All language subtitles for How.Did.They.Build.That.2021.S02E06.Upside.Down.and.Under.Sea.1080p.WEB.h264-CAFFEiNE_track3_[eng]

[Narrator] Why did engineers
build an upside down skyscraper?

[Hayley]
If you suffer from vertigo,

this building is not
the one for you.

[Narrator] How can a restaurant
sit 18 feet below

the surface of the North Sea?

[Corina] An underwater
restaurant is wild enough,

but putting it on one of the
planet's stormiest coastlines

is off the charts.

[Narrator] And how do you
engineer a heavy metal library?

[Jay] that was the equivalent of
20 Statue of Libertys.

[Narrator] This is the
age of the extraordinary.

[Hayley] It's like one of
those insect-eating plants,

only enormous and white.

[Narrator] Where ingenious
engineers have unleashed

unchecked creativity.

Now their secrets are revealed.

As we discover the inside
stories of their construction.

[Corina] This is
an incredible feat

of planning and engineering.

[Narrator] To try and understand

"How Did They Build That?"

All right, we start the program
with a tower like no other,

built in an earthquake zone
that looks like a twister.

Now, this building
is a real marvel.

By which I mean
it's a real building

that looks like something
out of a Marvel movie.

Yet the incredible
Vancouver apartment block

that you're about to see
is not a superhero fantasy.

There's no big muscles.
There's no CGI.

They really made this!

[Narrator]
Vancouver, British Columbia.

Canada's most densely
populated place.

Here every square inch counts.

But right in the middle
of the city is a plot.

A small triangle of land,

hemmed in on all sides

and subject to
stringent planning laws.

[Michael] There's a force field
that the city of Vancouver just

said "thou shalt not"
and there's no negotiating that.

[Narrator] No one's worked out
how to build on it,

until radical architects come up
with a gravity-defying design

for an architectural marvel.

[Hayley]
If you suffer from vertigo,

this building is not
the one for you.

[Narrator] A tower that gets
wider as it gets taller,

appearing as though it could
topple over at any time.

[Corina] We all know that
for ultimate stability,

you need a big base that gets
smaller as you go up,

not the other way around.

[Michael] The bigger concern was

what's going to happen
in an earthquake?

[Narrator]
It's 59 storeys of skyscraper

that forced engineers to flip
tower construction on its head.

This is Vancouver House.

So how did they build it?

In 2014 with property prices
shooting through the roof,

developers are eyeing up
every square inch of real estate

in Vancouver.

Because of this, a site
previously considered

too small and tricky
was on the table.

Right in the center of the city
it should be prime real estate,

but its proximity
to Granville Bridge

brings with it a serious
planning headache.

The city has banned building
homes near busy, main roads,

which is certainly
the case here.

The city of Vancouver has
safety offsets from bridges

and it's similar
to all their bridges.

It's about 98 feet
you can't encroach within.

It is 98 feet not just
sort of horizontally,

but it's sort of an envelope
that you can't have structures

encroaching it.

Imagine a 98-foot bubble
around the bridge,

and nothing else is allowed
to sit within that bubble.

[Narrator]
And as if that isn't enough,

any development there can't cast
a shadow over the local park

making the area even smaller.

Coming up with a design that
overcomes the restrictions

and creates a building
big enough to make a profit

will require architects
to do some serious

thinking outside the box.

But then that's what
Danish firm, Big are known for.

Take Copenhill, a power plant
topped with a ski slope.

The circular eight house
housing project,

the Marsk watchtower.

For them, there really is
no such thing as a problem.

This is a good example of how
constraints work

in the creative process.

What we always try to do
is define the parameters

that the project should fulfill,

and use them as drivers
in the design process.

[Narrator] So out of the
tiny, triangular plot

their plan is to build
a stunning new skyscraper,

which will bend its way
around the bridge

and get wider as it gets taller.

Pulling this off and stopping
it from tipping over,

will need some
serious engineering.

The columns holding up
the larger upper floors

will have to navigate the
building's massive curve

and merge, getting thicker
as they go down.

