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Engineer Explains Every Roller Coaster For Every Thrill

In this edition of "A World of Difference," Korey Kiepert, owner and engineer with The Gravity Group, goes through the 8 main types of roller coasters and breaks down how they work as well as the decisions behind why they get built in the first place. Korey explains the difference between a giga coaster and a strata coaster, as well as what separates a "wild mouse" from a "mine train." Korey Kiepert, courtesy of The Gravity Group Special thanks: Kings Island, Holiday World, Gröna Lund

Released on 03/05/2021

Transcript

[Interviewer] Here are a bunch

of different kinds of roller coasters.

This one is metal.

This one is wood.

Here's a wild mouse, a launched coaster.

There are a lot of different kinds of roller coasters,

but they all have a few things in common.

Coaster.

When you're designing a ride,

you have to draw people into the ride.

You want people to look at that ride and say,

I gotta give that a try.

[Interviewer] This is one of the engineers

who make these roller coasters.

I'm Korey Kiepert and I'm an engineer

and partner at The Gravity Group.

And these amusement rides, like the ones behind me,

that's my specialty.

[Interviewer] Can you explain

what a rollercoaster engineer does?

I will do some of the structural engineering

and the mechanical engineering for the ride.

So, there might be an amusement park that comes

and they say, This is the plot of land that we have.

This is the budget that we're thinking.

What kind of ride can you give us?

My job would be to say,

Yeah, I can fit something in that spot.

And it would be really cool if I could use

this hill over here to add a terrain aspect to the ride

where I actually use some of the ground features.

Or if there are buildings or other rides

that I could interact with,

I try to take all of that into consideration

when we're designing a ride.

[Interviewer] So why is it

that there are so many different types of roller coasters?

So, when we design a roller coaster,

we're trying to take something that's very much driven

by the same codes that would be used to design a building,

and we're working with those to create something

that gives you the illusion that it's daring and adventurous

but, at the same time, it's all very controlled.

That's the heart of what we do.

[Interviewer] Okay, what are all the factors

you have to consider when building a rollercoaster?

When we design a rollercoaster for a park,

the backbone of everything we do follows safety standards.

That can vary depending on the country.

Here in America, we might have the ASTM standards

that we follow.

Europe has their own standards.

China has their own standards.

So, we have to balance what is best for the rider

in terms of what are the safe limits.

But, at the same time, we're also making it exciting.

We're making it fun.

[Interviewer] Okay, so what do all these roller coasters

have in common?

The first thing is they all have a car.

And on these cars, you have a set of different wheels.

You have a top wheel or a road wheel.

The second wheel would be called a side wheel.

Sometimes they're on the outside of the tracks.

Other times they're on the inside of the tracks.

And that wheel is used as you're going around a turn.

When you're going over a hill,

if you just have those two wheels,

your rollercoaster would fly off the track.

So there's a wheel on the underside of the track

called an up-stop or an uplift wheel.

The track can be made of wood or it can be made of steel.

In between the rails, there's something called a crosstie,

and that's something that is holding the distance

between these rails constant.

Then we have supports.

If you have a steel roller coaster,

you have relatively few supports in large spans.

If you have a wooden roller coaster, the spans are tighter

and you have more of a traditional lattice

or truss structure.

Other similarities: they all have a braking system,

which consists of a long fin that runs through a pinch brake

or you might have some differing metal

that would run through a magnet

and actually slow the train using a magnetic force.

That's a more comfortable, more gradual way

to bring your ride to a stop.

[Interviewer] What forces do you have to take into account

when designing a roller coaster?

Primarily, a roller coaster is made up

of vertical G-forces, horizontal G-forces,

that's the side to side,

and the longitudinal, or front to back G-forces.

So, 1G, that's just me right now.

I'm sitting here. I'm 1G.

However, as I'm going over the hill,

that crest, you might feel a what's called the airtime.

And airtime, those are the negative G-forces.

That's where I feel like I could be launched out of my seat.

And then when you hit the valley,

you're pushed into your seat,

and that's a positive vertical G-force.

We're putting a lot of twists and turns

into our rides as well.

We call that banking.

We're controlling the horizontal G-forces,

or the side-to-side forces.

