Ancient Impossible (2014) s01e08 Episode Script
Biggest Builds
How could the ancients build colossal structures in less time than we can construct the biggest buildings of today? How could the ancient Egyptians produce thousands of chariots with assembly line precision? Why did the Romans create a massive underground industrial hell where thousands of slaves never saw the light of day? Monuments more colossal than our own, ancient super weapons as mighty as today's, technology so precise, it defies reinvention.
The ancient world was not primitive.
Their marvels are so advanced, we still use them now.
Travel to a world closer than we imagine, an ancient age where nothing was impossible.
The biggest builds of today are the result of mammoth engineering projects, huge structures that define the modern era.
But who were the greatest engineers of all time? Could there have been building projects just as impressive in ancient times? The Romans were not only the biggest and strongest power of the ancient world, but they were also the most technologically advanced.
They made amazing buildings and military machines.
They were so ahead of their time, that it's only recently that modern engineers have been able to replicate their techniques.
And one of the Romans' most incredible discoveries? Concrete.
It's only in the last 100 years or so that concrete has come to play such a large part in our architecture.
But it's actually a rediscovery.
Amazingly, the Romans were using it for their biggest builds over 2,000 years ago.
The science of concrete was perfected by the Romans thousands of years ago.
And when the Roman civilization fell, that science was lost.
And the most amazing example of this Roman engineering miracle is to be found here, at Caesarea, on the coast of present-day Israel.
Unbelievably, they built a huge harbor made of concrete, and it was one of the biggest artificial ports in the ancient world.
Imagine how our cities and ports might have developed if this knowledge hadn't been lost.
It was another 2,000 years before mankind could replicate this technology.
When the technology was rediscovered, it essentially shaped the modern world.
Everything around us relies upon the presence of concrete.
But what's so special about concrete? It can be shaped and molded.
With concrete, the Romans could make arches, vaults and domes.
This was revolutionary.
If you imagine times before concrete, you're relatively limited to what it was you could dream up, but then the minute that you could create these manmade stones in essentially any shape you wanted, architects were they were free to dream.
They were liberated, and they did dream.
And at Caesarea, they dreamt the impossible using concrete underwater.
This was something extraordinary.
In modern times, underwater concrete has only been used for about 150 years.
But the Romans were using it 2,000 years ago.
This sounds impossible, but here at Caesarea, the Romans made the impossible possible.
I'm standing amidst the ruins of the impressive artificial harbor in Caesarea.
This would have been an incredible sight in the ancient world.
The harbor was certainly an engineering marvel, over a million cubic feet of concrete embedded in the sea.
Just the thought of building a manmade harbor was a sign of the audacity of the Romans, and then the decision to use concrete was even more astonishing.
And the man behind it? Herod, the Roman's puppet king of Judea.
He's often thought of as an evil tyrant.
But because he was in league with the Romans, he was able to commission some of the greatest megabuilds.
King Herod needed a large harbor.
There were no natural places to anchor ships.
He decided to build one from scratch.
The harbor itself was unbelievably huge, big.
Nobody could see such a big structure worldwide.
It was the largest structure on earth at the time.
90,000 square yards that's a huge area.
The port extends on either side of where I'm standing to the south over 1,500 feet long.
On the northern side, about 1,000 feet long.
You have to think of about 40 acres or 30 football fields are comprised within the two arms projecting forward.
He created water-breaks that was 180 feet wide, huge you could have a highway on top of it.
It extended deeply to the sea almost half a mile into the sea.
Herod wanted to build a huge harbor to rival any in the world, and that's despite the lack of a good natural harbor at this site.
This was because he wanted his province of Judea to be the main trading route for east to west.
His incredible harbor could accommodate 300 ships.
It dwarfed anything found here before or since.
See part of the modern port over here.
The actual breakwater of the port of Caesarea is underneath, and it's sunken down about 5 meters beneath the surface.
But it extended twice the length out into the sea.
The concrete harbor was so impressive that king Herod built a new palace for himself on the waterfront.
And the port became the catalyst for a great, trading city and a new capital for Judea.
This port was a commercial center, a hub.
There's a massive market in the Western half of the mediterranean.
The Roman senators, they want the goods from the middle east and from the orient.
This became one of the key harbors that brought those goods from east to west.
But how did the Romans build this harbor? What was the magic ingredient that they used to make the concrete set? And how did they lay concrete underwater? It's only recently that we have uncovered the truth.
At this concrete factory in Austin, Texas, they have the ingredients prepared.
There are seven ingredients in marine mix concrete quicklime, clay, seawater, sand, fly-ash, large aggregates, and animal blood, in this case, pig blood.
One theory is that blood was used to strengthen the mixture.
But the key to underwater setting lay elsewhere.
They'd developed a kind of mortar that had extraordinarily good lime in it, and that made it strong to begin with, but the real key is the chemical reaction that happened when they added pozzolana sand to their mortar.
This special kind of sand came from volcanic ash.
It made the concrete so durable, it could harden underwater.
Luckily, thanks to mount vesuvius in Italy, the Romans could find this sand in abundance.
The fact that mount vesuvius was over 1,200 miles away wasn't going to stop them.
So they have to ship over this volcanic sand in enormous amounts.
We're talking about 44 ships with a 400-ton capacity.
Without that, this artificial harbor could not have been built.
So it's something that the Romans develop and perfect, and it allows them to pour this and have it harden in the saltwater.
Marine concrete hasn't been made in this way since Roman times.
Is it possible that it can be re-created today? We work with concrete all the time.
We're going to try today to re-create ancient marine concrete like used at the ancient harbor of Caesarea.
