Welcome to the Coaster Science Page, please use the jump menu to find what you're looking for. If you have ever wondered how a coaster works then here's your chance to find out. I've tried to keep the explanations as simple and short as possible. Think of this page as an idiots guide to coasters, without the idiots and in the nicest possible way of course. So, all those with a PhD in Physics, Mechanics and Engineering, go and enjoy the pictures. For the rest of us, including me... let's get started!
They move by using gravity. Sir Isaac Newton discovered gravity, you may have heard the falling apple and his head story. The force of gravity is invisible to us, but without it, everything that isn't nailed to the earth would just float away, including you. Everything on the planet is feeling this gravitational pull towards the earth and it's measured at about 1G of pressure. This 1G of constant pressure keeps everything firmly pinned onto the earth's surface.
Simply put, every time you drop a pen and it falls towards the floor, that is gravity, pulling it down. The further the dropped pen falls the more speed it will gain, coasters work in the same way. They change potential energy into kinetic energy.
So, let's see how a coaster gets this potential energy. Potential energy is stored by an object, in this case the coaster car, as it moves away from the earth. This is where the lift hill comes in. Most coasters start with a long climb up a hill, normally the tallest on the coaster, by using a chain or some other device. The higher the coaster car gets from the floor the more potential energy it is storing. At the top of the hill the chain will let the coaster car go, and we transfer the potential energy into kinetic energy, as gravity starts to pull us back down to earth.
Again, lets use the pen for a simple example. Pick up a pen from your desk and hold it in the air. You have just given your pen potential energy (the pen now has the potential to fall back down to the desk or floor). As soon as you let go it will transfer the potential energy, of you holding the pen in the air, into kinetic energy as the pen falls towards the desk or floor again.
Well, we have the potential energy, now let's look at how the coaster car gets the kinetic energy. Put simply any item falling towards the ground will generate kinetic energy. As you know, on a coaster, after the initial climb comes a drop of similar size towards the ground. This downward drop is where the coaster car generates its kinetic energy, by using gravity. The higher the first hill is on the coaster the faster you will be traveling at the bottom of it.
The coaster as it goes up hill = potential energy.
The coaster
as it goes down hill = kinetic energy.
The coaster uses this method to complete the full circuit of its track, as coaster cars don't have engines. The coaster will keep on going until it either, runs out of kinetic energy (hopefully your back in the coaster station by then) or if health and safety intervene with some brakes, to bring you to a complete stop.
There are four main forces working on your body as you ride coasters, Positive, Negative, Lateral and Linear G's. Remember 1G is acting on your body at all times. The G stands for gravity and the number in front of the G is the amount of gravity in effect on your body at a certain point of the ride.
What that means is If you weigh 100lbs and you experience 5G's on a coaster you will feel like you weigh 500lbs. With the constant change in the coasters height to the ground, your body will constantly change its weight all the way through the ride.
Ride designers have to be very careful with humans and G-Forces, there is only so much the human body can take. The magic number with coasters seems to be between the 3G and 5G mark. Anything over 5G's for an extended amount of time and the body will start to feel very strange indeed, you could experience a grey out or a red out. A grey out is where the blood is rushed away from your head and into your feet, causing your eyes to cancel out any colour it may see. A red out is the opposite, the blood rushes to your head and causes your eyes to see red.
Don't worry though, these things are tested over and over on computers and ride designers manipulate these forces by changing the rides height and direction, causing slightly different effects on your body throughout the ride. These G-Forces are only in effect for a matter of seconds on your body during any coaster ride. They are just repeated throughout the ride for a few seconds each time.
A positive G is reached at the bottom of any drop, as the coaster car pulls its way back up the next hill. Positive G's can also be experienced in sharp-banked corners taken at quite high speeds. The amount of G's experienced is worked out in a really boring mathematical equation that calculates how sharp the change is for the coaster car as it goes from going downhill to uphill.
This is how your body feels more heavier than it actually is. You multiply your body weight by the number of G's created, this is where this phrase comes in that we mentioned earlier... If you weigh 100lbs and you experience 5G's on a coaster you will feel like you weigh 500lbs.
A negative G is reached at the top of a hill or when the coaster car suddenly drops downhill at high speed. Anything less than 1G in the coaster world is considered a negative G, everywhere else on the planet considers a negative G to be -1G. These Negative G's are considered by enthusiasts to be the best force that the body will feel during a coaster ride, but they can also be quite dangerous.
When the body experiences a negative G, its pretty much the opposite as the positive G will make you feel. As you encounter a negative G your body will suddenly feel weightless, or lighter than you actually are. As you crest the top of a hill at speed, you will feel yourself lifting off the coaster car seat for a very brief period. This is a negative G, forcing you away from earth and against gravity that is naturally pushing you downwards. Defying gravity is always really good fun.
A lateral G on the body feels like going round a roundabout in a car, when you get pushed to the opposite side your turning. A coaster that goes around an unbanked corner at high speed will create high lateral G's, forcing the body sideways and normally quickly followed by a smack around the face by your restraint.
This is why lateral forces are considered bad on coasters. Most coasters have banked corners (when the coaster track is tilted to a certain angle of degrees), this changes lateral G's into positive G's.
Linear G's can be found on coasters that launch you in a straight line e.g. Stealth at Thorpe Park, which launches you from 0 - 80mph in just 1.9 seconds. Linear G's are working when you feel the skin on your face being pulled back.
That's about it for how coasters work and how the body feels the forces involved. I will remind you, all coasters are vigorously tested and G-Forces are completely safe on the coasters. Without these forces it would be a pretty dull experience. G-Forces are our friend.
Lets start with an old cliché that is very true, you are more likely to be involved in an accident traveling to the theme park, than you are during a coaster ride. Everything that you see on a coaster, from a small bolt to its effect on your body, track and car, has been vigorously tested.
Coasters have computer systems and hundreds of sensors on the coaster cars, restraints and on the actual coaster track that monitor just about everything and keeps the ride operator fully informed about what is going on. These computer systems are backed-up and the back-up computers will also be backed-up.
Should a system fail then the other computers will step in and take over, you won't even notice if something went wrong. Obviously when things do go wrong, very rarely on coasters, they are pretty awful with the speeds involved, but don't think like that, coasters are perfectly safe. It's normally rider error that causes the accidents by not reading the rides safety boards as you join the queue line. It's dangerous crossing over the road but we all still do it everyday, so jump on a coaster today.
Let's start with how the coaster train stays on the track without flying off. If you look at the diagram to the right of this writing, you will see a typical single modern wheel assembly for a coaster train, a coaster train will have many of these mounted.
As you can see on the diagram, there are six wheels that sit around the track very snugly indeed. All the wheels need to be in contact with the track for a smooth ride. There are two main wheels that sit on top of the track, called road wheels. Two wheels that hug the side of the track, called guide wheels. Finally there two wheels that run on the underside of the track, these are called upstop wheels and are what stops the train from flying off the track as you fly over hills at high speed.
Simple answer is Restraints, although some coasters do not need them. Restraints are simply there to make you feel a little better and to stop idiots from standing up. There are many types of restraint, but they all do the same thing, stop you from falling out.
Before you venture into the unknown, as you board your coaster seat you are greeted by a lap bar or an over the shoulder restraint (OTSR). These are the most common type of restraint. OTSR's are normally found on coasters that invert and the lap bar will be found where the coaster doesn't invert.
Again, all these restraints have been tested and approved for the ride involved and are perfectly safe and are monitored by computer safety systems. If just one restraint is not fully locked, the computer will not let the train leave the station.