Thousands of feet of tensioned
steel rebar will run all the way

from the top of the building
to the bottom,

literally pulling it into place.

And to make up
for the small footprint,

the foundations
will be super deep.

It's an ingenious way
to get the most out of a

limited plot like this.

[Narrator] Of course,
it's all well and good

having innovative design ideas,

but someone has to make sure
that when they build it,

it's going to stay standing.

[Michael] The architect
came up with that form

and then it landed on our desk
and said how can this work?

Turn it upside down.
And it works great.

[Narrator] And put very simply,
having a larger building

at the bottom getting smaller
at the top

would have overcome most
of the engineering problems.

[Ellie] A building with a square
or rectangular floor plan,

the gravitational pressures
are fairly equal.

Every floor is pushing down
with a fairly equal force.

But with this building, every
floor is a different shape.

This means that by the time you
get to the bottom

of the building, the forces at
the back of the building

are different from the sides

and different again
from the front.

And the result is a building

that not only
wants to fall over,

but it wants to twist
as it does it.

So, it's up to the
engineers to accommodate

and neutralize all those forces.

The obvious concern is the
building wants to fall over

under its own weight.

But for us locally,

the bigger concern was what's
gonna happen in an earthquake?

[Narrator] To find out,
the team builds a computer model

of the tower and tests it
to see what happens if it's hit

by an earthquake similar
to some of the worst

in North American history.

Like the magnitude seven,
Vancouver Island quake of 1946,

which caused chaos
across 100,000 square miles,

triggering devastating
landslides

and fires.

[Michael] Our initial runs
show that we could come up

with a design that was
within those limits.

Then test it against
twice the maximum credible

earthquake expected.

And with some tweaking
of the design,

we found even at that level

we could keep it within
allowable drift limits.

So we've essentially designed
it for double what any other

building in Vancouver
would be designed for.

[Narrator] It all looks well
and good on paper

and computer screens,

but just how well will
that translate to a

real-world skyscraper?

In 2016, it's time to find out.

Work gets underway,

starting with the supersized,
super strong foundations

critical to the
building's success.

The basement under the tower
was quite deep.

It was a challenge
to get that far down

with such a small footprint.

[Narrator] To anchor a building
into this tiny plot,

the team intends to create

140,000 cubic feet
of foundations.

It will weigh a staggering
10 and a half thousand tons.

And it's essential that
if it's to be strong enough,

all this concrete
is poured in one go.

If you have a break when pouring
concrete foundations like these,

you can have what
they call a cold join,

which is essentially a crack.

This is where the
bottom layer has set

and the next layer doesn't
bond properly to it.

And with a building like this,

you don't want
to take any chances.

[Narrator] What that means is
all the concrete

needs to be poured
before any of it sets.

It's going to be
a major challenge.

[Michael] It was the largest
continuous concrete pour

in Vancouver's history.

[Narrator] Next,

can they pull it off?

[Narrator] In Vancouver, Canada,
work is underway to create

the foundations for an
extraordinary new skyscraper.

All the concrete needs
to be poured in one go

before any of it sets

or it may not be strong
enough to do its job.

This needs some
serious organization.

It was the largest
continuous concrete pour

in Vancouver's history,
up around 4,000 meters.

It was so large that no
one company could do it.

So all three of the major
concrete suppliers in Vancouver

were involved.

And once it started,
they couldn't stop.

So it was basically 24 hours
of concrete trucks rolling up,

the concrete getting placed,
moving on, the next one in line.

[Narrator] The pour takes
24 hours straight,

But thanks to the team's
meticulous organization,

It's done.

With the foundations complete,

the engineers now
turn their attention

to building the columns

which will hold the building up.

[Michael] Because the building
grows as it as it comes up,

one of the challenges,
well, how are we going

to support each of these
floors as they get bigger?

[Narrator] On three sides,
there isn't a problem.

The columns go
straight up and down

like in a regular skyscraper.

But on the fourth,
the building twists

and gets bigger,
creating a massive challenge.

How to transfer the force
created by the bigger floors

above down through the building?

If they can't find a solution,

the top floors will
be left unsupported

and at risk of collapse.

