All language subtitles for Impossible Engineering s02e08 The Glass Skyscraper.eng

Today,
on "Impossible engineering,"

the Shard, a record-breaking
super tower...

Construction never been
attempted before on a building

this tall in central London.

Taking structural
design to new heights.

It's amazing to think
the first 21 stories

of this concrete structure

went up before they'd even
finished the foundations below.

It took
revolutionary engineering...

Look at the crazy amounts
of glass

that this building uses:
11,000 separate pieces.

What a stunning sight.

To make the impossible possible.

Some of the world's
most iconic buildings

dominate its skyline.

And, in 2012, a modern marvel

was constructed, altering
the city's look forever.

Meet the Shard.

At 1,016 feet tall,

this futuristic skyscraper
is the tallest in London.

Wow. Look at that.

It looks like a piece
of crystal,

a splinter coming up
through the earth.

It's so tall.

And it's such a prominent part
of the skyline

that you can't help
but notice it.

That's an incredibly audacious
piece of architecture

and some very impressive
engineering.

The Shard rises up from
the heart of downtown London.

This jaw-dropping tower
is over three times

the height
of the statue of Liberty.

Its facade is made

out of a staggering
11,000 glass panels.

That's enough glass
to cover 130 basketball courts.

Beneath the 196-foot spire
lies the spine of the building.

The colossal concrete core
supports 72 levels,

totaling over
a million square feet

of floor space.

Building these buildings
is always exciting.

You're building up taller
than anybody's gone in Europe.

But this one
was particularly difficult.

The population
in London is surging.

It's estimated that the city

could reach
10 million inhabitants by 2030.

With limited room to grow,

designers of any new buildings
are looking to the skies.

Looking across
the London skyline

as we approach from the south,

you can really see,
it's just crowded.

There's buildings everywhere.

Building in that tight space
is a very, very difficult task.

Finding enough open space

to build a mega tower
in this bustling city

is a seemingly impossible
challenge.

It's in this congested site

just in the corner
of a railway station,

things going on
all the way around it.

We had no spare site
in which to build it.

It's smack in the center
of London

with London bridge station
on one side,

guy's hospital tower
on the other,

the jubilee line of the two
passing very close underneath.

And to add
to all of that complexity,

there was a building
already on this site

that needed to be removed
before construction could begin.

The 25,000-ton weight
of the old tower

is problematic
for the engineering team.

When you put a building
on the ground,

the very heavy weight
compresses the soil.

It's like a sponge.

It creates a divot
where the building is.

And when you take
that weight off,

the ground wants to heave,

wants to respond and go back
to where it was originally.

And time is of the essence.

You want to put the weight back
onto that ground

as quickly as you can.

Building the Shard on this site

would be impossible without help
from a great innovator

from the past.

When it comes to building up...
- There we go.

Man has always defied the odds.

Well done.
Well done.

The builders of ancient Petra
carved vast structures

out of sandstone cliffs

in the Jordan desert...
- Very good.

Safely perched on a series
of giant stone steps.

Oops.

Sorry!

In 12th-century Italy,

warring noble families
in bologna

erected over 100 towers.

Bigger was definitely better.

Mama Mia, what a whopper!

Perhaps the first
skyscraper city

was 16th-century
Shibam in Yemen.

Adopting ancient techniques,
its engineers used mud bricks

to build high-rises
that were so impressive,

it's known as the Manhattan
of the desert.

In the 1950s, the bustling
Italian city of Milan

wanted to build a subway.

But tearing up the city streets
simply wasn't an option.

Engineers needed
to figure out a way

to build without
disrupting city life.

We've come here to a site

where the Metro network
is being expanded.

Being here and seeing
the scale of this site,

you can imagine the tremendous
disruption it would be causing

if you tried to do this
in the center of the city...

Really an enormous challenge.

Poor soil conditions
made tunneling

beneath the city streets
nearly impossible.

This is actually
a really good illustration

of one of the key problems
here in Milan.

We're down here at the bottom
of the excavation.

