As we have seen before, the roller coaster train itself has no electric motor: in the majority of the running process, the train is moving by gravity and momentum. In order to accumulate potential energy, the train needs to be lifted to the top of the first hillside or launched with great thrust.
A traditional lifting device is a long chain (or multiple chains), just like a bicycle chain, but much larger. It is mounted below the track and extends up the lift ramp. The chain is fixed in a loop that has a transmission at the top and bottom of the track. The transmission at the bottom of the track is rotated by an electric motor.
By rotating the chain loop, it continues to move toward the top of the track like a long conveyor belt. The roller coaster uses several chain lock springs and a strong hinge hook to catch the chain. When the train travels to the bottom of the hill, the lock spring will catch the chain links. Once the chain lock spring is hooked, the chain will pull the train to the top of the mountain. At the highest point, the lock spring is released and the train begins to move down the hill. The squeaking sound of the chain you hear is actually the sound from the anti-back slide device, in case the motor slips back to the station when the motor fails. Causing an accident.
In some newer roller coaster designs, trains are launched by means of catapult launches. There are several methods of launching catapults, but their functions are basically the same. Instead of dragging the train up the hillside to accumulate potential energy, these systems allow the train to gain a lot of kinetic energy in the very short time to get it running.
Linear Induction Motor is one of the commonly used catapult systems. Linear induction motors use electromagnets to create a magnetic field above the track and below the train, and to attract the two magnetic fields. The magnetic field above the moving track of the motor pulls the trailing train to move along the track at a very high speed. The main advantages of this system are its speed, efficiency, durability, accuracy and controllability.
The Hydralic Launching System appeared in the roller coaster produced by Intermec. This is a slider with a steel cable that is driven by a water-driven flywheel. When launching, the slider is stuck under the train, and the high-speed rotating flywheel quickly pulls the slider and rushes out together with the train.
At the end of the launch section, the slider is unhooked from the train, and the train relies on the resulting kinetic energy to rush to a height of about 100 meters.
This roller coaster uses dozens of rotating wheels to propel the train and climb it up the hill. These wheels are arranged in two adjacent columns along the track. They pin the bottom (or top) of the train and push the train forward. It is often used when climbing a slope (because the chain cannot bend horizontally on a horizontal plane) or the train is adjusted to a speed equal to the speed of the chain before the chain lifter. And the Hulk roller coaster at Universal Studios Orlando uses these wheels to speed up the tunnel for the train.