[Michael] On one side
of the building,

by the time we're at the base,

the building's only
seven feet wide.

So a seven-foot-wide column
to hold up 53 stories

is quite a challenge.

[Narrator] Because the floors
are smaller at the bottom,

so are the spaces
where engineers

can put the structural supports.

But somehow, they've got
to support everything above.

[Michael] What we came up with
was at the top of the building

where the floor plate's large,
there's a series of columns

and they come down.

As the building starts to come
in the column steps down

and joins the next
column in from the edge,

and join the next column down.

All the columns are of course,
coming down here vertically.

But then they start
to walk in here,

so that basically one column
ends up carrying the load

of four columns at the top.

[Narrator] On their own,

these columns may not be
enough to hold the building up.

We all know that
for ultimate stability,

you need a big base that
gets smaller as you go up,

not the other way around.

[Narrator] The clever design
has overcome

the site's planning issues,

but created some very real
engineering challenges

in the process.

To help give the building enough
strength to deal with the bigger

floors at the top, the engineers
construct a very special spine.

First, they run steel rebars
linking it top to bottom.

The bars are anchored into the
large footing at the base

to give the weight
to pull against

and then they were
run up continuously,

so every floor they're coupled
with high-strength couplers.

[Narrator] They plan to tension
the steel rebar every so often

using a hydraulic tensioner.

Turning it on for the first time

should start to pull
the spine straight.

For the building,
it's a momentous moment.

For everyone else, not so much.

[Michael] We were all
very excited when we head

to the first point of
putting tension into the bars

to see what would happen.

And I guess, in your head,

that you're expecting
this grandiose thing.

It's literally just
this hydraulic cylinder

that goes over top of the bar.

And they stick a
compressor up to it,

doesn't take very long.

And the little gauge
says the force in it.

You put a bunch of nuts
on it to lock it off.

And that was kind of it.
It was very undramatic.

[Narrator] Finally, in 2019,
Vancouver House is completed.

And the results
blows the city away.

[Thomas] Obviously,
as an architect all buildings

are controversial
and some people like the work

we do and some people don't,
but I think in this case

we've had very positive
feedback.

[Man] If you are going
to build skyscrapers,

I would like to see more
unique buildings like this.

[Woman] We're lucky to have such
a unique building in our city.

I love it.
Absolutely, I love it.

[Michael] Just seeing it
and seeing the attention it got.

And being able to say like, you
know, we participated in that,

I think is yeah,
it's very exciting.

[Narrator] This twisting,
turning tower is not just

a thing of beauty,
it's a gravity-defying wonder,

showing that overcoming
limitations can lead to

some of the most
creative thinking

and daring engineering
imaginable.

When I visit a
seafood restaurant,

the experience for me is always
way more enjoyable

if the restaurant is by the sea.

Delicious food as close
as it's possible to get

where it was caught.

The only way to be any closer
would be to eat in a restaurant

that's actually in the sea
itself, say 18 feet below

the icy waves of
the Norwegian North Sea.

But they couldn't, right?
They could.

And they have.

[Narrator] From majestic fjords

to the magic of the
northern lights,

Norway has some amazingly
special experiences to enjoy.

But in 2014, a hotel owner
decided it needed a new one.

A fine dining restaurant
that would be like no other.

A place with an eye-popping view
of a completely different world.

An underwater restaurant is wild
enough, but putting it on one

of the planet's stormiest
coastlines is off the charts.

[Narrator] Creating a restaurant
18 feet below the surface

of the North Sea would test
engineers to their limits.

I think it was the most
stressed I've ever been.

[Narrator]
It would take four years

and over eight million dollars
to build one of the coolest

restaurants on the bottom of one
of the world's coldest seas.

This is the
Under Norway Restaurant.

So how did they build it?

[Narrator] It's 2014,
and in Norway,

hotelier, Stig Ubostad
has a rather mad idea,

to combine two of
his favorite activities,

fine dining and scuba diving,

when he decides to build an
underwater restaurant.

To do a thing like this,

you need to have
a passion for the sea.

And I've been diving
since I was a small kid.

It's fantastic.

