Original subtitles

Narrator: How did a team of engineers

build the world's longest sky gardens,

over 500 feet above the ground?

Woman: It must have been incredibly nerve-racking,

they had to be so careful.

Narrator: What do you get

when one of the world's most radical architects

builds a railway station in the path of two natural disasters?

Man: Building in earthquake zones

is enough to make anybody, any engineer nervous,

but building in the shadow of a volcano?

Narrator: And how is the world's most slender tower

strong enough to survive winds of over 50 miles per hour?

Woman: Tall structures are prone to move.

They're particularly vulnerable to wind,

so the thinner they are, the more serious the threat.

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

Man: Where else can you swim

from one skyscraper to the other 300 feet in the air?

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?

In a tiny pocket of downtown Singapore,

the challenge was set:

To create a development of almost 2,000 apartments

where before it had been home to just 342...

On a site so small, engineers had to think outside the box.

It could have been another boring tower block

of identical floors and units,

but designers and engineers excelled,

creating the tallest public housing residential building

in the world:

The pinnacle at duxton.

Hayley loren oakes: This building is

a spectacular achievement on a site

that most developers would have just walked past

and not even given a second look.

Narrator: A stunning 7-tower, 50-story apartment complex

with 215,000 square feet of outside space...

But not on the ground.

Engineers did it

by building the world's longest sky gardens

500 feet in the air.

Nehemiah mabry: It's an amazing feat of engineering,

but obviously there are going to be some risks that come with it.

Narrator: A plot too small to build on conventionally...

Thousands of prefabricated concrete panels,

light enough to be lifted

but strong enough to support the 50-story towers...

And sky Bridges that were too heavy

to be craned the 500-plus feet in the air.

Just some of the complex problems

faced during construction.

So, how did they build it?

Like lots of cities, until recently,

downtown Singapore was home to the financial district,

but practically no one else.

Ready to reinvigorate the area

and attack the lack of affordable housing,

the government launched a design competition

to redevelop a tight and difficult plot.

Architect peng beng's design was picked from over 200 entries.

Peng beng: The two main aim of the pinnacle at duxton,

@it was to really inject new life into this neighbourhood

and also to increase theúpopulation density of this area.

Narrator: The plot was slightly larger than two football fields

and had been the site of two 10-story residential blocks

housing 342 apartments.

The government's plan called for at least triple that,

on the same space.

Ellie cosgrave: The other huge consideration

when you're building mass housing like this

where people are so densely packed together

is how do you make it pleasant,

how do you make it a place that people actually want to live in?

Narrator: The answer lay in a design

that would push engineers to their limits.

In a bid to increase capacity,

while also creating attractive, comfortable homes,

peng and his team drew up a plan

that would become the world's tallest

public housing residential buildings.

Packed into the awkward question Mark-shaped plot...

Would be seven 534-foot towers.

Each would be joined to the next at the 26th and 50th stories

by six enormous sky Bridges.

65 feet wide, these Bridges would provide

215,000 square feet of greenery and outdoor space

for the residents to enjoy.

And with each measuring over 1,600 feet long,

they'd create the longest sky gardens in the world...

If engineers could figure out how to build them.

Joshua macabuag: So the key question here

@is how to get the maximum amount of usable space

into what is quite a small and irregular plot,

and what they've done here is

they've arranged a building so as to kind of weave through the,

through the plot to really get as much

into the available space as possible.

Narrator: As construction began in 2005,

the site revealed the first of many problems.

There wasn't enough space to build the towers

using conventional methods,

and there was only one small access road in and out.

Peng beng: The site was so tight,

it was so small, plus it was in the cbd area,

the central business district area,

which meant that, you know, we would cause

havoc and traffic jams during construction.

Narrator: Already crammed with materials, heavy machinery,

and hundreds of labourers,

there was little space left.

Casting the 50-story concrete towers on site

would be impossible.

The solution was to prefabricate off site.

Peng beng: Using prefabricated technology was very important

because the site was so crowded.

Narrator: 90% of the structural elements

would be prefabricated in a factory 18 miles away.

Then each piece would be transported to the site.

