Roller Coaster Engineer Answers Roller Coaster Questions From Twitter | Tech Support | WIRED

Matters That Matter
38 followers
Jan 2, 2025 #Education
Hi, I'm Corey Kiepert.
I'm a rollercoaster engineer.
Let's answer some questions from the internet.
This is Rollercoaster Support.
At MudFence asked,
what's the tallest rollercoaster in the USA
and the fastest in the world?
The tallest rollercoaster in the world
and the fastest rollercoaster in the world currently
is Kingda Ka, Six Flags Great Adventure in New Jersey.
456 feet tall, 128 miles per hour.
I would not wanna be the one inspecting that ride.
Use a drone.
At Kristen Marie,
has anyone thought who invented the first rollercoaster?
Were they just like, let's sit in a cart
and drop up and down on rails for fun?
The first rollercoaster 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 coal mining operation,
like when it's not in use.
You can sort of see some of this
in Indiana Jones and the Temple of Doom.
Nat 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 rollercoasters.
At Shuffleupagus,
what causes that weightless feeling we get on rollercoasters
when experiencing a big drop or a loop?
You at home right now, you're experiencing one G.
That's one times your body weight.
Now, when you're accelerating down,
like through a valley of a rollercoaster,
suddenly you're experiencing maybe three or four Gs,
three or four times your normal weight.
When I'm going over a hill,
there's a force, the centripetal force.
It's like V squared over R.
So you have one G down normally, right?
And then you have another G pushing up
and that zeros 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 in space floating would feel.
And then there are other places on ride
where we just want to push you into the seat,
make you feel three Gs or four Gs on some rides.
There are some rides where it's just like
up to almost six Gs.
That's basically what a ride designer does,
is how can we manipulate the G forces
and give you like a thrilling ride experience.
That's 610 Sports KC 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 greater time everywhere.
Really, the best answer is like,
you need to try every seat on every roller coaster.
At CO Swoji, 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 kind of 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.
If you look on my screen,
you can see I'm measuring the G-forces.
Me, I'm one G, that's my weight.
But if we're going through that valley,
suddenly I might have like three times my weight,
three Gs 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 out of 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.
Atconingsteve says, which coaster is better,
old school wood or modern metal?
Before we can get into this,
we got to 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 track,
some you're sitting below the track,
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.
At Free Dajon Wells 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 kind of 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.
At Joe Cornick said, how do roller coaster designers
determine the perfect balance between thrill and comfort
for maximum rideability?
Oh man, that's like the Colonel'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 turn style
and ride that ride again?
I think as humans, we love the bouncy feel.
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 banked, 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 like
combination of G forces that exists
that can really thrill and excite people.
At misneeds 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.
At Dan Spencer 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 of numbers
and know whether a ride's gonna be good or not
before I sit down and ride it.
At Jake Coasters says,
why do all inverts have a curved first drop?
Would a regular 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 back seat going down that drop.
Other people are like, I want something majestic.
I want you to see the scenery around you.
At May Lacoboire 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.
Well, Marcus 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 a hundred rides, like all over.
I've worked on like in the 30s to 40s now.
At The Mullet Man, 513 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 like adding the potential,
like having the lift hill,
we'll put energy in like through some type
of launch mechanism, like a limb 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 like some type of crazy thrilling experience.
At Gia Maria 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 kiddie coaster.
That ride, you know, was designed by Schwarzkopf,
who is 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.
At I'm Sheo 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, Kittia
that's opening soon that'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.
At Johnny453 asked, is America the best at roller coasters?
What other countries are in the running?
Everybody talks about going to VelociCoaster
or the Hagrid's Motorbike.
I mean, you've 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, Kittia,
that's gonna have the new longest roller coaster
in the world.
You've got amazing rides all over.
At Ayakuni Yuki 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 in 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
and then they'll deal with other gravitational problems.
At Blakeademic asks, 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.
At Britbrat14, 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.
At Slam13, 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.
Coaster Touring, 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 ittle bitty layer of steel.
You know, maybe it's like three eighths
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.