And you can see this is an area

where they're just getting ready
to start to dig a tunnel.

And the engineers have gone
to really heroic efforts there.

Around that wall, you can see
they've put some rubber gasket.

And they've really tried
to keep the water

out of the site.

But, in spite of that,
you can see

how much water is still
flowing in.

So these are about
the worst conditions

you could hope to be
digging tunnels in.

Engineer Dr. Christian Veder

came up
with a brilliant solution.

Before Veder, a technique

called cut-and-cover was
the go-to option for tunnelers.

Let's imagine that I want
to dig a trench

down between these buildings.

And you can see what happens

when I do that
in this Sandy soil.

Initially, there's no problem.

But if I push just
a little bit too far,

you can see that, eventually,
I destabilize the soil

and my structures
will fall into the trench.

And, obviously,
that's completely unacceptable

on a site
in a congested urban center.

Veder turned the cut-and-cover
concept on its head.

Instead of building
one big trench initially,

he built two little trenches
down the sides of the buildings.

And into those trenches,

he inserted reinforced
concrete walls.

And these then became known
as diaphragm walls.

After dropping
in diaphragm walls,

Veder built a roof
over the tunnel,

allowing city traffic
to resume above.

Digging, tunneling
and construction

could take place without
disrupting life in Milan.

Instead of cut-and-cover,

Veder's technique
covered, then cut.

It's now known as top-down.

This method was adapted
around the world as a way

of completing major subterranean
projects with little

to no interruption
to the world above.

So what Veder
achieved here in Milan

was to pioneer a really
innovative construction method.

And it's fair to say that,
standing down here

in one of the new tunnels
of the Milan Metro,

it simply wouldn't exist without
that construction technique.

In 2009, engineers at the Shard

take Veder's top-down method
and turn it on its head.

Normally, a building
like this would be built

by building a basement first
and digging a big hole

down to the bottom level
of the basement.

And then starting the...
The core from that lowest level

and building upwards.

Now, we built the core
on stilts effectively

but held up the core

while we were
building it upwards.

And then we were,
at the same time,

digging underneath it
and going downwards.

That had never been done before.

It was an innovation
for the Shard.

Just 23 piles support
the Shard's concrete core

as it rises from a void
in basement level two.

As excavations
of the underground floors

continue around
the pre-sunk columns,

the core rises as if balanced
on a tabletop above.

This allowed the
engineers to shave, literally,

months off this project.

And the Shard was built
much more quickly

and much more cheaply than
it could otherwise have been.

This really is
an engineering marvel.

Pouring the Shard's
800-foot concrete core

requires an epic
engineering solution.

It's amazing to think
the first 21 stories

of this concrete structure

went up before they'd even
finished the foundations below.

At 1,016 feet,
the Shard in London

is taller than the Eiffel Tower.

It has 72 habitable floors,

44 elevators
and 306 flights of stairs.

Building this mega tower

required almost 2 million
cubic feet of concrete.

The Shard
is an incredible building.

It just stands high, proud
above the London skyline.

And this incredible bit
of architecture really

does put London on the map.

This is a really
radical building.

It imposes on the London skyline
like nothing else.

It ascends into the air.

And the whole thing shines
and glistens in the sun.

What a stunning sight.

The Shard's luxury
apartments, hotel,

and nearly 600,000 square feet
of office space

have set a new benchmark
in skyscraper design.

But huge ambition
comes at a price.

The $618 million project

required more
than 1,400 workers on-site.

As soon as a project
like this starts,

you're against the clock
every second of the day.

Time is money.

You need to keep going
and keep going quickly.

The slow bit of construction
is building a concrete core

that is the real basis
of stability for the structure.

It holds the building up,

holds the building
solid against wind loads

and is a very, very
important part of the building.

And getting that in... in place
quickly is a real challenge.

The Shard's
concrete floor consists

of over 350,000 cubic feet
of concrete.

Constructing it
would've been impossible

had it not been
for a groundbreaking method

developed over 100 years ago.

