Original subtitles

In a world of dangerous work,

modern machines and technological advancements

can mean the difference between life and death on the job.

From deep woods timber titans,

to mills of molten metal and rugged road warriors,

mighty machines are doing their part to keep humans safe

while getting the job done.

Welcome to the forest...

...where the deadly work of cutting, stripping,

and transforming towering trees into timber

is done by a team of powerful machines.

Cut off, we grab 'er, down she goes.

Timber isn't just raw material;

it's the backbone of hundreds

of other industries around the world.

When I see a tree, I'm sizing it up to see

what best I can get out of that tree.

These backwood goliaths

are tackling one of the most dangerous jobs on the planet.

Oh!

Perfect!

Getting a tree from the forest and into the mill

is no easy task.

In any terrain, anything can happen.

You've always got to be on your toes.

You've always got to watch where you're going.

Machines like the feller buncher,

forwarder, and harvester make the job look simple.

I do some of the work,

but the machine does most of the work to do it.

But this job is anything but simple.

This block we're in today,

it's about 1,000 acres.

Working in this environment, harvesting trees,

getting the bushes ready for logging operations,

makes it very, very challenging.

The trees aren't just sitting in front of you.

So, we're looking for a good quality,

generally pine trees - spruce, jack pine, red pine.

While the work

of bringing down timber is highly mechanized now,

it all started with axe-wielding lumberjacks...

Timber!

...who put their lives on the line each day

to make it happen.

Logging has always been a death trap.

You're dealing with huge, unpredictable trees

and rough terrain,

throw in nasty weather and heavy machinery,

and it's no wonder it's still one of

the deadliest jobs out there.

Forestry has been part of civilization

from the earliest times,

and so has the risk that comes with harvesting the timber

that builds our world.

Initially, humans took just what they needed,

but as the European colonies expanded,

so did the demand for lumber.

Back then, it was all about getting as much wood out

as fast as possible.

Occupational health and safety was almost non-existent.

Workers relied on their instincts

and what more experienced loggers taught them.

After World War II, machines took over.

Chainsaws replaced handsaws,

and harvesters did the work of entire crews.

The main hazards

in the original days was you got a man

out in the bush with a chainsaw, cutting trees,

limbing trees, they had felling hazards, overhead hazards.

Increased productivity brought increased risks.

Now, it wasn't just trees

that crushed people, but heavy machines, too.

The chainsaw led to

a dramatic increase in amputations and deaths.

These horrific accidents provided the evidence necessary

to create the vital safety standards we strive for today.

But machines dramatically improved safety.

Today, these woodland warriors are evolving, becoming smarter

and stronger.

Throttle up, get the engine to RPM,

turn on the hydraulics,

time to go cut some trees.

This mega machine,

the feller buncher, is 28 tonnes

of timber terminating power,

stretching five metres long and three and a half metres tall.

It's like a bulldozer crossed with a tank.

This is the feller buncher.

It's the machine that cuts the tree, picks it up, grabs it,

carries it around, puts it down wherever you want it to.

Imagine ten Paul Bunyan's

rolled into one steel giant.

This beast can bunch five trees in one go,

depending on their size.

With a machine like this, you could easily do

500 to 800 trees in one day.

Put 'em down nice and easy.

Right there. Perfect.

That's the equivalent of 12 men with chainsaws and axes

working an entire week.

It's a game-changer.

It gathers trees in its massive metal fist,

like grasping blades of grass.

This is what they call the 'big fingers'.

So, these fingers have all the power.

Once you cut a smaller tree, you close with both sets of fingers.

Small fingers will stay closed,

and you can open these ones up, and what happens is

the small fingers will hold the tree in place,

and you can cut more than one tree at a time.

These ones will open up and grab the next tree.

The fingers open wide,

the saw spins into action,

and the head closes in on the target.

Within a few seconds, it's on to the next conquest

to repeat the process.

Fingers, they're connected to the boom,

which does all the lifting work.

It picks it up, swings side to side,

and you can put it down wherever you want.

Down he goes!

The mammoth nine-metre boom arm

is longer than a city bus and can lift nearly six tonnes.

That's as much as a fully loaded truck trailer.

Add a 360-degree swing, and this steel giant

can grab trees from any angle

while locked in a single position.

