on the inner frame spin in what feels like every direction imaginable. As riders flip, gravity pulls them into and then out of their seats. Reitz says, “The experience is disorienting because you sort of get lost in where you are.”

This seven-story ride began turning riders head over heels last year. They strap into a row of seats along the bottom of a giant frame. It’s attached to pivots, so it can spin inside an even bigger frame. That frame spins inside a third giant frame. Each frame has its own axis of rotation, or line around which it turns. Reitz says, “You can be spinning in multiple axes at any given moment.”

The ride was inspired by a gyroscope. That’s a device with a wheel set inside larger wheels that can spin freely. Gyroscopes detect position in planes, ships, and even smartphones. The inner wheel of a real gyroscope spins in a fixed position. It doesn’t change even when the device tilts. Designers decided that wasn’t wild enough for the new ride.

Motors turn the three frames at the points where they connect. That makes riders on the inner frame spin in many different directions. As riders flip, gravity pulls them into and then out of their seats. Reitz says, “The experience is disorienting because you sort of get lost in where you are.”