Instead of seeing this as a problem,

the engineers turned it into an opportunity.

Peng beng: Sometimes when we do prefabricated

it is just a facçade panel,

but in this case we designed the structure,

the beams and the columns into these panels

so that as they were being put up,

the structure was also being built at the same time

and the rainwater downpipes were installed into the panels

that would drain water from the balconies and from the roof.

Narrator: So, prefabricating the building off site

would overcome the issue of the small plot

and allow peng to hide away some of the services

within the hollow walls.

But it also created its own unique set of problems.

Normally with a tower block like this,

the concrete would be poured on site.

It's the cheapest and most efficient way

of ensuring the structure,

with its central support columns of concrete and steel.

How would they be able to prefabricate concrete sections

that were strong enough to bear the forces

of these enormous towers

but also light enough to be lifted into position

by the tower cranes?

Coming up with a solution fell to the engineering team.

So what we have done

in order to reduce the weight of the component,

we have developed a hollow core system.

Narrator: Instead of being solid,

these panels are hollow, making them lighter.

They're also pre-stressed,

or compressed as they're being made,

which makes them much stronger than normal concrete.

Peng beng: These panels are connected together

in an interlocking way, just like a lego block,

and then we would put in high grade concrete

to seal up all the joints

so the joints would be cast in, in place,

and when this cured, it would be,

it would then act as a continuous unit.

Narrator: Although building using prefabricated concrete

is around 10% more expensive than pouring on site,

in this case, it turned out to be a savings.

Although there were additional costs initially,

the team got faster and faster at putting the towers together.

Instead of taking 10 to 12 days,

they were soon building whole floors in just 6.

@hayley: It just illustrates that to make a building like this,

you really have to approach it

from a completely different way of thinking.

Narrator: The next problem the team had to overcome

was to ensure that the 1,848 apartments

didn't seem identical on the inside or out.

Peng beng: Part of our challenge

was to use this way of construction

but produce something that looked totally unique

and, like as if it was impossible

to be fabricated off site.

Narrator: The solution was surprisingly simple.

They created five different styles of facçade panels,

then mixed them up,

so as you look at the exterior of the seven towers,

the design appears random.

In fact, it's anything but.

Nina loo: So you actually have a interesting facçade

and the same time you give the buyers and the residents

a choice of units.

So you can pick a unit with a balcony

and you can buy that unit

instead of having everything all uniform.

Narrator: The idea of uniqueness doesn't stop at the front door.

Prefabricating the towers

gave designers another great opportunity,

which would allow the occupants to make each unit their own,

but also to future-proof them,

for when the residents' lives changed.

Peng beng: If we could create opportunities

where people could make something unique

out of their own units

and they could feel like, you know,

they were part of the, the whole growth process

and the building didn't start to restrict you

but it start to give you a sense of freedom, a sense of choice.

Narrator: So how do you build cost-effective tower blocks

of affordable housing

while also creating apartments

that can be radically changed without radical building work?

Peng beng: In the typical high-rise

the columns and structure

would, would take up quite a lot of space within the units,

so we thought that if we pushed all of this structure

onto the periphery of the units,

the walls could then be easily taken down

so that if you wanted to

you could tear down all the internal walls

and you can have just one huge apartment.

Narrator: So, by building all of the structural strength

into the unit's exterior walls,

everything inside can be moved or even removed

to open up endless possibilities,

depending on the needs of whoever's living there.

The next major challenge came in 2009,

when the seven tower blocks were ready to be joined together

to create one interlinked plan.

On the 26th and the 50th floors,

a series of sky Bridges would connect one tower to the next,

creating over 215,000 square feet of outdoor space

for the residents.

Nina: We created additional communal spaces in the air,

which is actually at the sky bridge level.

So we actually multiplied

the amount of communal spaces available.

Narrator: The residents now enjoy

the world's longest sky gardens,

but to put these huge links between the towers

would be the biggest challenge yet

for the engineers to overcome.

Made up of giant steel trusses topped with concrete,

the heaviest bridge weighs 350 tons,

the equivalent of a boeing 747.

So how did they manage to get the sky Bridges

hundreds of feet in the air?

