Hi, I am Korey Kiepert.

I'm a roller coaster engineer.

Let's answer some questions from the internet.

This is Roller Coaster Support.

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@mudfence asked, What's the tallest roller coaster

in the USA and the fastest in the world?

The tallest roller coaster in the world

and the fastest roller coaster in the world currently

is Kingda Ka, Six Flags Great Adventure in New Jersey.

456 feet tall,

128 miles per hour.

I would not want to be the one inspecting that ride.

Use a drone.

@kristen_marriee,

Has anyone thought who invented the first roller coaster?

Were they just like, 'Let's sit in a cart

and drop up and down on rails for fun?'

The first roller coaster actually goes back

to Russian ice slides,

so basically like sliding down a hill on a block of ice

and then it evolved into like mine carts

and people said, Hey, maybe I could make money

off of this this coal mining operation,

like one that's not in use.

You can sort of see some of this

in Indiana Jones and the Temple of Doom.

[scream loudly]

Now it actually has a little bit of truth.

Someone named LaMarcus Thompson

opened the Switchback Railway at Coney Island in 1884.

He's known to many people as the father of roller coasters.

@shufflupaguss, What causes that weightless feeling

we get on roller coasters

when experiencing a big drop or a loop?

You at home right now, you're experiencing 1g.

That's one times your body weight.

Now when you're accelerating down

like through a valley of a roller coaster,

suddenly you're experiencing maybe 3 or 4gs,

three or four times your normal weight.

When I'm going over a hill, there's a force,

a centripetal force, it's like V squared over R,

so you have 1g down normally, right?

And then you have another g pushing up.

And that zeroes each other out,

so you actually feel this like weightless feeling.

Similarly, like if I'm on a swing set,

when I get to the very top,

there's that instant before I fall back

where you, again, feel that weightless sensation.

We're trying to give you some places on the ride

where you feel like no gs,

where you feel that weightless feeling like an astronaut

and space floating would feel.

And then there are other places on ride

where we just wanna push you into the seat

and make you feel 3gs or 4gs on some rides.

There are some rides where it's just like up to almost 6gs.

That's basically what a ride designer does,

is how can we manipulate the g-force

and give you like a thrilling ride experience.

@610SportsKC says, Where is the best seat

on a roller coaster?

I think in general, think about the extremes.

The front seat or the back seat?

The back seat of a ride,

that's where going down the first drop you get the airtime,

but if a ride has something like a double up,

then you get that front seat airtime

as you go into those hills.

When you have a really long train,

you might only experience more extreme airtime

on the front end or the back end of a ride,

but I think there's a whole group of rides

where you have just a fun experience

no matter where you're sitting on the ride.

Like I know a ride that we recently did,

I sat in all 12 different seats

and I just had great airtime everywhere.

Really, the best answer is like you need to try every seat

on every roller coaster.

@COsuoji, How do roller coasters get tested?

The very first time rides go around,

we fill them up with test dummies.

Many times parks use like water dummies

that are kinda shaped sort of like the body.

We send it around the track and we have something like this.

This here is actually an accelerometer.

What it does is it takes impulses of voltage

and relates them to the g-forces of the ride.

Like as you're going down the ride,

this thing will react to the accelerations.

You look on my screen,

you can see I'm measuring the g-forces.

Me, I'm 1g, that's my weight.

But if we're going through that valley,

suddenly, I might have like three times my weight,

3gs or something.

We'll use a device like this mounted in the train

and then we'll correlate that with our design data

that says, Hey, at this point in the ride,

we should have been this many g-forces.

And then year after year,

test the ride to make sure that it's not changing.

There's other testing that we do

throughout the process of the rides as well.

You know, like I have this part

that might be made outta steel

and I might do some non-destructive testing on that

to make sure that there are no cracks

from a material defect or from a machining defect.

There's a lot of work that goes on

behind the scenes at an amusement park to keep you safe.

Testing isn't just something that happens

before it opens up to the public.

It's an ongoing process.

@KoenigSteve says, Which coaster is better:

old-school wood or modern metal?

Before we can get into this,

we gotta figure out like what's a wood

versus a metal coaster?

Lucky for you, I happen to have brought

some wooden roller coaster track

and some steel roller coaster track.

On a wooden roller coaster,

you can see I've got all these layers of wood,

and then on the top, I have this piece of running steel.

There'd be two of these,

there'd be a mirror image over here.

Wood changes, you know.

On a day when it's wet, it expands a little bit

so you get a different ride depending on the environment.

Steel roller coasters, the top wheel might've been here

and the side wheel here and then there'd be a mirror image

like another piece of steel over here,

and then there'd be another tube down below.

They'd take this steel and they'd bend it into the shape

with your curves and your drops.

Some you sit above the tracks,

some you're sitting below the tracks,

some you're flying like superman on the tracks.

I personally like all the hard work

that goes into a wooden coaster.