For the Romans to discover 2,000 years ago that volcanic ash would have this effect was an enormous technological leap.
And this was done on an industrial scale.
Hundreds of slaves would have been used to carry, mix and pour the materials.
It must have been a massive operation.
This ancient concrete mix is going underwater.
It will be ready for testing in 30 days.
We're going to find out if this ancient concrete recipe really works.
The ancient empires of the mediterranean depended on sea power for military dominance and for trade.
The Romans were no different.
In fact, they always took things to another level.
They had to have the best ships, the best crews, and to go with them, the greatest, most up-to-date ports.
It's not so different today.
The major cities of the world are ports.
90% of all the world's trade is still transported by sea.
In ancient times, great cities such as carthage and Alexandria grew up around their ports.
But the Romans were able to do what for everyone else was impossible.
They could build a port like no other.
It was built bigger, and it was built to last.
And at Caesarea today, the massive 2,000-year-old concrete jetties can still be seen just under the water.
As a diver, what you see just below the surface of the water is huge constructions.
The poured concrete is intact, and as you swim along you'll see actual the imprints of the wooden framework into which the concrete was poured.
This is remarkable.
This concrete is 2,000 years old, and it's still intact on the seabed.
How did the Romans lay this concrete underwater? It's an engineering marvel.
Specially made wooden barges were partly filled with concrete and floated into position, then anchored.
More concrete was then poured in.
So you set those up, you pour in the concrete, and as it settles and hardens and solidifies you can sink it down to the bottom where it would harden and be able to withstand the force of the sea, and they're gonna build these in sections.
It's just a massive enterprise.
This process, repeated again and again, eventually led to the massive concrete jetties rising from the sea.
And the giant jetties would probably still be in use today if they hadn't been built on a seismic fault.
Over the years, earthquakes have taken their toll.
Still, the concrete has survived.
Modern concrete routinely shows signs of degradation after just 50 years.
The strength of concrete can be tested.
And at this engineering company in Austin, Texas, they have a special machine to do just that.
Basically what we do is we put a concrete cylinder in the press and apply a load, and see how much compressive force it can take.
New concrete like this holds out well.
If they had a similar cylinder of Roman concrete, they could precisely measure its strength.
In the nearby concrete factory, a mix of Roman concrete has been left to harden.
And now, the time has come.
How has the special Roman mix of underwater concrete fared? Well, to me this is amazing.
This block of marine mix concrete actually formed.
I didn't think it was going to form like this.
And you know, the crazy thing about this is that this concrete gets stronger over time, and this has only been 30 days' hardening.
This is ancient technology at work underwater concrete 2,000 years ahead of its time.
It's impossible to believe that this marine mix concrete sat underwater and hardened.
It's as hard as modern concrete.
But exactly how hard is it? How does Roman marine concrete hold up to modern testing? For the first time, the engineering workshop has a sample and will test the pressure it can withstand in psi, pounds per square inch.
That technology is a couple thousand years old, and I'd be surprised if it got up to 200 or 300 psi.
Soon it becomes clear that after just 30 days' setting, the Roman mix concrete is bearing up remarkably well.
Anything beyond 300 psi would be astonishing.
This came in at nearly 400 psi.
For an ancient technology, that's incredible.
With every week, the concrete will get stronger and stronger.
This concrete mix was 2,000 years ahead of its time.
And that's without all the modern machinery used in the industry today.
We're making modern concrete right behind me now.
It's impossible to think that all of this modern equipment is needed to replicate what the ancient Romans were doing 2,000 years ago.
Many of the biggest builds of the modern world are factories and places of industry.
Even food, which used to be made in the home, is now produced on an industrial scale.
In ancient times, could they have had factories like this? Surely impossible.
But these strange ruins on a hillside in Southern France have a remarkable story to tell.
For years, they were a puzzle.
But now history is being rewritten.
We normally think that it was the industrial revolution that gave us the modern idea of factories, and before that, we had cottage industries.
However, we've now got to rewrite our understanding.
The mysterious ruins are at barbegal, near the town of arles.
And the clue to what went on here lies above, beyond the hillside.
Here we find something spectacular.
We're in Southern France at barbegal, and this is a Roman aqueduct.
But it's unlike any Roman aqueduct you've seen before.
What makes this so special is how it was put to use.
The water from this aqueduct served a very special purpose.
What's so significant about this site is that there were 16 mills powered by water, right along this hillside.
A huge series of waterwheels.
This is something that's totally extraordinary.
We haven't seen the like until today with modern hydro-electric systems.
This is a huge undertaking.
They actually turn a natural hillside into a vast watermill system.
This is a really massive mechanical operation, and it worked.
The Romans didn't invent the watermill.
The ancient greeks were the first to use them.
But nothing like barbegal had ever been built before.
Together, these waterwheels comprised one of the biggest builds of the ancient world, a waterwheel super factory in the 2nd century A.
D.
Which has never been matched since.
And that's despite waterwheels remaining in use for another 2,000 years.
It wasn't until the age of steam that the mechanics of waterwheels were surpassed.
But not only was barbegal massive, it was also highly efficient.
It was much more advanced than any waterwheel technology that followed it.
Many waterwheels, like this 17th century mill at hereford in england, are powered by water hitting the bottom or middle of the wheel.
If we had a higher drop what we'd do is we'd be bringing the water in over the top and have an overshot wheel so the water fills all the buckets and turns it around-- more efficient, but you need to have that bigger drop of water.
Without a steep incline, a stream can still power a waterwheel.
But at barbegal the Romans made use of the high drop.
The water pouring down onto the wheels -- 66 gallons per second-- made each of these wheels two and a half times more efficient.
But it's not just the mills here that were an engineering marvel.
