All language subtitles for How.Did.They.Build.That.S01E08.Arctic.Modules.and.Auditoria.1080p.WEB-DL.DDP2.0.H.264-squalor_track3_[eng]

Narrator: How did
a team of engineers

nicknamed the extreme team

build a futuristic
research station

in the world's most
extreme climate?

Man: This is a really
savage environment

for any building to endure.

It's just really
harsh out there.

You've got temperatures
that go as low

as negative 58 degrees celsius,

and then you have wind speeds

that go as high as 160
kilometres per hour.

Narrator: How does
this stunning visual trick

make a 3,500-ton
concrete arch levitate?

Woman: It looks like the wing

is floating completely
unsupported.

Narrator: And how did they build

the world's first
rotating boat lift,

able to carry 500 tons
of water and two boats

over 65 feet into the air?

Woman: All the
falkirk wheel needs

is the equivalent power
of eight boiling kettles.

♪

Narrator: This is the
age of the extraordinary...

Man: This house
always is on the verge

of falling down.

Narrator: Where
ingenious engineers

have unleashed
unchecked creativity...

Woman: Everything
in this building

pushes at the boundaries
of what's possible.

Narrator: Building structures
so outrageous, they defy logic.

Woman: The forces on this thing

look like it should
be torn apart.

Narrator: Now their
secrets are revealed.

Discover the incredible
stories of their construction...

Woman: These are
extraordinary feats of engineering.

Narrator: To try and understand

how did they build that?

Imagine the engineering it takes

to build an advanced
scientific research centre

that can cope with
outside temperatures

of minus 58 degrees
fahrenheit and house 60 people.

It has to be completely
self-sufficient

for months on end

and be able to move locations
quickly when danger strikes.

Debbie sterling: It's
a brutal environment

for any building to survive in.

Narrator: But
that's the building

the British antarctic
survey needed,

a mobile research
station that could survive

in the most hostile place
on earth... Antarctica.

This ingenious
series of rugged pods

uses train and space
shuttle technology

so that top scientists can
study our planet's atmosphere

all year round.

But designing something that
could be built on a slab of ice

10,000 miles from home
was a massive challenge.

Ellie cosgrave: The
people who were building it

had to actually use
electrically heated gloves

to counteract the frostbite.

Narrator: The crippling cold
was only one of the hurdles

a dedicated team had to
overcome to pull this off.

[Crunching]

Every part had to be
delivered to an ice dock

that could crack
open at any moment.

Snowdrifts would Bury
the buildings and equipment

in the blink of an eye.

And the summer build
season was so short,

it would take five
years to complete.

The result was the extreme
mobile research station

called halley vi.

So, how did they build it?

For the last 65 years,
britain has been pioneering

the scientific study of
the earth's atmosphere

in the most extreme
environment on earth.

Joshua macabuag: This place
has 1.2 meters of snow a year,

and the snow that
does fall, it never melts.

Then you have the drifts.

This is a big wide-open space,
so anything that you put there

is going to gather
a lot of snow on it.

Narrator: Despite
the tough conditions,

the clean air and
low light pollution

are the reasons why the
British antarctic survey

has been building
research stations

in the antarctic since 1956.

In 1985, its scientists
discovered a huge hole

in the ozone layer,

a finding that led to the
global banning of cfcs,

reversing a
potential catastrophe.

Named after the great
astronomer Edmond halley,

the first four halley bases
were simple structures

that worked for a while,

but always ended up
buried deep under the ice.

In 1989, they upped their game,

building the fifth base
on adjustable stilts.

Hugh broughton: So,
halley v was quite clever

because it has
these screw Jacks,

which meant the building
could be jacked up every year

@by a meter or
a meter and a half

to help it escape from
the rising snow level.

Narrator: So halley v could
move upwards to avoid the snow,

but there was a bigger
problem it couldn't escape.

Every year the
ice shelf it's built on

moves 1,300 feet
closer to the sea.

Debbie: The halley v's
legs were fixed into the ice,

and so they had to
throw that design away

because there was a risk
that the ice could break off

and the whole thing
could just drift into the sea.

