All language subtitles for Ancient.Engineering.S02E01.1080p.AMZN.WEB-DL.DDP2.0.H264-chr00t_track3_[eng]

(dramatic music)

- [Narrator] The world's
greatest structures

push the boundaries
of engineering,

all fueled by a constant
desire to innovate.

- Without engineering there
would be no modern world.

- [Narrator] Gigantic buildings,
complex infrastructure,

and ingenious inventions.

- Engineering is the key that
turns dreams into reality.

- [Narrator] Many of today's
incredible achievements

rely on breakthrough
technologies

first devised by
ancient engineers.

- It's astounding how
they achieved this.

- [Narrator] Early
civilizations built

on an unimaginable scale and
with incredible precision.

- They raised a
bar for engineering

in a way that no one
thought possible.

- These are some of the
finest engineers in history.

- [Narrator] Redefining
the known laws of physics

and dreaming up the impossible.

They constructed
engineering wonders;

from colossal stadiums

to mighty waterways

and complex machines.

All with the simplest of tools.

- You cannot imagine the skills

people would've needed
to build like this.

- [Narrator] By unearthing
the mysteries left

by these ancient engineers

we can now decode their secrets.

- That so many of their
creations still survive

is testament to their
engineering prowess.

- [Narrator] And ultimately
reveal how their genius

laid the foundations for
everything we build today.

(dramatic music)

(intense rock music)

The desire to be
enthralled by spectacle

is as old as humanity itself.

The collective power of an
event on a massive scale

taps into the human need for
an exciting shared experience.

- Entertainment is
vital for us as humans.

It's such an important
part of a well-rounded life

to have that
opportunity to relax,

to enjoy a period of time
when you're not working

or involved in other
things in your life.

- It nurtures culture, it
promotes talent and creativity.

It relieves stress.

It really is one of the
things that makes us human.

- [Narrator] The appetite
for entertainment

has led to the construction

of some of the most impressive
buildings in history.

- The grandeur of the buildings
that we've constructed

to entertain
ourselves says so much

about how much we
value entertainment.

- [Narrator] Specifically
when it comes to stadiums.

Roofless venues with
tiers of spectator seating

surrounding an
outdoor sports field.

- We're talking about tens
of thousands of people

in one building.

Think of any other
building that can do that.

(suspenseful music)

- [Narrator] Colossal
structures, purpose built,

each with their own
unique appearance,

attributes, and atmosphere.

- Stadiums nowadays
are really complicated,

sophisticated bits of
engineering and architecture.

- [Narrator] Widely
known for its exterior,

Germany's Allianz
Arena consists of

the largest membrane
shell in the world,

with more than
300,000 LED lights

concealed behind its facade.

Making it possible to illuminate
in any of 16 million colors

with a flick of a switch.

And the University of
Michigan's stadium is recognized

as the largest football
venue in the United States,

despite opening back in 1927.

Steel and wire mesh were
used to create this behemoth,

holding an astonishing
107,600 spectators.

But the DNA of today's
spectacular stadiums

has ancient origins.

- Stadiums are not in any
way a recent phenomenon.

They've been part of
our towns and cities

far longer than the
Medieval cathedrals

or the railway stations of
the Industrial Revolution.

- [Narrator] Many that
have stood for millennia

are widely regarded as
engineering masterpieces,

with one surpassing all others;

(dramatic music)

the Coliseum.

A spectacle of design that
combined innovative engineering

with cutting edge construction

to create one of the world's
most iconic structures.

But this was far from the first
stadium to be constructed.

Their history dates back
more than 2,500 years.

Like many other historical
engineering feats,

the concept and
design for stadiums

was first developed
in Ancient Greece.

- The first stadiums arrived
in the 8th century BC,

and we're looking at
the skill and speed

and strength of athletes.

- If we go to the Greek world,

the earliest stadiums
that we know about

are for athletic
races, foot races.

(suspenseful music)

- [Narrator] With the
first stadium of its kind

found in the ancient
sanctuary of Olympia.

A 630-foot-long athletic track

sandwiched between two
massive embankments of earth.

- The Stadium of Olympia
is a remote place.

It's very quiet, but
at the same time,

there's almost an electric
sense of history there.

You know that there have
been really important events

on that track.

- [Narrator] Constructed
almost 3,000 years ago

and home to the very
first Olympic Games

in 776 BC.