Getting the water to them was a seemingly impossible task.
Between the aqueduct and the mills was the top of the hill.
What the Romans do is they actually physically cut a channel into the top of the hillside so the water can be fed through, and then it can hit the top of the mill with absolute force and then charge down 65 feet to the bottom, creating a huge amount of force and momentum.
The massive cutting was made through solid rock.
And it shows the incredible ambition of the Romans.
For them, when it came to building, no obstacle was too big.
What's really impossible, just think about barbegal.
Somebody had the vision to say we'll capture water six miles away, build an aqueduct, stick it through a mountain, and then we'll build a whole set of steps of water wheels to harness all that energy, 16 water mills all stacked up.
The scale was immense.
This was able to put out about 4,5 tons of flour every day.
But what was all this flour for? Today's mega-bakeries use machinery on an industrial scale to produce vast amounts of bread for our towns and cities.
Why at barbegal was the huge milling complex needed? We know there were at least 12,500 people living in arles and then some more military on top of that.
It looks like the wheels at barbegal produced enough bread to feed the entire population.
Keeping people fed was all a part of the Romans' grand plan.
Military might alone doesn't hold an empire together.
Very interestingly, there is no point in having an empire if your people are either subversive or starving.
So of course the way to keep them on side is to keep them well-fed.
During barbegal's peak years, the vast Roman empire was growing at a breakneck pace, bringing people together into urban centers, keeping them under control, civilizing them, it was all part of how the empire worked.
A city could be fed.
The people were then free to work, to make goods.
Goods equals wealth.
Wealth equals power.
A waterwheel? The power of the Roman empire.
But the empire didn't go on growing forever.
One theory as to why the Roman empire eventually declined is that it had so much slave labor, there was no incentive to embrace new technology.
Barbegal is important because it shows the opposite.
It's a water-powered factory.
I think when people learn about barbegal, they're always shocked and amazed.
Today we think about factories, we think about industrialization, we think about modern times.
But here the Romans are showing us what they were able to achieve on a grand scale, on an industrialized scale, 2,000 years ago.
I think it's rightly earned the reputation as being the greatest concentration of mechanical power in the ancient world.
It's phenomenal! Remarkably, this hugely important archaeological site has only really been fully understood in the last few decades.
And it's been a revelation.
Before this, no one imagined such a place could exist.
Is it possible there could be other sites like this which have yet to be discovered? The barbegal mills are a real success story.
As a historian and archaeologist, you're constantly thinking maybe, just maybe there's another example like this that is just waiting to be found.
And what's really interesting about them is that, in a way, this is the industrial revolution 16 centuries before the industrial revolution officially happens.
Throughout the centuries, warfare has driven technology.
Great scientific breakthroughs have been made in our quest for new means of destruction.
Defense is a huge industry, and is responsible for some of our biggest builds.
But could there have been an ancient military factory as big as those of today? This is the joint systems manufacturing center in Lima, Ohio.
It's the home of the Abrams tank, 70 tons of imposing military might.
All tanks for the U.
S.
army are built here.
During world war ii, it mass- produced tanks at a phenomenal rate.
Victory in Europe depended on it.
It's still one massive factory with a highly skilled workforce.
It's great knowing that you're building the best product in the world and soldiers are safe, one of the best-built tanks in the world.
This is the first time that I've been on a tank, and I have to say it's a real thrill.
I mean, up here you really get a most incredibly commanding view.
I'm a cavalry man at heart, and it's very much like being on a horse.
In many ways, the tank is the modern equivalent of an ancient fighting chariot, a mobile, state-of-the-art fighting force.
But it's also a command center, just like chariots were, mobile platforms for artillery on the battlefield.
It's not infrequently said, and I've often said it myself, that the chariot is the ancient tank.
What it does is provide mobility.
The fighting chariots of the ancient Egyptians were the meanest machines on the battlefield.
But were they factory-made, like the tanks at Lima? It's almost impossible to believe, but over 3,000 years ago, the great pharaoh ramses ii had his own huge factory for the state-run production of these fighting machines.
We have evidence of ramses' chariot factory both archaeologically and in tomb paintings, and what we can tell is it was on a massive scale-- state mass production, just like this tank factory.
Ramses demanded chariots, masses of chariots.
They were needed for a battle, a big battle, the battle of Kadesh, the greatest chariot battle that the world has ever seen.
In 1274 bc, Kadesh was the culmination of the incredible mass production of chariots under ramses ii.
And it was here, in the desert of modern-day Syria, that the Egyptian army clashed with the other superpower of the day, the hittites.
With thousands of chariots on each side, this was chariot warfare on an unprecedented and massive scale.
That's an awful lot of chariots on the field, and you imagine them swirling around in the dust.
It's a thick dust storm, and it's a real dogfight as they're all trying to outmaneuver each other, and the archers to pick off their opponents.
But how could so many chariots have been made? And where? The factory that produced the Egyptian chariots must have been massive, big enough to supply the huge numbers of chariots needed for the war with the hittites.
And a possible site has been identified at pi-ramesse in the nile delta.
What we have is stables for something like 480 horses, which means 240 chariots.
We have a training ground, and we have a place which is said by some people to be a chariot factory.
The site on the nile has yet to be fully excavated.
But one thing we know for sure is that, remarkably, the factory used an assembly line, just like the tank factory at Lima.
So here we are at the assembly line, and you can see tank after tank after tank stretching back there.
You're taking pre-formed pieces, and you're bringing them to an assembly plant, and skilled workers are putting things together.
It is almost impossible to imagine that over 3,000 years ago the manufacturing processes, the systems for making military hardware would be the same as they are in the 21st century, but they were.