Architectural historian Jen
Masengarb is in Minneapolis,

seeing for herself

how an innovation
in the baking industry

is influencing building
construction around the world.

In the 1880s,
Minneapolis was known

as the flour capital
of the world.

Raw grain was brought here from
across the northern prairie,

processed here and then
shipped across the country

and around the world.

Flour production
in the 19th century

was dangerous business.

Dry millstones
could ignite flour dust,

causing catastrophic explosions
inside wooden silos.

In 1878, the Washburn a,

one of the largest mills in the
city, exploded, killing 18.

Grain merchants were
facing a storage problem,

so, clearly,
a new solution was needed.

Their answer came
from engineer Charles Haglin

and grain trader frank Peavey.

Together, they designed
a safer, stronger silo.

So, this is
what they constructed:

The world's first reinforced
concrete grain silo.

The technique
that Haglin developed

for the cylindrical shape

was absolutely revolutionary
for its time.

Haglin built a wooden
cylindrical mold

and filled it with concrete.

Once the concrete set, the mold

was removed and placed
on top of the first section.

Haglin repeated this process

until he reached
his desired height.

Many of Haglin's peers

didn't think that concrete
could hold grain,

so Haglin's experimental tower
was filled and tested.

So, Peavey and Haglin's
experiment worked.

They had solved
the grain storage problem,

and they could take
what they learned here

and use it all over the state.

Inspired
by his experimental silo,

in 1908, Haglin built the
Washburn-Crosby elevator one,

part of the Washburn a mill.

At its peak, it could produce
almost 2 million pounds

of flour a day.

The most innovative thing
about this design

are these 15 cylindrical silos,

each measuring
about 100 feet tall.

Constructed by Charles Haglin,
they were the first large-scale,

concrete grain silos in the U.S.

To build the silos, Haglin

developed an ingenuous
new method called slip forming.

His new technique
allowed him to continually move

the concrete-filled mold.

So, what we've got here

is a simple demonstration
of how slip forming works.

I've got this bucket
of slightly wet sand here.

This is gonna represent
our concrete.

And I've got this other bucket
here with a hole cut in the top.

This is gonna represent
our slip form.

And here's
how the process works.

A little
of the concrete goes in.

And, slowly, about a few inches
every hour, the slip form

gets raised up and up.

And then I add a little more.

And raised up
a little bit higher.

The rig is continually
forced up by hydraulic Jacks

while concrete
is poured nonstop.

The concrete at the top
remains wet and fluid.

By the time the concrete
emerges from the bottom

of the moving mold,

it's dry enough to support
the growing structure.

The combination
of the speed of the rig,

how fast the slip forming moves
up the structure and the fact

that the concrete has to be
poured continuously into the top

so that the top layer
never fully cures,

this is the key to making
this whole process work.

Haglin's rig was so efficient,

it could scale 8 feet
in just 24 hours.

Each cylinder was poured
in just 12 days.

Haglin's use
of slip form construction

revolutionized the way

that tall buildings
are constructed.

And, today, concrete

has become one of the most
widely used materials

in construction,

allowing us to build higher
and faster than ever.

At over 800 feet,
the Shard's concrete core

is nearly eight times taller

than the Washburn-Crosby
elevator silos.

Engineers used
a super-sized version

of Haglin's pioneering rig.

The giant slip form rig
measured 85-by-72 feet.

It was moving upwards
at 3 meters a day,

almost a floor a day.

You have steel shutters,

which form the shape
of the concrete.

And then they are moved up
almost continuously,

6 days a week, 24 hours a day.

Thanks to a
high-capacity concrete pump,

the system was so efficient,

it reached the 21st floor
in just 10 weeks.

It's amazing to think
the first 21 stories

of this concrete structure

went up before they'd even
finished the foundations below.

The concrete core is still
sitting on just 23 piles

in the center of the basement.

Engineers need to pour
the rest of the foundation

before they can continue
building up the core.

This includes basement level
three's raft foundation...

A massive concrete pour.

It took 32 hours.

We poured the whole thing
in one go.

It's as much as 3 meters
thick in the middle,

underneath the core.