(suspenseful music)

- You don't need to
replace in your mind

an enormous lost
building as you do

in so many ancient sites,

just here it's the banks.

And you can imagine them
being filled with people.

- [Narrator] A
relatively simple design,

but the site at Olympia
was the inspiration

for countless other
ancient Greek stadiums

across the country,

as well as over the Aegean
Sea in present day Turkey.

Wherever they were constructed,

the stadiums were
filled to capacity

with avid sporting fans.

(crowd cheering)

The growing popularity
of athletic events

called for the construction
of larger venues.

Simple earthen banks
would no longer suffice.

Greek engineers had realized
the importance of the audience

and began designing
spectator-oriented stadiums.

- This is the next stage in
the evolution of stadiums,

built with the
spectators in mind.

They had to create benches
all the way around it.

It was an immense
feat of engineering.

- So we are now at a point where

we're to stone architecture,

not just simple earth
banks around an open field,

but a built environment.

It's a much more considered,

much more architectural setting.

- [Narrator] Rows and rows
of specially carved stone.

Fortunately, the
Mediterranean region

had abundant supplies
of limestone and marble,

among the chief building
materials in ancient Greece.

But while limestone was
relatively easy to work with,

marble came with
immense challenges.

- Marble is heavy and
it's difficult to work.

You can carve it to a
very beautiful finish

if you've got the right
tools and the right skill

and it costs you a lot of money.

- [Narrator] Even excavating
the luxurious stone

demanded engineering expertise.

Ancient Greeks began by carving
deep grooves into the rock

with hammers and picks

and relied on an unusual
quarrying technique

to then split the marble
away from the rock face.

- Quarrying marble is one
of the most difficult things

that anyone can do.

They had several techniques.

One of the things they
did was used wedges,

which they hammered into the
natural fissures in the marble.

- [Narrator] The wooden
wedges were soaked in water,

and as they became
saturated, they expanded,

forcing the stone to split
along its natural faults.

- Those wedges made
the marble crack away.

And from there they
could shape the marble

into the benches they
needed for the stadium.

- [Narrator] The stone masons
relied on a combination

of point, flatheaded,
and rounded chisels

to carve and smooth
the surfaces.

Such tools and techniques

enabled the Greeks
to construct venues

large enough for
the growing crowds.

Grand stadiums to host the
ancient sporting events,

all inspired by the ancient
Olympic games held at Olympia.

(crowd cheering)

(gunshot popping)

(rock music)

Since its resurgence in
the late 19th century,

the hosting of the
modern Olympics

has attracted enormous prestige.

- The revival of the
modern Olympic games

was really
significant for humans

because it created this event

that the whole world
could get behind.

- And they've turned from what
was already quite a big event

to a kind of epoch making
global megastar event today.

- [Narrator] Those that
won the right to host

the Olympic games were
required to construct stadiums

to host a variety of
large scale events

and the huge crowds that
would inevitably follow.

- Countries coming together
to do something great,

to want to demonstrate
athleticism,

but actually to want to
demonstrate engineering prowess.

- [Narrator] Munich's
Olympiastadion
was built to serve

as the flagship venue
for the 1972 Olympics.

Boasting an ethereal canopy
of 8,000 glass panels

and over 270 miles
of steel cables.

While Montreal's
541-foot high tower

is the tallest incline
structure in the world,

leaning over the
1976 Olympic stadium

at an angle of 45 degrees.

Spectacular sporting venues
designed for the games

standing as tribute to
the ancients' ingenuity.

(suspenseful music)

The popularity of
Greece's sporting
events continued to grow

along with the
variety of contests

that the crowds came to applaud.

Eventually a new
distinct type of arena

began to appear in cities
across their civilization.

- The ancient Greeks
loved horse racing

and they built horse racing
courses called hippodromes.

- Whereas the foot
races in Olympia

had been within a
rectangular track,

the Greeks now
extended their races

into more exciting horse races.

And so for the hippodrome
you need a curved end

that the horses can race around.

- [Narrator] As seen with
the modern reconstruction

in Athens, the locations
were generally dictated

by the terrain and were
dug into a hillside.

The excavated
materials were used

to construct the
embankments for spectators,

with tiered seating along
the two opposite lengths,

as well as around the
curved end of the track.