[Narrator]
Stig's family-run hotel

sits on the southern tip of
Norway's coast,

exposed to the full force
of the North Sea.

Building it on land
wouldn't be exactly easy,

so imagine trying to build it
under the sea.

This spot in Norway
is where the storms

from the north
and the south collide.

[Stig] We can get waves up
here to four or five meters

at the highest.

[Narrator] Below the waves,
strong, nutrient-rich currents

attract a diverse range
of marine life.

We wanted to have in rough seas,
not in sheltered water

because the marine biology
is a lot different.

[Narrator] Stig's plan is
to create a restaurant

where diners can enjoy swimming
with the fishes

while sampling the very best
the sea has to offer.

What's more,

they won't even have
to dip a toe.

To help pull this off,

he brings in the team
behind the Oslo Opera House.

The architects at Snohetta
know a thing or two about

building beauty by the water.

This though, will be
something different again.

It was a kind of a crazy idea,
to build the first

and biggest underwater
restaurant in Europe.

That was actually the brief.

[Narrator] Although a few
underwater restaurants exist

in places like the Maldives,

none has to withstand the day
in, day out force

of the North Sea.

Not only will it need
to be beautiful,

but also, very, very tough.

We couldn't create a building
where you,

at any point would feel unsafe,
going underwater, for instance.

So all these things
came together with a

very stiff kind of concept.

And we created more like a pike
that intersects with the water.

[Narrator] The architect's
ingenious design

calls for a tube of concrete
111 feet long

with walls about two feet thick.

One end will be attached
to the shoreline,

while the rest is submerged
under the sea

to create a huge,
sunken periscope.

It's piece de resistance will
be the world's largest clear,

acrylic panel, 36 feet wide,
11 feet high

and 12 inches thick.

This will create
a widescreen window

into the watery world beyond.

To avoid being swept away
by the powerful waves,

the restaurant will be firmly
anchored to a concrete base

connected to 18 steel piles sunk
into the seabed deep below.

If there's one thing an
underwater building needs,

it's firm foundations.

[Narrator] Luckily,
building heavy-duty structures

is big business around here.

The oil rigs
and pipelines needed

to exploit Norway's oil fields,

mean local engineers are experts
in building structures

that can survive this
seriously hostile environment.

Well, we get a
phone call one day saying,

oh, I've got this underwater
restaurant that needs to be

installed onto the seabed.
Can you guys help?

I hear that you're local and

know how to do marine
engineering.

[Narrator] Normally a structure
like this

would be built on dry land,
moved on heavy haulers

and finally lifted into the sea.

But the cost would be enormous.

So instead, they decide to
build the whole thing

on a barge on the water.

It's a cheaper solution

but comes with its
own set of problems.

[Ben] Every time you have
to pour a concrete formwork,

you end up changing the
stability of the barge.

We had to tell the guys,
well, if you pour 100 ton

of concrete over here,
then you need do something

with the ballast water
in the barge over here.

Otherwise,
it might all end up upside down.

[Stig] And also,
one of the biggest challenges is

if you get that in addition with
the high seas and big waves,

it's always moving around.
So it was quite challenging.

[Narrator] These aren't
the only waves

the team has to worry about.

They need to make sure the
structure is going to be

strong enough to cope
with whatever hits it,

even if that's a
once-in-a-decade storm.

To do that,
Ben turns to a piece of

cutting-edge computer
technology.

So the wave analysis is a
really interesting point.

It's based on computational
fluid dynamics.

Computational fluid dynamics are
calculations

that mimic wave actions.

[Ellie] In this case,
they can create a hypothetical,

powerful storm 12 miles offshore

and calculate the exact size
and power of the waves that,

that will create
at the restaurant site.

[Corina] They can then
feed these loads into the

structural analysis
for the design

and then strengthen
it accordingly.

[Narrator] They take advantage
of Norway's endless summer days

to move the build forward.

Work pushes on creating
thick concrete walls,

ceiling and floors.

And to minimize the chance
of fractures and leaks,

the main outer structure
is built as one completely,

continuous concrete shell.