And it was 5,500
cubic meters of concrete.

They had trucks coming in from
three different concrete plants.

It was tremendously exciting

to see all that concrete
arriving on-site.

To finish the Shard, engineers

are bringing in
some of the tallest,

most powerful tower cranes
in the world.

They started with
four cranes at ground level.

Those went up
to about 160 meters.

But, above that,

we've still got 140 meters
of the building to go.

How do we get the structure,

the construction equipment
up to that height?

A daring engineering
solution is needed.

In 2012, London's
skyline was transformed.

Three times taller
than the statue of Liberty,

the Shard
dwarfs everything around it.

Two of its biggest fans,

physicist Andrew Steele
and engineer

David knight are taking in
this architectural masterpiece

from every angle.

This is London's Burj Khalifa.
This is London's Shanghai tower.

It was built
in very trying circumstances

and at speed.

And London engineers are really
proud of that achievement.

Built from
a central concrete core,

the tower's unique,

hybrid superstructure
is pulled up around it.

40 floors, constructed of steel,

29 stories of concrete,

topped off by a monumental,
23-story spire

at the pinnacle of the building.

Building a tower this tall
in the middle of London

presents some unique
logistical challenges.

When you're building a tower
that's over 300 meters high,

one of the real challenges
is getting the people

and the materials up
to these incredible heights

when you're doing
the construction.

And the higher the tower
gets, the harder

that challenge becomes.

Construction had never
been attempted before

on a building
this tall in central London.

And it was a real challenge
to get men and materials

up to the top floor.

So how do you get
enormous amounts

of building material to the top
of a mega tower like the Shard?

It would be impossible
without help from the innovators

of the past.

To construct the great pyramids,
the ancient Egyptians

had to rely on elbow grease
and a lot of determination

to scale their network of ramps.

As cranes were introduced,
the treadwheel allowed engineers

to use leg power
with impressive results.

Faster, faster!

Only walking pace
was recommended.

Erecting a giant obelisk
in 16th-century Rome

required even more muscle.

It took 800 men
to raise a vast lifting tower.

Ah-choo!

Plenty of power
to get it up as long

as no one let you down.

A more reliable solution

to heavy weight-lifting
came 3 centuries later.

Dr. Rhys Morgan is exploring
the waterways of Venice,

soaking in a centuries-old
seafaring tradition,

which ultimately led
to an engineering innovation.

Throughout history, this city

has had
an unshakable affiliation

with all things waterborne.

And the mid to late 19th-century
was no different.

It was a time of great change
in the maritime industry.

And old, wooden galleys
propelled by oar and wind

were being replaced
by steel-hull ships

and great, big engines.

This new wave
of heavyweight ships

posed a huge problem
for engineers

at Venice's historic
naval shipyard, the arsenal.

Traditional,
manually operated cranes

couldn't handle heavy loads.

This seriously compromised

the Italian Navy's
boat-building program.

They turned to British engineer
sir William Armstrong.

He came up
with the perfect solution

to Venice's maritime
construction conundrum.

Because of the growing trend
of metal-hull construction,

the Navy decided to commission
just the thing for the arsenale.

And here it is.

A stunning Armstrong crane.

Completed in 1885,
this colossal structure

is an imposing addition
to the venetian skyline.

And today, Rhys has special
access to its inner workings.

And the way
it works is like this.

This huge boiler would generate
enormous amounts of steam.

And that steam would flow up
through the pipework,

down into these chambers below.

The steam drove
these enormous pistons

back and forth, back and forth.

And they, in turn,

helped pressurize
the hydraulic circuit.

The water was taken
from the lagoon outside.

And the pressure
from the pistons

generated huge amounts

of pressure
on the hydraulic system itself.

The Armstrong crane can lift
what was, at the time,

an unimaginable 160-ton load.

It transformed the fortunes
of arsenal.

It was the power that meant

that previously unimaginable
weights could be lifted.

And it opened up
a whole new frontier

in crane technology.

