| Theoretically, you could design a roller coaster | | | | is slowed by friction between parts of the brakes. |
| that would use up all its potential energy at the | | | | With fin brakes, one part of the brake is on the |
| exact point where it loops back to the start of | | | | track, and the other part of it is attached to the |
| the ride. The trains themselves, after all, have no | | | | bottom part of the train. The brake segment of |
| brakes. After being towed up the initial hill, they | | | | the track has a groove between the brake pads. |
| are propelled strictly from converting potential | | | | The brake fins, which are the part of the brakes |
| energy to kinetic energy. Once all the potential | | | | underneath the train, run through the groove |
| energy has been changed to kinetic energy, the | | | | when the train goes over the brake segment of |
| train either stops or must be towed up another | | | | the track. On the track is also a compressed air |
| hill. | | | | mechanism to open and close the gap between |
| But in reality roller coasters use so-called "trim | | | | the grooves. The more closed they are, the |
| brakes." The train will go faster if there are | | | | tighter they grip the fins, and the more open they |
| heavier passengers on it, and slower if there are | | | | are, the more loosely they grip the fins. |
| lighter passengers on it. Weather, believe it or not, | | | | Finally, the brakes in the station where the train |
| can also affect the speed of the train. Trim | | | | comes to a stop are similar to the trim brakes. |
| brakes are adjustable so that each train can be | | | | These brakes also have a bar running parallel to |
| made to travel at the same speed. Most modern | | | | the tracks that is used to release the lap bars of |
| coasters have automatically controlled trim brakes. | | | | the train when the ride comes to a stop, and to |
| Roller coasters are also equipped with what are | | | | lock the lap bars of the train when the next load |
| called fin brakes. Like with a regular car, the train | | | | of passengers are ready to go. |