All language subtitles for E.E.S01E01.1080p.WEB.h264-EDITH_track3_[eng]

[Narrator] These are
the engineering wonders

of the United Kingdom,

their secrets revealed
in a way never seen before.

Pioneers here help to forge
the modern world,

inventing the railway and
constructing vast bridges,

tunnels, and ships.

Today, UK engineers are
building on this legacy,

creating cutting-edge
structures

and machines
on an extraordinary scale.

In this series, we reveal
the secrets of the engineering

that built Europe's
great nations,

the wonders that shape
its cities,

landscapes, and history.

We reveal the astonishing
innovations

and surprising connections

that help to forge
this mighty continent.

♪ ♪

♪ ♪

The United Kingdom sits on the
northwestern edge of Europe.

It's made up of
England, Scotland,

Wales, and Northern Ireland,

and its wealth of natural
resources and pioneering spirit

famously sparked
the Industrial Revolution

in the 18th century.

Today, the United Kingdom
is building

on its industrial legacy to
meet the demands of the future

and continuing
the visionary work

of its engineers
and innovators,

who invented the steam train,

built revolutionary
ships and seacraft,

and helped to connect the globe

with radio
and the world wide web.

♪ ♪

Throughout the centuries,
UK engineers have pioneered

some of the world’s
most extraordinary machines.

♪ ♪

The Spitfire famously helped
win the Battle of Britain

during World War II,

while British engineers
developed the jump jet in 1967.

That spirit of innovation
continues

to push the boundaries
of aviation today.

In a remote airfield
near Cirencester,

UK engineers are
leading the race

for the future
of flying machines.

♪ ♪

This is a pioneering electric
battery-powered craft.

♪ ♪

Its propellers tilt to allow
takeoff like a helicopter,

but it also has wings
so it can soar like a plane.

Its designers hope
these innovative aircraft

will fill the skies to
revolutionize commuting,

carrying four passengers
up to 160 kilometers per trip.

The market for electric craft
like this

could be worth
a trillion dollars.

The team have built two of
these prototype craft to date.

The first person to fly them
is Simon Davies.

[Simon Davies] When you look
at this aircraft,

there’s a high degree
of novelty.

There's battery electric power,
electric motors,

miniaturized digital
flight controls.

The level of complexity is more
like a small fighter airplane

than a general
aviation aircraft.

[Narrator] The eVTOL,
as it's known, must undergo

rigorous testing before
it can enter mass production.

Each step of certification
tests its limits,

flying higher,
further and faster.

A crucial milestone is
to reach 20 knots,

a speed that creates lift,

making the craft fly more like
a plane than a helicopter.

[Simon] That might not sound
particularly fast,

but it's really important,
because that's where we start

to get real benefit
from forward speed.

[Narrator]
It's a critical moment,

and the engineers
are on high alert.

[Carmen Evans] We have a whole
team in the control room.

We have specialists from
all the different disciplines,

looking at the batteries,
the engines,

the loads, flight controls.

[Simon] Okay, we’re cleared
onto the runway.

[Carmen] I am ready.

[Narrator] Simon makes a final
check of power levels

as he taxis into position.

[Simon] Have sufficient voltage.

[Controller] Confirm.

[Carmen] Confirm.

Control is go for flight.

Control is go for takeoff.

[Simon] All cams look good,
and coming up to the hover.

♪ ♪

[Narrator] The eVTOL reaches
the required height.

[Simon] Turning into winds.

[Narrator] And turns on the spot
with eerie precision

to line up
ready for the speed test.

All eyes are fixed on the data,

as Simon begins
his forward run.

[Simon] TAC, accelerating.

[Narrator] As the plane
approaches the target speed

of 20 knots, the air
rushing over the wings

begins to lift the eVTOL
for the first time.

Lift is vital, as it
compensates for the weight

of the heavy batteries

and means the electric craft
can travel further,

hitting their
160-kilometer target range

on a single charge.

[Carmen] Test at 20 knots,
looks good.

[Narrator] The test is short
but successful.