Over a 30-year period,

nine more of Armstrong's cranes
were installed around the world,

ushering in a new era
in crane development.

By pushing the boundaries
of what cranes were capable of,

Armstrong created a landmark
in engineering history

and paved the way
for incredible projects

that we see all
around the world today.

Engineers at the Shard

took Armstrong's
historic crane design

to the next level.

Building this superstructure

meant building
some of the tallest,

most powerful tower cranes
in the world.

They started with four
cranes at ground level.

Those went up
to about 160 meters.

But, above that,

we've still got 140 meters
of the building to go.

How do we get the structure,

the construction equipment
up to that height?

Engineer John Parker
and his team

came up with a radical idea.

Mounting a tower crane
to the Shard's concrete core.

What was unique about the Shard

was that the tower crane
was supported on that slip form.

Usually, you have to fix
the crane to the concrete.

We avoided all that so
they could both go up together.

As hydraulic Jacks pushed
the core and crane higher,

the machinery is kept stable
against wind speeds

in excess of 100 miles per hour

by extending the lower section
of the crane

into one of the already cast
lift shafts.

Installing the Shard's spire

required an even more
radical approach.

They then had to use the crane

that was attached
to the slip form

to build another crane

which cantilevered off
the main building

and allowed them
to build this final spire

on top of the structure.

Engineers elevate
the tower crane

to a staggering 1,040 feet,

enabling them to install
the custom-built steel sections

that form the 23-story spire.

The section could arrive
on a truck.

They could attach it
to the crane,

lift it up to the top,
bolt it in place

and then get the hook back down
to lift up the next section

in 20 minutes.

Over 500 tons of steel

is installed in
nearly 100 separate lifts.

The Shard was really gonna
hit the absolute limit

of how high
you could build in London.

With the building
at its full height, designers

can finally begin to visualize
the monumental shard.

40 floors of steel house
almost 600,000 square feet

of office space.

For the hotel
and residential accommodations,

concrete is used
to enhance acoustics

and limit the building's sway.

¶¶

Safety is a top priority
for the builders

and engineers of the Shard.

We know from previous
fires in tall buildings

that it's a real challenge

to get people
out of the building safely.

And that's an absolute focus

to engineers working
on tall buildings like this.

To ensure the Shard's
inhabitants are safe

if there is a fire,

its designers need to draw
on an innovation

that's over 100 years old.

Professor Luke Bisby
is in Edinburgh, Scotland,

recreating an engineering marvel
that changed the face

of building safety
around the world.

Now, it might be difficult
for many of us today

to recognize that fire
was once a very serious

and everyday threat
to our homes and businesses.

Heating and lighting were both
largely reliant on open flame.

And, in combination
with the fact

that many of our buildings
were made largely from wood,

this is obviously not
the best combination.

In 1874, Connecticut
businessman Henry Parmelee

developed a system

that helped combat
the threat of fire.

With inefficient fire
extinguishers,

factories in many U.S. cities
were burning to the ground.

Insurance costs
were skyrocketing.

Parmelee was determined
to control the premiums

on his piano factory,

so he came up
with an ingenuous form

of fire prevention.

So what we're gonna do here

is try to recreate
a simplified version

of Parmelee's invention.

So what I'm gonna do is I'm
gonna start a small fire here.

Any fire in a building
is a bad situation.

And fires are particularly
a problem

in industrial buildings
of the type

that Parmelee was using because,

if you have a localized fire
such as this one,

that fire can then spread
to other flammable contents

of the building.

During evening
and even some daytime shifts,

many areas of Parmelee's factory
were unattended,

so human detection wasn't
a reliable solution.

So the problem
that Parmelee faced was,

how do you detect a fire

and then put that fire out
if there's nobody around?

So the solution
that Parmelee came up with

is actually here next to me.

And the really critical piece
is this little cap right here.

And what I have here
is a little, metal valve.

And, on the underside
of the valve,

I have a secondary piece
of metal.

And we've attached that
in this demonstration

just with some wax.

Now, Parmelee actually used
a low-temperature-melting alloy.

