Original subtitles

Yep. [ explosion ]

Narrator: In stockholm, sweden...

[ jackhammer hammering ]

...This elite team of engineers

Is embarking on an epic endeavor.

[ shouts indistinctly ]

They're building one of the most ambitious megaroads

In the world.

This gigantic new highway

Is made up of a 35-mile network

Of massive, underground tunnels...

[ shouting indistinctly ]

[ explosions ]

...And six huge, new bridges

Soaring nearly 2,000 feet

Across stockholm's busiest highway and railway.

[ explosions ]

To build this colossus,

The team must battle fractured rock...

[ machine whirring ]

...Dangerous explosives...

Okay, blasting.

[ explosions ]

Narrator: ...And punishing deadlines.

Yeah, this is a ticking click.

Narrator: This monster subterranean highway

Ranks among a league

Of ambitious, new engineering wonders

That are bigger, faster, taller,

And more advanced than anything ever constructed before.

This is the inside story

Of the extraordinary challenge of building these giants.

-- Captions by vitac -- www.Vitac.Com

Captions paid for by discovery communications

♪

Stockholm, the capital of sweden,

Is a unique city.

Its eye-catching mix of historic and modern buildings

Is constructed across 14 separate islands,

Connected by 57 bridges.

And spectacular nature reserves

Lie just a few miles from the city center.

The city's complicated layout

Makes navigating it a huge challenge

For the 2 million people who live and work here.

The 350,000 cars and trucks traveling daily through the city

Are channeled onto a single road

That passes right through its center.

This creates gridlock with massive rush-hour delays.

To overcome this problem,

City engineers are gearing up to build

The biggest infrastructure project sweden has ever seen.

A massive new megahighway

That will allow traffic to circumnavigate the whole city.

Johan brantmark is the project's director.

This megahighway will connect

The regions north and south of stockholm

Via 13 miles of new road.

To preserve the stunning scenery,

An astonishing 11 miles of the new road

Will be buried underground.

Twin tunnels, each 50 feet wide,

Allow for three lanes of traffic each way

At depths of up to 260 feet,

Giant ventilation shafts fitted with powerful fans

Supply fresh air and remove traffic fumes.

250 jets suspended above the roadway

Keep the air circulating.

Aboveground, a huge, 2,000-foot-long bridge

Will cross over busy highways and railways

To ensure the smooth flow of up to 140,000 vehicles per day.

Johan's team faces the formidable challenge

Of digging these massive tunnels.

Stockholm sits on some of the hardest rock on the planet

And is crisscrossed by deep water channels.

So johan's team devises an ambitious plan.

To tackle this massive build,

Workers labor above- and belowground simultaneously.

To excavate the 35 miles of tunnel,

They'll use high explosives to blast through

21 million tons of super-hard granite.

But one section of the tunnel passes through

An ancient geological fault line,

Where the rock is dangerously fragile.

So, here, engineers have to use steel and concrete

To painstakingly reinforce the surrounding rock.

[ tapping on rock ]

[ explosion ]

Aboveground, workers must simultaneously

Construct 2 miles of new highway

And overcome the toughest challenge of the whole project:

Build a 650-foot-long span of the massive road bridge

Across a busy railway in just three weeks.

♪

Work on the build begins in 2016.

Aboveground, workers start construction

Of new road bridges to the north.

♪

And belowground,

They start blasting the new tunnels from the south.

[ explosion ]

♪

[ explosions ]

Project manager linus levinson and his tunneling team

Painstakingly drill hundreds of holes

Into the solid granite...

...And use high explosives

To blast away 20 feet of tunnel at a time.

[ shouts indistinctly ]

[ explosions ]

It takes three years

To excavate nearly 3 miles of brand-new tunnel

Through the ground.

The crew makes good progress

Until they run into this patch of dangerously unstable rock

Caused by an ancient geologic anomaly.

It sits right below the 230-foot-deep lake malaren.

This is a crucial moment for the whole project.

The rock along most of the route is solid granite,

But beneath lake malaren,

Right in the path of the tunnel,

Lies an ancient geological fault line --

A huge crack of fractured rock over 650 feet wide.

Geologists call this the crush zone,

Where a mess of ruptured rock, mixed with clay and sand,

Makes the ground highly unstable.

Tunneling through this zone is incredibly dangerous.

[ machinery tapping ]

If the team continues to blast as normal...

[ warning siren wails ]

[ explosion ]

...They could cause a collapse...

[ rock crumbling ]

...Or open fissures to the lake above,

Flooding the entire tunnel.

[ water rushing ]

In order to continue blasting,

Linus needs to find a way

To get through this deadly fault zone,

Because they only have one chance to get it right.

Narrator: In stockholm, sweden...

[ explosion ]

...Engineers are building one of the largest

Underground megaroads in the world.