Wooden molds are used to create
the shape around a network

of reinforcing steel bar.

At one end,

there's an opening for
the huge underwater window

36 feet wide
and over 12 feet high,

which is being made
at a specialist factory

in the Netherlands.

[Rune] The special thing with
this, is it also,

this is 25 centimeters thick

and it's made out of acrylic,
11 meters wide

and I think 3.8 high
and it consists of

three different pieces,
which are glued together

so that's very special
with this big window

that also its position
in the construction,

so the water pressure itself

make it even more watertight
because of the pressure.

[Narrator] The completed
shell weighs 2,500 tons.

It's now got to be moved
to its final position

across the bay

before being sunk
and fixed to its foundations.

First, they need to get it off
the barge and into the water,

which normally wouldn't be
too much of a challenge.

[Ben] When we install
big oil rigs offshore,

we use barges
that are properly sized.

So we sink the barge down

and you can float off
the structure that holds

the oil platform on top,

and everything goes
extremely smoothly.

But in this case,

the barge that we built the
restaurant on was too small.

[Narrator]
Conscious of project costs,

the team builds the concrete
structure on a small barge,

but that creates a new
problem to overcome.

So if we tried to
submerge that barge

with the restaurant
on top of it,

there was a 100% chance
that it would flip upside down.

So we didn't want
that, of course.

We end up having to put
what we call the reaction barge

onto the end of the installation
barge just like this

with a pivot point.

And it added extra buoyancy
or extra stability.

[Narrator] At 3:00 AM on the
morning of July 27, 2018,

the moment comes to float the
concrete shell off the barge

and move it into position.

They've waited for the
best possible weather,

but they can't take any chances.

So installation must be
completed in one seamless,

24-hour operation.

[Stig] When doing it, it needed
it to be dead calm on the sea,

and luckily enough, it was.

And we just had that one shot.

[Narrator] Stage one goes well.

But the project now faces
its biggest moment of danger.

Once it has floated
free of the barge,

the shell is uninsured.

[Ben] As the restaurant
was coming off the barge,

that was by far the most
stressed I've ever been.

[Narrator] In Norway,
work is underway to build

an extraordinary
underwater restaurant.

The uninsured concrete shell
is being towed out

into the deep water of the bay.

Waiting there is one of the
largest floating cranes

in Norway.

Only when that is attached
to the shell

will the insurance kick back in.

[Stig] For the construction
on the barge,

you get normal insurance,
building insurance.

And when it's attached
to the ship then its marine.

But in the between,
you don't have any insurance.

[Narrator] To great relief, the
crane is successfully attached,

and the shell is insured again.

It guides the shell in and over
the concrete foundation slab

18 feet below the surface.

Now they've got
to sink the restaurant,

which turns out to be a
surprisingly difficult task.

[Ben] To get it down
onto the seabed,

we had to pump 500 tons
of seawater

into the restaurant itself.

[Narrator] Moreover, they have
to do that without damaging

the restaurant's most
important feature,

the 36-foot-wide window
onto the underwater world.

[Ben] We have this beautiful,
really expensive window,

and we couldn't put any
seawater or water in general

onto the inside of the window.

So all of the water ballast
is actually contained in

in massive garbage skips.

[Narrator] It takes nine hours,

but slowly,

the restaurant sinks towards
the steel piles.

It is bolted onto
the foundations.

[Ben] So it was quite a
simple, novel arrangement,

really beautiful actually,

from an engineering
point of view.

[Narrator] The rest
of the time on site

is more like a traditional
restaurant installation

with plumbing,
electrical, insulation

and ventilation
systems all added.

Bespoke furniture is
commissioned

from local furniture makers

and made from local forest wood.

The world's newest and largest
underwater restaurant

is finally ready.

In March 2019, it serves its
first food to 40 lucky people.

The 18-course tasting menu
with wine, at $430 dollars,

is of course, delicious,

but all eyes are on
that unique view

made possible by that
12-inch-thick acrylic window

that bends by up to
an eighth of an inch.

[Ben]
That window is very special.

In fact, on the biggest storm
events,

if you put your hand
on the window,

you can feel
the waves crashing through.