[Simon] It’s good,
I’m decelerating now.

[Carmen] Terminate and land.

...on ground.

[powering down]

Alright, well done.

[Simon] Thanks. Test out.
Good job, everyone. Thank you.

[Narrator] The dream of bringing
this craft to market

is surprisingly close.

Final certification could be
just three years away,

and full production could start
shortly after that.

[Simon] I think we'll see
the growth of heliports

in urban centers as people
see that these aircraft

are actually practical,
useful, and affordable,

a safe means of moving
people around.

♪ ♪

[Narrator] UK engineers not only
have a long tradition

of building pioneering
machines for the air.

A strong naval heritage
means they also excel

at constructing craft
for the sea.

They invented
the aircraft carrier in 1918

and the hovercraft by 1955.

On the Isle of Wight, engineers
turn to electric energy

once again to power the next
generation of aquatic machines.

♪ ♪

These remarkable
hybrid electric ferries

have revolutionized
green urban transport,

thanks to their
groundbreaking use

of ultra-lightweight materials.

Now the team is going
one step further.

They are nearing completion
of their first

fully electric ferry,
the Thames Orbit Clipper.

It's being fitted out to carry
both pedestrians and cyclists

and will provide a fast,
carbon-free route

across the Thames,
seven days a week.

Tom Lilley has been involved
with the project

for the last year.

[Tom Lilley] You can see we are
in the very latter stages

of construction in here.

And here is our access
for passengers,

and these two doors will allow
the access for all the cyclists

coming on and off.

[Narrator] Traditional ferries
are made of steel,

but steel is too heavy for
a battery-powered seacraft.

So the team's
groundbreaking solution

is to use an aluminium alloy
that's uniquely formulated

to the shipyard's requirements.

[Tom] Our aluminium
is brought on site,

cut and ready for construction,

and it essentially comes in
with a number of codes on it,

and those codes relate
to our designs that we have,

and it's essentially
like constructing

a large Meccano set.

[Narrator] Although aluminium
is light and strong,

it’s much harder to weld
than steel.

The slightest moisture or even
the grease from a fingerprint

is enough to compromise
the strength of the joint.

This means that assembling
these cutting-edge craft

is a skilled job,
which must take place

in carefully controlled
conditions.

[Tom] So here we are inside
one of the hulls of the vessel.

And just past
this bulkhead here,

we house all of our
battery cells.

Along with that, all of the
cooling system that's required

to keep those battery cells
at the temperature

that’s safe and efficient.

[Narrator] Orbit's huge
batteries give it

up to 17 hours operation
on a single charge.

The ferry will also save energy
by traveling in a straight line

back and forth
across the river.

The craft's ingenious
rotating thrusters

means it doesn’t waste energy
turning around.

[Simon] These are one of our two
360-degree rotational thrusters.

We have one of these
at each end of the vessel.

[Narrator] Instead of
the whole boat turning,

the motors simply rotate
to face the opposite direction.

And to operate the ship,

the crew simply spin
their chairs around.

[Tom] The boat will go
into this berth, lock in,

and then when we come back
for the return journey,

the helmsman will spin
180 degrees

and be able to look out through
this forward window here.

[Narrator] It’s taken engineers
18 months to build the Orbit.

And now the pioneering craft
is almost complete.

[Narrator] Six weeks later,
the Thames' first

fully electric passenger ferry
is finally unveiled.

Once in service, it will
transport 20,000 Londoners

every weekday, helping to make
the capital's air cleaner

and marking the next chapter

in the UK’s proud
maritime history.

♪ ♪

UK engineers have
not only spearheaded

the invention
of extraordinary machines,

they've also pioneered
the construction

of epic
infrastructure projects.

♪ ♪

The Industrial Revolution
sparked a boom

in bridge building,

reshaping the landscape
with iron and steel.

Iron Bridge in Shropshire,

the world’s first
cast iron crossing.

And the Forth Bridges
in Scotland,

each one a testament
to three centuries

of engineering brilliance.

♪ ♪

In London, there's a bridge
that best defines

Britain’s industrial legacy.