It was the same principle-- assembly line factory work.
Henry Ford is known as the creator of the production line in the 20th century, but 3,000 years ago, impossible to believe, the Egyptians did the same-- an assembly line that churns out relentlessly chariot after chariot after chariot.
On the floor of the tank factory, the individual components come together.
They're state-of-the-art and made by specialist teams.
It was just the same in the chariot factory.
First, the body of the chariot-- lightweight wood curved into shape by steaming it, just big enough for two standing men.
The undercarriage was a fixed axle and a central pole made by one artificially bent piece of wood.
Quite a large wheelbase directly beneath the body to keep the chariot stable.
The frame for the horses is also made of bent wood, and it attaches to the end of the pole.
You can't have a chariot without wheels.
One quick assembly.
A deadly, mobile fighting machine.
The Egyptians understood the importance of using the perfect materials, and imported wood especially, in particular, ash.
Even today, one specialty builder of sports cars in england still uses ash just as the ancient Egyptians did.
This is the Morgan car factory, where skilled craftsmen have been assembling cars in this way for over 100 years.
Ash of course would be ideal for a combat vehicle, a chariot, for the same reasons that we use it-- it's not only extremely strong, it's lightweight.
The lighter you could make a structure like that, the easier the horses could pull it, the more flexible it would be and a more effective fighting machine.
Being flexible, it can act as a shock absorber.
It's the same with us here in Morgan.
The frame will flex and bend with the chassis, and this all adds to the road-holding and the handling of the cars.
The factory here makes around 100 cars a month, handcrafted with skill and precision.
Ramses ii needed chariots in their thousands.
The fact that his chariots could be mass-produced was in itself a source of wonder and terror for his enemies.
Ramses' systems were so advanced, so efficient in producing the great numbers of military vehicles that he needed.
It's almost impossible to conceive that factories of this scale existed 3,000 years ago, but they did.
Some of the most iconic buildings ever constructed are huge cathedrals such as notre dame in Paris and st Paul's in London.
But incredibly, one of the biggest builds in history is a cathedral from ancient times.
In 6th-century constantinople, when the magnificent cathedral of hagia Sophia rose from the ground, it was as if the impossible had happened.
This is the hagia Sophia.
It is one of the most impressive architectural constructions in the world.
It exerted an influence for 1,000 years after its construction.
"Hagia Sophia" means "holy or divine wisdom" in turkish, and the building is the supreme masterpiece of byzantine architecture, and for almost 1,000 years, it was the biggest cathedral in the whole world.
Still standing after 1,500 years, with minarets added at a later date, this was an incredible build, with techniques centuries ahead of its time, a Roman Christian cathedral that was a revolution in architecture.
This is such an amazing space.
You've got something that's intact, something that's constructed in the 6th century A.
D.
, and the thing is, it's just hard to get a sense of how massive this space is because there's so many openings, there's so much light.
It's almost impossible to imagine what people thought of it when they first saw it.
They must have thought that they were looking at something impossible.
They wouldn't have understood how it stayed upright.
A lot of people thought that god himself was holding the building.
That's how special it was.
And this was exactly the intention.
The man behind it, the emperor Justinian, needed to assert his political power.
To do this, he wanted to be linked with god in the most visible way.
He wanted it to represent not only his greatness on earth, but god's greatness in heaven, and to draw that link for people to say, "I am god's representative on earth.
" In the 6th century, the Roman empire was based in constantinople, modern-day Istanbul.
But the empire was fading.
Justinian knew that if he didn't make his mark in some grand way, he would be just a footnote in history.
He wanted to be great.
He was determined that as well as being something massive, his cathedral was going to be something completely new.
So he didn't go to the master builders of his age.
He went to mathematicians.
He depends upon these experts of math and geometry and science to go in a new direction, to create something that no one had ever seen before.
To understand it, we need to start with the dome.
The dome is the most impossible achievement.
It's 102 feet across and 180 feet high.
It's huge.
It's broader than the dome of the capitol building, and that was built 1,300 years later.
But the most amazing thing is that the dome doesn't seem to be resting on anything solid.
Essentially you have this massive dome, which seems to just rest lightly on these 40 windows so it's something that's ethereal, almost light about it.
And for a dome to be built on a square base rather than a round one was something completely new.
For the Romans to achieve this was truly remarkable.
These four piers are essentially building supports, and in the hagia Sophia, they're huge.
They were built to support the dome.
Well, four arches were built on top of the columns.
Then, the spaces in between were filled with masonry.
They fill in the upper corners of the space and so form a circular support for the dome.
This was a giant leap in architecture.
It must have been incredible then, because today it still looks awe-inspiring.
Hagia Sophia is huge, about 65,000 square feet, but the speed of its building was impossible, too.
Normally, cathedrals took decades to build.
The construction of notre dame hundreds of years later took over a century.
And just the dome of the capitol building took 11 years.
This is a large structure that's built in a mere five years.
That is incredible.
To give a modern comparison, the Burj Khalifa in Dubai, which is the tallest building in the whole world, took six years, and that's with all the modern technology that we now have.
That is a tribute to Justinian's vision to make this engineering miracle happen.
Some of the biggest builds of the ancient world were factories and places of industry.
And, just like today, some of the most impressive of these were built because of our insatiable desire for precious metal.
The Romans' need for copper and silver brought them here, to rio tinto in Spain.
And for 2,000 years, the mine held a dark secret deep beneath the surface.
This is the Rio Tinto mine in the heart of andalucia in Southern Spain.
It's absolutely vast, almost 20 square miles.
The first people to start exploiting metals in these hills were over 5,000 years ago.