The window actually deflects,

I think a maximum
of four millimeters.

[Narrator]
The vibrations soon turn

from nerve wracking to good,

as the unique seafood and view
combination creates a big stir

on the international
restaurant scene.

[Stig] It's been immense.

We had 2.2 billion digital views
within the first half year

and around 3,000 articles
in 104 different countries.

This beautiful architecture,

like we saw that
on the Instagram.

It's worth a trip to you know,
visit here.

[Corina] I have to see it,

so I've made the earliest
possible reservation

in two year's time.

You know, if engineers
had their way,

we'd just make completely
symmetrical square boxes

and we'd put them on the seabed
with no windows.

But that wouldn't be beautiful,
would it?

Our next building is one of
those baffling feats of

engineering that appears to be
exempt from all laws of gravity.

At first glance,
this Seattle landmark

resembles a stack of books
on the verge of toppling over,

which is kind of the idea, since
it's the city's new library.

Watch how Seattle rewrote the
book on big, bold public spaces.

[Narrator] Seattle, Washington.

Famous for its coffee,
the Space Needle and grunge.

And now to add to that list,
an extraordinary library.

Ready for the 21st century.

And boldly going where
no one has gone before.

[Corina] This giant stack
of boxes and slopes

seems to teeter dangerously
over the street.

[Narrator] In building this
temple to calm and quiet,

engineers would have to prevent
almost 5,000 tons of steel

from toppling over.

[Jay] That was the equivalent
of 20 Statue of Libertys.

[Narrator] They need to
stop it from becoming too

hot to handle in summer.

[Hayley] That curtain of glass
could turn the building

into a giant greenhouse.

[Narrator]
And if that wasn't enough,

prevent flooding from day one.

We had a tremendous amount of
groundwater pouring in.

It was pretty dramatic.

[Narrator]
But that's only the beginning

because it's a building that
really wants to fall down.

[Ellie] With virtually no
columns to keep it standing,

it seems an impossible feat.

[Narrator] It needs a vast,
steel lattice to battle

catastrophic earthquakes.

This is Seattle Central Library.

So how did they build it?

It's the end of 1990s

and America's northern-most
major city is booming.

Seattle's population is now
approaching half a million.

And to be honest,
it's doing pretty well.

But in this modern city,
there are fixtures and fittings

that are beginning to feel
a bit out of place.

Not least, its library.

Established at its
current site in 1960.

[Andrew] The city of Seattle
was growing quickly.

And the library needed
to expand its size

and range of collections,
services and programs

to meet a growing population.

[Narrator] So the city decides
it's time to build a new one.

But this time,

it's going to be different like
no library we've seen before.

Libraries have traditionally
been thought of as kind of

musty, dark places,
and really, the vision

for this library was to turn
that whole idea on its head.

[Narrator] The library also
wants to embrace the dawning era

of digital technology.

These are the heady days
of the dot.com boom.

And Seattle has some
of the biggest players

right on its doorstep.

In a place that's home
to some of the most

forward-thinking tech companies,
the city looks outside its walls

to find someone to design it.

[Rem] It was in a very
interesting moment when

Microsoft and Amazon
were all emerging

and influencing
the condition of Seattle.

[Narrator] They turn to
Dutch architect, Rem Koolhaas.

From his revolutionary
skyscraper for China's

CCTV station in Beijing,

to Holland's so-called vertical
city in Rotterdam.

He's not afraid
to bust the boundaries.

[Ellie] He's right up there
with Geary or Hadid.

He pushes engineers
to their absolute limits.

[Narrator] Koolhaas's
design doesn't disappoint,

and will redefine
what engineers can build.

Set on a steeply sloping
downtown site,

the new library will consist
of four huge boxes

stacked one on top of the other

to create an 11-story building.

But Koolhaas wants each box
to be massively offset,

jutting out precariously

with just a slim,
central concrete core

shared between them.

A network of ingeniously
positioned super slim columns

will add support
to the boxes above,

crucial in this
earthquake-prone area.

Finally, sloping walls of glass
will envelope each of the boxes,

exposing all areas to vast
amounts of daylight.