Narrator: It was time for a new,
better halley research station.

Architect Hugh broughton
Rose to the challenge

of designing a station
that could overcome

the difficulties of being built
and operating in Antarctica.

From the start, he faced
an unusual set of limitations.

Hugh: Everything that
needs to be delivered to halley

first of all gets unloaded
from a ship onto sea ice,

and the maximum
weight of component

could be no more than nine tons.

Then the other challenge
is that this building

needed to be relocatable
between 15 to 20 kilometres,

so quite a decent move.

Narrator: Being able
to move the station

to avoid being
stranded on an iceberg

topped the already
formidable design criteria.

Some radical
thinking was needed.

Hugh: The first thing we decided

is that we should come
up with a modular solution,

so break the requirements of
the British antarctic survey's brief

down into a series of
interconnected buildings,

and the reason we did
that is that those buildings

could be disconnected
and moved more easily

from one site to another.

Nehemiah mabry: The modular
construction is really fitting

for remote
environments like this,

much likeúthe
international space station,

where you can put
things together bit by bit

without having
to dig foundations

or anything that you
would traditionally see

in a more reasonable
environment.

Joshua: The eight pods,
there's two sleeping pods,

two science pods, two
generator and plant pods,

one command pod, and
one double height living pod.

Narrator: Along with a
team of expert engineers,

the architects
created a blueprint

for what would be
the most complete,

extreme environment
accommodation ever built.

Eight individual
pods would be linked

through enclosed
gangways, like train carriages,

to create one integrated
living and working organism.

To cope with the
constantly rising snow,

huge hydraulically
adjustable legs would allow it

to be raised and lowered,

and each leg would sit on
a massive teflon-coated ski.

If danger threatened, each
module could be detached

and moved to a new location,

where the station
would be reconnected,

avoiding a catastrophe.

The modular plan solved
many of the problems

the extreme
environment presented,

but there was no getting away

from the greatest
single challenge

facing its construction,

the extremely short
summer building season

of just 12 weeks between
December and February.

Hugh: The construction
season in the antarctic

is unbelievably short.

Days in January and December,
which might be minus 5,

suddenly at the end of
February, beginning of march,

you're working at minus 25,

and that's pretty hardcore
if you're working outside,

so then you've got
to leave your site

for the following 10 months,
until you can come back again.

Narrator: While the
construction crew could fly in

on a Russian transport plane,

all their tools and supplies
had to be delivered by ship.

The logistics here
were tough enough,

but it was that short
three-month window

when external work was possible

that meant a traditional
approach to construction

was impossible.

Hayley loren oakes: The
only really sensible solution

was to prefabricate
everything in a warm country,

in this case, South Africa.

Narrator: To
maximize efficiency,

the engineers test-built two
complete modules near Cape Town.

This meant they could
perfect components

and train the construction team

before shipping all the parts
4,300 miles to Antarctica.

Hugh: The buildings were
built as in a kind of kit form,

and that's because
it's hard to move things

when the ship arrives
at the edge of the sea ice.

Narrator: The on-site
build began in 2007.

Icebreaker ships
had to straighten

the edge of the ice shelf.

Once in position, everything
was unloaded at breakneck speed.

The planning had
been meticulous.

Hugh: We wanted to be
able to unload components,

for the components
to be as big as possible

within that weight
restriction of nine tons,

and for all the parts to
be able to click together

as quickly as possible.

The biggest part that we
made was the steel frame,

which forms the base
of each of the modules,

which is basically a whole
series of tubes joined together

in a three-dimensional
form to maximize strength

and making it easier
to move from the ship

to the building site.

Narrator: For seven days,

caterpillar tractors
worked nonstop,

pulling 500 tons of
cargo 7 1/2 miles inland,

to the still-functioning
halley v base.

The result was an
extraordinary collection

of prefabricated components
awaiting assembly on the ice.

Joshua: Everything was
arranged in a very well-organized,

very well-labeled line,
four kilometres long.

Narrator: The plan was to
get each module on its legs

and with all the key components
fitted before winter arrived,

which would shut down the
site until the following year.