♪

But work has slowed to a crawl

As project manager linus levinson

Figures out how to excavate

Through the shattered and crushed remains

Of an ancient fault zone.

Traditional drilling and blasting

Could bring the tunnel down on top of them...

[ shouts indistinctly ] ...So they need to determine

How to support the tunnel roof as they go.

To tunnel through the dangerous crush zone,

The team must first reinforce the fractured rock.

They drill 62 holes into the rock above

And to the side of the tunnel,

And insert 6-inch-thick hollow steel pipes.

[ drill whirring rhythmically ]

Next, they pump in liquid cement,

Which flows out of small perforations in the pipes

And into cracks in the loose rock.

This forms a super strong roof of reinforced concrete

That holds up the loose rock above.

Next, the team carefully blasts the tunnel face.

[ explosion ]

They must work cautiously,

Removing just 7 feet at a time.

[ explosion ]

Once they reach the end of the reinforced rock,

They start again.

By repeating this process over and over,

The team can slowly tunnel through

Even the most treacherous terrain.

♪

Over a grueling week,

The team painstakingly drives the long steel pipes

Into the fragile rock

And fills them with liquid concrete.

This new concrete-and-steel shield

Should stop the rock from collapsing

As the team blasts out the tunnel.

It's finally time

To see if their hard work is up to standard

By blowing it up.

To place the explosives,

The team needs the help of a special machine.

♪

[ driller rig whirring ]

♪

This drilling rig is a 35-ton monster machine.

[ drill tapping rock ]

It has three computer-guided hydraulic arms

That drive hundreds of holes into the rock face...

...Following a programmed pattern

With millimeter precision.

The team loads each hole

With a precise amount of explosive...

We go up there?

...And retreats to safety.

After weeks of work,

The moment of truth is here.

It all comes down to one press of a button.

If the new concrete-and-steel roof doesn't hold,

The face might give way and collapse the entire tunnel.

Okay.

Okay, blasting.

[ explosions ]

♪

Linus won't know if the tunnel is still standing

Until he can take a closer look.

♪

As the dust clears, he can just make out the face.

The tunnel is intact, and their plan has worked.

They've advanced the tunnel another 7 feet

Through the crush zone.

They'll need to blast more than 100 times

To get all the way through

The deadly zone of fractured rock.

♪

18 miles to the north...

...The megahighway build crews

Are battling a very different challenge.

Engineers need to construct a series of bridges

To connect the new underground tunnels

To stockholm's existing road network.

For months, the team has built section after section

Of solid concrete bridge deck...

...By spreading tens of thousands of tons

Of steel and concrete

Into giant molds.

♪

Today, the team faces their toughest task yet.

They must build a 650-foot section of molded bridge

Over one of sweden's busiest railways.

This will be a very intense period of time for all of us.

Narrator: And they've only got three weeks to do it.

Basically, this is a ticking clock.

♪

Narrator: In stockholm, sweden...

Okay, blasting.

[ explosions ]

...Engineers constructing a 13-mile-long megahighway

Face a daunting challenge --

Building a 650-foot concrete bridge

Across one of sweden's busiest railways

During the summer off-season.

They have just three weeks.

In charge of this mammoth task

Is engineer anna lempicka.

The hoses are connected.

They're not bent. I don't see any leakages.

Her team has special permission

To shut down the railway in order to build the bridge.

If they can't finish in time,

They won't get another shot to complete the job

Until the following summer.

If we don't make it in these three weeks,

We need to basically stop the project for a year.

To help them hit their deadline,

The team uses this giant, movable concrete mold.

It will allow workers to complete

This huge section of the bridge in one go.

This is how it works.

First, workers detach the 400-ton moveable mold

From the leading edge of the bridge

And use hydraulic jacks to push both sides out by 7 feet

Onto temporary support towers.

Next, they slowly slide both sides of the mold forward,

Inching outwards into thin air, a few feet at a time,

To reach a support tower, 400 feet away.

Once in position,

The hydraulics push both sides of the mold together again.

Now the team fills it with steel reinforcement

And super-strong concrete

To create the next span of the bridge.

Once dry, the mold can shift forward

To repeat the process,

Now safely clear of the railway below.

♪

The countdown begins.

With the train tracks closed,

The team's first task

Is to lower the railway power lines.

♪

They work through the night to get the site ready.

♪

Now the race begins to fire up the moving mold.

The object here is to get this part of the mss

Exactly to the abutment part.

Touchdown will happen here.

Narrator: Hydraulic jacks start to pull

The concrete mold over the railway.

♪

These inch the mold forwards

Like a mechanical caterpillar,

Once half at a time, little by little.

♪

♪

The team works seamlessly.

But a few feet from touchdown...

Man: Stop, stop!

...They run into trouble.

The concrete mold can't advance any further.

