Roller Coasters

D.J. Barksdale

Premier Rides' Diving LIM Shuttle Loop Coasters: Mr. FreezeTM: The Coolest Coaster on the Planet at Six Flags St. Louis.

The world of roller coaster design is thriving with creators who continue to push the limits of velocity, vertical drops, and intricate track designs. Premier Rides utilizes a Linear Induction Motor (LIM) to propel their Six Flags attraction, Mr. Freeze. Similar to the variety of electric motors found in your home, which produce a rotary motion, the LIM creates linear (straight line) motion. An induction motor operates with alternating current supplied directly to an electrical coil called a stator. If the rotor and stator are unrolled into a flat plane, the induction motor becomes a linear induction motor. An electrical current pulses through the stator coils creating an electro-magnetic force that pulls at the now flat metal bars, thus creating forward motion.

In Premier Rides' LIM-powered coasters, the flat metal bars are conductive aluminum fins on each side of the train. They are mounted between each train's wheel assembly and the seats. The stator coils are found in a series of anchored motor housings, which extend out from beneath the loading platform along the track to more than 200 feet, ending at the base of the first hill. As the train accelerates, each fin passes between a pair of stator coils. The stator coils are powered consecutively in a time sequence, pulling the train forward until it reaches a speed of more than 70 mph in just over three seconds. The momentum created in this brief launch period carries the train up the first hill. Gravity and momentum, the forces found on traditional roller coaster rides, then carry the train through the remainder of the course.

What this actually converts to is a minute thrill ride creating 4.5 G-Forces on your body. The pinnacle of 235 feet is reached with the track perpendicular to the ground, your face staring at the sky. As the ride slows to a stop and reverses, you experience negative G-Forces and 2 to 3 seconds of a weightless sensation. From personal experience, I can verify that all of this leads to an incredible experience that will have you yearning for more.