It all creates a uniquely
open, welcoming space

for research and learning.

Koolhaas's building has space
for more than a million books,

but is unrecognizable
as a library.

This is a 21st century
information store.

[Rem] What you see is a stack
of open, closed, open, closed,

open, closed elements.

This element is shifted in the
direction of Mount St. Helens.

This section is shifted
to have a view of the sea.

And then in-between,
there was a big livingroom

where they could develop a lot
and change a lot over time.

[Narrator] When the construction
team sees the transparent

glass and steel design model,

they know they have an
almighty task on their hands.

There's no interstitial space,
you can, you can cover

over connections or anything.
Everything is exposed.

In some ways
its completely unforgiving

as far as a
construction team is concerned.

[Narrator] In 2001,
construction begins,

and they're faced with their
first major challenge.

The new library is being built
on the site of the old one.

And that's on a very steep hill.

[Jay] A pretty significant
portion of the building

is below grade.

So structurally, how do you
hold back that much dirt?

[Narrator] The team comes up
with an ingenious answer

to keep the existing basement
wall of the library,

which is currently
holding back the hill.

[Dale] We had to support
the wall laterally

before we could
demolish the building.

Because the structure
of the building was holding

that wall up originally.

And that proved
to be a real challenge.

[Narrator] To do this,
they need to underpin the wall

with vast steel piles
driven into the ground.

Then they'll have
to fix tiebacks,

huge iron rods,
which will be attached

to the wall, then fixed
securely into the ground.

But they quickly run
into a major problem

that threatens to bring down the
entire wall

and hillside with it.

[Dale] We had a tremendous
amount of groundwater

that was pouring in
along that wall,

so we had to actively de-water
under the road

in order to relieve a lot of
that pressure,

which was a bit of a scramble.

It was a constant challenge to
mitigate all the groundwater

that was coming through.

And also, it didn't help when
we were building in December,

January, February are
the wettest months here.

[Narrator] With the weather
fighting against them,

the team ends up constructing a
new wall in front of the old one

in a last-ditch effort
to prevent it from giving way.

It was a definitely
pretty dramatic.

[Jay] There was a bunch
of challenges for that.

They're like,
I think we just kind of

outsmarted ourselves
on that one, you know?

[Narrator] With the wall steady
and danger averted,

the serious work of laying
the foundations begins.

The next problem
facing the engineers

is how to support
the various floors,

which the designers want
to float above one another

without using vertical columns.

For the construction team,

it seems an
impossible challenge.

[Jay] When I looked
at the model,

they had these
little vertical columns

that they under
different parts of it.

And I said, well,
what are those?

And they said,
well, we need those

to make the model stand up.

And I said, well, there's
probably a good chance

that if you need them
to make the model stand up,

I'm gonna need
something like that

to make the building
stand up, too.

[Dale] Rem Koolhas wanted us
to remove

as many interventions
as possible.

He wanted the building
to look slightly dangerous.

[Jay] And that's where it got
to be really tricky.

And we spent a lot of time
trying to figure out,

well, how in the world
are we going to do that?

[Narrator] The answer they
come up with is to tilt the

supporting posts at an angle.

These raking columns
will be placed at key points

around the building and will
support its vast steel frame.

[Nehemiah] The benefit of raking
columns is that

you can transfer the load
at an angle.

The downside, however
is that they require

very careful calculations.
There's not much room for error.

[Dale] That made it incredibly
challenging for us to build

because we had to figure out
how to get these

huge columns into place
at the right sequence.

[Narrator] With the help of the
latest 3D computer modeling,

the team is able to work out
exactly where,

and in what order,

these columns should be placed.

But if that wasn't enough,

the team also has to make sure
the building will be able

to stand up to whatever mother
nature throws at it.

And here that
includes earthquakes.

[Narrator] In Seattle,
work building the new

central library's vast steel
skeleton is progressing.

But engineers have to make
sure it can deal with

one of the biggest natural
problems the city faces,

earthquakes.

In 2001,
the huge Nisqually quake

ripped through Seattle's
buildings and infrastructure.