This is what they call a 'hot saw'.

So, once you turn it on,

it's going continuous at a very high rate of speed.

It doesn't stop until you turn it off.

In the past,

a lumberjack was only as good as his axe.

A modern logger is just as reliant on their saw blade.

This over metre-and-a-half wide circular cutter

spins at almost 1,200 rotations per minute -

the equivalent of over 300 kilometres per hour -

meaning the blade can slice through

just about any tree trunk like a flash of lighting.

Now, let's see how long it takes to stop that blade.

The blade's turned off.

That's how much momentum that blade has,

even when it's turned off.

But all that work can bust up the blade

and lead to catastrophe.

The saw is the most dangerous part because

there's obstacles in the woods, like there's stones and stuff.

Sometimes you will hit a stone.

These are just carbide teeth.

If you do hit a stone,

sometimes, the teeth will break and they'll fly.

They can fly up to 500 feet.

You don't know where they're going to go.

You can't see them when they're going that fast.

Even on the boom, it says, "stay back 500 feet,"

and that's the reason why.

This forest crusher ploughs through the trees

with a 284-horsepower engine,

about the same as a modern-day muscle car.

But out here, the machine takes a bigger beating

than a racer does on the track.

Every morning, I have to do a circle check.

One thing I do is I check the oil.

Oil dipstick is right here; you take it and you pull it out,

you take a look at the level. Level's good.

Then, over here is the air breather,

where it takes-- the engine needs fresh air to operate.

Sucks a lot of dirt in there.

The machine's got to work really hard

to get that air sucked through that filter.

If the filter gets plugged, then the exhaust will turn blue.

You'll lose a lot of power; you'll know.

Once the trees come down, they're sliced, diced,

and ready for the mill by a 28-tonne tree slayer

known as the harvester.

Its role is to strip every branch

from the trunk and cut timber

to the exact size needed.

I don't know what's better - the strip it or the rip it.

This machine's so powerful,

it can pick up an entire tree,

and at least pick it up and move it where I want it.

It can probably pick up a few hundred pounds.

It feels like I can move pretty much the world with it.

It's anything I can fit that head around,

I can probably move it.

The harvester

has turned timber extraction into an oversized game

of pick-up sticks.

Its colossal eight-metre boom arm

grabs trees with savage power,

as the massive mechanical saw head

rips and chops them to size in seconds.

Wheels pull the tree through the head's enormous two-metre grasp

like threading a giant needle with a telephone pole.

Traveling at five metres per second,

each of the four delimbing blades

trim the branches from the trunk.

It grips the wood,

as it gathers the perfect measurements for the mill.

Finally, the 75-centimetre cutter

slices the trunk into custom lengths.

But this is mostly ideal for big, gnarly timber.

The biggest tree I've ever cut with this

is probably around a 28-inch tree.

The operator sets the knife pressure

based on the size and what kind of trees you're cutting.

Then, smart tech kicks in

and automatically adjusts the pressure to strip off branches.

This keeps the tree's natural protection intact,

so you don't waste valuable wood.

I like this machine

because it takes all the guesswork out of everything.

It does it all for you.

It's a pretty smart machine, pretty sophisticated.

Back when machines were purely mechanical,

operators had to do everything by hand.

After a few hours,

your arms were dead from wrestling the controls.

And if a tired operator missed a lever

or made a wrong cut, it could be deadly.

Now, onboard smart systems like GPS,

safety kill switches,

360-degree cameras, and autonomous navigation

keep operators out of the most dangerous areas

and take over tasks,

so there's way less chance for deadly human error.

But all the tech in the woods

still can't outsmart gravity.

I've got to watch out for a dead tree

that can break off at any time and come back and hit me.

So, these bigger trees,

like this red pine, you have to be careful.

I've had quite a few come and hit the cab.

Falling trees

are a constant hazard when working in the woods.

You need to deal with them immediately

and get them off the site.

They're structurally sawdust -

a very dangerous tree.

These dead trees have to be cut

because they could fall at any time.

You got to worry about them falling on the cab

and possibly damaging the cab

and possibly killing you, more or less, too.

Cabs like this have reduced

fatalities and near-fatal injuries.

They're armoured cocoons, made of steel,

and the windows are made from Lexan,

which is essentially bulletproof.