(dramatic music)

Greek engineers had created
the ideal environment

to host their
sporting competitions.

But one ancient civilization

would adopt the Greek
hippodrome structure

into their own society:

The Romans.

- The Romans took the idea
of the Greek hippodrome

and in classically Roman
fashion, they improved it.

- [Narrator] Both
structures were designed

for equestrian events.

However, while the hippodromes

were the largest
sporting structures
created by the Greeks,

the Romans took their
magnitude to the next level

with the circus.

(suspenseful music)

But race tracks of
this grand scale

required careful planning
and calculations.

- They were very well built.

Precision architecture,
precision craftsmanship,

blocks fitting
together beautifully,

really solid choice
of materials.

And that didn't
happen by accident.

They used excellent
tools on site

to survey what they needed

and measure and put
things into place.

- To make all of this possible

the Romans needed
some engineering tools

and their most
important was the groma.

This was used for measuring
straight lines and right angles,

both of which were fundamental
to all Roman architecture.

- [Narrator] A long
staff supporting
horizontal cross pieces

mounted at right
angles on a bracket,,

each with a plumb line
hanging vertically at the end.

Once positioned, the
surveyor would use

the aligned plumb
bobs as a visual guide

for laying out markers in a
near perfect straight line.

- If two of the lead
weights are in line

with a man with a stick,
you've got a straight road.

And then to build the next
section of straight road

you move the groma to where
the man with a stick is.

He goes a bit further along,

and then you've got another
section of straight road.

And on and on.

And you can design road.
You can design buildings.

It's an incredible invention.

- [Narrator] A device that much

of Roman construction hinged on.

By the 6th century BC,

the first circus was
constructed in Rome

and became a roaring success.

They would go on to be built
throughout the Roman empire,

including Israel, Egypt,
and Great Britain.

Chariot races had become
the Superbowl of their day,

but they weren't the
only event circuses held.

- Other things
the Romans enjoyed

included parades, wild
beast hunts, executions.

We imagine all of those things
also happened in the circus.

- [Narrator] And one contest
for the blood thirsty mob

was fast becoming
the favorite of Rome:

Gladiator games.

- While the circus was
really good for things

like chariot racing, because
they happen along a long path,

with two people fighting

they don't need to travel
very far whilst fighting.

So it didn't really suit itself

to what was becoming
Rome's favorite sport.

- [Narrator] The Roman
engineers had to devise

a more practical arena,

designed specifically for
huge numbers of people

facing an enclosed
central space.

Dating back to the
first century BC,

the Romans set out to build
a new type of sporting venue

for gladiator combat.

- What you need for that
is a piece of ground

a bit bigger than a boxing ring.

And you need to be able to
look down on the action.

So they needed
purpose-built arenas,

and they turned to an oval arena

where gladiatorial
combat happens.

The amphitheater,
like a double theater.

- [Narrator] Amphitheaters
were a triumph

of the ancient world,

with some still standing today.

- If you want to experience
what it really is like

to be in a fully
built amphitheater,

then the best one to go
into is the one in Pompeii.

- [Narrator]
Constructed in 70 BC,

the Amphitheater of
Pompeii is recognized

as the very first to
be built out of stone

in the Roman world.

443 feet long and 341 feet wide,

it could hold up to
20,000 spectators.

The largest of its kind.

- It's got a deep oval arena
with a high parapet wall

so that the people down
in the arena floor,

the combatants, are
separated from the seating,

and then ranked seating in a
big bowl all the way around.

So you could imagine
several thousand Pompeiians

cheering in the seats.

- [Narrator] But the Roman
engineers had to devise a way

not only for the crowd
members to access their seats,

but for the
gladiators themselves

to enter and exit
the arena floor.

Their solution?

An internal corridor

that ran the entire
circumference of
the amphitheater.

In order to construct
such a passage way,

the ancient Romans needed a
key architectural element:

the barrel vault.

- An arch is a very
stable and effective shape

for creating structures
that are very strong.

So a barrel vault is
essentially a series of arches

connected together
to create a corridor.

- [Narrator] The weight of
the earth and stone above

is absorbed by the key stones
in the center of the vault

and distributed evenly over
the entire span of the arches

and then down into
the side pillars.

This allows the pillars
to bear enormous loads.

- Barrel vaults are a
really fantastic feature

that we kind of have seen all
the way through architecture.