In Roman hands, this mine became the single greatest mining complex in the whole of the ancient world.
And it was here, in 1919, that an astonishing discovery was made a huge wooden wheel buried deep in the ground.
Further investigation revealed that it was almost 2,000 years old.
But what was it for? The answer is almost impossible to believe.
A clue was found here, at a gold mine in Dolaucothi in Southern wales-- a similar wheel and well- preserved enough for a scaled-down replica to be made.
Remains of that wheel were found 150 foot down, so far down that it's reasonable to expect that more than one wheel were used.
And this is a replica of what one of those wheels may have looked like.
It became clear that the wheel was used to lift water to prevent the mine from flooding.
Water from the bottom was scooped up and then fell out at the top into a channel that drained it away.
And someone must have stood deep underground turning the wheel.
What a horrendous job.
A human hamster in near pitch- black conditions.
The Romans were masters of waterwheel technology, but with a waterwheel, normally moving water turns the wheel.
At both Dolaucothi and at Rio Tinto, what the Romans did was turn that concept on its head.
They used manpower to turn the wheels, and then the wheels moved the water.
Move the water, drain the mine, miners work.
Genius.
But could a large wooden wheel really have been any use here at Rio Tinto? This mine is massive, and the Roman shafts went deep into the earth.
We now know that at Rio Tinto, the use of these wheels was taken to impossible extremes-- underground caverns, carved by hand from the earth, and inside? Eight pairs of huge waterwheels powered by slaves, walking the wheels.
To a modern engineer it would seem incredible.
To the ancients, it must have seemed impossible.
But it was an impossible task that the Romans faced and mastered.
This was ancient engineering on a massive scale, and it made the impossible possible.
The wheels were probably prefabricated and constructed within the mine.
Building a whole series of these huge waterwheels underground is almost beyond belief.
Today it would be incredible.
2,000 years ago, simply impossible.
As the slaves trod the wheels, the water was channeled from one pair to the other, eventually rising over 100 feet before being drawn to the surface by a huge Archimedes screw.
This wasn't hell on earth.
It was hell deep within the earth, dark, hot and working with toxic, mineral-soaked water.
The slaves who operated these waterwheels had the worst job in the whole mine.
Their life expectancy once they got down here was about 12 to 16 months.
It was that poisonous, and they were constantly coated in the water.
And when they finally died, which they inevitably did, the Romans didn't even bother taking their bodies to the surface.
But whatever the terror of the wheels, they were truly an ancient wonder, an incredible, fantastic construction.
Unbelievable structures built with techniques thousands of years ahead of their time, the biggest builds of the ancient world were as astonishing and awe-inspiring as anything built today, a world of wonder, of terror, and of the impossible made real.
The ancient world was not primitive.
Their marvels are so advanced, we still use them now.
Travel to a world closer than we imagine, an ancient age where nothing was impossible.
The biggest builds of today are the result of mammoth engineering projects, huge structures that define the modern era.
But who were the greatest engineers of all time? Could there have been building projects just as impressive in ancient times? The Romans were not only the biggest and strongest power of the ancient world, but they were also the most technologically advanced.
They made amazing buildings and military machines.
They were so ahead of their time, that it's only recently that modern engineers have been able to replicate their techniques.
And one of the Romans' most incredible discoveries? Concrete.
It's only in the last 100 years or so that concrete has come to play such a large part in our architecture.
But it's actually a rediscovery.
Amazingly, the Romans were using it for their biggest builds over 2,000 years ago.
The science of concrete was perfected by the Romans thousands of years ago.
And when the Roman civilization fell, that science was lost.
And the most amazing example of this Roman engineering miracle is to be found here, at Caesarea, on the coast of present-day Israel.
Unbelievably, they built a huge harbor made of concrete, and it was one of the biggest artificial ports in the ancient world.
Imagine how our cities and ports might have developed if this knowledge hadn't been lost.
It was another 2,000 years before mankind could replicate this technology.
When the technology was rediscovered, it essentially shaped the modern world.
Everything around us relies upon the presence of concrete.
But what's so special about concrete? It can be shaped and molded.
With concrete, the Romans could make arches, vaults and domes.
This was revolutionary.
If you imagine times before concrete, you're relatively limited to what it was you could dream up, but then the minute that you could create these manmade stones in essentially any shape you wanted, architects were they were free to dream.
They were liberated, and they did dream.
And at Caesarea, they dreamt the impossible using concrete underwater.
This was something extraordinary.
In modern times, underwater concrete has only been used for about 150 years.
But the Romans were using it 2,000 years ago.
This sounds impossible, but here at Caesarea, the Romans made the impossible possible.
I'm standing amidst the ruins of the impressive artificial harbor in Caesarea.
This would have been an incredible sight in the ancient world.
The harbor was certainly an engineering marvel, over a million cubic feet of concrete embedded in the sea.
Just the thought of building a manmade harbor was a sign of the audacity of the Romans, and then the decision to use concrete was even more astonishing.
And the man behind it? Herod, the Roman's puppet king of Judea.
He's often thought of as an evil tyrant.
But because he was in league with the Romans, he was able to commission some of the greatest megabuilds.
King Herod needed a large harbor.
There were no natural places to anchor ships.
He decided to build one from scratch.
The harbor itself was unbelievably huge, big.
Nobody could see such a big structure worldwide.
It was the largest structure on earth at the time.
90,000 square yards that's a huge area.
The port extends on either side of where I'm standing to the south over 1,500 feet long.
On the northern side, about 1,000 feet long.
You have to think of about 40 acres or 30 football fields are comprised within the two arms projecting forward.
He created water-breaks that was 180 feet wide, huge you could have a highway on top of it.