And so sometimes you might just bank at 45 degrees,

you know, and there might be other times

where we try to be extreme

and you have what are called overbanked turns.

And that's something where we go beyond 90 degrees.

That's another tool.

And so, now you can start combining some elements

a little bit.

And so, you might have a certain vertical G-force

and horizontal G-force,

and you can arrange them in such a way

that eventually you can do an inversion.

And depending on the G-forces that you have

as you're going through this inversion,

you can have something where you feel like you're floating

and we would call that like a zero-g roll.

[Interviewer] So, what are all the different types

of roller coasters out there?

So when we're talking about a ride

and we're calling it a wooden roller coaster

or a steel roller coaster,

in general, what we're talking about

is what is the primary track material.

In a wooden roller coaster, it's all about the stack.

We have these plies of woods stacked on top of each other

that we then put steel rails on.

With wooden roller coasters, there were certain layouts,

like there'd be out-and-back roller coasters

where you went out and came back,

or there'd be twisters or a cyclone-style roller coaster

like in Coney Island.

The Cyclone is a wooden roller coaster.

It's one of the oldest rides still operating

in the United States.

It was built in 1927, I believe.

And that's a compact ride.

It has a very tight footprint.

Just kind of goes back and around on itself multiple times.

You know, it has the drops, it has some of the turns

and it's just a rollicking, fun ride.

To many people, it just represents

what a nostalgic wooden roller coaster is

and is meant to be.

[Interviewer] You mentioned an out-and-back coaster.

What is that?

An out-and-back roller coaster is all about airtime.

And one of the best out-and-back roller coasters

that I can think of is one called the Voyage,

and it's in a park called Holiday World in Indiana.

And the Voyage is the second largest wooden roller coaster

in the world.

And you start in one section of the park,

and then you just go out into the woods.

And what's really iconic about this ride

is it has three hills.

The first three hills on the ride are all over 100 feet.

So you have these drops one after another, 100 feet or more.

And so, that really gives you the airtime.

And the Voyage, when it was designed,

the goal was to make an out-and-back roller coaster

that had more airtime than any other ride in the world.

That's probably the most iconic version of an out-and-back.

The most nostalgic out-and-back that I think of

is probably the Blue Streak at Cedar Point.

It's just a classic, small wooden roller coaster.

It has kind of the white structure

hearkening back to Coney Island Cyclone as white.

[calm instrumental music]

[Interviewer] What other materials

are roller coasters made from?

Certainly, when you look at an amusement park,

there are a lot of steel roller coasters.

They kind of harken back to actually Disneyland.

The Matterhorn was actually the first

tubular steel rollercoaster, and that was Aero Development.

They worked with Disney to create this ride.

And from there, the roller coaster just continued to evolve.

And so, when Cedar Point built the Magnum in 1989,

they broke the barrier, you know, of what was really common,

what was knowledge.

And it started a category of rides called the hypercoaster.

Any roller coaster that breaks like the 200-foot mark

is considered a hypercoaster.

And the Magnum started the big arms race,

the big coaster war that we have today.

And from there, you know, as our technologies improve,

as different manufacturers have evolved

with new ride styles,

we've gone from the hypercoaster which was 200 feet

into a new category called the giga coaster.

A giga coaster is now a ride that is in the 300-foot range.

You have Fury 325 or Intimidator 305.

Kings Island recently added Orion,

which is also a giga coaster.

It has that dropped that's 300 feet.

So, as people thirst for more and more

and something that's more and more thrilling,

the hypercoaster has become

more of a common roller coaster,

and then the giga coasters,

I think there are only about maybe 12 of them

on the planet right now.

And then you have coasters that are even beyond that.

You have these strata coasters now.

Kingda Ka at Six Flags Great Adventure in New Jersey

is 456 feet tall.

And these become highly thrilling rides

that are intimidating to people, but they're also iconic.

But as you go taller and taller with a ride,

you're changing that bigger potential energy

into more kinetic energy.

And that in turn means that you have to be concerned

about the additional speed

and the duration of some of these G-forces,

not only on your body but the track as well.