We've seen them in churches.

We've seen them in
historical buildings.

They just see them everywhere.

They're just a
prominent feature.

And I think it's maybe because
how beautiful it looks,

but also how important it was
as a load bearing structure.

- And one of the great things

about using arched construction
in these stone arenas

is that you can move a lot
of people around the complex

by using tunnels in the
underside of the thing

to distribute them around
the area of seating.

- [Narrator] The
amphitheater's design

was optimal for crowd control,

built to withstand
thousands of spectators

coming in and out.

But there was one force
that the Roman engineers

hadn't planned for.

After slumbering for centuries,

on the 24th of August 79 AD,

Pompeii began to shake.

(dramatic music)

Mount Vesuvius had reawakened.

- When Vesuvius erupted the
sky would've gone black,

the noise would've
been deafening.

It would've been truly
the most terrifying thing

that anyone had ever
experienced before.

And they all fled
for their lives.

- The pumice, the dust, the
hot gases swept over people.

It basically
incinerated them in situ

and it covered Pompeii
with this volcanic dust,

which entombed it for
centuries afterwards.

- [Narrator] Buried
by volcanic ash,

the amphitheater survived

úthe eruption of
Vesuvius almost intact.

But not all structures
are so fortunate

against the forces of nature.

(dramatic music)
(thunder crashing)

As natural disasters continue
to shake the modern world,

it's up to engineers to ensure

that buildings are designed

to have the best
possible defense.

- Engineers are always
looking to advance the designs

or materials they're using

to make their structures
more resilient

to natural disasters.

- [Narrator] Buildings
are now designed

to sound engineering principles.

To withstand all
foreseeable loadings

and extreme conditions
throughout their lifespans.

And as new technologies and
components are embraced,

ever bigger, more amazing,
and safer structures

take shape across the globe.

But whether it's a skyscraper,
stadium, or school,

these buildings all still rely

on a single material
for their strength.

One made hundreds of years ago,

with properties that make
it especially valuable

for natural
disaster-resistant buildings:

Steel.

- Steel is a great material to
use for a number of reasons,

but definitely when it comes
to disaster protection.

- It's strong, it's durable,

and of course it's
not flammable.

But also, steel is so critical

because it's ability
to resist buckling.

And that gives you a
confidence in designing with it

and building with it.

- [Narrator] Still used to
create some of the world's

most distinctive buildings.

Completed in 2008,

the Beijing National
Stadium was at the time

the largest steel
structure ever constructed.

The only catch?

It's located in
one of the world's

most active seismic zones.

In order to earthquake-proof
the 91,000-seat stadium,

the design was critical.

- So the inside
bowl of the stadium

is not connected to
the outer structure.

And also the bowl itself

is separated into
different segments

that all have their
own stabilizing system.

- Therefore, if there was
going to be an earthquake,

bits would actually just move

and it would flow and adapt more

rather than be still
and actually collapse.

- [Narrator] An incredible
feat of engineering

to conquer the most destructive
of natural disasters.

(suspenseful music)

By the beginning of
the 1st century AD,

amphitheaters could be found
across the Roman Empire.

- Amphitheaters become a
symbol and badge of Romaness,

wherever you get a
Roman settlement in
the Western empire,

it will have probably
an amphitheater.

- [Narrator] Their
size and intricacy

often reflected the
importance of the city or town

in which they were situated.

But without a doubt,
the sprawling empire
center was Rome.

- At its peak in 400 AD

Rome consisted of
a million people

and no other city
would surpass that

until Victorian London
in the 19th century.

- We're talking
about the largest,

one of the most
carefully planned cities

in the ancient world.

- [Narrator] Gleaming white
marble temples and palaces,

bustling markets, theaters,
and bath complexes,

with an extensive
network of aqueducts

supplying fresh drinking
water throughout the city.

- Ancient Roman must have been
like nowhere else on Earth.

The Romans created
a sprawling city

peppered with incredibly large
and sophisticated structures.

- Then, in 80 AD,
Rome became home

to something the world
had never seen before.

The largest building the
Romans ever constructed.

(dramatic music)

The Coliseum.

- You cannot miss the Coliseum.

It is a goliath
amongst structures.

It's still an anchor
within the city of Rome.

- If there's one structure
that still survives,

that makes you truly appreciate

the genius of Roman engineering,

without doubt,
it's the Coliseum.

