All language subtitles for If.We.Built.It.Today.Series.1.Part.2.Battle.of.Brooklyn.Bridge.1080p.HDTV.x264.AAC.MVGroup.org.Eng

And oxygen that ultimately
eat away at steel.

Narrator: The recipe for steel
is simple --

Heat iron ore until liquefied,
boil out impurities,

Add some carbon for strength,

Then let it solidify
into whatever shape you desire.

And if we want our bridge
to last,

It's going to take some work.

So steel will be coated
in paint systems.

Paint systems will not last
for 200 years on their own.

You'll require touch-ups
and repairs

And possibly re-coating

Throughout the life
of the structure.

Narrator: Paint protects against
the humidity

You really had not had steel
used at this scale before.

Now, what about the deck
of the bridge?

This will be
a massive undertaking.

And back in the lab,
mamdouh el-badry is working

On a state-of-the-art solution
to solve that problem.

The composite materials
el-badry's using promise

To make his bridge system
invincible.

So why don't we build
the super-bridge of the future

Out of el-badry's super
strong composite?

Well, we could.

But we wouldn't necessarily
achieve the performance

That we're
looking for right now.

I think we also have to look
at not

So today, we could definitely
use granite,

Narrator: We need our towers
to be strong and stately,

Not crumbling and corroding.

In canada, mamdouh el-badry
is addressing the problem

In a lab
at the university of calgary.

He's swapping traditional rebar

For a mix of fiberglass,
plastic, and carbon.

So if we use corrosion-free
composite rebar reinforcement,

We can build our towers
from concrete.

But how's that going to look

Next to this icon
of architecture?

We would like to have a look
that blends

With an older environment.

Just the strength
of the materials,

But we most likely would use it
as a facing.

And granite facing becomes
very beautiful.

Narrator: Got it --
modern-day muscle inside

And classic good looks outside.

Next up, we need to
string our cables

And build our bridge deck.

♪

To do that,
we'll use the molten material

That forms the backbone
of the brooklyn bridge -- steel.

John roebling, in particular,
pushed forward steel wire.

And this was the first
steel-wire bridge.

We still have to do,
you know, the physical test.

Taken to ensure
environmental compliance.

Narrator: Todays engineers test
for environmental impact

As well as safety.

John roebling was intuitive
of the aerodynamic analysis

And the situation
that he knew was prevalent,

But couldn't put numbers to it.

So today, we take the bridge
that we want to build

And we use a model
that's exact-scale,

Put it in a wind-tunnel test,

And that information is hugely
important to the analysis.

So even with
our sophisticated modelling --

Which gets us almost there
but not quite --

Because there's a lot more steps

Narrator: Mamdouh el-badry's
been working on this prototype

For more than 15 years.

The good news --
his trusses are tough.

♪

We are loading the girder
and the deck, actually, with

Cycles of loading simulating
traffic on the bridge.

And then we are kind of
measuring

How many million cycles

The girder and the deck
will survive.

Narrator: While billions of
simulated sedans

Put these girders
through the motions,

A second prototype
is chilling in here.

Now we need to figure out
who is going to build it.

But also the stiffness.

No one likes bendy,
flexible bridges.

They're unnerving.

And fiber composites
often have --

Are more flexible than steel
and concrete equivalents.

Narrator:
El-badry has the solution.

So, the best way to utilize them
is actually to combine them

With the conventional materials

To make a hybrid system like
the one that I have developed.

So we're going to build
two new bridges

Out of a blend of materials

That will set a new standard
in bridge architecture.

And it does look a bit
disturbing after a while.

Narrator: We're going to turn
the old brooklyn bridge

Into a pedestrian walkway

And build two brand-new bridges
on either side.

Our design experts said
we ought to opt

For a cable-stayed bridge
made of concrete,

Steel, stone facing,

And state-of-the-art
composite materials.

So we must be ready
to build now, right?

Not so fast.

Scollard: Preparation time today

Is a lot longer
than it used to be

Once you have the towers up,
you can start erecting the deck.

When gertie collapsed,

More than 1,500 people
have been killed

In bridge failures
in this century alone.

That can't happen
to our new brooklyn bridges.

We need to find the world's
best engineers and ask them,

Should we build a cable-stayed
or suspension bridge?

Scollard: A lot of it comes down
to the cost.

And a big difference
between a cable-stayed bridge

And the suspension bridge

Is usually the duration
of construction.