♪ ♪

This is Tower Bridge.

It’s one of the UK’s most
beloved engineering wonders.

♪ ♪

It was built
in the Victorian era

to connect the 39%
of London's population

that lived to the east of
its existing river crossings.

The bridge's road deck is
designed to swing open

to allow tall ships to pass
between its towers.

20,000 vehicles
and 40,000 pedestrians

cross Tower Bridge every day.

Amazingly, river traffic
has priority here.

By law, the bridge must open
free of charge at any time

to allow ships over nine meters
tall to pass through.

Operating the bridge is
a heavy responsibility

for the workers on duty.

Jamie is about to carry out the
first bridge lift of the night.

[Jamie] It's Friday night,
it's just after rush hour,

but the traffic is
still very busy.

So, the more bridge lifts
we have,

the worse the traffic's
going to get,

and some nights,
the traffic will stay bad

till 11, 12 at night, depending
on how many bridge lifts we do.

[Narrator] The first lift is due
in half an hour

for the Dixie Queen, a replica
Victorian paddle steamer

carrying party-goers.

Jamie goes to the engine room

to check that
everything is ready.

On his way,
he passes the bridge's

original steam-powered
mechanism,

which sits alongside
the modern electrical motors.

[Jamie] In the old days,
there would be a lot of guys

struggling, filling
the coal bunkers up

to charge up the accumulators.

Obviously, we don't use
that these days

as we’re using electrical power.

[Narrator] The two decks
of Tower Bridge

weigh 1,200 tons each.

Raising them is a challenge
even for electrical power.

But Victorian engineers built
in 400-ton counterweights

to balance the load.

So the bridge swings open
almost effortlessly.

♪ ♪

As the Dixie Queen
comes into sight,

Jamie stops the traffic
and clears the bridge.

[Jamie] This is
a public announcement,

bridge lift operations
are about to commence.

Standby, bridge staff,
start the motor.

[Narrator] While the bridge
empties of traffic

and pedestrians,
Jamie powers up the engines,

ready to pressurize
the hydraulics.

[Jamie] Here we go. Now we have
the bridge ready to move light.

[Narrator] Only when all these
procedures are complete

can Jamie open the enormous
bridge using a simple joystick.

[Jamie] I’m gonna have one final
check for anyone on the bridge.

It’s all clear.

I’m gonna pull it back, and
we’re gonna open the bridge.

[Narrator] Modern motors tilt

the Victorian era
counterweights downwards.

And the two halves
of the bridge begin to rise,

to the delight
of the party-goers

on the paddle steamer.

[Jamie] For a vessel
the size of this one,

we'll take the bridge
up to about 30 degrees,

and that’s plenty of room
for it to get through.

[horn blows]

[Narrator] To close the bridge,

Jamie runs through
the sequence in reverse.

Ingenious engineering
across a century

means this iconic structure
can continue serving London

for years to come.

♪ ♪

In the Victorian era, visionary
engineers transformed the UK

with bold
infrastructure projects.

Isambard Kingdom Brunel
built groundbreaking bridges

and railway lines.

And Sir Joseph Bazalgette
revolutionized London

with a subterranean
brick-lined sewer.

150 years later,
it’s about to get an upgrade.

[Narrator] Deep beneath London,
engineers are hard at work

constructing a brand new
4.5 billion-pound

underground megastructure.

The project is called Tideway,

but it’s better known
as London’s Super Sewer.

Its scale is unprecedented,
with a vast tunnel

stretching 25 kilometers along
the route of the Thames.

Its engineers are working
nearly 70 meters deep

to avoid burrowing
into the city's

famous underground metro lines.

They use colossal
digging machines

to excavate the sewer tunnel,

which is as wide
as three London buses.

Yuriy Melnycho is
a city engineer.

[Yuriy Melnycho] Knowing that
you're working on a project

of this scale
and this importance,

it’s challenging,
but also rewarding.

[Narrator] London's Victorian
sewage system is designed

to overflow into the Thames

when it’s overwhelmed
with sewage and rainwater.