The construction crew of 40 men,

who lived in prefabricated
huts near halley v,

worked in shifts around
the clock to stay on schedule.

Hugh: In order to maximize

the efficiency of the
construction process,

we approached it in the same
way almost that you would

an assembly line for making
a car or something like that,

so we had one crew
doing steel frames,

another crew building shell.

Joshua: Given the dangers
of being in the antarctic

and the limitations on space,

all of the builders had to be
able to do more than one job.

Hugh: There would be a team

installing the primary
building services,

things like the generators,
the sewage treatment,

the water production unit,

and then the service connections
that go between the modules.

Joshua: These were
definitely no ordinary builders.

In fact, they were
nicknamed the extreme team.

Man: Behind me is the
second energy module

with all the plant and equipment
placed upon the floor deck.

The obvious ones to point out

are the big pink tank at
the back, which is fuel,

and the big grey tank at
the front, which is water.

Narrator: Every single
unit that could be pre-built

before arrival had been.

Man: As you can see, there's
the prefabricated bedrooms,

plant room, and wc.

Next stage for this is to have

the structural steelwork
erected around it.

Hugh: The bedrooms had the
beds in, the desks in, the wardrobes.

We didn't go as far as putting
the duvets and the pillows on,

but it was pretty close to that.

Narrator: By the
time the extreme team

had the pod
frames on their legs,

with the key
components fixed inside,

the days were becoming
very cold and short.

It was time to
wrap the structures

and prepare the site for
the bitter winter to come.

They could only hope

the equipment and
materials would survive.

Hugh: So, if you're
going to leave

any of your equipment there,

you need to make sure
that it's durable enough

to withstand the
harsh antarctic winter,

and that was a hard thing to do.

There are materials
which are used

in food cold stores
and things like that,

but they typically
go down to minus 25.

But to say to someone,

"oh, no, your product's actually
going to go down to minus 55,"

that's sort of a
different level.

Narrator: During
testing off-site,

the module cladding
was found to be too brittle.

As a result, no work
was done in the antarctic

the following summer season,

while the materials were
perfected in South Africa.

Finally, 21 months
after wrapping them up,

the extreme team returned,

and the half-built modules
were released from winter's grip.

Man: Ok, so here we
are on the halley vi site,

and these structures are
going to be towed up a ramp,

and the snow height here
is about 20 foot at the back,

so we'll clear it
out, make a ramp,

tow the structures out,
and take them to the south.

Narrator: Cladding
the modules was next.

It was these improved panels

that would give the halley vi
pods their distinctive shape,

a look inspired by a
50-year-old kids' TV series.

Ellie: I can totally
see this in the design,

but apparently the
architects and the engineers

for this project were inspired

by the sixties puppet
show "thunderbirds."

Hugh: I was a massive
fan of the thunderbirds.

I think the influence
is pretty clear,

and thunderbird 2 was coursing
through the design from day one.

Narrator: The
thunderbirds-inspired pods

wouldn't just look good.

Crucially, they would
be the first line of defense

against the harsh weather for
everything and everyone inside.

Hayley: The walls are made
of glass-reinforced polymer,

or grp, and more commonly
known as fibreglass.

It's 75 percent lighter
than the steel equivalent,

and it's super strong,
and it's lightweight,

and it can actually
resist corrosion,

and best of all, it's
a brilliant insulator.

Narrator: Although fibreglass
was known to be tough,

Hugh needed to be
sure it would survive

the antarctic conditions.

Hugh: When we were having

the glass fibre
shell manufactured,

we went through a really
rigorous process of testing.

We subjected it to the effects

of the ice being
blown in the wind,

so we blasted it with
sand to simulate that.

We sprayed water at
the cladding material,

or the building shell material,

and then lowered the
temperature really quickly

to see what happens under
freeze/thaw kind of cycles.

Narrator: The
glass fibre cladding,

backed by 12 inches of
high-performance insulation,

would protect the
researchers from the cold,

but there is another extreme

from which people
here need protection...

The light or lack thereof.