Cable-stayed bridges
can typically be built

One year faster than
a suspension bridge can be.

Narrator: Though thankfully
no one died

And so as you put in the cables,

You are progressively putting
in the deck at the same time.

And so there's more operations
being done in parallel,

Rather than in sequence.

Narrator: It seems that
a cable-stayed bridge

Is the way to go.

But will we ever be able
to match

The original brooklyn beauty?

Aesthetics is personal and
subjective, but forgive me --

I can't imagine
looking at that structure

And not just being in awe.

♪

But the biggest problem
was the girders.

Roebling's zeal for safety.

♪

The tacoma narrows bridge
in washington,

Nicknamed "galloping gertie"

Because of the unintended
undulations

Experienced during high winds,

Was the third-longest bridge
in the world

When it opened in 1940.

Four months later, it collapsed.

What went wrong?

The bridge was too narrow
for its length,

And the towers
weren't strong enough.

Narrator:
It's a hard act to follow,

Every long-span bridge
has girders --

Horizontal beams that help hold
the weight of the deck.

Gertie's were tall
and made from solid metal,

Which caught the wind
like a sail --

A major misunderstanding
of aerodynamics.

Engineers look to this bridge

For an example
of what not to do.

Scollard: Engineers have
a professional responsibility

Not to do things that they
aren't certain will work out.

A mistake by a surgeon
would perhaps hurt one person.

Our mistakes can kill
a number of people.

Narrator: To avoid stone's
hefty weight and expense,

Is a towering task.

There is limestone, there's
granite, and it's masonry.

It's stone.

Narrator: Stone has proven its
durability throughout time

And all over the world.

But our modern-day engineers

Are wary of creating
a money pit.

Granite
is an expensive material.

And considered on the scale
of a bridge tower,

It would be
prohibitive in itself.

You imagine how heavy
the granite and limestone towers

Would be at the end?

Narrator: And topping these
stately pillars

Most bridge towers today

Are built with steel
or steel-reinforced concrete.

Nowadays, we would use
high-performance concrete

With high-strength steel bars,

Which gives us the capacity
to resist loads better.

Narrator: But this method comes
with its own challenges.

The big problem with concrete
that we see in towers now

Is actually the reinforcement
corroding.

Once the steel corrodes
and starts expanding

With rust layers,

It pops off the concrete
that's surrounding it

Are probably the key
determinants of the life

But modern-engineering smarts

Seem to produce
knockout good looks.

The purest form
of bridge aesthetics

Is to design
a clean, simple structure

Where the elements follow
the natural load paths

That are required.

Structurally efficient design
is inherently

Aesthetically pleasing.

Narrator: We'll plan for
two new bridges --

One on each side
that compliment

But don't interfere
with the existing bridge.

Choosing the right materials
and construction quality control

El-badry: So, this is
an environmental chamber

That you actually get
out of the bridge.

Narrator: We want our new
bridges to be an icon

For centuries to come.

And that challenge
begins with our towers.

Narrator:
At 278 feet tall apiece,

The brooklyn bridge's
gothic-style towers

Are two of its most
recognizable features.

And they're crucial.

The towers for
a suspension bridge,

And even for
a cable-stayed bridge,

Really define the structure
quite a bit.

And state-of-the-art composites
to do it.

Narrator: And when
the whole thing is done,

We'll re-create
the same grand parade

That crossed the original
brooklyn bridge.

A herd of elephants will show
the world

The strength of our new span.

[ elephants trumpet ]

♪

♪

We did it!

We built two new brooklyn
bridges over the east river.

They're cable-stayed bridges,

And we've used concrete,
stone, steel,

Painting the lines on the
roadway, and things like that.

With all the testing and
preparation, it took 14 years.

In total, 750 people
worked on the project.

So, how does the cost
of our new bridge

Compare to the cost
of the original?

The $15.5 million
construction cost in --

In the late 1800s nowadays
would be the equivalent

Of about $1.3 billion.

And based on
similarly complex projects

And similarly large projects,

I would certainly say
it's more than $1 billion.

$2 billion would be
a good starting place.

Narrator: But not everyone's
convinced that $2 billion

And then hang the deck
truss segments from them.

And preparing of the site
for the actual construction.

Narrator: Next, it's time
to build our towers.

Then typically, the construction
goes from the bottom up.

So the first thing would be to
install all of the foundations,

And then getting above
the ground,

They would build the towers.