It extended deeply to the sea almost half a mile into the sea.
Herod wanted to build a huge harbor to rival any in the world, and that's despite the lack of a good natural harbor at this site.
This was because he wanted his province of Judea to be the main trading route for east to west.
His incredible harbor could accommodate 300 ships.
It dwarfed anything found here before or since.
See part of the modern port over here.
The actual breakwater of the port of Caesarea is underneath, and it's sunken down about 5 meters beneath the surface.
But it extended twice the length out into the sea.
The concrete harbor was so impressive that king Herod built a new palace for himself on the waterfront.
And the port became the catalyst for a great, trading city and a new capital for Judea.
This port was a commercial center, a hub.
There's a massive market in the Western half of the mediterranean.
The Roman senators, they want the goods from the middle east and from the orient.
This became one of the key harbors that brought those goods from east to west.
But how did the Romans build this harbor? What was the magic ingredient that they used to make the concrete set? And how did they lay concrete underwater? It's only recently that we have uncovered the truth.
At this concrete factory in Austin, Texas, they have the ingredients prepared.
There are seven ingredients in marine mix concrete quicklime, clay, seawater, sand, fly-ash, large aggregates, and animal blood, in this case, pig blood.
One theory is that blood was used to strengthen the mixture.
But the key to underwater setting lay elsewhere.
They'd developed a kind of mortar that had extraordinarily good lime in it, and that made it strong to begin with, but the real key is the chemical reaction that happened when they added pozzolana sand to their mortar.
This special kind of sand came from volcanic ash.
It made the concrete so durable, it could harden underwater.
Luckily, thanks to mount vesuvius in Italy, the Romans could find this sand in abundance.
The fact that mount vesuvius was over 1,200 miles away wasn't going to stop them.
So they have to ship over this volcanic sand in enormous amounts.
We're talking about 44 ships with a 400-ton capacity.
Without that, this artificial harbor could not have been built.
So it's something that the Romans develop and perfect, and it allows them to pour this and have it harden in the saltwater.
Marine concrete hasn't been made in this way since Roman times.
Is it possible that it can be re-created today? We work with concrete all the time.
We're going to try today to re-create ancient marine concrete like used at the ancient harbor of Caesarea.
For the Romans to discover 2,000 years ago that volcanic ash would have this effect was an enormous technological leap.
And this was done on an industrial scale.
Hundreds of slaves would have been used to carry, mix and pour the materials.
It must have been a massive operation.
This ancient concrete mix is going underwater.
It will be ready for testing in 30 days.
We're going to find out if this ancient concrete recipe really works.
The ancient empires of the mediterranean depended on sea power for military dominance and for trade.
The Romans were no different.
In fact, they always took things to another level.
They had to have the best ships, the best crews, and to go with them, the greatest, most up-to-date ports.
It's not so different today.
The major cities of the world are ports.
90% of all the world's trade is still transported by sea.
In ancient times, great cities such as carthage and Alexandria grew up around their ports.
But the Romans were able to do what for everyone else was impossible.
They could build a port like no other.
It was built bigger, and it was built to last.
And at Caesarea today, the massive 2,000-year-old concrete jetties can still be seen just under the water.
As a diver, what you see just below the surface of the water is huge constructions.
The poured concrete is intact, and as you swim along you'll see actual the imprints of the wooden framework into which the concrete was poured.
This is remarkable.
This concrete is 2,000 years old, and it's still intact on the seabed.
How did the Romans lay this concrete underwater? It's an engineering marvel.
Specially made wooden barges were partly filled with concrete and floated into position, then anchored.
More concrete was then poured in.
So you set those up, you pour in the concrete, and as it settles and hardens and solidifies you can sink it down to the bottom where it would harden and be able to withstand the force of the sea, and they're gonna build these in sections.
It's just a massive enterprise.
This process, repeated again and again, eventually led to the massive concrete jetties rising from the sea.
And the giant jetties would probably still be in use today if they hadn't been built on a seismic fault.
Over the years, earthquakes have taken their toll.
Still, the concrete has survived.
Modern concrete routinely shows signs of degradation after just 50 years.
The strength of concrete can be tested.
And at this engineering company in Austin, Texas, they have a special machine to do just that.
Basically what we do is we put a concrete cylinder in the press and apply a load, and see how much compressive force it can take.
New concrete like this holds out well.
If they had a similar cylinder of Roman concrete, they could precisely measure its strength.
In the nearby concrete factory, a mix of Roman concrete has been left to harden.
And now, the time has come.
How has the special Roman mix of underwater concrete fared? Well, to me this is amazing.
This block of marine mix concrete actually formed.
I didn't think it was going to form like this.
And you know, the crazy thing about this is that this concrete gets stronger over time, and this has only been 30 days' hardening.
This is ancient technology at work underwater concrete 2,000 years ahead of its time.
It's impossible to believe that this marine mix concrete sat underwater and hardened.
It's as hard as modern concrete.
But exactly how hard is it? How does Roman marine concrete hold up to modern testing? For the first time, the engineering workshop has a sample and will test the pressure it can withstand in psi, pounds per square inch.
That technology is a couple thousand years old, and I'd be surprised if it got up to 200 or 300 psi.
Soon it becomes clear that after just 30 days' setting, the Roman mix concrete is bearing up remarkably well.
Anything beyond 300 psi would be astonishing.
This came in at nearly 400 psi.
For an ancient technology, that's incredible.
With every week, the concrete will get stronger and stronger.
This concrete mix was 2,000 years ahead of its time.
And that's without all the modern machinery used in the industry today.
We're making modern concrete right behind me now.
It's impossible to think that all of this modern equipment is needed to replicate what the ancient Romans were doing 2,000 years ago.