As stable as the machine looks,

they can be rolled over onto their sides,

if you're not careful in the rougher terrain.

Once the machine goes over, it can shake you up pretty bad.

The cab is very safe.

It's designed to roll over,

and it's also designed to take a hit from a fairly big tree.

It's basically, a steel shell that keeps you alive

when the forest is trying to kill you.

Every day is a great day when you're in the bush alone,

so just enjoying nature.

However, all the harvester's

hard work means nothing

if the timber just sits there.

They've got to get it to the mill.

Enter the forwarder.

The forwarder may not look as tough

as its timber teammates,

but it has a major role: collecting the felled trees

and cleaning up their mess.

Shouldering up to 13.5 tonnes of timber at a time,

this muscle-bound loader swoops in

with its eight-wheel drive transmission

and clears timber to safe ground before it's too late.

The forwarder isn't just hauling;

it's on a rescue mission.

Every log lying in the woods

is losing value every minute that it sits.

Weather and bugs can quickly turn that premium wood

into waste.

Forestry machines feed

a $992 billion global market.

To put that into perspective,

all the wood generated around the world

could be enough to produce over 100 million homes each year.

And it doesn't stop there.

Timber isn't just for houses,

it's for your packaging, telephone poles,

coffee cups, and toilet paper.

If timber stops coming down, everything crashes.

Nearly 33 million jobs depend on it worldwide.

And once it arrives at the mill, that timber becomes currency.

We are exporting our product all over the world.

Every one of these logs that you see here in the yard

will become a piece of lumber or a square.

We have some of the best quality in the world.

From untamed wilderness

to global marketplace,

that's the power of an industry built on timber.

The future of the forest industry looks bright.

We need that for housing, we need that for everyday supplies,

and the best thing is it is renewable.

It'll always be there for us,

as long as we tend to it and we look after it.

So, you know, the cycle just continues.

These mechanical guardians of the woods

are conquering the forces of nature,

fulfilling their duty in the face of danger.

They persevere, harvesting tomorrow's world,

while keeping today's workers alive,

one massive tree at a time.

In Iowa,

a team of mechanical titans are waging war with fire and fury.

These are no ordinary machines.

They are industrial dragons,

spewing rivers of molten metal and red-hot steel,

harnessing temperatures hotter than the Earth's core.

This is one of America's

most challenging industrial environments,

where scrap metal is reborn as mighty steel.

And at the centre of this superheated steel mill

stands the ultimate melting machine.

An electric arc furnace - a mechanical inferno

continuously fuelled by scrap metal.

The electric arc furnace

is used to melt scrap steel

into liquid steel, as our iron base,

to make new steel plate for our customers.

Sometimes, it's a little nerve-racking, you know?

All right, guys.

175 tonnes of steel scrap

that goes in will get melted down

in around 45 minutes and tapped out into a ladle.

To turn scrap into steel,

you need a steady supply of shredded metal

to charge the furnace.

So, right now, you can see

these cars right in front of us have

what's called 'shredded scrap'.

This plant devours everything

from old cars and trucks, to appliances and bed frames.

You can take a railcar full of scrap out here,

throw it into our furnace, and start the melting process,

and within eight hours,

we'll have another railcar at the other end of the plant

with a brand new steel plate product leaving our facility.

The advantage of this process

is we are taking recycled steel scrap, making it new,

and then we can do it again, over and over,

almost indefinitely.

Before electric arc furnaces,

blast furnaces were the leaders of the pack;

their larger, dirtier predecessor

that have been used for nearly 2,000 years.

Blast furnaces don't use scrap steel.

They rely on extracted raw materials, like iron ore

and are powered by fossil fuels like coke - a byproduct of coal.

And once a blast furnace is running,

it can stay burning for up to ten years.

Though electric arc furnaces have been around

since the early 1900s, they weren't popular

because they were expensive to set up

and needed lots of electricity.

But today, mills like this one

are pushing towards perfecting a CO2-free

steelmaking process.

Where there's a readily available stream of scrap,

we can utilize the electric arc furnace

and recycle that steel scrap and melt it into new, fresh steel

for a new end application.

The electric arc furnace devours 160 tonnes

of scrap metal, like melting down 875 refrigerators

every hour.