Narrator:
After the towers are erected,

We've got to string the cables.

So, how did they do that
for the brooklyn bridge?

After the towers reached
the -- their top height,

Then the steel cables would've
been hung across the river.

With the steel cables in place,
they could place the suspenders

Is going to fit the bill.

Narrator: But remember, we're
building a cable-stayed bridge.

And we can build that
even faster.

With a cable-stayed bridge,

Once you have the towers up,
you can start erecting the deck.

And so as you put in the cables,

You are progressively putting in
the deck at the same time.

Narrator:
With the deck in place,

We're almost ready
for rush hour.

There would be
the finishing works

To actually prepare
the bridge for use --

Tying it into the rest of the
roads, putting on the barriers,

And engineers tend to -- to be
experts in math and science.

And I hope it will
outlive my children.

Beyond that, I don't think
any of us can imagine.

But you know,
the future is a mystery.

We can see where we've been
with great clarity.

We have only the dimmest idea
of what's coming.

Narrator:
No matter its life span,

The brooklyn bridge will live on
as a beacon of inspiration.

Bridges are actually, perhaps,
the only structure

That stimulates imagination,
creativity.

Scollard:
Bridges are complex objects.

They look simple, but there's
actually a lot of complex work

That goes into them.

I certainly hope
it will outlive me,

It's that math and science
that allows us to do it

In a safe and efficient way.

Narrator: Icons of
civic infrastructure

Like the brooklyn bridge

Don't build themselves.

It takes hard-working men
and women,

Brilliant innovators,
and big dreamers.

The brooklyn bridge reminds us

That what seemed
impossible yesterday

May be possible tomorrow.

And we can always find a way
to connect our communities

And our cities
if we built it today.

Inspired by
the city's high line project.

One of the most endearing
qualities about engineers

Is their optimism.

And you need that optimism
to get anything built.

But they're often dead wrong

About what the costs
of their projects will be.

The brooklyn bridge
cost three times

What people thought it would
cost back in the 19th century.

Narrator: So let's triple it.

For $6 billion, we can build
two new brooklyn bridges.

But we're not done yet.

We've still got to pay
to transform

The old brooklyn bridge
into a pedestrian walkway

Of the construction team
and the clearing

The way we see it,
it's worth blowing the budget

To give a second life

To a walkway
with a million-dollar view.

There is definitely
an important reason

To try to keep this bridge
as it is and rehabilitate it.

Narrator:
But will there come a day

When the brooklyn bridge
can't be saved?

No owner of a bridge
or developer of a bridge

Is looking for forever.

I would say, I don't think
there's an end in sight

For the brooklyn bridge.

We don't read about
all of the assistant engineers,

But remember, washington
roebling ended up bedridden.

And so his responsibilities
in the field

Fell to his wife, emily.

Barbas:
Emily roebling was the eyes and
ears of her disabled husband.

She was the one who had
to take the design

And make sure those instructions
were implemented in the field.

In the late 1800s,

It was unheard of for a woman
to be in that position.

Narrator:
But building the brooklyn bridge
took more than a great family.

It took a massive team.

When we read the history
about the brooklyn bridge,

We read about the key figures.

In design and construction,
as well.

All of the field engineers,
all of the people on-site

Actually overseeing the work
and making it happen.

Narrator: It took an untold
number of construction workers

To build the brooklyn bridge.

And at the bottom of it all
were the so-called sandhogs.

Baker:
The people who built the bridge

Were some of
the earliest sandhogs --

Some of the same amazing tribe

Who would build the subway

And many of the tunnels
under the rivers.

Narrator: To this day,
sandhogs can still be found

Working below grade.

Narrator: So we're facing
11 years of project development

That we actually put
the prototype inside

And subject them to cycles of
temperature

Between cold and warm.

Narrator: Our bridges will
stand up to the weather, too.

This process definitely
takes time.

But does it actually take longer
to build bridges today

Than in the 19th century?

The brooklyn bridge
took 14 years to build,

Which is, by modern standards,
a very long time.

Overall length of development
is probably similar

To what it was at the time
of the brooklyn bridge,

But it's spent differently.

This is the construction force

And three years
of construction --

14 years altogether, just like
the original brooklyn bridge.

We've got our design plans.

We've picked our materials.

Now we have to put together
the workforce we need

To get the job done.