- [Narrator] The ultimate
stage for gladiator combat.

Yet, this was much
more than an arena

of death and suffering.

The Coliseum was a
carefully engineered

entertainment complex,

and one of ancient Rome's
greatest accomplishments.

- This is an arena built
on a monumental scale

to exacting standards using
supreme Roman engineering.

- The planning that went
behind the construction

of the Coliseum
would've been immense.

The Roman engineers
understood the need

for appropriate foundations
for a building that size.

- [Narrator] After
reaching a firm clay bed,

a gigantic donut-shaped
base was laid out,

39 feet deep and over 1,700
feet in circumference.

Foundations strong
enough to support

the largest freestanding
amphitheater in the world.

(suspenseful music)

The story of the Coliseum
dates back almost 2,000 years,

at the end of the infamous
Emperor Nero's reign in 68 AD.

- The emperor Nero was
a notorious tyrant.

He built enormous
monuments to himself.

The money that came into Rome,
he largely spent on his self.

He had what's called the
golden palace of Nero.

And as part of this palace,
he had a pleasure lake.

This is monumental selfishness,

and that grated against
the people of Rome.

So he became deeply unpopular.

- [Narrator] Nero was
eventually declared

an enemy of the
people by the Senate

and committed suicide
shortly after.

- The problem with
Nero's departure

is that there are a number
of short-lived emperors

who wrestled to take control.

And this created an era of real
instability in Ancient Rome.

So a stabilizing
influence had to be found.

- [Narrator] Around
71 AD, a new emperor,

named Vespasian,
came up with a plan

to restore the city of
Rome to its former glory.

- He was determined
to reaffirm trust

from the Romans
in their leaders.

Vespasian wanted to get the
people of Rome on his side

and the way he did
that was to build

the ultimate place
for entertainment.

- [Narrator] He began
construction on an amphitheater

unlike any that came before,

right on top of
Nero's pleasure lake.

But a building is only as good

as the material that
binds it together.

Many ancient mortars
were notoriously weak.

But Roman ingenuity
solved the problem

with a new mix that
beat mortar hands down.

They called it
opus caementicium.

We call it concrete.

- You mix sand and mortar
and water and aggregate,

and you can then lay it
into any shape you want.

So it's material that's
cheap and versatile

and quick and super strong.

- [Narrator] Roman concrete's
phenomenal resistance

and durability against
elements of nature

made it the perfect material
for the Coliseum's foundations,

as well as the structure itself.

But such an ambitious
construction project

would need more than
just the right material

to ensure its success.

- When you look at the Coliseum,

one thing you
notice very clearly

is that it's a freestanding
enormous structure.

It doesn't have a lot of
buttressing around the side.

And that is because of the
genius design they used

to create this amazing
piece of engineering.

- Rather than relying on
the landscape for support,

this was a free
standing structure.

They built everything
from scratch.

- [Narrator] In order to
form their great monument,

the Romans had to turn

to several key
architectural innovations,

including one that changed
the construction playbook:

The groin vault.

- A groin vault is really taking
the arch to the next level.

If you consider
two barrel vaults,

which are corridors of
arches coming together,

when they intercept
at the middle

and you've got this cross
of arches coming together,

it means that each arch is
supporting the other arches.

And you have this amazing
open space underneath,

but very, very stable
and self-supporting.

- [Narrator] With the combined
strength of four posts,

groin vaults require
less buttressing

and therefore are an
even sturdier structure.

- So it's this
vaulting technology
that allows the Romans

to build freestanding
entertainment buildings

like theaters or amphitheaters.

And you see it really
perfected at the Coliseum.

- [Narrator] A combination
of barrel and groin vaults

ran around the Coliseum's arena,

supporting the
seating areas above

while allowing
for high ceilings,

and ultimately the
monumental stadium.

And the Coliseum's
exterior consisted

of 240 gigantic arches,

each up to 23 feet high.

- Every tier has arches
marching around this building.

Aesthetically it creates
a real unifying effect.

Structurally it creates
greater solidity.

- The use of arches in the
construction of the Coliseum

was also important because
it created natural entrances

and a variety of them.

And that meant
that Roman society,

which was divided
into numerous classes,

could all have
their own entrance.

- [Narrator] A well-organized,
durable super structure

with a capacity of over 50,000.

