Have you ever been on a roller coaster and wondered how the train stays on the track? Have you ever watched a roller coaster and thought to yourself, "Why don't the cars fly off the tracks?"
If so, you're far from alone. There are several explanations as to why roller coaster trains stay on their tracks.
On top of the rails are the train's running wheels on which the train cars run. Further more the wheel assemblies on their axles go on both sides of each rail, so that they "hug" the rails.And if that weren't enough, the wheel assemblies have guide wheels in the middle of the assembly. These wheels help prevent lateral (side to side) motion. The guide wheels on wooden roller coasters are on the insides of the rails. But on steel rails the guide wheels might be either on the inside or the outside.
And finally, there are special wheels underneath the rails called upstop wheels that prevent the trains from lifting off the rails.
But the most important reason theme park rides don't go off the tracks is that the curves and turns are banked properly so that the gravitational force in combination with other forces acting on the train are balanced so that the wheels stay on the tracks as a result of the sum of all the forces acting on them.
When a coaster does a loop and goes upside down, the loops are specially designed to have the tightest radius at the very top of the loop and to have much larger radii at the entrance and exit of the loop. Because of this shape of loop, the g forces necessary to hold the train on the tracks are low enough that the human body can withstand them without physical harm. But to be sure, those g forces are strong enough to give people quite a thrill! This gives roller coaster loops a shape very much like that of a regular helium balloon.
The "sticking power" that keeps roller coaster trains on their rails can be mostly attributed to the laws of physics - specifically the law of gravity.
Author Resource:
Andrea Smith is a freelance writer and Theme Park enthusiast from the UK. She writes for Techy Zone about roller coasters, thrill rides and theme parks in the UK.