First thing -- we need to find
a team of engineers

To rival the family firm
that built the brooklyn bridge.

The family
that actually designed

And built the brooklyn bridge --
they were completely in charge

Because the head
of the family was expert

To alleviate traffic
between brooklyn and manhattan.

In the field day-in
and day-out,

Providing labor
and actually doing the work.

Narrator:
So let's put it at 100 workers

For the 14-year duration
of the project,

And another 650 people
to come in

During the three-year
construction phase.

That's 750 people total.

At industry wages,

We're looking at
a labor bill of $335 million.

Now it's time for
the finishing touches

Before we can unveil
our masterpiece to the public.

Narrator: We're imagining
a 21st century roadway

Of that, about 650 of them
are actually working

It will be made of
the strongest,

Most durable materials --

Concrete, plastics,
stone, and steel.

And it will take 750 workers

And 14 years to plan
and construct this beast.

We've got our team in place,

And their first job
is to demolish enough

East river real estate to make
room for our bridge towers.

Scollard: Most bridge
construction projects

Probably have five key stages.

The first is gonna be
the mobilization

In the latest safety equipment.

That specializes
in working underground.

If it looks like
a tough job today,

Imagine the conditions
a century ago.

They tended to be
local residents,

So a lot of them
were immigrants.

They worked very cheap --
$2.75 for a four-hour shift

In which you risked your life.

20 to 40 of them died
building the bridge.

And just the vagueness of that
number gives you an indication

As to how little
their lives were valued.

20, 40, who knew?

Narrator: Our modern-day bridge
builders will be outfitted

Narrator: Unfortunately,
not all of them inherited

When the brooklyn bridge
was being constructed,

There was not the kind
of regulation we have today.

And workers did not even
have hard hats or boots.

They came to work dressed
in white-collared shirts

And maybe a top hat,

And workers were often
not paid fair wages.

Narrator:
When hiring our workforce,

It's wise to take a lead

From the team overseeing
the new tappan zee bridge.

How many people does it take
to build a bridge nowadays?

We have about 750 people
working on the project.

Brooklyn was a separate city --

Safety culture in construction
is very different.

Narrator: It took 14 years to
build the first brooklyn bridge.

Can we build a new one
even faster?

How hard can that be?

To find out, we'll have to
line up all the parts, pieces,

And people we'd need
in order to get the job done.

♪

Back in the 1860s, it took
more than a new york minute

To catch a ferry
between brooklyn and new york.

Baker:
The millions of new yorkers
who commuted from brooklyn

Were tired
of waiting out in the cold.

In the 1880s when the brooklyn
bridge was going up,

Scollard: No injury,
no loss of life is acceptable.

The third-largest city
in the country.

New york was the first --
just manhattan --

Then chicago, then brooklyn.

Ferries ran every 10 minutes,
but still,

Out here on the river,

It was quite a cold process.

So they wanted to build
the bridge

To really connect
the two cities.

Narrator: But not everyone was
pleased with the merge.

Robins:
There were people in brooklyn

Who opposed the building
of the bridge.

"you build that bridge,

It's in a densely populated
urban area on both

Well, we may not have a choice.

The brooklyn bridge
is getting old,

And billions of dollars
are being spent on life support

For this aging landmark,
leaving some to wonder

If it wouldn't be
more fiscally responsible

To tear it down and start over.

♪

Narrator: The brooklyn bridge
may be beautiful, iconic,

And a marvel of its age.

But the bridges we build today
are longer, wider, and taller.

Maybe we can learn
something from them.

But replacing an icon
is not going to be cheap.

And new york
will swallow brooklyn."

The manhattan
and the brooklyn side.

So the construction will be --
will be expensive.

Would certainly say
it's more than $1 billion.

Narrator: And money may be
the least of our problems.

♪

We've got to decide what kind
of bridge we're building here,

And what we're going
to build it out of.

I think going forward,
it's gonna be so exciting

Because we can really
push the envelope.

Narrator: We may be able
to push the envelope,

But we definitely cannot stretch
the safety rules.

The brooklyn bridge
has provided new yorkers

Narrator:
And, believe it or not,

The perfect location is exactly
where the original bridge lives.

Can't we just demolish it
and start again?

Robins: You have to look
at the larger picture.

You have to recognize that
there is a cost benefit

To having
the brooklyn bridge standing,

And you need to throw that into
the calculations before deciding

Whether it makes sense
financially to rip it down.

