How Does a Roller Coaster Work?
A roller coaster works by turning stored energy into motion. A motorised chain pulls the train to the top of the first hill, where it builds up potential energy. Gravity then takes over: as the train drops, that potential energy becomes kinetic energy, and inertia carries the train through the dips, curves and loops that follow. Friction and air resistance slowly take energy away, so each hill after the first is usually a little lower. Here is how each stage of these funfair rides works, and how you can bring roller coasters to your own event.
What Gets a Roller Coaster Up the First Hill?
At the start of the ride, a motorised lift chain pulls the train up the first hill, which makes the familiar clanking sound. As the train climbs, it pulls against gravity and stores potential energy. Potential energy, also called positional energy, is the work the coaster can do once it starts to roll down the other side, in the same way a ball gathers speed as it rolls down a slope.
How Does Gravity Keep the Train Moving?
Once the train passes the top of the hill, the chain lets go and gravity takes over. Objects falling near the Earth’s surface speed up at about 9.8 metres per second, every second, so the potential energy quickly turns into kinetic energy, the energy of motion. That is what carries the train along the rest of the track without an engine on board.
What Part Does Inertia Play?
Inertia comes from Sir Isaac Newton’s first law of motion: an object in motion stays in motion until a force acts against it. The speed built up on the first drop keeps the train moving through every hill, curve and loop. You can read more about this in our guide to how roller coasters go upside down without falling off.
Why Does a Roller Coaster Slow Down?
Two forces gradually take energy away from the train. Friction between the wheels and the rails turns some of the energy into heat, and air resistance pushes against the train and riders as they move. This is why the track is designed with each hill a little lower than the last, and why brakes bring the train to a smooth stop at the station.
What Do Riders Feel on a Roller Coaster?
As the train goes through curves and loops, the changes in speed and direction push riders into their seats and then lift them slightly. The short floating feeling at the top of a hill comes from gravity and inertia briefly balancing out. Our guide to the forces experienced on a roller coaster explains this in more detail.
Can I Hire a Roller Coaster for My Event?
Yes. Our roller coaster hire range includes family rides such as the Apple Coaster and children’s rides like the Go Gator Children’s Roller Coaster. For younger guests, see our full range of mini and children’s roller coasters. Every ride is delivered, set up and run by trained staff, at events throughout the UK, from London and Birmingham to Manchester and Leeds.
Roller Coaster FAQs
Do roller coasters have an engine?
Most roller coasters have no engine on the train itself. A motorised lift chain or launch system gives the train its starting energy, and gravity and inertia do the rest.
Why do you feel weightless on a roller coaster?
At the top of a hill or loop, gravity pulling you down and inertia carrying you forward briefly balance out, which gives that moment of floating.
What slows a roller coaster down?
Friction between the wheels and the rails, and air resistance against the train and riders, gradually take energy away. Brakes bring the train to a safe stop at the end.
Can I hire a roller coaster for an event?
Yes. We supply roller coaster hire for fun days, festivals and school events, including family and children’s coasters, with trained staff included.
For more answers, see our roller coaster FAQs.
Ready to book? We can help you choose a coaster that suits your guests, space and power supply. Call our Birmingham team on 0121 293 1377 or our London team on 0203 302 4757, or use our contact page to check availability for your date.
A Roller Coaster Is a Journey Through Changing Energy and Movement
Roller coasters are designed around a sequence of climbs, drops, curves and other track elements. Rather than every part of the course producing the same movement, the train's speed and direction change as it progresses, creating the different sensations passengers associate with a coaster.
What Are the Forces Experienced on a Roller Coaster? looks more closely at what those changes can mean for the people riding.
Getting the Train Moving Is Only the Beginning
Different roller coaster designs can use different systems to move a train through the course. On many traditional designs, gaining height early in the ride is important because the subsequent descent allows gravity to play a major role in the train's movement.
For the broader engineering context, How Are Funfair Rides Powered? explains how power is used by different types of fairground equipment.
Hills and Drops Turn Height into Speed
The relationship between height and speed is fundamental to many coaster layouts. As a train descends, gravitational potential energy can be converted into kinetic energy. As it climbs again, some of that kinetic energy is converted back into gravitational potential energy, while energy is also dissipated through factors such as friction and air resistance.
This is why the shape and sequence of the track matter so much. A roller coaster is designed as a complete course rather than as an arbitrary collection of hills.
Curves and Inversions Redirect the Train
Roller coaster tracks can also redirect the train horizontally, vertically or through more complex elements. Not every coaster contains inversions, but those that do are engineered so that the train follows the intended track geometry through the complete manoeuvre.
How Do Rollercoasters Go Upside-Down Without Falling Off? focuses specifically on inversions and explains why an upside-down coaster should not be imagined as a vehicle simply balancing on top of a rail.
Roller Coaster Trains Are Designed to Follow Their Track
The relationship between the wheels, train and track is central to coaster operation. The train is mechanically guided along its intended route rather than relying on gravity alone to keep ordinary wheels sitting on top of a track.
This principle allows designers to create substantially different layouts. What Are the Different Types of Roller Coaster? explores how coaster designs vary, while mini & children's roller coasters shows how the concept can also be adapted for smaller attractions.
Braking Is as Important as Acceleration
A roller coaster also needs controlled sections where the train can be slowed or stopped as required by the particular design. The systems involved are part of the engineered ride rather than the train simply losing speed naturally until it reaches the station.
A ride stopping unexpectedly does not automatically mean that something has mechanically failed. What Causes a Funfair Ride to Stop? explains some of the wider reasons an attraction may stop during operation.
Roller Coaster Engineering Extends Beyond the Track Layout
Understanding gravity, wheels and track geometry explains only part of a working roller coaster. Passenger seating and restraints, control systems, inspection, testing and maintenance all form part of the wider attraction.
How Funfair Rides Are Tested for Safety provides further information on testing, while Daily Safety Checks for Funfair Rides and Funfair Ride Periodic Maintenance look at other stages of the operational process.
Follow the Roller Coaster from Engineering to Rider Experience
Once the basic mechanics are understood, several related questions become easier to explore. What Is the Best Seat on a Roller Coaster? considers how position within the train can affect the experience, How to Cope with Motion Sickness at the Fairground covers individual responses to movement, and How to Stay Safe on Roller Coasters provides passenger guidance.
You can also read What Is the History of the Roller Coaster?, visit Rollercoaster FAQs, browse roller coasters, continue through our Guides, or contact us about roller coasters and other fairground attractions for an event.