Many of the biggest builds of the modern world are factories and places of industry.
Even food, which used to be made in the home, is now produced on an industrial scale.
In ancient times, could they have had factories like this? Surely impossible.
But these strange ruins on a hillside in Southern France have a remarkable story to tell.
For years, they were a puzzle.
But now history is being rewritten.
We normally think that it was the industrial revolution that gave us the modern idea of factories, and before that, we had cottage industries.
However, we've now got to rewrite our understanding.
The mysterious ruins are at barbegal, near the town of arles.
And the clue to what went on here lies above, beyond the hillside.
Here we find something spectacular.
We're in Southern France at barbegal, and this is a Roman aqueduct.
But it's unlike any Roman aqueduct you've seen before.
What makes this so special is how it was put to use.
The water from this aqueduct served a very special purpose.
What's so significant about this site is that there were 16 mills powered by water, right along this hillside.
A huge series of waterwheels.
This is something that's totally extraordinary.
We haven't seen the like until today with modern hydro-electric systems.
This is a huge undertaking.
They actually turn a natural hillside into a vast watermill system.
This is a really massive mechanical operation, and it worked.
The Romans didn't invent the watermill.
The ancient greeks were the first to use them.
But nothing like barbegal had ever been built before.
Together, these waterwheels comprised one of the biggest builds of the ancient world, a waterwheel super factory in the 2nd century A.
D.
Which has never been matched since.
And that's despite waterwheels remaining in use for another 2,000 years.
It wasn't until the age of steam that the mechanics of waterwheels were surpassed.
But not only was barbegal massive, it was also highly efficient.
It was much more advanced than any waterwheel technology that followed it.
Many waterwheels, like this 17th century mill at hereford in england, are powered by water hitting the bottom or middle of the wheel.
If we had a higher drop what we'd do is we'd be bringing the water in over the top and have an overshot wheel so the water fills all the buckets and turns it around-- more efficient, but you need to have that bigger drop of water.
Without a steep incline, a stream can still power a waterwheel.
But at barbegal the Romans made use of the high drop.
The water pouring down onto the wheels -- 66 gallons per second-- made each of these wheels two and a half times more efficient.
But it's not just the mills here that were an engineering marvel.
Getting the water to them was a seemingly impossible task.
Between the aqueduct and the mills was the top of the hill.
What the Romans do is they actually physically cut a channel into the top of the hillside so the water can be fed through, and then it can hit the top of the mill with absolute force and then charge down 65 feet to the bottom, creating a huge amount of force and momentum.
The massive cutting was made through solid rock.
And it shows the incredible ambition of the Romans.
For them, when it came to building, no obstacle was too big.
What's really impossible, just think about barbegal.
Somebody had the vision to say we'll capture water six miles away, build an aqueduct, stick it through a mountain, and then we'll build a whole set of steps of water wheels to harness all that energy, 16 water mills all stacked up.
The scale was immense.
This was able to put out about 4,5 tons of flour every day.
But what was all this flour for? Today's mega-bakeries use machinery on an industrial scale to produce vast amounts of bread for our towns and cities.
Why at barbegal was the huge milling complex needed? We know there were at least 12,500 people living in arles and then some more military on top of that.
It looks like the wheels at barbegal produced enough bread to feed the entire population.
Keeping people fed was all a part of the Romans' grand plan.
Military might alone doesn't hold an empire together.
Very interestingly, there is no point in having an empire if your people are either subversive or starving.
So of course the way to keep them on side is to keep them well-fed.
During barbegal's peak years, the vast Roman empire was growing at a breakneck pace, bringing people together into urban centers, keeping them under control, civilizing them, it was all part of how the empire worked.
A city could be fed.
The people were then free to work, to make goods.
Goods equals wealth.
Wealth equals power.
A waterwheel? The power of the Roman empire.
But the empire didn't go on growing forever.
One theory as to why the Roman empire eventually declined is that it had so much slave labor, there was no incentive to embrace new technology.
Barbegal is important because it shows the opposite.
It's a water-powered factory.
I think when people learn about barbegal, they're always shocked and amazed.
Today we think about factories, we think about industrialization, we think about modern times.
But here the Romans are showing us what they were able to achieve on a grand scale, on an industrialized scale, 2,000 years ago.
I think it's rightly earned the reputation as being the greatest concentration of mechanical power in the ancient world.
It's phenomenal! Remarkably, this hugely important archaeological site has only really been fully understood in the last few decades.
And it's been a revelation.
Before this, no one imagined such a place could exist.
Is it possible there could be other sites like this which have yet to be discovered? The barbegal mills are a real success story.
As a historian and archaeologist, you're constantly thinking maybe, just maybe there's another example like this that is just waiting to be found.
And what's really interesting about them is that, in a way, this is the industrial revolution 16 centuries before the industrial revolution officially happens.
Throughout the centuries, warfare has driven technology.
Great scientific breakthroughs have been made in our quest for new means of destruction.
Defense is a huge industry, and is responsible for some of our biggest builds.
But could there have been an ancient military factory as big as those of today? This is the joint systems manufacturing center in Lima, Ohio.
It's the home of the Abrams tank, 70 tons of imposing military might.
All tanks for the U.
S.
army are built here.
During world war ii, it mass- produced tanks at a phenomenal rate.
Victory in Europe depended on it.
It's still one massive factory with a highly skilled workforce.
It's great knowing that you're building the best product in the world and soldiers are safe, one of the best-built tanks in the world.
This is the first time that I've been on a tank, and I have to say it's a real thrill.
I mean, up here you really get a most incredibly commanding view.
I'm a cavalry man at heart, and it's very much like being on a horse.