Next to a major fault line,

the big one is expected
to hit anytime soon.

[Jay]
We have very high seismicity,

large earthquakes,
fairly frequent.

We get relatively high wind
loads through here as well.

And again, it's a lateral load,

a horizontal load trying to move
the building horizontally.

[Narrator] The team comes up
with an awe-inspiring solution.

They're going to cover the
entire building with a vast

steel lattice of diamond shapes.

It will look dazzling
and protect it.

The shape of the panel
allows for redistribution

of that lateral load.

So the number of sides that it
has by being diamond shaped

allows it to share the load
with more adjoining panels,

making it easier to resist.

[Sam] If there's an earthquake
or if there's a high wind event,

the load is transferred
into the diamond grid,

and the diamond grid
is resisting that.

[Narrator]
There is no room for error.

This grid has to be cut
and installed

with pin-point accuracy.

The stability of the library
literally depends on it.

[Dale] We were really challenged
because the tolerances

on the seismic steel
are almost perfect.

We had to be within one half
inch plus or minus

with all of it.

[Narrator]
While they're building the mesh,

the team holds it in place
with sections of temporary

ironwork called false work.

These have the added purpose
of helping to support

the entire steel framework.

But all of that
will have to come out.

[Dale] I kept asking the
ironworkers for their plan

of how they were going to
remove all this false work.

And they gave me this sketch.

And it showed the
ironworker apprentices

torching all the columns.

The journeymen ironworkers
in the bar across the street

and the structural engineer
would stand in the middle

of the building.

Because they figured if the
engineer was willing

to stand in the middle
of the building,

then the plan
must be successful.

[Narrator] Finally, the day
comes for the engineers

to put their money where
their mouths are.

Time for the temporary
steel to come out.

There was no going back.

We literally were torching
the columns off at the bottoms.

If something started to go awry,

I don't think we really had much
of a recovery plan for it.

[Narrator]
The team waits anxiously.

Everyone stands well back.

Will some 5,000 tons of steel
skeleton remain standing?

[Dale] There was a range
of anticipated deflection

that the engineers calculated,
and it barely moved

within that range.
It was quite successful.

[Narrator]
With the steel lattice complete,

it's time for the
finishing touches.

10,000 glass panes
to shroud the exterior,

almost the size of three
American football fields,

letting in natural light.

Though that creates
the next challenge

for the team to overcome,

the heat of the Seattle sun.

[Dale] Basically, this is
a giant greenhouse,

and we didn't want to have to
cool the building excessively.

[Sam] We also don't want
too much sun coming in

and making people uncomfortable.

[Narrator]
To overcome the problem,

the team come up with
an ingenious solution,

clever glass.

Each window will be made from
two panes sandwiched together

and in-between there will
be a tiny air space containing

an aluminum mesh
to soften the sunlight

at key times of the day.

The idea is that it creates
essentially like

mini sun louvers

as you look through it.

So it's transparent
as you look through

and it's blocking the sun
as the sun is coming down on it.

[Narrator] Invented especially
for this building,

it's believed to be the one
of the world's first

microscopic sunshades.

[Corina] In summer when
the sun is high and hot,

they create shade.

In winter when the sun
is cool and low,

they let light in.
Win, win.

[Narrator] In 2004,
following six years of planning,

designing and building,

the city of Seattle has an
extraordinary library

ready for a new age.

It was like nothing anybody
had seen before.

[Andrew] The New York Times
memorably called it

a library with fishnet stockings
going to the disco.

[Narrator]
The 130,000 square foot

glass curtain on the outside

together with the vast,
cavernous spaces on the inside,

and topped off with a 3-story
book spiral in the center,

all combined to
make this library

a very special place to be.

[Sam] The great thing about the
spiral that it allows us to do

is to have a continuous
run of books,

so the Dewey Decimal run is
uninterrupted from 000 to 999.

It's never been done before.

[Narrator] The construction team
on the ground

can stand proud
of their success.

It's such a brilliant building.

It's such an amazing icon
for the city.

[Hayley] Creating magnetic new
public spaces like this

is what will keep city centers
alive in the future.