Corina: It's no joke trying to get 200 tons of steel

to the very top.

They couldn't use a crane.

Narrator: Ten years ago,

tower cranes couldn't lift such heavy loads,

and the site was too cramped to bring in bigger ones.

So the engineers came up with an ingenious solution.

Hayley: At the top of the two buildings

where the sky bridge was being lifted between,

there was a hydraulic Jack connected to a winch.

Narrator: Each sky bridge was attached to steel cables,

and then lifted into place

using four hydraulic Jacks and winches...

Two on each building.

Computer controlled, they all moved

at exactly the same time and speed

to lift the sections into place.

Ellie: It must have been incredibly nerve-racking,

they had to be so careful.

Narrator: If there was any wind at all,

they'd have to stop and tie off both ends of the bridge.

It took 10 hours to lift each bridge into place,

completing an extraordinary piece of engineering,

and in the process,

changing the way the residents would live.

Nina: At the sky Bridges we have communal gardens,

we have jogging tracks for the residents,

we have play areas,

and we also have elderly fitness stations

and we also have breakout corners,

little gardens where people can sit down and chat

with their neighbours.

Narrator: Construction was finally completed in 2009,

at a cost of over $205 million.

The end result is amazing...

A complex that serves residents' every need.

Neil Kim Powell was one of the very first people

to move into the pinnacle, and has been here for 10 years.

Narrator: Over 5,000 residents from every walk of life

live here.

Now this vibrant community enjoys these sky-facing spaces

high above the hustle and bustle of the city...

A tourist destination, thanks to its stunning views.

The pinnacle at duxton

has successfully injected life into this district

and continues to be a model of world-class public housing.

Hayley: The pinnacle at duxton is amazing.

It's like an engineering magic trick. It's wizardry!

♪

Narrator: On britain's south coast,

the city of Brighton,

like many English seaside spots, with its piers and seafront,

has been trading on its victorian past.

But in 2006, Brighton decided it needed

a new, state-of-the-art landmark attraction

to bring the city into a new century and millennium.

Joshua: It's something that's going to have to really be built

to stand the test of time.

Narrator: It took 13 years of planning

and would challenge both architects and engineers.

Julia barfield: It's right on the edge of the possible.

Narrator: But the results would be

an extraordinary and innovative vertical pier

that would allow visitors to walk on air.

Nehemiah: It looks a lot like an amusement park ride,

like it's supposed to be spinning or something,

moving up and down really fast.

Narrator: As well as being a marvel of engineering,

the i360 is also the world's most slender tower.

A 46-million-pound landmark

that whisks 200 passengers up to a height of 450 feet

in the face of buffeting coastal winds.

Constructing at this kind of height,

where even cranes couldn't reach,

engineers had to think outside the box.

So, how did they build it?

The Jewel in Brighton's seaside crown

was once the west pier.

It had been the finest victorian pier in britain,

but throughout the 20th century, it had fallen into disrepair.

And then, in 2003,

it was all but destroyed by an arson attack.

Brighton council were on the hunt

for a must-see attraction

that reflected the original pioneering spirit

of the west pier,

but with a 21st century twist.

Meanwhile, 60 miles away,

the architectural wizards behind the iconic London eye,

Julia barfield and David marks,

had come up with a new and exciting visitor attraction

that they thought would be the solution.

Julia: The success of the London eye

@was such that we got approached

by many people wanting to replicate it,

and so we kind of looked at what was the essence

of the London eye,

and we then looked at how we could replicate that experience

in a different form.

Narrator: David and Julia's design for the i360

would see visitors rise up into the sky

to get a panoramic peek at the breathtaking surroundings.

It was decided the perfect spot for it

would be in the shadow of the remains of the old west pier.

Julia: It is the site of the original west pier,

which is one of the only grade I listed piers in the country.

It was one of the most innovative piers in its time,

and sadly it burnt down,

so it was like the Phoenix from the flames, really.

Narrator: The final design for the i360

would be a world first,

as well as the tallest structure in all of Sussex.

The 531-foot tower is made up of 17 stacked steel cans

that get taller and thinner as they go up.