Hugh: We decided that
at the heart of the station,

in the main big
red social module,

it'd be really great
if we could have

a big double-height
space with a big window

because you just
get really nice light

in the antarctic in the summer,

and it would just provide
a really great social focus

for the community.

But of course, the big challenge
you have in the antarctic

is if you create a big window,

then it's also a source of
massive heat loss potentially,

so we, we really searched
high and wide around

and discovered this
incredible material

that was invented by
NASA, called nanogel.

Narrator: Nanogel was used
on the space shuttle nose cone

to protect it from the
extreme heat of re-entry,

but it is equally effective at
protecting from extreme cold

and also happens
to be translucent.

Hugh: Around 50 percent
of light is actually transmitted

through this material,

so we have this big window
at the heart of the station

which allows lots of
good natural light in

without letting lots of
heat out of the building.

Narrator: With 1,300
feet of the ice shelf

flowing out into
the sea every year,

by December 2011, the
third season of the build,

it was time to tow the modules
nine miles inland from halley v

and the ever-approaching edge.

But by now, with
modules fully built,

even the smaller blue pods
weighed as much as 100 tons.

Ellie: The biggest
challenge to getting the pods

to their new home over
the last 15 kilometres

was overcoming
something called stiction.

This is the static friction
that needs to be overcome

to get objects to move.

Narrator: The designers
turned to a very common material

found in almost every kitchen.

Hugh: The skis are made
out of high-grade steel

that's suitable for
a cold environment,

and then they have
a layer of teflon,

which is essentially
fixed to the underside,

to help them to
glide across the ice.

Narrator: The skis
were so effective,

the extreme team
had to make sure

the 100-ton pods
didn't run out of control.

Man: Stage two. Last
night, it was pulled off

the construction
line at this end,

turned round, and a
few tests done on it.

What we're interested in
is how slowly can we tow it,

how easily you can control it,
and how quickly you can stop it

or what the stopping
distances are

because when we
get to the other end,

they will have to be a
certain distance apart.

Narrator: Twice the
size of the blue modules,

the red command module
proved much harder to move.

Man: We're definitely
over 200 tons with it,

so it's out of our
comfort zone slightly,

but a good team on the job.

If anybody can shift it, we can.

Operator: Ok, on the count of 3.

♪

Narrator: Moving
the eight modules

the nine miles took days,

and as each module arrived to
meet its new next-door neighbour,

they were introduced
with a bang.

[Bang]

The connecting gangways
proved to be resilient components.

Ellie: They connected the pods
using a double-layered version

of the kind of
concertina connections

that you see in many
railway carriages.

Hugh: They're insulated
when they're used

in the Scandinavian
countries, so again,

it's normally used
in the rail industry,

but we just transferred
it over to our buildings.

Narrator: Finally, all eight
modules were linked and sealed

from the weather.

The only exterior connection
was a safety gantry,

an intentional
firebreak to protect

one set of modules
from the other

in the event of a
catastrophic fire or explosion.

The last job of the year
was to prepare halley vi

for the next blast of winter.

Hugh: Because the snow
level is constantly rising,

what you do is
that each leg in turn,

you lift it up, using
the hydraulics,

you push snow underneath

to make a platform of around
one to one and a half meters,

and when you've
done all of the legs,

you then use the hydraulics
again to Jack the building up

so it's sitting on
these snow platforms

well above the
surrounding ice level,

and then when it snows

and the wind blows snow
around over the winter

and the level rises by
one and a half meters,

it brings the whole thing
kind of up to a level again.

Narrator: In February 2012,

over five years
after the build began,

halley vi came into service

as the British antarctic
survey's new research base.

Its 60 occupants had
never known such luxury.

Nehemiah: If you're
going to do research

and you're going to live in
one of the coldest places,

if not the coldest
place on earth,

then the least you can do

is have a really
cool place to chill in.

Narrator: Halley
vi is without doubt

the most complete
extreme environment

accommodation ever built,

but in the antarctic,

mother nature
takes no prisoners.

In 2016, a huge new
500-foot-deep crack

appeared in the ice shelf.