Narrator:
With current technology,

Is there a way to build around
the old bridge

And still solve
the modern-day traffic debacle?

Narrator:
Since its construction in 1883,

Do we want to build the bridge
in the same place?

With a convenient crossing
over the east river.

But traffic has become
a major issue,

So we're going to see if we can
build a new, better bridge.

And instead of tearing down
the old icon,

We're trying to
give it new life.

Robins: Should the time come
that the brooklyn bridge

Can't support traffic
for some reason --

Meaning automobile traffic --

It will do just fine
as a pedestrian bridge.

Narrator: 7,000 people already
cross the brooklyn bridge

By foot every day on a roadway
above the cars.

Maybe we can upgrade
their experience.

And built to last.

And that is, in fact,
what happened.

Narrator: The brooklyn bridge
completely transformed new york.

But the problem it was built
to solve --

Traffic --

Is now worse than ever,

Thanks in part to
a growing population.

There's just been massive,
massive delays and problems

With just commuting
on a basic level.

Narrator: But maybe we can help.

If we re-create
a 19th century icon

To break up
a 21st century traffic jam,

Our new bridge has got to be
beautiful, brag-worthy,

Narrator: But could we build
the brooklyn bridge today?

And that mission will guide
every decision we make

On our modern-day
brooklyn bridge.

Where are we going to build it?

What kind of bridge
are we building?

What materials
are we building it out of?

How long is it going to take,
how many people,

And how much
will whole thing cost?

But first thing's first.

We've got to know
where we're going to build it.

If I were tasked to build
the brooklyn bridge today,

I think at first
I'd have to really figure out,

Could we even do it
if we built it today?

Narrator: What have we learned

Since the bridge
was originally built?

We're going to see
if we can do it better

Using the heaviest equipment,
the latest technology,

And an unlimited budget.

Choosing the right materials
and construction quality control

Are probably the key
determinants of the life

That you actually get
out of the bridge.

Plastic is always
stronger than steel.

Narrator:
We're on the jobsite of one of
the world's greatest wonders.

And we're wondering --
how long would it take,

How much would it cost,
how many workers would we need?

That are more
in need of repair?

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

Captions paid for by
discovery communications

New york, new york --

Where the most ambitious
dreamers come to make it big.

And back in 1869 when ground
broke on the brooklyn bridge,

The big apple
got a little bigger.

This was gonna be far

And away the biggest
suspension bridge in the world,

And it turned out to be so --
5,989 feet.

Narrator: Flip
the brooklyn bridge upright,

And it's as tall as
five empire state buildings.

Its gothic-style towers reach

They were new.

One of america's finest
architectural achievements,

Proudly connecting brooklyn
to the island of manhattan

Since 1883.

The brooklyn bridge
is the brooklyn bridge.

There's no bridge quite like it.

El-badry: At the time that
brooklyn bridge was built,

It was something completely new,
completely innovative.

There are features
that handle wind loads

In such a way
that is genius.

Narrator: Yet constructing this
masterpiece came at a price.

It hadn't been done before.

And the techniques --
they weren't tested.

As high as new york's
first skyscrapers --

And in many cases,
they were risky, as well.

Back in the day
in the late 1880s,

There was not the kind
of regulation we have today.

20 to 40 of them died
building the bridge.

Narrator: And maintaining
the bridge for commuters

And pedestrians
is an expensive venture.

Blau: It could go up to
about $500 million.

There was a massive,
massive overhaul.

I mean, there was peeling paint,
there was holes in the --

Like, in the steel.

Can that money be spent
for assets

So the idea that
it couldn't be built

And smashes into the dock.

It smashes the toes
on one of his feet,

Which would've been all right

Except he insisted on only
applying his water cure to it.

Well, after lockjaw and a coma
of several days, he died.

And responsibility for building
the bridge --

Most of the building
of the bridge --

Went to his son,
washington roebling.

Narrator: By 1869,

The brooklyn bridge's
chief engineer was gone.

But this construction project
wasn't going away.

Scollard:
It hadn't been done before.

One of the ferries
comes in too hard

Was actually very nearly true --
very difficult work environment,

Very risky in terms
of the construction.

Narrator: To many, it's the most
important bridge ever built --

An inspiration to engineers
around the world.

El-badry: At the time that
brooklyn bridge was built,

It was something completely new,
completely innovative.

Barbas:
They did not yet understand

Aerodynamic effects
at that time.