The Super Sewer will capture
this overflow

and send it spiraling
into the new sewer tunnel

deep beneath the river.

The tunnel stretches
25 kilometers across London,

taking the wastewater east

to a state-of-the-art
water treatment plant.

♪ ♪

It's taken eight years of hard
work to dig the sewer tunnel

and clad it with
waterproof concrete blocks.

It’s an epic
engineering wonder.

The team now have one
final task to complete.

They need to fit
the main tunnel

at Abbey Mills Pumping Station

with the UK’s largest ever
manhole cover.

The tunnel's circular lid

weighs an astonishing
1,200 tons.

That’s around the weight
of three jumbo jets.

[Yuriy] Everyone's put in
countless hours

of planning and preparation.

And yeah, all falls down to, you
know, today, and picking it up

and putting it down
in the right place.

[Narrator] The gantry sits
on a self-propelled

modular transporter,
a heavy lifting machine

invented for moving
enormous loads,

such as bridges
or even spacecraft.

♪ ♪

♪ ♪

Once the lid is in position,

the team can begin
to lower it down.

[Yuri] It’s going pretty good.

So hopefully by the end
of the day, we’ll get there.

♪ ♪

[Narrator] The lid finally
drops into place,

and the entire eight-year
Super Sewer project

is complete.

Now London can look forward
to a clean future,

no matter how big
its population grows

in the decades to come.

♪ ♪

Railways are an essential part
of the UK's infrastructure,

and the country has a proud
history of rail innovation.

In the age of steam, British
factories led the world.

Engineers here pioneered
the first locomotive,

the first intercity services,

and the first
subterranean railway,

the London Underground.

Now, a landmark project between
the nation's largest cities

builds on this legacy, creating
a record-breaking railway line

for the 21st century.

This is HS2, the UK’s biggest
construction site.

Due to be completed
within a decade,

this 57 billion-pound railway
will form a high-speed link

connecting Birmingham
in the Midlands

and London in the southeast.

With four vast new stations,

31,000 workers,

and over 300 kilometers
of track,

it’s Europe’s largest
infrastructure project.

Construction supervisor
Ion Cocieri is working on

one of the project's
most demanding sections,

where the line
crosses the River Cole,

just outside Birmingham.

[Ion Cocieri] The metal segment
is the biggest

from the River Cole viaducts.

Currently, we are working on
the west part of the viaduct.

[Narrator] Engineers are laying
HS2's twin high-speed tracks

side by side, on top of wide
viaducts and through tunnels.

But here at the Cole River,

they need to do
something different.

To preserve the natural
shape of the river

and prevent flooding,

the line splits into
two slim line viaducts.

One will carry trains
south to London,

and the other will carry them
west to Birmingham.

Landscaping around the viaduct

will create a sheltered,
natural haven.

[Narrator] The HS2 viaducts over
the Cole River must withstand

the force of trains traveling
at 360 kilometers per hour.

So engineers use massive steel
box sections like this one

to strengthen their cores.

The eastern viaduct
is already in place.

Now it's time to lift its twin

onto its prefitted
concrete pillars.

But its enormous weight
and size makes moving it

a serious
engineering challenge.

[Ion] The segment that you see
around there have 273 tons,

is 73 meters length, and all
the weight will be transported

by these self-propelled units

that you can see
under the segment.

[Narrator] The team first
transport the gargantuan girder

on two self-propelled
modular vehicles

to the site’s
heavy-lifting crane.

Each vehicle has
24 steerable wheels,

which turn in unison
to give this behemoth

an extraordinary
maneuverability.

The driver stands
outside the vehicle

to get a much better view
of tight spots.

It takes 30 minutes
to transport the segment

the 400 meters to the site’s
massive crane.

♪ ♪

Ion watches anxiously
as the most delicate part

of the operation begins.

With just a few meters
of clearance

from the eastern viaduct,

the team must maneuver
the new massive girder

at a snail’s pace
to avoid collision.

The Cole viaduct is part
of the project's wider remit

to work with nature.