(suspenseful music)

In 80 AD the four-story
amphitheater was
finally completed.

- A decade after
construction began,

it was Vespasian's son, Titus,

who had inherited the
throne of emperor.

And under him, the
thing was completed.

- [Narrator] Titus
held a hundred-day-long

inaugural games where
spectators came out each day

to watch hours of entertainment.

- The opening games at the
Coliseum were spectacular.

And they went on for days and
days under the Emperor Titus.

These games were enormous
ongoing jamborees.

- So they had
gladiatorial fights

and wild animal
hunts and skirmishes.

It was the ultimate
opening ceremony.

- [Narrator] 5,000
animals are believed

to have been slaughtered
in a single day

during the opening games.

- The Coliseum is really a
temple to violence in many ways,

essentially what thrilled
people was the spectacle,

the jeopardy involved
in life and death.

- [Narrator] But the
Coliseum is believed

to have gone one step further

with an event bordering
on the impossible:

Mock naval battles with
real floating ships.

- Historians have been
debating this idea

of holding mock naval battles

in the Coliseum for generations.

And one thing that
is certainly true

is that it would definitely
have been possible.

- [Narrator] Some argue that
moving such a vast amount

of water in and out
of the amphitheater

would've been unfeasible,
even for the Romans.

Yet, if the claims
are to be believed,

then the water would
have to have been

no higher than around five feet

to avoid spilling over into
other rooms and corridors.

requiring more than a
million gallons of water

to flood the arena
up to that depth.

- Not just having hard ground

for these blood thirsty battles,

but actually flooding the
Coliseum for warship battles.

It blows your mind to think

how they may have
even done that.

- [Narrator] It's also
thought that the Coliseum

could be flooded for sea
battles in the morning

and drained quickly enough

for gladiator combat
in the afternoon,

a feat that would've required
serious hydraulic engineering.

- We know it's
possible because of

the extraordinary Roman
ability to manipulate water.

There were 11
separate aqueducts,

all bringing water
directly into Rome.

The water was certainly there

and they could have got
it inside the Coliseum.

- [Narrator] A large tunnel
running under the walls

of the Coliseum is
thought to have fed water

into a labyrinth of channels,

all leading to the
center of the arena.

An extensive hydraulic system

that could have
delivered enough water

to flood the arena floor.

And some believe they
have uncovered a system

used to get the water out.

- They use their
engineering ingenuity

to remove the water as well.

So they actually built
four large storm drains,

which they pulled to drain
the water from the arena.

- The size of the drains
and their ability to empty

into the cloaca, the
main sewers for the city,

suggests that you
could almost certainly

have emptied it within
the course of an hour.

- [Narrator] The water is
believed to have flushed out

at a rate of up to 280
gallons per second,

equal to more than 10 of
the most powerful fire hoses

blasting all at once.

If confirmed, then the
Coliseum would've been

one of the world's first
multipurpose stadiums.

A feature that engineers
continue to explore,

with some stadiums

pushing the boundaries
of what's possible.

When Tottenham Hotspur FC
embarked on its mission

to replace its old stadium,

it aimed to create a truly
world class multi-use venue

capable of staging a variety
of major sporting events,

each requiring different
sized and surfaced fields.

This called for a feat
of innovative engineering

never seen before.

- Amazingly you can turn
the natural grass pitch

into a synthetic grass pitch

to transfer it for use from
soccer into American football.

- [Narrator] Its
full-sized football pitch

has been engineered to
split into three sections

and retract into a storage
area beneath the south stand,

revealing the synthetic American
football field beneath it.

Mounted in three enormous trays,

the 9,800 ton pitch
weighs roughly as much

as the Eiffel Tower, yet takes
just 25 minutes to retract.

- Fans who experience one
sport may not ever know

that they can experience
different sport

in the same stadium and
that is great engineering.

It's great innovation.

- [Narrator] The
world's first dividing,

retractable grass
football pitch.

(suspenseful music)

The Coliseum guaranteed
an unforgettable show

for anyone with a ticket.

But the Roman engineers
also had to consider

the comfort of
the paying public.

- It's hot in Italy
in the summertime.

And if you're sitting there
all day on marble seats,

watching gladiatorial
combat and getting excited

and cheering, you're really
gonna get uncomfortably warm.