What I now have is essentially
a valve

on the bottom of this pipe
that is temperature sensitive.

And so the system that Parmelee

had invented basically consisted
of a reservoir of water.

That reservoir is connected
through a hole

in its base to this copper pipe.

That copper pipe runs across
and down to the valve

that Parmelee had created.

Now, let's see what happens

when we introduce fire
into our system.

And, as I do that,
the valve gets warm,

and the wax that is holding
the plate in place

should release the copper plate.

And the valve
almost instantaneously,

sensitive to the temperature,

releases water
down onto my fire.

And so what Parmelee
had invented

was really the world's first

automatic fire
suppression system

that both detects and reacts
to a fire very quickly.

Parmelee called his invention
the automatic fire extinguisher.

It was rapidly adopted
in the U.S. and Europe.

His game-changing piece
of engineering paved the way

for modern sprinkler systems
around the world.

Engineers at the Shard

are taking Parmelee's
automatic fire extinguisher

to the next level.

They're incorporating one
of the world's most advanced

fire suppression systems
into their mega structure.

The sprinkler system
is all centrally controlled

by a building management system.

Total fire engineering
control here,

getting the water
around the building

to where the fire
is likely to be.

Driven by 200 kilowatt motors,

two mega pumps feed water
to seven sprinkler zones.

Three pumping stations
are located at different levels,

insuring even pressure
for the building's hydrants.

Access for firefighters
is via three shafts.

Each includes stairs
and a fire elevator,

allowing occupants
to leave by the same means.

This is one
of the first buildings

where people can use the lifts
rather than just the stairs

when being evacuated in fires.

¶¶

The designers of the Shard

are pushing the limits
of architecture.

To build
this audacious structure

required, literally,

acres of glass,
56,000 square meters,

which is equivalent
to nearly eight football fields.

Their goal is to make the Shard
the most beautiful structure

on the London skyline.

The Shard in central London

is rewriting
the engineering rule book.

Its 73 stories
are a mind-blowing sight.

This jaw-dropping tower
is over three times

the height
of the statue of Liberty.

Its facade is made

out of a staggering
11,000 glass panels.

That's enough glass
to cover 130 basketball courts.

Beneath the 196-foot spire
lies the spine of the building.

The colossal concrete core
supports 72 levels,

totaling over
a million square feet

of floor space.

It's just incredible.

It's this audacious piece
of architecture,

a splinter of crystal
bursting out of the earth.

And, amongst this grand center
of London,

all these different buildings,

the Shard just
towers above all of them.

For structural
engineer David knight,

its stunning looks
come down to one material

that appears to rise straight
out of the river Thames.

Look at the crazy
amounts of glass

that this building uses,
11,000 separate pieces.

It's extraordinary.

It just extends above me
in a great, big ribbon of glass

up to the sky.

To build
this audacious structure,

required literally
acres of glass,

56,000 square meters,

which is equivalent
to nearly eight football fields.

But glass is weak.

So how do you create London's
tallest building out of it?

It would be impossible
without some inspiration

from an architectural risk
taken 150 years ago.

Engineer Dr. Rhys Morgan

is in the city
of Liverpool in the U.K.

To see the building
that holds the secret

to modern skyscraper design.

In the 19th century,

as cities like Liverpool
grew ever more dense

and space for buildings
became smaller,

architects were faced
with a real problem.

They had to build upwards,
but, in doing so,

they had to build
thicker and thicker walls

to support the increasing weight
of their structures.

So they needed a new
engineering solution.

Local architect
Peter Ellis provided the answer.

He came up
with a revolutionary design

for his high-rise building.

This is the oriel
chambers building,

tucked away in Liverpool’s
financial district.

And, although a relatively
unassuming building,

it contains one of the world's
most important engineering

and architectural blueprints.

In 1864, U.K.
Architect Peter Ellis

designed a structure

which holds the key
to modern skyscraper design.

This is the oriel
chambers building,

tucked away in Liverpool’s
financial district.

And, although a relatively
unassuming building,

it contains one of the world's
most important engineering

and architectural blueprints.