Yet if you look at
the brooklyn bridge,

There are features
that handle wind loads

In such a way that is genius.

Helped shape new york city's
skyline and self-image.

Two-thirds the height
of the great pyramid of giza.

The seven-story-high towers
were the --

Were the largest buildings
built in america to that point.

Narrator: Cathedral-like arches
support massive steel cables

300 feet above the east river.

Baker: The main cables --
there are four of them --

Are almost 16 inches thick.

And inside them are 5,434
separate pieces of steel wire.

There's enough wire
in the bridge cables

To go across the united states
and then some --

Over 3,500 miles of steel wire.

Narrator: There's no question
that the brooklyn bridge

We're picturing something
like this --

Robins: The brooklyn bridge is
probably the most famous

Of all our bridges --

Probably because of
its technological breakthroughs,

Because it linked
the two cities,

Because it led to the creation
of the city of greater new york,

But just because
it's so beautiful.

Narrator: But this symbol of
human achievement

Had an unlikely beginning.

The engineering genius
behind it,

John augustus roebling,
goes and surveys it.

And in a bit of
poetic vengeance,

Using new technology
in the construction,

Narrator: 25 years after
the brooklyn bridge opened,

The manhattan, willamsburg,
and queensboro bridges

Were also spanning
the east river.

Many of these bridges
incorporated

The suspension design
pioneered by john a. Roebling.

But today, you can find bridges
of all shapes and sizes.

If you look at the bridges
that are being built right now

Throughout the world, there are
lots of innovations in them.

And the innovation comes
actually from the best systems

Used from this type of bridge
and that type of bridge.

Perhaps these ideas will lead
to a new type of bridge,

A new structure system,
built of new materials,

Their location, their
visibility, and their design.

And this can actually be
an iconic bridge,

As well, for the future.

Narrator: So, what kind of
bridge is best for our needs,

And will it ever be able
to live up to the great lengths

That the brooklyn bridge
reached?

To find out, we'll need
to bridge past and present

By going back to the basics.

Narrator: The brooklyn bridge
may be one of

The most iconic
bridges in the world.

Yet it was built on years
of engineering know-how.

The earliest bridges
were beam bridges,

As simple as a tree trunk

Could they have bridged
completely over the water?

Or concrete pilings
have their -- their place.

But it's really gonna depend
on the particular

Ground conditions at the site.

Narrator: Is our foundation
going to be a boxy caisson

Or a long pile?

Turns out, thanks to
modern engineering,

We have a third option.

You might still revisit
that decision and see

Whether there's opportunity
to pull the towers

Out of the -- the water.

The brooklyn bridge had
their foundations in the waters,

Because they could span
only so much at that time.

Stretching across
a babbling brook.

Today, we can.

Generally speaking,
it will simplify construction,

Lessen the environmental
footprint for the project

Because you're not doing
all of that in-water work.

Narrator: We're going to build
more efficiently

By constructing on land.

But what are these bridges
going to look like?

Robins: There are something
like 6,000 bridges

Of all sizes in new york.

But most of them are unknown.

A few of them are just so iconic
because of their size,

With that conservatism.

In that it has both parallel,

Traditional suspension cable
systems as well as stay cables.

Narrator: A cable-stay bridge
is supported by cables

Tied between the bridge deck
and the towers,

While a suspension bridge
is more like a clothesline.

Horizontal wire is strung
between two towers,

Which in turn support
the vertical wires

That carry the load
of the deck.

It's kind of a hybrid system

That takes advantage
of the two systems

Together to build
a better bridge.

Brooklyn bridge was
intentionally designed

Scollard: The brooklyn bridge
is actually quite unique

You read reports that it was
designed for six times

The load that it was
actually anticipated to carry.

Narrator: Spanning
the east river is an innovation

That propelled engineering
into the 20th century.

This is really a test case.

And you build all kinds
of incredible things such as

The golden gate bridge
in san francisco,

Which is the first
suspension bridge of that size

Built on what's actually
the open ocean.

So this is something that
teaches generations

Of american engineers.

He perfected
the suspension bridge.

Then came arch bridges,

A favorite of
the ancient romans.

This design made it possible
to span greater distances

By distributing the weight
over signature curves.

The next innovation was this
system of load-bearing triangles

And squares called a truss,

Similar
to the popsicle-stick bridges

You probably built
back in school.

