The Assassin (Sha ren zhe Tang Zhan)

Kingda Ka...

The world's tallest roller coaster.

This is definitely something special.

For engineering that packs a punch...

Oh, my gosh!

The sensation of a launch... This is something akin

to jet-fighter stuff we're talking about.

Designers had to look

to innovations from the past.

This is one of the last remaining rides of its type

in existence anywhere in the world.

These are U.S. Navy F-18s.

You can feel the power.

What an experience.

To make the impossible possible.

captions paid for by discovery communications

in ocean county, New Jersey, stands an engineering colossus.

This is Kingda Ka...

the fastest roller coaster in America...

and the tallest in the world...

with jet-like acceleration.

Arms down, head back, hold on!

And twice as high as the statue of Liberty at 456 feet.

This finely tuned construction

is the perfect balance of science and engineering.

And roller-coaster engineer Michael Reitz

was central to its construction.

You take it when loaded, a 22,000-pound train,

and you launch it up to 128 miles an hour in 3 1/2 seconds.

That in and of itself is an amazing feat.

This record-breaking roller coaster

has another engineering trick up its sleeve.

Built within the structure of the 456-foot top-hat tower

drop of doom...

the highest and fastest drop ride ever built.

I think a ride of this size and this complexity

doesn't come around very often.

It takes a lot of time and it takes a lot of money

and it takes a lot of energy to create something this dramatic.

This 3,100-foot-long, adrenaline-fueled ride

has pushed roller-coaster design to its limits.

A 12,500-peak horsepower launch system fires trains

from zero to 128 miles per hour in an astonishing 3.5 seconds.

After scaling the 456-foot tower,

riders plunge into a 3/4 spiral, crest a second hill,

and complete the ride in just under a minute.

And if that's not enough,

engineers also incorporated Zumanjaro,

a 415-foot, 90-mile-per-hour drop of doom.

With each rise and fall, twist and turn,

the rider experiences a mixture of acceleration

or gravitational forces

which form the foundation of the ride experience.

But to design and build a ride of this massive stature

meant pushing engineering

to match the limits of human endurance.

We're always looking for ways to top something

that's been done before.

We want to have the steepest drop

or the most inversions or the tallest or the fastest.

But it's hard to innovate.

I mean, physics are physics, you know?

You can only do so much to the human body.

So, how do you build a ride this tall and this fast

that people will still enjoy?

This would've been impossible without the breakthrough design

that brought gravity and physics together... the scenic railway.

It's said that 17th-century Russia

was the birthplace of the roller coaster.

Giant ice slides were constructed

to amuse the likes of Catherine the great.

Wahoo-shki!

But the slides relied on cold weather.

We are not amused.

Oy! that's my line.

In 1828, in Pennsylvania,

a gravity railway was built

to bring coal down from the mountains.

Yeehaw!

But it was so much fun

that tourists started paying to use it, too.

Scream if you want to go faster.

But while it took half an hour to ride down the mountain,

it took four hours for mules

to pull the carriage back to the top.

Bored now.

Fortunately, one man realized

the mountains didn't have to be real.

American inventor Lamarcus Thompson

was inspired by the gravity rides

of the Pennsylvanian coal railway.

Are you ready?

Oh, let's do this!

And science communicator Kate Mulcahy

is in the Danish capital, Copenhagen...

experiencing the ups and downs

of Thompson's truly game-changing design.

This is the Rutschebanen, one of the last remaining rides

of its type in existence anywhere in the world.

Back in 1914,

it was the pinnacle of roller-coaster design.

Its creator would go on to become known

as the father of the gravity thrill ride.

In 1887, Thompson introduced the scenic railway,

a purpose-built ride that incorporated artificial scenery.

With it,

he innovated a 2,000-foot-long figure-8 route.

The scenic railway allowed passengers to get on and off

at the same point...

And something else even more hair-raising.

There's an electric motor that operates a chain lift

that raises the passengers to the top.

At the top of the 85-foot-high hill,

the laws of physics take over.

As the cars roll down, gravity creates acceleration

and kinetic energy

until the next hill forms potential energy.

This pattern then repeats as the free-flowing

roller-coaster motion takes hold.

The Rutschebanen can reach speeds

of up to 36 miles an hour.

Now, because this ride relies on gravity alone...

Ooh!

There's a brake person behind me...

So if we get too fast,

the brake person manually slows us down.

Without that, there's a chance

that the carriages might lift off the track.

With his breakthrough engineering,

Thompson's scenic railways were in high demand,

and by 1888, his thrilling rides totaled 44 worldwide.

Thompson laid the foundation for the modern roller coaster.

He was a genius of his time.

And without his work,

this wouldn't nearly be as much fun.

Built from over 1,500 tons of tubular steel

and over 40,000 metal bolts,

Kingda Ka's truss frame construction

is a modern engineering masterpiece.

And like Thompson's scenic railway,

it relies on a mixture of momentum and gravity

to turn potential energy into kinetic energy...

But with a spine-tingling twist.

So, the easiest way to put energy into a roller coaster

is what we've traditionally done.

That's to take a train up to the top of a hill.

This flips that on its head,

and we're gonna put all of the energy in down on the ground.

Hold on!

The energy needed to reach that height is immense.

When the train launches,

it's unlike any other coaster.

Being pushed into the launch position.

That amount of energy,

from zero to 120 miles per hour in 3 1/2 seconds,

it's so intense, you're stuck to the seat.

You can't move.

I mean, you probably have never felt anything like it.

Oh, my gosh!

Whoo!

Known as an accelerator coaster,

the required kinetic energy is generated at the launch.

Oh, wow! We are up at the top already.

But crucially, for passengers, the speed is converted

into a ride experience that can be tolerated.

This misconception that people have

of height and speed relating to g-forces,

it's really only related to the acceleration.

I mean, as long as we stay within the accelerations

that have been established

and what the body is capable of handling,

then we can go taller, we can go faster.

Wow.

That ride is intense every time.

The human body can't feel speed,

only changes in speed.

But engineers can build controlled acceleration

into the track itself.

The radius and gradient of each curve

is carefully calculated

to keep g-forces within the realms of pleasure,

not pain.

Coming up with new ways to give people controlled fear,

it can be challenging.

It can be somewhat difficult

because we've pushed the limits of physics

and we've pushed the limits of building,

but somehow or another, we seem to keep doing it.

Kingda Ka's engineers have succeeded in building

one of the most audacious rides on the planet.

But to fire this roller coaster

over a 456-foot tower over 500 times each day,

engineers had to look to the past...

The pilots inside the plane experience 6 g.

That's double what astronauts underwent

during a space-shuttle launch.

To create more impossible engineering.

Kingda Ka is America's fastest roller coaster

and the tallest on earth.

In this 500-acre park,