- [Narrator] The
engineers had to come up

with a way of shading the
audience from the sun.

- Their solution was to
build a kind of awning,

a retractable roof
over the Coliseum,

made from canvas taken from
similar designs to ships sails.

- [Narrator] Known
as the velarium,

this enormous
retractable canvas awning

would be a welcome feature

to many state-of-the-art
sports stadiums even today.

And recent research has
provided a good idea

of what it must have been like.

- We know from marks
and holes in the masonry

right up at the top,

that there were places for
huge wooden spars to jut out.

And it was across those, using
a complex system of rigging,

that these sails were spread,

providing shade
for everyone below.

- [Narrator] But
raising the velarium

was a complicated procedure

and demanded a team of
specialist operators.

- It's been estimated
that these sails

weigh as much as 24 tons.

That was an extraordinary
feat of power and teamwork

to get these hoisted
and to get them set.

And it made perfect sense
that the only people

qualified to manipulate this
huge awning were sailors.

- [Narrator] More than a
thousand experienced sailors

were drafted in from
the Roman fleets,

stationed in barracks around
the corner from the Coliseum.

- They know how to pull on ropes

and handle canvas in the wind.

Crucially, they can also respond

to orders over a
distance, right?

They'd be very reliable,
disciplined body of men

to get this very
complicated, quite fragile,

piece of heavy engineering
up into the air.

- [Narrator] The velarium
was an incredible

piece of engineering.

Not only protecting
the audience members,

but also enhancing the
spectacle on the arena below.

- The velarium extended
its sail-like canopies

into the area of the Coliseum,

but it didn't cover
the whole area.

It left an open
oval in the middle.

- So you can imagine this
big gap in the middle

with the natural
sunlight coming through

acting like a spotlight
onto all the things

which were happening
in the arena.

- [Narrator] A phenomenal
ancient achievement,

no one would surpass the
Coliseum's retractable roof

for almost 2,000 years.

(suspenseful music)

Then, in 1989,
construction finished

on the Rogers Center
in Toronto, Canada,

a 52,000 seat stadium

with a feature unlike
anything seen before.

- The Rogers Center in Toronto

is really a spectacular example

of what is possible
in engineering.

This stadium had the first
fully retractable roof.

- [Narrator] Covering an area
of around 340,000 square feet,

the roof is made of four
massive steel panels

and weighs a total of
more than 9,800 tons.

One panel is fixed

and the other three slide
on a system of steel tracks.

- You might think
retracting the roof off

to be quite a long operation
taking hours and hours.

Well, it only takes 20 minutes.

And that's the power of
some innovative engineering.

- [Narrator] Driven by more
than 70 10-horsepower motors,

the roof panels slide
at a whopping rate

of 71 feet per minute.

Impressive engineering
used to create

the world's first
fully retractable roof.

With its scale and
impeccable design,

the Coliseum was the envy
of the ancient world.

Then several years
after its grand opening,

Emperor Titus's younger
brother, Domitian,

decided to improve the
amphitheater further.

- The Romans were always
on a constant quest

to improve whatever
they created.

And that certainly
applied to the Coliseum.

- [Narrator] It was
completely remodeled

with one of the most
significant changes

made away from the
view of the spectators.

- They invent
effectively an undercroft

underneath the
floor of the arena,

where there were
designed sets and stages.

- [Narrator] An
underground complex

on a scale, never
seen before in Rome:

the Hypogeum.

This subterranean labyrinth
worked as a backstage area,

allowing the games to be mounted
on an even grander scale.

- The Hypogeum allowed people
to be moved very quickly

to different parts of the
floor of the Coliseum,

by means of tunnels and
trap doors and such things.

You could see it as a
kind of backstage area.

The kind of thing that a
modern theater might depend on.

- [Narrator] As the
crowds begged for blood,

hundreds of gladiators
took their positions,

blacksmiths prepared weapons,

and arena slaves hurried
to keep the show moving

on the sands above.

- It would've taken
an actual army

of people behind the scenes.

It would've been
quite miserable. It
would've been dark.

It would've been hot.
It would've been smelly.

- [Narrator] And it
wasn't just people

that inhabited this
torch-lit underworld.

The Hypogeum was also home to
hundreds of exotic animals,

imported from all over the
empire to be killed for sport.

Most were kept in sturdy pens,

but transporting them
up to the arena above

would require an
engineering innovation.