In order to preserve
the landscape,

HS2 engineers have built
many bridges, tunnels,

and cuttings along the line.

The enormous cost needed
to achieve this

has caused controversy.

But for those
behind the project,

it is a necessary investment

to minimize the track’s
environmental impact.

At the site, the team
successfully lowers

the massive steel unit
into place.

♪ ♪

It's taken over 10
painstaking hours,

but the engineers can celebrate
another milestone

in this remarkable project.

[Ion] It's just one more day
that is making us closer

to have a fantastic
new rail network.

♪ ♪

[Narrator] Scotland is
modernizing its industrial past

with groundbreaking
new infrastructure.

The Falkirk Wheel uses
water-filled gondolas

to carry boats between two
former industrial canals,

an upper and lower one.

And in Glasgow,

sci-fi structures
from museums to arenas

line the nation’s famous
heritage shipyards.

Now, the city is home
to a river crossing

that builds on the legacy
of that industrial might.

[horn blows]

This remarkable site
is precisely half

of Scotland’s newest bridge.

Engineers are moving it from
a workshop in the Netherlands

to its new home
in Renfrew, Glasgow.

The team have already installed
its matching half,

and once united, they'll form

the Clyde’s first-ever
swing bridge.

♪ ♪

This stretch of the river
is tidal,

so timing the arrival of the
new bridge section is critical.

Site engineer Eilidh Love
has been part of the project

from the beginning.

[Eilidh Love] We're working in
a really tidal area here,

so we've had to look at
the tide times to work out

when the best time for the barge
to arrive was.

[Narrator] Finally, the
barge sets off on its journey

up the Clyde.

Over 100 years ago, the Clyde
was home to shipbuilding,

and the new bridge is part of
a 1.3 billion-pound project

to regenerate the river’s
former industrial areas.

♪ ♪

As night falls, two massive
wheeled transporters

use hydraulic jacks to raise
the 92-meter-long section.

They inch forward, crossing
the 18-meter gap to shore

on precisely positioned
platforms.

If the team's calculations
are correct,

the bridge will glide perfectly
onto its rotating base.

[Eilidh] There's 108 bolts,
which are part of the bearing,

and the bridge has 108 holes
which have to line up perfectly

for the bridge and the bearing
that we've built here in Renfrew

to fit together.

[Narrator] Once the bridge is
lined up in position,

the team gradually lowers it
onto its bearing.

All 108 bolts fit
snugly into place.

[Narrator] As day breaks
over Glasgow,

the first swing bridge
on the Clyde

is finally ready for testing.

[Jim Armour] Nice still day
for moving the bridge.

It’s good conditions.

[Narrator] The two sections must
not only swing to and fro,

but also lock securely
in the middle.

[Jim] The bridge will swing,
slows up, meets in the middle,

then the expansion joint
closes up.

[Narrator] The bridge will
expand or contract,

depending on
the air temperature.

So a special joint deploys
between the two halves

to make up any gap.

The big question, will it work?

♪ ♪

♪ ♪

The two halves
line up perfectly,

and the expansion joint
closes up the gap.

Two years of meticulous
construction and planning

have paid off.

♪ ♪

♪ ♪

UK engineers have not only
blazed a trail

for cutting-edge
infrastructure projects,

they are also pioneers

of spectacular
architectural wonders.

♪ ♪

The United Kingdom's
legacy of innovation

goes beyond industry.

They invented many sports, too,
including football,

establishing its official rules
in 1863.

The UK is home to some of the
oldest clubs in the world,

which play in
state-of-the-art stadiums,

where history meets
modern engineering.

In Liverpool, there's a new
stadium that showcases

the city’s proud legacy
in both football and shipping.

♪ ♪

Here, British engineers are
racing to complete construction

of a spectacular new home
for Everton Football Club

in the city’s historic
docklands.

This next-generation
500 million-pound stadium

will seat over 52,000 fans.

♪ ♪

What's extraordinary
about this stadium

is how it's being built,

without damaging the protected
dockland it sits on.