Just 18 miles from
halley and moving fast,

it posed a grave risk to
the station and the team.

Hugh: This crack was discovered
on the 31st of October 2016,

so it's known as
the Halloween crack,

and it was moving at some speed,

and so they then
took the decision

that because there was one
crack going in one direction

and another at 90 degrees,

that the new site for halley vi
had become far more dynamic

than they had
originally envisaged

and there was risk of
leaving people over a winter

of not knowing how those
two cracks would interact.

Narrator: They decided to act.

It was time to test out
halley vi's built-in mobility

and move the base to
safety and a new site inland.

It was a timely reminder of how
brilliant engineering and design

can make the
impossible possible.

Hugh: You know, somebody living

in an antarctic
research station,

you know, their life
is at risk constantly

because of the
extreme environment,

so you need to think
of every single situation.

You know, building a
research station in the antarctic

is equivalent to building
a formula one racing car,

and, you know, you just
can't leave anything to chance.

You know, there are a
number of parameters

that you have to design within,

and you have to give each
of them a great deal of respect

because failure to do
so will be catastrophic.

♪

♪

Narrator: 5,900 miles
north of the antarctic circle,

just off the coast of Morocco,
are the Canary Islands.

With year-round
sunshine and warmth,

buildings here have no need

to protect their occupants
from harsh weather.

Instead, they can be built

purely to celebrate their
surroundings and purpose,

which is exactly what
this incredible concert hall

was built to do.

Its 426-foot-long,
3,500-ton arch

is engineered to hover
above the auditoria below.

Ellie: It's an incredible
optical illusion.

It looks like the wing is
floating completely unsupported.

Corina kwami:
It's the improbable

made to look impossible.

Narrator: Inside
is a stunning space

for over 2,000 music lovers,

but it's outside where the
building hits the high notes.

The incredible 190-foot-tall
arch is only possible

thanks to a secret
skeleton of hard-core steel.

The concrete cladding
that creates its skin

was so pioneering, an
extraordinary new machine

had to be
custom-built to make it.

Curved walls glisten

with over three million
tiny handmade tiles,

and the giant wing
flexes in the powerful wind.

Auditorio De tenerife

is a stunning
engineering performance.

So, how did they build it?

In 1997, work began
on a new concert hall

in Santa Cruz De tenerife
in the Canary Islands.

Spanish modernist
architect Santiago calatrava,

who'd recently finished the
awesome oculus transport hub

in New York's trade centre,

had designed a building that
could match any music venue

in the world for visual
drama, both inside and out.

His design of flowing forms

performing impossible
engineering gymnastics,

all clad in seamless concrete,

would be one of the greatest
construction challenges

of its time.

The most difficult to build

would be the three
curved components

at the heart of the structure.

Each would have a nickname.

The nut would be the
147-foot-high central building

to house the two
performance auditoriums.

It would also provide a
single point of crucial support.

The nut would be
flanked by the two sails.

The curving slabs are
actually the outer walls

of the main concert hall.

On top is the wing.

This massive structure, weighing
the same as ten 747 aircraft,

would be made of a steel frame,

clad in a thin layer of
ingeniously cast concrete.

It would rest on that
small point of support

provided by the nut.

Debbie: To create
a structure like this,

there is no
off-the-shelf solution.

You have to create
something entirely from scratch.

Narrator: The bespoke
building technique

that was key to the
creation of the auditorio

was the concrete formwork
that produced its cladding.

Joshua: The simplest form would
be to take two wooden boards,

support them in place,

put reinforced concrete
in the gap in between,

fill it all with
concrete, let it set,

and take the boards
away, and you've got a wall.

Narrator: Concrete
formwork can be used

like blocks to build walls,

one layer added
on top of another,

as many times as the steel
reinforcing inside allows.

Stacking layers like this is how
engineers virtually hand-built

the huge concrete
walls of the sails,

but the massive arcing wing

would present a completely
different challenge

and a solution that
was a world first.

By 2001, the nut and sails
were structurally complete.

It was time to
build the giant wing.

Like the sails, the
surface of the wing

would be concrete formwork,

but hidden inside would be
the heavy-duty engineering

that made this
outrageous shape possible.