- How do you get
extremely heavy animals

up to the floor of the Coliseum?

- [Narrator] Deep under the
arena there are patterns, holes,

and grooves in the walls,

clues to curious machinery

housed in the
Coliseum's underworld.

- One of the most
interesting design features

of the Hypogeum was
a number of lifts,

which were used to hoist
up animals and props,

whatever it might be, up
onto the stadium floor.

- [Narrator] Some of the
earliest examples of lifts

seen in the ancient world.

- You can see in
those Coliseum lifts,

the beginnings are
something that one day

would be parallel to
our passenger lifts.

- [Narrator] dotted
throughout the Hypogeum,

there is evidence of as many
as 28 ancient lift systems,

where beast handlers
herded animals into them

before being cranked
up to the arena.

Each lift is thought
to have had cap stands

with four rotating arms

that would've been used to
lift up to 600 pounds each,

all the way to the arena
floor, 23 feet above.

- Having all of these
lifts at their disposal

meant that they could put on

the most extraordinary
spectacular shows.

Just imagine the impact
of dozens of lions

suddenly appearing
out of nowhere.

(crowd cheering)
(lions roaring)

- [Narrator] But even
with hundreds of laborers

working away,
lifting these weights

would still have been
extremely strenuous.

Either the lift operators
or ropes themselves

would eventually
reach breaking point.

The Roman engineers
had to find a way

to keep the show
running smoothly.

- These primitive lift systems
that very likely relied on

a simple engineering innovation
that we still use today,

the pulley, the reason
why it's so effective

is because it massively
reduces the amount of force,

the work you need to
do to lift a load.

- [Narrator] Adding a pulley
splits the weight evenly

between the two
sides of the rope.

And another pulley changes
the direction of the force.

Easier to pull down than up.

With one pulley
attached to the cage,

it feels half the weight.

Attaching two
pulleys to the cage

makes it feel like a
quarter of the weight.

- The more pulls you have,
the more effective that is,

and the less kind of muscular
human effort is required.

- [Narrator] With these
ancient lift systems in place

men and beasts could emerge

all onto the
Coliseum arena floor.

The spectacle seen by
the screaming crowds

was now more impressive
than ever before.

- There's that
element of mystery,

not knowing what's
coming up from that lift.

So there's also that sense of
the additional entertainment.

- You could just imagine
the energy in that stadium

with the number
of people in there

and watching the drama unfold
right before your eyes.

It would've been an incredible
thing to experience.

- [Narrator] Unforgettable
gladiator battles,

with men and beasts
appearing as if from nowhere.

This was the Coliseum
in all its glory.

The backstage lifts
operating in the Coliseum

set the foundation
for the development

of modern stage technology,

raising the possibilities of
arena and stage production.

But these brilliant contraptions

go far beyond enhancing
entertainment in
the modern world.

Now ubiquitous throughout
modern industry,

lift systems have
also transformed

urban architecture
and landscapes.

- Without lifts we wouldn't
have the high rise buildings

that we rely on in cities.

Lifts are a critical part
of engineering today,

and they have been for years.

- They move millions of people

and millions of tons
of goods all the time.

And we'd struggle to
operate without lifts.

- [Narrator] Continuing to
carry further and faster

than ever before.

Today, one of the
world's fastest elevators

is installed in the
128-story Shanghai Tower,

the second tallest
building in the world.

It rises almost
1,800 feet vertically

through the skyscraper,

traveling at a speed
of 46 miles per hour,

nearly twice as
fast as Usain Bolt.

- Very few people would realize

that almost 2,000
years beforehand,

the Romans had settled on
essentially the same technology,

even if it was fit for a
very different purpose.

- The possibilities of
what engineers will create

in the future around lift
systems is just never ending.

There will always be new heights

that engineers will take us to.

- [Narrator] Ancient
engineering brilliance

that helps keep the
world running smoothly.

Stadiums have come a long way
from their humble origins,

with the ancient
Greeks and Romans

recognized as the
true stadium pioneers.

Many of their ideas
and techniques are
still utilized today

in some form or another.

Found in designs far
larger and more ambitious

than those that came before.

As humans continually
strive to create

an engineering wonder as
symbolic as the Coliseum,

one of the ancient
world's grandest

and most spectacular
engineering achievements.

(dramatic music)