The oriel chambers building

doesn't need exterior
supporting walls.

An iron framework carries
the load of the structure

on the inside.

This allowed Ellis
to create a facade

on the outside that doesn't have
to support the building.

Ellis' iron frame structure
not only carried the weight

and provided
structural stability,

but it also opened up
a whole new world

of architectural possibilities.

Walls could be thinner
and lighter.

Previously unimaginable amounts
of glass

could cover
the building's exterior.

Ellis created
the glass curtain wall.

In 1864, it was
a really radical idea.

And Ellis was criticized
by his contemporaries

for creating
an architectural aberration.

Architects
may have been skeptical,

but developers
saw the potential.

The building has
56 road-facing bay windows

over five floors.

The windows flood
the interior with light,

creating premium office space.

150 years later,
the benefits are still clear.

It would've been a real luxury

to work in here
with the abundance of light

coming in through
these bay windows

or oriel windows,
as they're properly called.

And, to compare it

with the building
across the street

where the stone construction

means the windows
are very small,

this would've been
an amazing place

to work in because of the light
coming in from all directions.

And you also didn't have
to use electricity

to use lighting
in the wintertime,

a real advanced idea
for the 19th century.

The fact that these chambers
were built in 1864,

over 150 years ago,

makes it one of the world's
first examples

of a glass curtain wall

installed on
a multi-story office building.

And to think
that he was derided for it

and was so far ahead of his time
is quite extraordinary.

Ellis' groundbreaking work
on the chambers building

has inspired American architects
for centuries...

And is still
shaping the skylines

of the world's greatest cities.

It's incredible to think that,
without Ellis' pioneering use

of the curtain wall concept,

the glass-clad
super towers of today,

which dominate cities
across the world,

might not ever
have been invented.

It's a real masterpiece
of engineering.

Engineers at the Shard

are building
on Ellis' glass curtain wall

to create their own
one-of-a-kind structure.

13 acres
of glass cover the Shard.

What's incredible is that,
from outside the Shard,

it looks like it's a structure
made entirely of glass.

But, actually, this glass
takes none of the weight.

That's all borne by the steel

and the concrete
structure inside.

An incredible piece
of engineering.

The steel and the concrete
makes the building stand up.

That's provides the strength
and the stiffness,

stops it swaying about,
supports all the loads.

And one of the loads it supports
is the weight of the cladding,

the weight of the glass.

Unlike the rectangular
oriel chambers building,

the Shard's extraordinary
super structure

allows its designers
to hang eight sloping facades,

defined by the tower's
iconic vertical fractures.

It's often called
the Shard of glass.

And the idea was to have

a beacon here
that would shine out.

And this sloping shape
is very good

at reflecting the sunlight
and making it shine.

Creating a vision
of glass on this scale

calls for extraordinary measures

never before attempted
in London.

The steel super
structure of the building

is enveloped by 11,000 panels
of glass,

each of them weighing
300 kilograms.

And the only way to install them
was for each of them

to be installed individually
by a specialist engineer.

And looking at it from up here,
you can see that's not a job

for the faint-hearted.

The final
glass section is fitted,

signifying a milestone
for the Shard.

It is good to be
at the cutting edge

and driving things forward

and doing stuff
that's never been done before.

This seemingly impossible
architectural achievement

took less than 4 years

from breaking ground
to grand opening.

It's the result
of brilliant planning,

design and testing
by hundreds of engineers.

I'm personally excited
because I see symbols of London

that now include the Shard.

It's very exciting

to be involved
with something like this.

This is, uh, it's a one-off.

It's a once-in-a-lifetime
achievement.

By learning from
the great pioneers of the past,

adapting, upscaling,

and making innovations
of their own,

engineers have changed the face
of skyscraper design forever.

The Shard isn't just
an amazing piece of engineering,

but it's captured
the public imagination too,

become a tourist attraction
in its own right.

And that surely is amongst
its greatest achievements.

The creators of the Shard

have succeeded in making
the impossible possible.

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