The impact factors on these rides forces manufacturers

to look at more material, more steel,

the foundations are bigger.

And so the expense of these rides

just exponentially increases as well.

[calm instrumental music]

[Interviewer] Okay, what other types

of roller coasters are there?

When a park has a lot of hills or terrain,

often as a ride designer

like we wanna take advantage of that.

If there's a valley that you can drive

your roller coaster into, you wanna do that.

And so, on a wooden roller coaster,

you especially have that advantage

where you can make your path follow this terrain.

We can gather information about the hillside,

trees, rock formations.

And the great thing about that is you make a ride

that's very efficient because there's maybe less structure

that you have to build.

You don't necessarily have to build a lift hill super high

if you can take advantage of building

some of that lift on the hillside.

And then if you can drop into that valley,

you have a bigger drop and increased speed

and it can just add to the sensation.

Sometimes at the end of a ride,

if you're up on one elevation

and you can just drop off the hill into the valley,

it just adds so much speed to the ride.

Typically, rides, as you go on,

they feel like they're getting

a little bit slower and slower.

The hills have to get smaller.

But if you have terrain, you can go into that valley

toward the end of the ride and suddenly have a 50-foot drop

that maybe you couldn't have had otherwise.

And in many ways, what I love about them

is they're kind of like high-speed nature trails.

You know, you have the trees or rock formations

that you're just whipping past you super fast.

It just gives you that thrill

that you're going maybe a little bit faster

than you really are.

[Interviewer] What's the best example

of a terrain coaster?

The Beast here at Kings Island.

It's probably the most iconic

of the terrain roller coasters.

It also is the longest wooden roller coaster in the world.

And it's been the longest wooden rollercoaster

for a long time.

I mean, it's over 40 years old.

[calm instrumental music]

The wild mouse, it's just a classic-style ride.

It can be made out of steel or they can be made out of wood.

When I think about a wild mouse,

the thing that's most iconic about them is the hairpin turn.

So you go up a lift hill and then you do a lot of zig zags.

But when you're doing these zig zags, they're super tight.

I mean, they might be like a 10-12 foot radius

or even smaller.

And you typically have maybe one or two cars maximum

that make up the length of the train.

So, when you're making these sharp turns that are unbanked

there's a high lateral force or a horizontal G-force

that you experience.

Another thing is there's not structure underneath you.

So you go out way over and it's just straight down

and you're in this tight car

and you have a feeling like, is this safe?

Should I be doing this?

And so, it's those turns, those tight turns,

on the wild mouse that really make it special.

One of my favorite wild mice is like the Vilda Musen

at Grona Lund.

And the reason I love that ride

is it's a very large wild mouse,

and it's also in and around all of these other rides

in the park as well.

And that just adds to the thrill.

It invites the guests that are walking through the park

into that ride experience.

[calm instrumental music]

[Interviewer] What's a good introductory roller coaster?

Mine train coasters in general are a freeform ride.

There's not a set rule that they have to follow,

but the trains, they're these boxy trains

with a relatively simple chassis or carriage or wheel system

to give it that rickety look.

And it's essentially a ride that gives you

that out-of-control feeling, like Indiana Jones or something

where there are tracks all over the place.

[dramatic instrumental music]

It wasn't necessarily about speed.

It wasn't necessarily about the height.

It was about being out of control.

And that's what mine trains are great for

is just introducing your guests

to that first roller coaster experience.

[calm instrumental music]

[Interviewer] Okay, what can you tell me

about launched rollercoaster?

You know, that you're on a launched roller coaster

if you're sitting in the station

and then like five seconds later

you're going through an inversion

or something at like 70 or 80 miles per hour like crazy.

[riders screaming]

What we're doing on a launched roller coaster

is we're using some external means,

like a linear synchronous motor,

a fancy way of saying like these electromagnets

that just in a line they just shoot you out super fast,

or flywheel launch or a hydraulic launch

where they're focusing the energy of something

into a device that maybe propels you quickly

using like a cable or something.

But in general, you don't have to have that lift hill

in front of you.

You could be flat on the ground and just go zero to 60

like no one's business.

[Interviewer] What's a good example?

The Incredicoaster is an example

of a launched roller coaster.