They're held together by 1,336 bolts,

weighing a combined 30 tons.

The 900-ton tower supports

a 59-foot-wide toughened glass and steel pod

that's 10 times the size of a London eye capsule

and can hold up to 200 people.

It uses state-of-the-art cable car technology

to drive the pod up and down at less than one mile per hour.

Construction started in June 2014 on the beach,

mere feet from the sea.

A tower of such height and weight

would be enormous pressure on the base,

so its foundations had to be extremely strong.

But the engineers would first need to construct

a stable area to build them on.

Dr. John Roberts,

who'd been chief engineer on the London eye,

was tasked with the job.

John Roberts: So what looks like shingle here,

looks like the beach,

in fact is just covering up...

The concrete,

so this is, that's actually the top of the foundation,

the concrete is just there.

Narrator: It was just under a year

to lay the foundations for the tower.

The first stage was holding back the sea.

John: We're about 3 meters below ground level here,

and the concrete foundation is 3 meters thick,

so we had to dig an excavation

more than 6 meters intoúthe beach from the beach level.

As you are aware, we're right on the edge of the sea,

so when you dig below sea level, you usually come across water.

Narrator: The team drove in concrete piles

around a 260-square-foot area of beach,

and then started to excavate 7,000 tons of rocks and pebbles.

On hitting sea level,

they had to pump out water day and night

until they reached the chalk bedrock over 20 feet down.

Only then could they begin pouring

the 4,000 tons of concrete.

John: We had to use concrete coming from every concrete plant

in the whole of Sussex.

I mean, this was one of the largest concrete pours

that has been done in this area for many many years.

It was done in two halves,

and even then each half took more than 30 hours.

You have to have a supply

and you had to have a backup in case the supply goes wrong,

'cause once you start you can't stop,

so in fact nobody else in the whole of Sussex

could have any concrete at all on those two days.

Narrator: In 2015, with the foundations in place,

the team made a start on building the main structure,

comprised of 17 gigantic steel cans

and rising over 530 feet.

Each of these steel cans, or tubes,

differed in size and thickness and had to be carefully tailored

according to where they appeared in the tower structure.

John: There's very few places in the world

where they can be made.

So the tubes were, were rolled and welded together

in a special rolling machine in the south of the Netherlands.

Narrator: It took over 18,000 man-hours of welding

to make them,

before being sailed by barge from Rotterdam

across the north sea,

arriving right in front of the construction site.

John: You can also see here, with this hole,

this is a hole through the tower,

and you can see how thick the steel is in the tower.

This is 85-millimetres-thick steel,

and this is the bottom section, this is can number one,

the one that sits on the ground

of the 17 cans that make up the tower.

Narrator: They may have gotten them there,

but the next problem was how to put them on top of one another.

Nehemiah: The big problem when you're building tall things

is that the maximum lifting height of cranes

is 100 meters, or about 330 feet.

The i360 is over 500 feet, or 160 meters.

Narrator: So how do you build something

that's taller than the maximum lifting height of a crane?

The ingenious engineering solution

was to build from the top down.

A temporary 200-foot jacking tower

was fitted over the spot where the i360 would go.

Then, the steel can that would be at the top of the tower

was put at the bottom

and then lifted up by the 16-ton collar

just high enough for the next can to go underneath.

These two would then be bolted to one another

before being lifted again.

John: So if you put number 17 in first and lift it up

and then put 16 underneath it

and put the next one underneath that,

you can build it that way instead

and you don't need a crane.

Narrator: This procedure would be carried out again and again

until the tower reached its maximum height of 531 feet.

John: The very last operation

to put the last piece in at the bottom,

the tower that you're picking up weighed a thousand tons,

so you had to lift a thousand tons into the air

to put the very last piece in at the bottom.

It was done in just 10 weeks from start to finish.

Narrator: Now, they had to make sure it stayed there,

despite being such an exposed location

and being battered by winds of over 50 miles per hour.

Corina: Tall structures are prone to move.

They're particularly vulnerable to wind.

So the thinner they are, the more serious the threat.

Narrator: At 531 feet high and just over 12 feet wide,

the i360 is the world's most slender tower.