What makes the scrap steel process so effective

and sustainable is that there's no gas and no coal.

What the arc furnace does have

is a massive electrode,

a glowing hunk of graphite wired with electricity.

It's really bright, and I'm looking at the electrode.

Graphite electrodes are crucial

for their high thermal and electrical properties;

that allows them to withstand the intense heat

without warping or melting too fast themselves.

We're just starting to bore in on our scrap.

To melt down just one ton of scrap steel,

the electrode consumes roughly

360 kilowatt hours of electricity -

enough to power a house for 12 days.

Right now, it's arcing.

The light flashing is the arc.

Once inside the furnace,

it's like an electrical storm.

High voltage power blasts through the electrode,

forming an electric arc, a lightning-like plasma burst.

The arc becomes the electrical bridge,

letting the current leap from the electrode

down through the scrap pile,

literally jumping through thin air.

The raw energy from the arc turns that steel into liquid,

with 1,600 degrees Celsius of unstoppable heat.

This is a 24-hour, 365-day operation.

Over time, the electrodes will wear and melt down

with the constant heat of the furnace.

So, crews have to be very careful moving

these components around, as breakage can be costly.

Hey, clean them and don't drop that.

Give us a minute, all right?

Every day, these skilled steelworkers

are operating and navigating super-heated machines.

They can't afford to let their guard down,

especially when they're tapping into this fiery furnace.

Putting on my PPE.

We're getting ready to go out and tap steel out of a furnace.

It's a layer of heat protection,

so that we don't get burned.

The electric arc furnace has two taps -

one on the side to remove slag or molten waste material

that flows to the top of the liquefied steel,

and the other on the bottom

is used to transfer the final mixture of steel

to the next machine of the process.

Hey Dan, leave your slag door open

while we're tapping, please.

Say, leave it up, Tim.

Leave your slag door open please.

Alrighty.

Once it gets up to close to 3,000 degrees,

we go out, take temps, check chemistry.

During the tapping process,

operators have the chance to get up close and personal

with the furnace.

Those heat-resistant suits are all that separate them

from the molten steel.

One splash and...

When it comes to steel production,

safety is paramount.

We're going to get ready to swing the roof off

the top of the furnace, so that we can inspect the furnace

for water, make sure there's no refractory damage,

and all the internals look good.

The refactoring material

are the heat-resistant ceramic lining

that insulate the furnace from the extreme temperature.

It's like the inner part of a thermos

that keeps your coffee hot.

If that protective lining breaks down,

the mechanical part gets worn, or water gets into the furnace,

that damage could be catastrophic.

Around the globe, at other steel facilities,

accidents have happened.

Water and steel can be an explosive combination.

If water gets into a hot arc furnace,

it would rapidly vaporize into steam,

creating a violent expansion of gas

and a shockwave that could send molten metal

and machine parts flying.

We've got our safety light,

so we're safe to go up on the furnace.

Okay, I'm looking over the edge of the furnace...

You really can't get any closer than this.

Melts the gloves, melts the helmet, melts the face shield.

The reason we want to make sure there's no water inside

this furnace...

It creates a reaction

and it will blow things all over the place.

This is a very dangerous aspect.

Probably one of the more dangerous jobs that we do,

while we're here making steel.

It's a risky job, but someone's got to do it,

to make sure this steel melting machine continues to pour.

As everything looks good,

this furnace inspection is complete

and we can exit the sump on the top of the furnace.

Now comes the hazardous job

of hauling molten metal

from the arc furnace across the mill floor

to the next machine in the system.

I operate the hot metal crane,

which moves liquid steel around in a ladle, they call them.

Now, I'm just going to set this full ladle up on the caster,

and then they will open it up from underneath

and let the steel flow down.

Manoeuvring this blazing hot liquid steel

requires nerves of steel.

The pedals at my feet, the one on the left is a brake,

which stops me from moving north and south -

the bridge brake we call it -

and the pedal on the right is a siren.

Every precaution must be taken

to keep the mill and the crew safe.

The siren gets people's attention.

Always looking out for people.

The hulking hot metal crane

delivers the ladleful of molten metal to the top

of the colossal continuous casting machine.

This multi-floor machine is so huge,

it needs a control room with multiple sets of eyes

to oversee all its moving parts.