[ speaking native language ]

Some of the steel beams on the mold are too long

And block its path to touchdown.

Anna needs to come up with a solution fast.

Do you remember the drawings?

Man: Yes.

There is one element doesn't fit,

And we need to cut either from our side or from mss.

Narrator: She makes the bold call

To slice off the excess steel.

And we would need to organize them

Like a cutting machine.

With a tight schedule to keep,

This issue could cost the team vital hours.

This will take some time.

Workers cut 2 feet

From each of the problematic beams.

It was going so good. So good.

Well, we'll see.

♪

With the steel cut,

They try to move the mold forward again.

♪

It works.

The concrete mold finally gets to the other side.

Anna can breathe a massive sigh of relief.

But the team still faces a daunting challenge.

[ drills whirring ]

♪

They close up the traveling concrete mold

To form the finished shape of the bridge.

And the ironworkers

Lay 150 tons of steel reinforcement by hand.

On this super-tight schedule, the pace is relentless.

They have to work fast.

Narrator: The team works flat-out for five days

And is still placing the last few pieces of steel

As the concrete trucks start to arrive.

It will take 50 of them to fill the mold.

♪

♪

The bridge builders need to pour

The whole bridge section in one go

So it sets in a single, solid slab.

So once we start, we can't stop.

♪

The team works nonstop through a punishing shift...

...To pump all 50 trucks of concrete into the mold.

♪

They're on the homestretch.

But if the concrete doesn't set fast enough,

The team won't be able to remove the mold

And clear the site,

Bringing this important train track

Screeching to a halt.

Narrator: In stockholm, sweden...

[ shouts indistinctly ]

...Engineers are racing to build a 13-mile long megahighway...

Okay, blasting.

[ explosions ]

...That travels through

Record-breaking subterranean tunnels.

On the north side of the city,

Anna's team is working to complete

A crucial part of the highway --

A concrete bridge that crosses over a busy railway.

They've had just three weeks to do it,

And they're running out of time

Before the train track needs to reopen.

We are almost at the end of our track-closure period,

So we have three days left.

Narrator: They've got one last vital task.

This bridge span is so long

That concrete alone won't support the weight of traffic.

This 650-foot-long span needs some extra support

To help it withstand the wear and tear

Of 140,000 vehicles a day.

[ concrete cracking ]

Without reinforcement,

The flow of traffic over it could cause it to sag and crack.

To overcome this,

Engineers must bury plastic pipes

Inside each section as they cast it

And run cables inside the pipes.

The team will use a giant hydraulic jack

To stretch the cables tight with 500 tons of pressure.

This technique locks the concrete sections together,

Making the whole bridge strong enough

To support heavy loads for decades to come.

♪

The concrete has finally hardened.

And after running 10 miles of cable through the bridge,

It's time to tension them.

The team needs to work fast.

Lempicka: Guy is here installing the jack

That is going to pull the cables.

Workers attach the massive hydraulic jack

To the exposed cables

And start to pull them tight.

It's hard work, yes, but I make it every day.

The jack pulls the steel cables

With an exact amount of force,

Stretching them

And securing the concrete sections together.

For the cable crews, the pressure is on.

The railway beneath their feet needs to reopen.

It takes 16 hours of grueling work

To tension all of the cables...

So, this side and the other side is all finished.

Narrator: ...Locking this section of the new bridge

Together across the railway.

Stop, stop!

Finally, they move the mold away from the tracks...

♪

...And clear the worksite.

They reopen the railway just in time.

This is a huge moment for anna and the team.

The hardest part of this massive bridge is finished.

Lempicka: The post tensioning was definitely a success.

Finally, it starts to look like a bridge.

♪

♪

Narrator: With work on the monster highways,

Bridges, and tunnels progressing well,

Design begins on the next phases of the project.

The team needs to construct 16 vast ventilation shafts

And 48 huge fans to push fresh air

Through the highway's 35 miles of tunnels.

Safety specialist henrik modig

Oversees this stage of the operation.

Narrator: With so many vehicles

Traveling inside this confined space,

Fumes from car exhaust would quickly build up

To dangerous levels.

To supply fresh air to the tunnels,

Henrik's team develops

A sophisticated ventilation system.

250 jet fans

Blow more than 200,000 cubic feet of air per second

Along the tunnel.

The air picks up more and more car fumes as it travels,

Until it reaches giant fans stationed every 2 miles.

These blow the harmful fumes through 26-foot-wide shafts,

Up and outside, like a giant exhaust...

...And suck in clean air from the surface

Back down to the tunnel.

This system will provide plenty of clean air

To even the deepest sections of the underground highway.

♪

The giant fans in the new megahighway's tunnels

Will need deep vertical shafts

That run all the way to the surface.

But digging the shafts

Through the hard rock of stockholm's islands

Will be no simple task.