Hayley: So you can imagine that when the wind blows

the structure vibrates.

Think of it like a guitar string.

Narrator: This phenomenon is known as vortex shedding,

where turbulence caused by the wind

makes the tower vibrate.

Unchecked, these vibrations

could induce motion sickness in visitors

and even cause metal fatigue in the structure itself.

So John and his team devised a solution.

They would add a 5-millimetre- thick aluminum cladding

with a special finish to disrupt the flow of the wind.

John: The cladding has been perforated and deformed in a way

that stops the wind blowing smoothly

around the tube of the tower,

and it's done to prevent vortex shedding.

Narrator: It was time for the team

to turn their attention to its crowning glory...

The 59-foot-wide curved glass pod

that would take 200 people up into the sky.

Hayley: The point of this clever engineering

is an observation tower that stands completely safely

in a blustery and highly populated spot

overlooking the English channel.

Narrator: The pod would need to be strong enough

to carry passengers and survive all weather conditions,

while offering 360-degree panoramic views

of the Sussex coast.

The glass would not only be key to the view,

but also play a major part

in the pod's structure and stability.

John: So instead of glass

just being added on as a window afterwards,

the glass is part, it is a glass and steel structure

and it doesn't have any bracing.

Julia: Yeah.

John: The glass is bracing the structure.

Julia: Yeah, yeah.

John: It's an extremely strong shape

'cause it's curved in all directions,

it's curved around around the side,

it's curved in all directions, and curvature gives strength,

so it's a very strong shape.

Narrator: Manufactured by hand in Italy,

the toughened glass sections were sent to France,

where they were assembled,

to ensure its complex geometry fitted together perfectly

before being shipped to Brighton.

In January 2016, the last pieces were put into place.

Now it could be hooked up to its power source

underneath the tower.

John: This is the machine room of the i360.

This is the heart of the project in terms of making the pod move.

Narrator: The 94-ton pod is connected

to an 80-ton counterweight inside the tower

by eight steel cables.

Raised to the top by an electric winch,

on the way down it's much more sustainable.

John: The motor then operates as a brake

to let it down gently,

and the braking force regenerates electricity

in the, in the same device,

so the motor becomes regenerative

and generates electricity when it operates in reverse,

and you get back a little over half

of the electricity that you used on the way up.

Narrator: Over two years of hard work in all weather,

the i360 was opened to the public in 2016

and has taken over a million visitors into the clouds.

It set the standard for must-see city attractions.

Julia: The whole process was a huge adventure

and something that has been really, really positive

for Brighton.

It certainly regenerated the whole of the seafront.

Narrator: Fabricated in Netherlands,

using German steel and Italian glass...

Trialed in France, and built on the British coast,

the i360 is an international celebration

of innovative architecture and engineering combined.

Narrator: In Italy in 2003,

an ambitious high-speed rail project was proposed

to improve train travel

between the north and south of the country.

At its heart would be a stunning new rail hub in Naples,

a curved structure over a quarter mile long,

snaking over eight new train tracks...

A stunning, passively-cooled corridor

for millions of passengers to sweep through

to its platforms below.

Nehemiah: It's so perfect in all of its angles.

It also communicates movement and action.

Narrator: To create this ingenious building,

engineers would have to work in the shadow of vesuvius,

the volcano that destroyed Pompeii and is still active,

in an earthquake zone,

to create a fearless architect's impossible design

and figure out how to keep the huge, glass-roofed complex

cool in the scorching mediterranean summer sun.

This is the napoli afragola railway station.

So, how did they build it?

In the late 1990s, with train travel in Italy on the increase,

it was decided that four new high-speed lines,

three regional lines, and a single local commuter line

needed to be merged together at a new railway station

7 1/2 miles from Naples.

It needed to be capable of handling an increase

from 10,000 to 30,000 passengers a day.

But this would be no ordinary concrete box.

This station would raise the bar

for stunning looks, passenger experience,

energy footprint, and seismic resistance.

Such an ambitious plan called for a trailblazing architect...

Queen of the curve.