Project Director Gareth Jacques
has been supervising the build

for the last four years.

[Gareth Jacques]
Another busy day today

down at Everton Stadium.

We've got just short of 800
people working on site

at the moment, and we’re doing
our final testing, inspections.

[Narrator] Work began
on this build in 2021.

The first task was to create
a solid base for the stadium

in the existing Victorian dock,
filled with water.

The remarkable solution
was to pump in

nearly half a billion
cubic meters of sand,

scooped from the Irish Sea.

To speed up the process,
engineers mixed the dry sand

with water, forming a slurry
that flowed easily into place.

Once drained and compacted, the
sand created a level surface

for the stadium to sit on

while leaving the dock below
untouched.

[Alix Waldron] The construction
methods that we've used

was all around protecting
the dock itself.

So if somebody at some point
in the future wants to come

and reverse engineer it
back into a dock,

it is possible to do so.

[Narrator] The team then erected
the stadium from giant modules,

fabricated off-site,

slotting them together
like flat-pack furniture.

This minimized the need
for construction machines

which could damage the historic
dock with their weight.

Everton’s old home
is Goodison Park.

When it was first built
in 1892,

it became England’s first
purpose-built football stadium.

And over the years,

it has been expanded
and modernized many times,

and once boasted
England’s biggest stand.

But the club has now outgrown
Goodison Park,

and with no room for expansion,
they had to find a new home.

[Alix] There's so much
about Goodison

that we absolutely
love and adore,

and it’s going to be really sad
when we have to leave.

But we sell out
week to week now,

and we've got a growing
waiting list of fans

who want to be able to purchase
a season ticket with us,

so we’ve had to look elsewhere.

[Narrator] The most striking
part of the new stadium

is its wraparound
aluminium roof.

Each panel is perforated
to buffer the wind

and to divert rainwater
into underground tanks

to water the pitch.

The stadium's facade of
red brick is designed to blend

with the dock’s famous
hydraulic tower.

It once housed a steam engine
that opened the lock gates.

Gareth's team is on track

and nearly ready for
the new season to begin.

[Gareth] I sincerely hope that
the fans love the stadium,

and it becomes their home
for years and years to come.

And if they love it, and
the atmosphere is brilliant

and it helps Everton win,
then we’ve done our job.

♪ ♪

♪ ♪

[Narrator] The UK has
a long history

of groundbreaking
high-rise architecture.

Liverpool's Royal Liver
Building was one of Europe's

first skyscrapers in 1911.

While the 310-meter-tall Shard

became the nation’s
tallest building in 2012.

♪ ♪

In Bedford, one UK company
builds on this legacy

with a remarkable new way
to reach the sky.

♪ ♪

This bustling site is
a remarkable assembly line

for skyscrapers.

Here, workers build
high-rise homes, room by room,

on a factory floor.

Each apartment is built from a
series of fully fitted modules,

complete with windows,
insulation, wiring,

and even bathrooms.

Workers transport
the modules to site,

where cranes stack them
together like building blocks.

♪ ♪

This method brings
indoor factory efficiency

to large scale
outdoor construction,

whilst avoiding weather delays,

which can wreak havoc
with builds outdoors.

The factory-built skyscraper is
the brainchild of John Fleming.

[John Fleming]
When designing a building,

we allow the architects
a total flexibility,

and we manufacture units
as per their design.

[Narrator] John and his team
have been building

these high-rise towers
in the UK for over 10 years.

And in South London,
they are undertaking

their biggest
challenge to date,

constructing the tallest
modular tower cluster

in the world.

It takes the team
a little over a year

to erect two tall
concrete cores.

The cores enclose
the stairs and elevators

and act as a spine for
the modules to stack around.

But the higher they build,
the tougher the job becomes.

[Narrator] London's
record-breaking

modular skyscrapers
are taking shape,

but the construction must be
geometrically perfect

so that the towers don’t tilt
as they grow taller.

[John] The most critical part
of the erection process

is erecting
the modules accurately,

not even out a millimeter,

to make sure everything will
follow correctly above it.