Steel flows from the ladle into the top of the structure,

where it will travel through basins, moulds, and rollers,

that will quickly transform molten metal

into a single strip of solid steel.

The operator over here is pushing what they call 'mould',

puts it on the nozzle.

They just opened the slide gate up,

and he's just letting the operator know

that steel is passing through the shroud, so it's open.

The crew opens the tap at the bottom of the ladle

to release 1,600 degrees Celsius liquid steel

into a holding tank, also known as a 'tundish'.

Right here, we have the tundish and a submerged entry nozzle.

As the molten metal leaves the tundish,

it flows into a water-cooled copper mould.

When the molten metal meets

the 40 degree Celsius walls of the mould,

it forms a solid outer skin,

like the hardening of a rock shell of a lava flow.

Steel rollers drag the solidifying metal down,

while water jets hammer the outside, cooling it further.

Nearly 23,000 litres of water per minute cool the metal

while inside this mammoth machine.

We've got the strand coming out of the casting machine.

It's approximately 1,400 degrees.

These solid steel slabs weigh 41 tonnes

and are up to 15 centimetres thick.

The slabs are an unfinished product.

You can't build a car with them.

You can't use them for construction.

So, the mystery becomes,

what can you do with them?

Inside the rolling mill,

mighty metal magicians turn these giant slabs

into workable steel.

First stop, the reheat furnace.

By the time the slabs leave the casting machine,

they've cooled and solidified.

The reheat furnace's job is to get them hot enough again

so they become pliable.

That way, they can be stretched and reshaped.

Think of the reheat furnace

as a massive industrial toaster oven,

where steel slabs bake for two hours,

reheating them to a softened, red-hot 1,300 degrees Celsius.

Hey, Joe, you got a slab coming out.

So, at this point now, we just want to make sure

that it does sit down nicely on the discharge table,

it's not skewed, it's not hung up on anything.

And once everything's at a home position,

the slab will take off.

It's just a lot of things have to go right

for the process to work.

No news is good news.

Usually, the more steel we put through the furnace,

the better day we're having.

A side effect of the reheat furnace

is the formation of visible scale,

impurities that form on the surface of the metal.

So, we had a slab just now, discharged the furnace.

It's going to come through what we call a 'descale'.

If the scale is not removed,

it can really lower the quality of the steel,

and it will decrease the metal integrity. Nobody wants that.

Descale is now blowing 2,500 PSI water pressure,

and it'll blow off the scale that forms inside the furnace.

Next up,

the hot, softened steel is rolled out and compressed

with four gargantuan rollers that squeeze the metal

with bone-crushing force.

It'll square up the slab and it'll take its first pass.

First reduction on the mill

is about an inch of reduction on the mill.

Several passes through the mill will make our final product.

With 25,000 horsepower -

the power of up to 12 diesel locomotives -

this metal flattening beast

squeezes the steel until it's longer and wider

than a semi-truck trailer.

This mill is very important to the process.

If it's down, we're not making any money, obviously;

we're not making any product.

The Steckel mill passes the freshly pressed steel

to the next machine...

...an industrial Edward Scissorhands,

where a series of mechanical shears cut the steel to size.

The piece right now currently

just come out of the static shear.

He's going to measure that to the correct length

to where he'll make the cut.

The work of transforming scrap

into new steel never ends.

These heat-resistant,

battle-tested monster machines of the mill

push out plate after plate and keep going

to supply the world with steel.

I like seeing the finished product go out the door.

It feels great doing what we do.

We take all these old, used products, turn them into

brand new steel.

Everybody out there, they're seeing, they're using steel

every single day, and we're all a part of that.

These industrial titans

have revolutionized steel production,

transforming one of the world's most demanding jobs

into infinitely safer work,

as they forge the backbone of civilization.

From ripping out the old...

to mixing the new,

laying it down, and smoothing it out,

paving new roads is a dirty and dangerous non-stop process

done by some of the mightiest machines on the planet.

This is the night shift.

Kansas City Metropolitan Area

Highway I-35.

To conquer an interstate highway with fresh pavement,

you need a coordinated collection

of heavy-duty machines.