I think they're more beautiful,

but I've had some amazing rides

on steel roller coasters too.

@FreeDajonWells asked,

How do roller coasters stay on the tracks?

I'm gonna bring out my handy dandy

wooden roller coaster track model again.

It's quite a workout for me today.

When you look at this track, and the same is true

with the steel coaster piece that I have.

There's a running surface for a top wheel, a side wheel,

and then what's really cool is there's this place

on this track for an undercarriage wheel.

So we have multiple wheels that are holding it on track.

This is a model of a roller coaster car

where you can see the top wheel,

some side wheels, and then an uplift wheel,

and that just kinda locks on this track

and prevents it from coming off.

That technology actually goes back to the early 1900s.

John Miller, who's a classic wooden roller coaster designer

that was trying to push the limits,

that was something that he patented.

So technology from the early 1900s is still used today.

@joekornik said, How do roller coaster designers

determine the perfect balance

between thrill and comfort for maximum ride ability?

Oh man, that's like the Kernel's seven herbs and spices.

Totally secret, right?

To me, the measure of success

isn't like seeing how many people

are running toward the trash can puking.

The measure of success is like, are people laughing?

Are they smiling?

Are they getting off the ride

and wanting to just go through that turnstile

and ride that ride again?

I think as humans, we love the bouncy field.

I think that's why airtime is just so much fun.

But I mean, we all love like race car drivers

and just like being bank going around that curve

at a high speed being pushed into your seat,

and it's like music.

We only have so many notes, but we're varying the rhythm.

We're varying the order of the notes

and how fast we play certain notes.

We haven't come up with every song that exists yet,

and similarly, we haven't come up

with every combination of g-forces that exists

that can really thrill and excite people.

@MissSneed said, Engineers are so cool.

Like how tf you build a whole roller coaster.

Thank you, by the way, for calling me cool.

First of all, these are not roller coaster building hands.

These are mouse clicking hands.

I spend a lot of my time

behind a computer doing calculations and CAD work.

The first thing that we do

is we like to look at like say a Google Earth image

or a site plan of the park.

And then I love going to the parks and just walking around

and getting a sense for the site.

If there are certain hills or undulations

or if there's a certain ride that's nearby

that I could interact with,

that's gonna add to the experience.

There was a ride once where we had the first drop,

and then there was a log flume

that was coming in the opposite direction,

and if you time that ride just right the way we designed it,

you can get splashed from that log flume,

and to me, that just added like a little bit

of extra something special to the ride.

@DanSpenser says, Being a roller coaster designer

seems pretty easy.

'How big was the last one?

Yeah, yeah, make this one bigger.

Maybe faster, too.'

Different parks have different criteria.

Sometimes a park might be saying,

I want something with this marketing hook,

I want something that's taller, faster, steeper.

But there are a lot of times where parks might be,

You know, we want something that's for families.

There are just so many different levels

to the design of a ride from both the structure,

the ride path, and then also just the ride vehicle itself.

For us, it's all about numbers.

I can look at a table numbers

and know whether a ride's gonna be good or not

before I sit down and ride it.

@jake_coasters says,

Why do all inverts have a curved first drop?

Would a regular a drop be painful?

Not thrilling?

So I think like the inverted rides

that you're talking about, it's true.

Like there's like Batman: The Ride,

Alpengeist, different rides like that,

that might all have like a curving drop.

Some of it could have to do with clearances.

When you have people's legs dangling,

you have to make sure that you can keep an adequate distance

from one car to the next car.

It could also have to do with the parks.

Parks will say, Hey, I want the high point

of the ride here.

The only way you can have a high point there

is if you have an immediate curve.

I like a nice straight drop

so that I can have good airtime in the backseat

going down that drop.

Other people are like, I want something majestic.

I want you to see the scenery around you.

@maellekabore said,

How many roller coasters does a roller coaster designer

design over their roller coaster designing career?

I think that really varies.

John Miller is a prolific wooden roller coaster designer

from the early 1900s.

LaMarcus Thompson, you know,

the father of wooden roller coasters.

At 19 years old, he brought John Miller under his wing,

and then John Miller did like over a hundred patents.

Some of which we still use today,

like at Kennywood Amusement Park, there's the Racer,

the Thunderbolt, they're still fantastic today.

He started designing in the late 1800s

to the mid 1900s or so.

He did like over 100 rides, like all over.

I've worked on like in the 30's to 40's now.

@TheMulletMan513 asked, How do roller coasters work?

It's all about energy.

We have like kinetic energy,

we have potential energy, friction.

You're putting some energy into the system

so that you can go on a crazy path.

Sometimes like instead of adding the potential,

like having the lift hill, we'll put energy in

like through some type of launch mechanism

like a LIM or an LSM.

We take energy out of the system at the end,

and that's the ride.

And we do that in a safe manner.