A huge steel framework
was prefabricated in Spain

and shipped in 17 pieces,

before being assembled
into larger sections on site.

Juan Carlos was
the site engineer.

Juan Carlos ramflo ramos,
translated: Each piece weighed

around 200 to 250 tons.

They were lifted with a
crane, and once they were up,

a system put together the
mobile and the fixed part,

welded it, and then let it go.

It's unique.

Corina: You have
a steel skeleton

that was constructed
to give the whole thing

a rigidity and strength,
24 rows of beams.

Narrator: Once the steel frame
of the wing was assembled,

scaffolding was built
under the inner areas

to support traditional
wooden formwork molds.

But using formwork to
make the concrete outer shell

on the huge areas of the
wing was not an option.

The scaffolding required to
work at such heights and angles

would have made the
build impossibly slow,

complex, and expensive.

These problems meant
the construction company

had to come up with
something special.

[Speaking Spanish]

Juan Carlos: With
the wing, the big curve,

this was such a complex
process of engineering

that they had to design
a special machine

to put the iron
and the concrete in,

and this was supported
by the same steel wing.

It's unique and was
built especially to do that.

Narrator: This machine
is called a carriage crane.

It was assembled on
the back of the wing,

and its huge arms wrapped
around and underneath

to support the formwork.

Adjustable in every direction
and guided on huge rails,

it enabled concrete to
be attached along the wing

in previously
unreachable places.

Hayley: This was a very slow
process to create the wing.

@they had to align the formwork,

pour the concrete,
let the concrete set,

then move the machine
up and realign the formwork

in a different, narrower
shape and a different angle,

and then re-pour the
concrete and let it set

and repeat that 32 times.

Narrator: The final result is
an extraordinary fluid shape

that, despite weighing 3,500
tons, appears to levitate.

Debbie: This is an
amazing optical illusion

because when you look at
it, it just looks like this wing

is just completely
floating in space,

but from certain angles,

you can see behind
the smoke and mirrors.

Narrator: The wing is
supported at just five points,

an amazing feat considering
the powerful winds

that almost constantly sweep
across the Canary Islands.

But one of these supports

is a special, steel,
shock-absorbing tube

that moves up and
down with the wing

to stop it from tearing
itself off the building.

Ellie: In really high winds,

you can hear it just
bouncing up and down,

which I'm sure
sounds pretty terrifying,

but I'm sure they knew
what they were doing.

Narrator: The auditorio's
architect, calatrava,

wasn't satisfied with
just making the concrete

achieve impossible shapes.

He wanted his building to have
an outstanding surface as well.

The concrete was mixed
with a high proportion

of sand and titanium dioxide
to brighten it almost to white,

but calatrava wanted more.

To make the building
gleam, he wanted it covered

in 3 1/2 million tiles,

all hand-laid in a
style called trencadís.

But surely, even
on this project,

that was too going too far.

@miriam Gil: Basically trencadis
means broken ceramic tiles

all together on the
same work, right?

Anyway, mosaics is
good, and I will show you,

@they're one-square-meter panels

that came pre-madeúon a
flexible net from valencia,

with different numbers.

You can see like a wave,
a zigzag curve, right?

Can't you?

And just one meter up,
there is another one here.

Right? And there is
another one over there.

Once you have this information,

you can see the different
levels of the surface.

We have made a
Jigsaw puzzle here.

Juan Carlos: Truly, the
only word that comes to mind

is spectacular.

The effect you get
when the music plays,

something that
truly transports you.

Narrator: Close inspection
may reveal a small cheat,

but stand back, and its
full effect is plain to see.

It all adds to create a
glistening introduction

to a music lover's evening.

♪

In Scotland, in the mid-1990s,
an audacious plan was hatched

to reconnect two of
britain's most historic canals.

They were only 980 feet apart,

but one was almost 80
feet higher than the other.

For waterways that were once

the superhighways of
the industrial revolution,

that is worlds apart.

But an effort to
reconnect these two canals

overcame the huge problem,
with an engineering solution

of stunning simplicity
and efficiency.