That one, they wanted it to look

like a traditional roller coaster

so there's some uphill portion to the launch.

Other launched roller coasters,

there's like Thunderbird at Holiday World,

which is a winged coaster,

in addition to being a launched roller coaster.

[calm instrumental music]

[Interviewer] Okay, what other elements

are rollercoaster engineers playing with?

Aside from just the configuration of the ride

in terms of the path, the other thing that we can play with

as a ride designer is the configuration

of how guests are seated on the ride.

Instead of being a traditional car

where you're just sitting,

there are cars where you are standing,

such as Green Lantern.

There are rides where you're flying

and you're on your belly going through the elements.

There are other roller coasters

where instead of sitting facing forward,

I might have a car or two where I'm sitting backwards.

Sometimes parks opt to take a ride and run it backwards.

Batman: The Ride in many Six Flags parks,

they've opted to run their Batman rides backwards

during certain seasons.

Another thing that we can do with a roller coaster

is we can put you under the track.

So instead of riding in a car

that's directly above the track,

now we're below the track.

And are were suspended roller coasters,

like the Big Bad Wolf at Busch Gardens in Williamsburg

where you're on this cart below the track

and as you go around the curves,

the car actually kind of swings out and swings back.

A more modern version of a ride

where you ride below the tracks is something called

an inverted roller coaster.

And the great thing about an inverted roller coaster,

you have your legs they're just dangling freely on the ride.

And that just adds a completely different sensation.

When you're going through a valley and you go down that drop

and you hit the bottom,

suddenly, like your feet weigh, you know,

four or five times what they're used to

and you can feel that.

Monster, it's being built at Grona Lund this year in Sweden

and that's one where it's an inverted roller coaster

and they have so many buildings

and other rides that are so close together at this park.

You're gonna feel like you're gonna hit something

with your foot almost.

At Alton Towers, they had a ride called Nemesis

that they built, which is an inverted roller coaster.

And there are height limits at some parks,

and you can't build a ride that's very tall.

So Nemesis, what they did is they cleverly built

these canyons, or gorges, that the ride dives into.

It just adds so much to the ride experience.

On a winged coaster what you do is you have the track

in the center but you're outside of the track.

So when you're riding this ride,

you don't necessarily see the track in front of you

as much as, you know, you see this other land beside you.

Thunderbird at Holiday World is a great example of that.

Tron's motorbike coaster at Shanghai Disneyland

is an example of something where I'm riding this ride

and it's as though I'm on the lightcycle from Tron.

And so, the position that I'm riding this roller coaster

is completely different.

By mixing up the configuration of how you're seating,

it just adds a whole new dimension to the ride.

[calm instrumental music]

[Interviewer] Any other types?

Yeah, the 4D coaster, which is kind of abbreviation

for the fourth dimension roller coaster is just something

where they were trying to take the standard roller coaster

and add another element to it.

What they did is they took a winged roller coaster,

so I'm off the side of the track,

but I'm free to spin upside down while I'm on this ride.

And so you have a crazy course,

but at the same time, you're spinning out of control

around and around.

And when you're spinning freely like that,

every ride is different.

[calm instrumental music]

[Interviewer] So, what new kinds of roller coasters

are engineers envisioning?

Yeah, I mean I think what we're seeing

in the amusement industry is just a blend

of technology with rides.

You know, certainly I think that you can add VR

or augmented reality to rides.

There are some roller coasters that have already tried

the virtual reality.

You know, that's certainly a possibility.

And I think that, you know, there's a further blending

of just fine tuning the technology,

how we play with the launches and the storytelling.

At Hagrid's Motorbike Adventure, you know,

they added extensive theming and there's sort of a story

along with the roller coaster experience,

other things that you can look for.

And I think that what we're trying to do

is we're trying to take modern technology

and apply it to something that traditionally

has been very handcrafted.

We're trying to take something

that is 100-year old technology

and make something new out of it to reinvent it.

And that's the goal of the whole industry, you know.

This steel tubular track ride, how can I reinvent it?

What else can I do?

And I mean, I could tell you some stuff right now,

but I'd get in trouble. [laughs]

Starring: Korey Kiepert