[Narrator] The tallest tower
will be 50 stories high,

reaching up
a dizzying 163 meters.

Its 546 apartments
are constructed

from over 1,500
separate modules,

which must sit perfectly
square to each other.

The precision of
the assembly on site

begins the moment the crane
connects to the module.

[John O'Dwyer] The more level
it is, the easier it is

for the install crew
on top of the 43rd floor

to put it in place.

[Narrator] The team carefully
stack the modules,

floor by floor,
lining them up as they go.

They must position each module
with an accuracy

of 0.7 of a millimeter,

the thickness
of two business cards.

They use up to six
structural connections

to secure each module
to its neighbors.

Using traditional methods,
a project this ambitious

could take up to
half a decade to build.

But as the team unloads and
clamps the last few modules

into place, they complete these
record-breaking towers

in just 26 months.

It's a proud moment
for the whole team,

as these pioneering
new skyscrapers

join the UK skyline.

♪ ♪

Engineers in the UK
have a long history

of building extraordinary
architectural wonders

designed to nurture
exotic plants.

In the 18th and 19th centuries,
mega-scale greenhouses,

like Kibble Palace in Glasgow,

wowed visitors with their scale
and unique specimens.

♪ ♪

Now, engineers in Cornwall have
taken this horticultural legacy

to a whole new level.

♪ ♪

This extraordinary construction
is known as the Eden Project,

a pioneering glass house
without glass

that warms and protects
the world's

biggest indoor rain forest.

Its design is inspired
by soap bubbles,

and the biggest dome
soars 50 meters tall,

high enough for the Tower
of London to squeeze inside.

A steel skeleton supports
over 800 inflated pillows,

made from a plastic

just 1% of the weight
of traditional glass.

♪ ♪

Engineering manager Kevin Bate
is in charge of maintaining

these remarkable
lightweight domes.

[Kevin Bate]
I think we like to say

we’ve got cling film
with attitude.

If the biomes were ever
made of glass,

the weight would be incredible,

and quite dangerous,
to be honest.

So that's why this material
was chosen;

minimum material for
the greater strength.

[Narrator] These groundbreaking
plastic pillows

are now 25 years old.

So Kevin is leading a project
to replace them.

[Kevin] After some extensive
surveys, it was determined

that some of the pillows
are starting to turn opaque

due to natural aging.

If they turn opaque, they don't
allow quite so much sunlight

to penetrate through them to
be able to heat the biomes up.

[Narrator] The new panels are
made up of three sheets

of plastic
sealed at the edges.

The team need to inflate them
like a balloon.

First task, they must remove
the old pillows

without letting out
the vital heat

that helps to nurture
the tropical plants.

[Worker 1] We’re gone for
valve placement first, so.

[Worker 2] This is where
the valve is, good.

[Worker 1] Yeah.

[Narrator] Once it's aligned,
the new panel acts

like a blanket to prevent
the hot air from leaking out,

as they cut away the old pillow
underneath, section by section.

They slide metal beads around
the edges of each pillow

and hammer them into slots that
sit between the metal tubes.

[Worker 1] Here it goes!

♪ ♪

[Narrator] Finally,
the weather-damaged sheets

drop down inside.

Once the panels are airtight,

it's time for one of the team's
daring specialists

to climb 35 meters
to the top of the dome,

to connect the new pillow to
the clever inflation system.

♪ ♪

Once inflated, each pillow
is strong enough

to support the weight of a car.

But on a hot day,
pressure inside them

can rise beyond breaking point.

So there are sensor pillows
dotted over each dome,

which detect changes
in pressure and trigger pumps

to keep all the pillows
in perfect shape.

♪ ♪

As the team finish up
for the day,

they know that the fragile
ecosystem that grows below

this extraordinary wonder
is safe for another 25 years.

♪ ♪

♪ ♪

The UK is a nation
of innovators

who transformed the world
with their daring ideas.

Today, its engineers
continue this legacy

and push innovation
to the limit,

to create a brighter future
for this great European nation.