So hopefully, we make it seem like you got off your sofa

and had some type of crazy thrilling experience.

@gioomaria asked, Carnival rides are very sketchy.

If a roller coaster can be folded up and trucked away,

that just ain't safe.

To paraphrase.

One of my bucket list rides that I would love to ride

is something called Olympia Looping,

which is the tallest, largest portable steel roller coaster,

and it goes around Europe all the time.

It's like 110 feet tall and over 4,000 feet long.

So it's not a little kitty coaster.

That ride, you know, was designed by Schwarzkopf,

who's a very legitimate ride designer.

You know, I think it's unfair to just isolate

and say carnival rides are sketchy.

The same people that inspect rides at amusement parks

are inspecting rides at carnivals.

If I made a portable roller coaster,

the people at the carnival company,

they'd have a checklist of daily inspections,

weekly, monthly, and yearly inspections

that they need to do on the ride.

@imxio asked, Why do roller coasters only last two minutes?

Can they be longer?

The length of a roller coaster is a function of the cost.

Whatever the building material is of the ride,

that's a direct cost driver of how long that ride is.

When I was growing up in the 1990s,

there was kind of an arms race of roller coasters

where parks were always trying to outdo one another.

The Beast, which is the longest wooden roller coaster

in the world, it's over 7,000 feet long.

That ride can take about six minutes.

There's a ride in Saudi Arabia at Six Flags Qiddiya

that's opening soon, that it's almost 14,000 feet long.

Parks are also concerned about throughput,

like how many people can ride that ride every hour?

You need to have more and more trains,

and all of those things add cost.

@Johnny453 asked, Is America the best at roller coasters?

What other countries are in the running?

Everybody talks about going VelociCoaster

or the Hagrid's Motorbike.

I mean, you got some good rides in Florida.

You also have an amazing collection of rides overseas

in Europe, Australia, China,

just about every developed nation in the world.

In fact, the biggest g-force of any ride is in South Africa.

We have roller coaster manufacturers here in America,

like that's where I'm based.

But you also have a whole slew

of roller coaster manufacturers in Europe.

There's a big park being built in the Middle East right now.

Six Flags Qiddiya that's gonna have

the new longest roller coaster in the world.

You've got amazing rides all over.

@Ayakuniyuki asks, What are roller coasters

going to be like in 40 years?

If I think about Coney Island and The Cyclone,

like that thing's been there forever,

and it's probably gonna continue to be there forever.

There are rides that are a hundred years old

like the Wildcat at Lake Compounce

here in the United States.

So I think 40 years from now,

some of those same rides that are classics now

are gonna be classics on the future as well.

I also think some of the amazing thrill rides

that we just are blown away by right now,

you know, like Kingda Ka or Top Thrill 2.

I think there's still a place for them

in the future as well.

There's still gonna be good rides produced tomorrow.

We already have drops that go 90 degrees,

so maybe we'll continue to push that envelope.

Maybe they'll put a roller coaster on the moon,

then they'll deal with other gravitational problems.

@blakacademic asked, Why do roller coasters

put that little break in the middle of the ride?

That's called a block break,

that allows them to have another zone

so that they can have another train on the track.

You have to break up a ride into multiple zones

so that you can have space

between the different roller coaster trains

that are on the track at a given time.

That has to do with capacity.

You wanna maximize the number of people

that can ride an attraction.

@britttbrat14, Why do coasters make me tired?

Anytime we have a ride,

we have like a lot of adrenaline rush,

like we're super scared.

You come down off of that afterwards,

and you're like, I need a nap now.

@slamb13_, Why do roller coasters always break down?

Well, first of all,

I don't know that roller coasters always break down.

Sometimes like there's new technology

that you have to develop for a ride,

and you're doing it on a roller coaster for the first time.

It's not a very great environment.

You've got rain, wind, snow, earthquake.

You also have like the vibration from the ride itself.

When you have a lot of moving parts,

when you have a lot of electrical parts,

from time to time, there are things

that might need to be replaced or looked at,

and unfortunately, sometimes that does happen on the day

that you visit a park.

Just know like from our hearts that we're doing all we can

to keep rides open as much as possible.

@coastertouring, How thick does the metal running plate

on a wood coaster have to be before it's a steel coaster?

I think what Marcus is getting at is,

see on the top,

I have this like little bitty layer of steel,

you know, maybe it's like 3/8 of an inch thick or so.

There are some rides where they're replacing this wood,

you know, with more and more steel

to the point where some of it, they keep the form factor,

the shape that you might see on a wooden roller coaster,

but it's really not made of wood anymore.

Once it becomes something that's just cosmetic

and not there for structural value,

it's no longer a wooden roller coaster.

It's a hybrid.

All right, well, thank you so much.

That's all the questions for today.

Don't forget to go out and ride those roller coasters.

Thanks for watching Roller Coaster Support.

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