A project like this requires

continuous paving, a method where asphalt

is laid without interruption, using specialized machines

to maintain a steady flow of pavement,

and it's all gotta happen before the morning commute begins.

The goal of this is that our paving process never stops.

If you stop paving, it can cause a bump in the highway.

It takes a lot of moving parts

and a heavily coordinated effort.

If someone isn't paying attention

or something breaks down,

it not only shuts down the operation, it can be fatal.

Out here, in the middle of the night,

danger is everywhere.

The asphalt industry as a whole

is an extremely dangerous profession.

You know, the asphalt's coming out of the trucks 300 degrees,

a lot of heavy machinery.

We have pinch points everywhere, where people can get

ran over by a machine, injured.

Worst case scenario, you know,

something we never want to experience is a fatality.

But when your job

is in the middle of a speeding highway,

things can go sideways fast.

Highway work is one those jobs

that always comes with a certain degree of risk.

Because there's so many uncontrollable factors,

like traffic and weather,

crews are on high alert at all times.

We're working right in the middle of the highway.

We got traffic coming southbound at 65 miles an hour

on the highway.

On the northbound side,

we've condensed four lanes of highway down to one,

so the traffic is a lot slower,

a lot safer for our people on the ground.

Even with numerous safety strategies in place,

the dangers are still there.

It's dangerous work, so you got to keep your head on a swivel.

You got to watch everything and watch out for your brothers.

I've seen people get hit. I've seen machines get hit.

We've had people throw bottles at us,

out, as they've drove by.

Street races right by us, going over 100 miles an hour.

We've had people come flying up in our work zones.

And it's an adventure every night.

Overnight paving crews risk everything

to keep America moving,

and these machines have the crew's back when it counts.

Long before paving can begin,

a machine with an appetite for destruction

gets this pavement party started.

Enter the cold planer.

Filling out the concrete surface,

making a transition for the paving crew to tie into.

A cold planer peels away the damaged layers of old pavement

down to the healthy layers underneath,

leaving behind a perfectly prepped canvas

for fresh pavement.

Weighing in at 34 tonnes,

this beast is ravenous for the road.

Its two-metre cutting drum spins at 118 revolutions per minute

with diamond-shaped teeth,

ripping through pavement like a gluttonous predator.

You can tell the machine vibrates and shakes a lot.

That's the constant beating of the teeth,

tearing up the material below us.

This is very hard concrete with granite in it.

It takes a lot of work to pull up.

These are carbide-tipped teeth -

a carbon mixed with metal

that creates a way tougher compound than steel.

They can be spaced differently,

depending on what they're ripping up,

so each tooth doesn't take all the punishment.

The mill has a drum with about

200-plus teeth spinning, rotating,

chipping away at the concrete surface.

That drum is then loading it up into a conveyor chamber,

going out into the dump truck.

With all those teeth tearing up the road,

this gladiator needs to constantly rinse its mouth out

to keep crushing.

There are multiple sprayers.

There's sprayers over our drum,

there's sprayers in our dust suppression system,

all along our conveyor belt -

everything to keep dust to minimal.

Water runs dry,

the teeth start breaking, shattering, nothing good.

Don't run without water.

They must keep the teeth sharp

or the planer becomes a toothless tiger.

Dull bits mean extra passes, killing productivity,

as time and cars fly by.

Every night, when you're done, you should check your teeth.

Now, I'm looking for any of them that are broke.

Sometimes, you get away with not changing teeth,

but sometimes you could change them every hour.

There's a broken one

that's all shaved down and broke,

and that's how it looks brand new.

A massive 636 horsepower engine

with a 1,105 litre fuel tank

brings serious muscle

and endurance for ripping up pavement all night long.

No other machine could do the job quite like this.

Right now we are putting pressure on it

so it will match my previous cut.

We want to make it smooth

so that when they put the asphalt down,

it's a smooth ride.

The cold planer lays the literal groundwork

for every part of the paving process that follows.

The planer isn't the only thing tearing up our roads.

Mother Nature's brutal impact on pavement is relentless,

no matter the time or season.

When snow and rain rains on asphalt,

it will cause the moisture inside the asphalt to freeze.

Under cold conditions,

it will expand and de-bond the material,

and then, when it thaws out,

it will cause the particles to fall apart.

