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Every Mechanism

Home How a Roller Coaster Works

No engine on board

How a roller coaster works

A motor hauls the train up the lift hill once. Gravity does the rest, and a computer keeps the trains apart.

Shape the hills
32m
to the top of the lift
83km/h
at the bottom of the drop
4g
in the dip after the drop
560m
of track, there and back
A steel roller coaster in a green park under a summer sky: the tall blue-columned lift hill on the left, a golden-yellow track swooping over a camelback hill, and a red train upside down at the top of a teardrop loop on the right, with trees, a path and kiosks around it.
A red train over the top of the teardrop loop, the lift hill and the camelback behind it.

Video

How a Roller Coaster Works - No Engine on Board

Watch on YouTube

3D model · full size · ride it

Ride it, slow it, take it apart

The whole coaster at full size. Press Dispatch, drag to look around, scroll to zoom, click any part.

Try itPress Dispatch. The computer checks the lap bars, the gates and the track ahead, then opens the station brake.
Loading the 3D model…

Meet the parts

A car taken apart, at the top of the lift

The front car taken apart near the top of the lift, beside its motor. Tap a part or pick a name.

A red coaster car taken apart above the lift hill near its top: the body with its nose and white stripe at the top, the black seats with yellow lap bars below it, the dark chassis with the copper brake fin, and the two wheel assemblies with teal wheels round the golden-yellow rails. The chain runs up the middle of the track between the saw-toothed anti-rollback racks, and on the right the blue electric motor and its gearbox stand on a steel deck beside the track.

Hover or tap the picture. Golden rings mark every part.

The ride from above

From the station and back again

The whole circuit from above, numbered in the order a train meets each place.

The whole roller coaster seen from above and to the south, with fifteen numbered places: the station and its control panel on the left, the long straight lift hill, the crest, the first drop and the valley, the camelback hill with a red train on it, the teardrop loop and the banked turn on the right, and the brake run, the block brake and the long return track along the back.

Train A, red, is over the camelback hill. Train B, violet, waits in the station.

    How it works, step by step

    Twenty-two steps round the ride

    The video’s steps. Press Show me in 3D to put the model at that moment.

      The roller coaster in its park.
      Step 1 of 22

      No engine on board

        Demo · where the energy goes

        Shape the hills

        Drag the hills up or down and send the train. Make one too tall and it won’t get over.

        • Blue: height energy.
        • Orange: motion energy, the speed.
        • Red: energy lost as heat.
        • Yellow line: how high the train’s energy could still lift it.
        –speed
        –height
        –riders feel
        –lost as heat

        Demo · forces in a loop

        A circle or a teardrop?

        Send a train round a circle or a teardrop and see what the riders feel at the top and the bottom.

        • Green: a comfortable push, up to 3 g.
        • Orange: strong, 3 to 5 g.
        • Red: too much, over 5 g, or hanging in the lap bar below 0 g.
        –at the bottom
        –at the top
        –the most
        –speed at the top

        Demo · magnets that never touch

        The magnetic brake

        A moving copper fin stirs up currents that drag on the magnets: the faster, the harder. No contact, no power needed.

        • Copper fin under each car.
        • Orange swirls: the currents in the fin, stronger the faster it moves.
        • Red glow: the fin warming up as the speed becomes heat.
        –speed
        –braking force
        –slowing at
        –heat made

        Demo · keeping trains apart

        One train per block

        A train may enter a block only when it is empty. Dispatch, add a train, or cut the power.

        • Red block: a train is in it.
        • Green block: clear.
        • Orange bar: a closed brake; it turns green when air opens it.
        –trains moving
        –held at a brake
        –blocks in use
        –rides finished

        More to know

        Kinds, history and safety

        Six kinds of roller coaster

        This oneSit-down steelRides on top of a tubular steel track.
        Timber trackWooden coasterLayered wooden track topped with steel strips.
        Hanging belowInverted coasterThe train hangs under the track, feet dangling.
        No lift hillLaunched coasterMotors fling the train to speed in seconds.
        One small carWild mouseSingle cars, sharp flat turns.
        Cars that turnSpinning coasterEach car spins freely on a pivot.

        From ice slides to steel loops

        1. Russian ice slides: the “Russian mountains”.
        2. Promenades Aériennes, Paris: cars locked onto their track.
        3. Thompson’s Switchback Railway opens at Coney Island.
        4. Matterhorn Bobsleds: the first tubular steel track.
        5. The Corkscrew: the first modern inversions.
        6. The Great American Revolution: the first modern vertical loop.
        7. Flight of Fear: the first linear-motor launch.

        Keeping it safe

        • Every morning, staff walk the track and send the trains round empty.
        • Wheels wear and are checked and replaced regularly.
        • Sit back and keep your hands and feet inside.
        • If a ride stops, stay seated: the brakes hold and staff will come.

        Things worth knowing

        One motor for the whole rideThe lift gives the train all its energy in about 20 s.
        About 7 clacks a secondThe anti-rollback dogs, a tooth every 45 cm at 3 m/s.
        Below zero gUp-stop wheels hold the train down over sharp crests.
        Four times your weightFor a moment at the bottom of the first drop.
        Brakes that need no powerPermanent magnets work even in a power cut.
        Why a teardropA circle would pull 6 g or more at its bottom.
        Quick check

        Four questions