♪

And when john a. Roebling
moved to the u.S.

From germany in 1831,

He wrote the next chapter
in the history of bridges.

In modern construction,
both caissons and steel

Scollard: The idea of building
a suspension bridge

Was not unique, but pretty new.

Narrator: Roebling
built suspension bridges

In pittsburgh,
delaware, niagara falls,

And then this colorfully
restored bridge

Across the ohio river.

But the brooklyn bridge
was his most ambitious design.

It's the most famous
suspension bridge in the world.

But ask an engineer about it,

And they'll let you in
on a secret --

Roebling also used
what are called stay cables.

And what we all strive to do
is get out of the water.

Open to traffic.

It's been open for a year now.

And we're getting ready
later this year

To open the second bridge
to traffic.

Narrator: The new bridge,

Named after former new york
governor mario m. Cuomo,

Is almost three times
longer than the brooklyn bridge.

Work began by building
a foundation

In the middle of the river.

That's where our new bridge
will get started, as well.

Kick: For the construction
of the new bridge,

It all starts in the water.

We have one of the parallel
cable-stayed bridges

Right here, we're right
in front of the main stand.

And this is one of
our pylon piers.

These were some of
the most challenging

Substructure elements
that we had to construct.

Barbas: We have about 700 feet
of very, very poor soil.

And the engineers had to
design foundations

That were quite innovative
in terms of steel diameter piles

That would go down
maybe 300-plus feet

And rely on friction, because
they couldn't get to bedrock.

Narrator: It's called
a friction pile foundation.

Here's how it works.

Imagine a super thick
chocolate milkshake.

We'll build two brand-new
bridges for commuting --

Manhattan's high line,
an elevated rail line

That's been transformed
into a pedestrian paradise.

Blau: I mean,
they've literally just converted

Into the most amazing thing

Where you can kind of
look over the city.

And it was kind of the most --

Kind of for lack
of better terms --

A sort of urban blight
from before.

Narrator: So we'll keep
the existing brooklyn bridge

And give it a makeover.

To address the traffic jam,

We'll build a new marvel
on the same stretch of land.

Stick in a straw, and try
to balance a credit card on top.

One westbound, one eastbound,

On either side
of the current one.

Before we start building
our new bridge,

We can learn a thing or two
from another project.

Man:
Three, two, one, ignition, fire.

Narrator: Just one hour upstate,

The six-decade old tappan zee
bridge is being demolished

And replaced
with a brand-new bridge.

Barbas: It was becoming
extremely expensive

To rehabilitate
the existing bridge.

We are fully into construction,
quite in the later stages.

When workers came up
doubled over in pain,

And they lowered it
to the riverbed.

And workers went in.

Air was put in there so that
it would keep the water out,

But also so the workers
could breathe.

And they would excavate and take
up all the soil and the muck.

Narrator: Although it seemed
like a good idea at the time,

This pine box
was actually quite dangerous.

Baker: You had to deal with
going deep under water

In these highly pressurized,
highly dangerous situations.

Nitrogen builds up
in your blood,

And you need about 20 minutes
at this level to decompress.

They did not understand this.

Barbas: So they put this box,

They called it caisson disease.

Turns out, it was the bends
from coming up too fast

From underwater --
nitrogen in the blood.

Narrator: Among the afflicted

Was chief engineer
washington roebling.

He watched the rest
of his father's bridge go up

From his sickbed.

Now, in the 21st century,

We need to solve
a similar problem.

What kind of foundation
are we going to use?

♪

Which is drastically different

The straw is the pile,
and the credit card is the pier.

The structure is unstable
and won't support any weight.

Now, imagine two, four, or even
eight straws doing the same job.

The stability increases,

And the credit card
is able to bear a load.

That's how the cuomo --
or new tappan zee bridge --

Works,
except with 1,220 piles

Each about the length
of a football field

And built out of more
than 100,000 tons of steel

And concrete.

Kick: We decided to use
steel pipe pile foundations

To limit the amount of water
work that had to be performed,

Narrator: The brooklyn bridge --

Than building a bridge
in the old days,

Like when the brooklyn bridge
was built

And they were forced
to utilize caisson.

The caisson style
of construction

That the brooklyn bridge
employed

Was really like using --

Was yellow pine wood
like an inverted giant box

Where the opening
is at the bottom.

Narrator: It's true.

The brooklyn bridge sits on top
of a wooden box

Filled with concrete.