Hayley: This is the
only Ferris wheel boat lift

in the world.

Narrator: This is
the falkirk wheel...

A fusion of sculpture
and engineering,

breathing new life
into a historic canal,

and now a tourist
destination in its own right.

The wheel can effortlessly
lift nearly 500 tons of water

and two boats 78 feet,

while not spilling a
drop or breaking a sweat.

So, how did they build it?

250 years ago,
these narrow channels

helped transport goods
around the country,

fuelling britain's
booming economy.

Here, the beautiful union canal

runs to Glasgow
in one direction,

and the forth & Clyde canal
runs to Edinburgh in the other.

Corina: These canals
were the lifeblood

@connecting
Edinburgh and Glasgow

during the
industrial revolution,

and it also provided a
luxury high-speed service,

the bullet train of its day.

Narrator: The waterways
were completely reliant

on a system of locks, which
allowed these two canals

at different heights
to be connected.

But by the late 1800s,
trains were all the rage,

and the canals and crucial
lock system between them

were barely used.

Corina: Due to the
height difference

between the forth &
Clyde and the union canals,

11 locks were needed to get
the boats from one to the other,

but these fell into
disrepair in the 1930s.

Narrator: Not surprising
when you consider

that taking a boat
through these 11 locks

took almost an entire day.

Eventually, they
were demolished,

and the stretch of locks and
the waterway between them

lay unused.

Glasgow and Edinburgh were
no longer connected by canal.

Tony kettle: It was broken,
fractured you might say,

during the 1960s and '70s,
úwith roads and other obstacles.

Narrator: By the mid-1990s,
canals were back in fashion,

now used for pleasure
rather than industry.

British waterways wanted
the old route restored.

To join the canals,

they would have to dig

a new canal,

but overcoming a massive
height difference was tricky.

Rebuilding the hopelessly
slow staircase of locks

that once connected the
two canals at different heights

was not an option,

so in the mid-1990s, the search
for a modern solution began.

The design that was
given the go-ahead

was a completely
original concept.

Tony: This is the world's
first rotating boat lift

that can take boats
in a circular direction

from one canal to the other.

What we've created
here is a piece of sculpture

that becomes a landmark
and a destination for Scotland.

Narrator: The falkirk wheel is
a 200-ton steel Ferris wheel,

with two gondolas, or caissons,

pivoting around a
giant central axle.

The caissons act as huge buckets
that hold water and the boats.

The wheel turns, moving the
boats and 500 tons of water,

to connect them 78 feet above
or below to the other canal.

At the top, it's all
connected by an aqueduct

that would have done
the romans proud.

The romans would prove to
be this project's first obstacle.

A Roman earth
fortification once stood here.

Today, all that's
left is a grassy hill.

But 2,000 years ago,

it was the northernmost
border of the Roman empire.

Jim Steele: Where we stand is

a unesco world heritage site,

which is the antonine wall

and that was built in a.D. 142,

so we had to
actually get the canal

underneath the antonine
wall, through a tunnel...

@the tunnel was about 200
meters long, 8 meter in diameter...

On to the north side
of the antonine wall,

extend it on to an aqueduct

and then on to
the falkirk wheel.

Narrator: Digging a 650-foot
tunnel under the antonine wall

was achieved without drama.

Building an aqueduct
80 feet high over the basin

was a more serious challenge.

Jim: If you had been
here 20 years ago,

what you would have seen is
a whole forest of scaffolding.

So, everything was
supported by scaffolding,

so it basically takes a
small part of the load

of the wet concrete
as you're pouring it

and as the four
piers are poured,

the gap to the deck itself,

that's all supported and all
constructed in four sections.

Narrator: No one had
built a canal in Scotland

for 200 years.

That lack of practice initially
caused a few more problems.

Jim: Inevitably there were
some leaks, not in the structure,

I would have to say, but
in actually the earthworks

approaching to the viaduct.

But over a series of a few
weeks or months, you know,

we actually plugged all the gaps

in the waterproofing
of the canal.

And then on we go,
and to my knowledge,

it's never had a problem in the
20 years since it's been open.