Narrator: In stockholm, sweden...

[ explosion ]

...Engineers are battling

To blast a subterranean megahighway

Through 11 miles of super-hard scandinavian rock.

To remove harmful exhaust fumes

From the thousands of vehicles that will use these tunnels,

Huge fans will blow fresh air along their length.

But to work, they need gigantic shafts

Blasted all the way to the surface.

This part of the build

Rests on the shoulders of engineer charlotta somalias.

Today her team gears up

To blast part of a 130-foot vertical ventilation shaft.

To create the huge ventilation shafts,

Charlotta's team needs to blast from both below

And above.

First, they drill upwards into the tunnel's ceiling

And blast away 20 feet of rock.

[ explosion ]

Now the operation switches to the surface.

[ drills whirring ]

Here, blasters drill more than 100 small holes

Down to the tunnel below

And fill the bottom with explosives.

They use a precisely choreographed series of blasts

To detonate the explosives... [ explosions ]

...Causing the bottom layer of rock

To fall into the void below.

Then, they charge the next section

And blast again. [ explosions ]

The team blasts the ventilation shaft

Slice by slice, all the way up to the surface.

Working from the bottom up

Means they only need to clear the debris

Once the shaft is complete.

The surface team prepares the blast

Under the watchful eye of demolition expert pier goliats.

Take them two-by-two.

Then we get through our detonator

Like this.

He needs all of his 37 years of experience

To get the shaft through this super-hard granite.

First, the crew drills more than 100 holes

Deep into the ground.

They charge the drill holes with dynamite...

...And prepare to detonate it in a precise pattern.

But just as they get ready to blast,

They run into a problem.

Every time they try to place the explosives

In one of the holes, they keep falling through.

Pier needs to take a closer look

With a special fiber-optic camera

That he lowers down into the ground.

It's vital that the team places all the dynamite in solid rock.

But a large area is missing where they expect to find it.

Man: Yes.

They need to determine where the solid rock starts.

All of the explosives must be placed at the same level,

So the team sets them at this new height.

With the explosives in,

The countdown begins.

Belowground, charlotta gets clear of the danger zone.

♪

[ alarm blaring ]

All of their hard work comes down to one short blast.

Okay?

Yep.

[ explosions ]

[ horn honking ]

♪

♪

The team has done it.

♪

Further along the route of this megahighway,

The tunneling team has reached another critical moment.

After four years of work, two long tunnel sections

Sit on either side of a narrow wall of solid rock.

Now the crew is ready to join them together.

[ drills whirring ]

It's called a breakthrough,

And this one won't be easy.

♪

Narrator: In stockholm, sweden,

Engineers are racing to build one of the largest

Underground highways in the world.

[ explosions ]

Over four years, they've been blasting two sections

Of road tunnel toward each other.

[ machines whirring ]

Today, just a few feet of solid granite

Separates these two passageways.

Now, demolition crews need to blast away the rock

To connect the two tunnels together.

[ laughs ]

Narrator: Demolition expert bjorn andersson

Is in charge of placing the explosives,

But it's not going to be easy.

There are large holes in the rock,

So he can't blast it in the traditional way.

The wall of rock separating the two tunnels

That bjorn must demolish is an unusual shape

And it already has blast holes in it

From the tunneling on either side.

To get through it,

They first drill more than 100 channels

Into the existing rock face

And fill them with explosives.

To break through safely,

They must detonate in a precise order.

First, they blast a circular pattern

Around each existing hole... [ explosions ]

...To clear the rock.

Seconds later, they detonate the rest of the explosives

From top to bottom.

They must time each blast perfectly,

Or the team will fail to break through.

The drilling team quickly prepares

More than 100 holes for the blast.

Every hole must be in a specific place

And to an exact depth.

Now bjorn places the detonators.

Each has a precise delay,

So we must be sure to position them in the right holes.

With the detonators in place,

Bjorn fills each hole with a special liquid explosive.

By itself, the liquid can't explode,

But when bjorn pumps the liquid out of the tank,

He mixes it with a special gas

That makes it volatile and ready to blow.

With the explosive primed and ready,

Project manager linus comes down to watch the blast...

From a safe distance.

This is the moment four years of intense work

Has been leading up to.

♪

[ explosions ]

Linus steps out of the shelter to take a closer look.

Peering through the dust...

...There's light at the end of the tunnel.

The wall has gone,

And the blast has been a success.

With this breakthrough,

This massive project is

A huge step closer to completion.

♪

As the titanic tunnels

And vast bridges

Extend out across the city,

This revolutionary megahighway

Transforms stockholm's traffic network...

Lempicka: The city needs it.

Everyone who's passing here

From the north to the south of sweden

Or the south of europe,

They really need it.

Narrator: ...To keep this unique city moving

As it grows into the future.

♪