Zaha hadid had most recently designed

the jaw-dropping antwerp port authority extension.

Hayley: When zaha hadid designs a station,

you know it's not going to be an ordinary station.

Narrator: The first challenge was

that pulling all the lines together

would normally cut off the area in the north

from that in the south.

Filippo innocenti was the project architect.

Filippo innocenti: Quite an ambitious brief.

The area is divided in two by the presence of the rail,

so as it often happens, the rail,

it creates a barrier in between two sides,

so it is fundamental to provide a straight, clear connection

in between the two sides

of these areas separated by the railway.

Narrator: Zaha's solution was to create

a huge, 320,000-square-foot, elevated passenger concourse

on five levels

that would bridge over the tracks

and link the north and south.

1,640 feet long and 140 feet wide,

the steel and concrete structure would rise up 98 feet

to straddle the railway lines.

Built from curved, poured structural concrete,

the design was so complicated,

it would take computer rendering to make it possible.

The five floors would be covered

by a 5,400-square-foot glass roof

cleverly engineered to let the light in and the heat out.

These windows would flood sunlight into the atrium

in the centre of the elevated concourse.

The entire complex would be cooled

without an air-conditioning unit in sight,

by creating a system of underfloor pipes

filled with ice cold water

from the natural aquifers 260 feet below.

Not only would this be a place to catch or change trains,

it would be a meeting place for the local community

and 30,000 travellers every day.

Hayley: Most large stations have an entrance hall

with ticket machines and cafeés and shops to one side

and maybe an entrance hall next to the railway tracks

on the other side,

but here they've put all of that on the actual bridge

above all the railway tracks.

Narrator: Construction on the 60-million-euro project

started in 2009,

and the engineers working here

had a constant reminder on the horizon

of a clear and present danger.

Filippo: In afragola we are quite close

to one of the most important volcanoes we have in Italy,

which is the vesuvius, which is still active.

Narrator: Mount vesuvius is the only active volcano

on mainland Europe.

Its last eruption in 1944 killed a hundred people,

and the danger remains very real,

with the potential to unleash the thermal power

of 100,000 Hiroshima-sized atomic bombs.

Volcanic activity isn't the only threat.

The area is also at serious risk of catastrophic earthquakes.

Filippo: The seismic area of afragola is 3,

in the range of zero to 4, so still quite challenging.

Nehemiah: Building in earthquake zones

is enough to make anybody, any engineer nervous,

but building in the shadow of a volcano,

that destroyed Pompeii,

yeah, you need to take that very seriously.

Narrator: Builde

the 1 million square feet

of the station's exterior

from 50,000 tons of poured concrete using formwork.

This is where concrete is shaped using molds

and reinforced by steel.

While it's strong and durable, it's also inflexible,

making it more vulnerable to damage from earthquakes.

If the engineers ignored this danger

and created a continuous

1,640-foot concrete and steel structure,

the station could fracture and collapse

in the event of an earthquake.

But the engineers had a plan.

@joshua: The more modern approach

is to allow movement of the building,

so in this case as well

where you have a number of flexible joints,

what happens is it concentrates all of that movement

at the flexible joints

and then allows the movement energy to dissipate as heat,

so it means that you get some movement there,

you get some cracking as well,

but you don't, you limit the structural damage

to the rest of the building.

Filippo: When you are exposed to seismic loads

these movements can be significant,

can be in the order of 10 to 15, 20 centimetres,

which means that the whole building

has to be broken into elements,

and these elements has to possibly move one

with respect to the other

in the event of a serious seismic load.

Narrator: They decided to divide the building

into a sequence of separate zones,

each no longer than 164 feet,

and each able to move independently by up to 2 inches.

Tommaso martellucci was the project's engineer.

@tommaso martellucci, translated: These Bridges on the second,

third and fourth level are connected at the hub

with expansion joints that can absorb the stress and movement

during seismic activity.

Narrator: So the station was engineered to be tough enough

to withstand an earthquake,

but that wasn't the only force of nature

engineers had to deal with.

The design featured a continuous glazed roof

to allow in as much natural light as possible.

But here in southern Italy,

it would also be subject to the fiercely hot summer sun.