Narrator: With the
forth & Clyde canal

connected through
to the aqueduct,

the wheel itself
could be installed.

This system required trapping

250 tons of water
in each caisson

and moving one up
and the other down

78 feet to the basin below.

To engineer a structure
able to carry 500 tons of water

on the end of two steel arms

while keeping everything
steady and under control

meant relying on some
key laws of physics.

Tony: It's like a balanced beam,

and that weight really
means it's very, very efficient,

and the water and
the boat balances out,

so we had this unique
balanced beam idea,

that I don't think
there's another boat lift

that uses that principle.

It uses other
elevator-type principles

with weights and things,
but not a balanced beam,

which is the
fundamental system here.

Narrator: The natural balance
of having equal amounts

of water at each
end makes sense,

if both caissons
are holding boats.

But how does the falkirk
wheel stay balanced

if it's only
transporting one boat

and the other caisson is empty?

To answer the question,

engineers made clever use
of the Archimedes principle.

Tony: Archimedes
had a Eureka moment

when he realized that if
he put an object in his bath,

the weight of the object

was displaced
exactly with the water,

and it's the same
principle here.

Nehemiah: So, in this case, as
a boat floats into the chamber,

it's going to remove the
exact amount of water

that's equal to the
weight of the boat,

so that means that
as long as you keep

the water levels the same,

it's going to continue
to weigh the same

with or without the boat.

Narrator: Now, the massive
payload needs to be rotated.

@hayley: Normally moving 500
tons of water 24 meters in the air

@takes the same amount of energy

as a typical Scottish
household over three days,

but all the falkirk wheel needs

is the equivalent power
of eight boiling kettles.

Narrator: The balancing act
means the wheel is easy to turn.

As the wheel lifts one tank,

the downward force of
the tank on the other side

does most of the work.

Like a seesaw, water
keeps the wheel balanced,

but it creates another problem.

Each massive tank
contains 66,000 gallons,

and if this water starts
sloshing from side to side,

there could be trouble.

Corina: The biggest
problem is the water.

You have to keep the
gondolas, or the tanks, level.

Plus, when you
start to move water,

it creates a critical mass
that's really hard to stop.

The entire structure
could tip over

if it's not carefully
controlled.

Tony: We had to solve the
problem of how to stop the water

from making the
caissons turn over

because as you move them
round, they're inherently unstable.

You know, if you
take a ferry full of water

and the water flows
from one side to the other,

you know, it's very
difficult to control it

once it starts to move.

Narrator: The best solution
proved to be the simplest.

Tony: It's connected by a
simple system of cogs and wheels,

and we have five cogs, of
which the central one's fixed

and the outer two are
fixed to the caissons,

and then the two
wheels in between

are allowed to
freely move around,

and what they do is
they allow caissons

to always remain horizontal,

no matter what
forces are applied

to the two beams going around.

Narrator: As the wheel turns,
the central axle drives cogs

that run up the
arms of the wheel.

These are geared to create
an always-correct connection

to the caissons,

which stops any internal
force affecting their position,

prevents the caissons
from swinging out of control,

and keeps them
permanently level and safe.

The falkirk wheel is
the perfect marriage

of beautiful design
and clever engineering,

reconnecting a
historic canal route

with a uniquely modern solution.

Hayley: The finished wheel
is a piece of pure engineering

meets Celtic sculpture,

providing a breathtaking example

of how human problem-solving
can achieve the spectacular.

Jim: It's still very
well-attended,

it's one of the main tourist
attractions in Scotland,

and it actually sits
as an iconic structure

within all the other
iconic structures

that have been built in
the UK and in Scotland.

And again, very proud to
have been part of the team

that actually delivered this.

Tony: It's in the British
passport, you know,

it's on the Scottish pound note,

and it's really great
that something of today

that takes old technology
and reuses it in a different way

and is innovative in the
way it approaches things

and is actually celebrated,

and I think that's the
best thing of all, you know.

If people can enjoy and
know that there's a future

and there are more
things to be discovered,

@that's the most exciting thing.

♪