After the planer rips out the old surface,

the material transfer vehicle -

commonly referred to as 'the shuttle buggy' -

emerges from the darkness

to get the new pavement prepped.

The paving starts up there, with them trucks

delivering the asphalt into the shuttle buggy.

We got the asphalt truck up here,

he's carrying 20 tonnes of asphalt.

We got three more asphalt trucks in front of him.

The goal is to get this truck in, he dumps in the hopper here.

Asphalt mix is dumped into

the 17-metre-long gatekeeper of the paving battalion.

100%!

People say I'm the lynchpin of the operation,

being up here on the shuttle buggy.

Inside this small but mighty shuttle buggy,

unrefined materials -

mostly stone, sand, and gravel - become roadworthy.

The shuttle buggy takes the mix out of the dump trucks,

puts it in the belly of the machine,

and then it remixes the aggregate and the oil

so everything's combined perfect

before it goes into the paver.

Pavement as hot as 150 degrees Celsius

falls into the tank or hopper.

With an auger - a corkscrew-like blade -

it works like a behemoth blender,

violently shaking the mixture down through the system.

The spinning action evens out the temperature

and texture of the mix,

before spitting it out onto a conveyor belt

headed for the paver.

Well, while I'm up here with the conveyors on,

it feels like I'm always in a mild earthquake.

DR. EL-SAYEGH: The key to laying really good pavement

is to keep the paving process moving in perfect sync -

no stopping, no gaps,

just one smooth operation.

Before asphalt,

American roads were dirt, gravel, and cobblestone.

They got you where you needed to go,

but these roads were rough and poorly designed,

leading to the death of up to 40,000 people every year.

Engineers had to come up with a material

that could be durable, hard enough

to hold up to the heavy traffic that was to come.

America's desire for freedom

of the open road demanded infrastructure

that could support multiple vehicles,

carrying multiple people, going multiple directions,

and asphalt was the answer.

We do hope to step up the Good Road program

throughout the United States.

We can turn rivers in their courses,

level mountains to the plains.

By the 1950s,

President Eisenhower's grand plan called for

a nationwide interstate highway system

of 64,000 kilometres of highway.

Over ten years, he conquered the nation with pavement.

Today, America is crisscrossed

by nearly 80,000 kilometres of interstate highways,

connected to another

six-and-a-half million kilometres of roads.

On modern roads, crews are constantly maintaining

the empire that keeps our world moving.

The real hero of this process is the paver.

We're ready to go, ready to start paving.

Slow and steady wins this race

against time and traffic.

This 20-tonne road warrior

lays more than seven kilometres of pavement every hour.

How they feed that mix

through the trucks and through that material transfer vehicle

in front of the paver and back underneath that screed

is absolutely critical to get that smooth ride.

The screed is a heated metal plate

that hangs off the back of the paver.

Hot asphalt flows down the hopper,

to the screed, which smooths it out

exactly to the right thickness, as the paver moves forward.

Now, I'm too low.

The operator continuously adjusts the screed

to change the depth of the pavement.

Its massive half-metre treads

spread its weight like snowshoes on fresh powder.

They won't crush the hot asphalt underneath,

while keeping this metal barbarian steady

for flawless pavement.

This is like the cream of the crop right here.

In order for you to have a great, smooth road,

this is what you need.

But some things still need the human touch.

Even with all the machines that we have out here,

it still takes a person

with a tool in their hand to make a road a road.

These are two rollers

that are considered breakdown rollers.

They're trying to make it smooth,

and I'm trying to make it compacted.

And they're doing it with a machine

that's aptly named the compactor.

So, right now, they're making their pass back,

and they're vibrating the asphalt

to get the density that we need.

It can be pretty stressful

knowing that I'm the last guy that touches it,

just because, you know,

if there's any imperfections in it,

that's the guy that, you know, everyone looks to.

You've got your breakdown who breaks it down,

and you've got your finish guy who makes it look pretty.

This is what it takes out here.

It's heavy machines, asphalt at 300 degrees, dump trucks.

It takes the men and women on the ground to provide a road.

An hour to lay, 20 years to stay.

- Great job, guys. - Thank you.

As dawn breaks over the I-35,

these steel gladiators return to the shop.

What was once a battle-scarred, crumbling highway

is now a flawless foundation for decades to come.