Nehemiah: Building a glass structure

makes a lot of sense

when you have a lot of people that need to move through

and it needs to be well lit,

but that becomes a different situation

when you're dealing with temperatures

as high as 36 degrees celsius, or 100 degrees fahrenheit.

Narrator: So how would engineers overcome the challenge

of filling the concourse with daylight

but cooling it in an eco-friendly way?

Filippo: Naples can be extremely humid.

There are days where the temperature goes really high

and the humidity is really unbearable.

I have to say that I was quite nervous

at the idea of having a building with a big glazed roof.

Narrator: They needed a solution,

because normal air-conditioning would have come at huge costs,

both to the budget and the environment.

Filippo: What you're trying to do is

to maximize the daylight that you can have inside a building

and minimize the costs of the ventilation

that you would have to fight against the solar heat.

Narrator: Expert environmental engineers

stepped in to solve the problem,

using state-of-the-art technology

based on ideas developed by the romans 2,000 years before.

First, they built internal shading fins into the roof,

which filter the sunlight, holding heat above it,

and preventing it from coming through

into the passenger areas.

A series of roof vents running the entire length of the station

then allow the hot air to be funnelled out.

Filippo: The building is based on a mixed ventilation concept;

it's combining natural ventilation

together with mechanical ventilation.

Narrator: On its own, this isn't enough to cool the concourse.

The main cooling system

is underneath the public area of the station,

in the service tunnel.

[Speaking Italian]

Tommaso: Here we are in one of the underground rooms

at the heart of the plant that runs the station.

One of the keys to the success

of the building's energy sustainability

is the air cooling and reverse cycle pump systems.

Narrator: This passive air cooling system

keeps temperatures down even on the hottest of days.

Engineers drilled down 260 feet

to access cold water from the natural aquifers,

running through the rock under the station.

This is then pumped up and into a system of pipes,

similar to underfloor heating,

that have been laid throughout the station.

But instead of giving off heat, the cold water absorbs it,

and then it's pumped back down into the aquifers,

taking the heat with it.

Nehemiah: A water source heat pump

actually works very well in this situation.

It's really good at absorbing the heat into the water

and then running the heat out using the water as a medium.

This was a idea that was actually developed

pretty early on in the 1850s,

but the first one actually wasn't built

until about the 1940s.

Narrator: In a world increasingly concerned

about our environmental impact,

these passive systems have come a long way,

including creating the very coolest of chairs.

Tommaso: Within these seats there is a system

that allows hot or cold water to circulate

and cool or heat the seats for the passengers.

Narrator: Set throughout the station

to allow passengers and locals to congregate,

the elegant seating offers the perfect place to admire

one of the most innovative uses of materials here.

To cover the concrete surfaces inside and out,

the designers wanted a smooth, weather-resistant finish

that could flow over the building's ever-changing curves.

They chose a material developed 50 years ago

for domestic kitchens.

Tommaso: The outer skin of the building

has about 20,000 square meters,

has been realized in corian.

Ellie: Corian is a brand of durable acrylic

that most people might know from their kitchen worktops,

but more recently it's being used to clad entire buildings.

Filippo: And we were looking for a material

that could be bent easily

and to follow the simple curve of the building

and to resolve the residual torsion

of a number of areas of the facçade,

and the corian was ideal for that

because a continuous surface

that allows to be bent at very low temperature,

basically around 100 degrees,

and can be put into shape very easily.

Narrator: The panels were computer-modelled

and cut with 2-millimetre tolerances.

Filippo: Corian is made in panels,

and then they are bent in order to serve the purpose

of allowing the curve of the facçade.

You basically treat it as wood panels,

you can cut them and you can glue them perfectly

without any trace of the junction between the panels.

A very easy way of, of creating shapes with it.

Narrator: In 2017, napoli afragola was finally able

to welcome passengers onto its elegant concourse.

For now, only four train lines are open,

but by 2022, all eight lines will be in service.

This station will then beúat the heart of the rail network

in southern Italy,

still keeping a low energy profile,

but standing tall as an example

of how ambitious design and engineering

can make life a little bit better.