In many ways, the tank is the modern equivalent of an ancient fighting chariot, a mobile, state-of-the-art fighting force.
But it's also a command center, just like chariots were, mobile platforms for artillery on the battlefield.
It's not infrequently said, and I've often said it myself, that the chariot is the ancient tank.
What it does is provide mobility.
The fighting chariots of the ancient Egyptians were the meanest machines on the battlefield.
But were they factory-made, like the tanks at Lima? It's almost impossible to believe, but over 3,000 years ago, the great pharaoh ramses ii had his own huge factory for the state-run production of these fighting machines.
We have evidence of ramses' chariot factory both archaeologically and in tomb paintings, and what we can tell is it was on a massive scale-- state mass production, just like this tank factory.
Ramses demanded chariots, masses of chariots.
They were needed for a battle, a big battle, the battle of Kadesh, the greatest chariot battle that the world has ever seen.
In 1274 bc, Kadesh was the culmination of the incredible mass production of chariots under ramses ii.
And it was here, in the desert of modern-day Syria, that the Egyptian army clashed with the other superpower of the day, the hittites.
With thousands of chariots on each side, this was chariot warfare on an unprecedented and massive scale.
That's an awful lot of chariots on the field, and you imagine them swirling around in the dust.
It's a thick dust storm, and it's a real dogfight as they're all trying to outmaneuver each other, and the archers to pick off their opponents.
But how could so many chariots have been made? And where? The factory that produced the Egyptian chariots must have been massive, big enough to supply the huge numbers of chariots needed for the war with the hittites.
And a possible site has been identified at pi-ramesse in the nile delta.
What we have is stables for something like 480 horses, which means 240 chariots.
We have a training ground, and we have a place which is said by some people to be a chariot factory.
The site on the nile has yet to be fully excavated.
But one thing we know for sure is that, remarkably, the factory used an assembly line, just like the tank factory at Lima.
So here we are at the assembly line, and you can see tank after tank after tank stretching back there.
You're taking pre-formed pieces, and you're bringing them to an assembly plant, and skilled workers are putting things together.
It is almost impossible to imagine that over 3,000 years ago the manufacturing processes, the systems for making military hardware would be the same as they are in the 21st century, but they were.
It was the same principle-- assembly line factory work.
Henry Ford is known as the creator of the production line in the 20th century, but 3,000 years ago, impossible to believe, the Egyptians did the same-- an assembly line that churns out relentlessly chariot after chariot after chariot.
On the floor of the tank factory, the individual components come together.
They're state-of-the-art and made by specialist teams.
It was just the same in the chariot factory.
First, the body of the chariot-- lightweight wood curved into shape by steaming it, just big enough for two standing men.
The undercarriage was a fixed axle and a central pole made by one artificially bent piece of wood.
Quite a large wheelbase directly beneath the body to keep the chariot stable.
The frame for the horses is also made of bent wood, and it attaches to the end of the pole.
You can't have a chariot without wheels.
One quick assembly.
A deadly, mobile fighting machine.
The Egyptians understood the importance of using the perfect materials, and imported wood especially, in particular, ash.
Even today, one specialty builder of sports cars in england still uses ash just as the ancient Egyptians did.
This is the Morgan car factory, where skilled craftsmen have been assembling cars in this way for over 100 years.
Ash of course would be ideal for a combat vehicle, a chariot, for the same reasons that we use it-- it's not only extremely strong, it's lightweight.
The lighter you could make a structure like that, the easier the horses could pull it, the more flexible it would be and a more effective fighting machine.
Being flexible, it can act as a shock absorber.
It's the same with us here in Morgan.
The frame will flex and bend with the chassis, and this all adds to the road-holding and the handling of the cars.
The factory here makes around 100 cars a month, handcrafted with skill and precision.
Ramses ii needed chariots in their thousands.
The fact that his chariots could be mass-produced was in itself a source of wonder and terror for his enemies.
Ramses' systems were so advanced, so efficient in producing the great numbers of military vehicles that he needed.
It's almost impossible to conceive that factories of this scale existed 3,000 years ago, but they did.
Some of the most iconic buildings ever constructed are huge cathedrals such as notre dame in Paris and st Paul's in London.
But incredibly, one of the biggest builds in history is a cathedral from ancient times.
In 6th-century constantinople, when the magnificent cathedral of hagia Sophia rose from the ground, it was as if the impossible had happened.
This is the hagia Sophia.
It is one of the most impressive architectural constructions in the world.
It exerted an influence for 1,000 years after its construction.
"Hagia Sophia" means "holy or divine wisdom" in turkish, and the building is the supreme masterpiece of byzantine architecture, and for almost 1,000 years, it was the biggest cathedral in the whole world.
Still standing after 1,500 years, with minarets added at a later date, this was an incredible build, with techniques centuries ahead of its time, a Roman Christian cathedral that was a revolution in architecture.
This is such an amazing space.
You've got something that's intact, something that's constructed in the 6th century A.
D.
, and the thing is, it's just hard to get a sense of how massive this space is because there's so many openings, there's so much light.
It's almost impossible to imagine what people thought of it when they first saw it.
They must have thought that they were looking at something impossible.
They wouldn't have understood how it stayed upright.
A lot of people thought that god himself was holding the building.
That's how special it was.
And this was exactly the intention.
The man behind it, the emperor Justinian, needed to assert his political power.
To do this, he wanted to be linked with god in the most visible way.
He wanted it to represent not only his greatness on earth, but god's greatness in heaven, and to draw that link for people to say, "I am god's representative on earth.
" In the 6th century, the Roman empire was based in constantinople, modern-day Istanbul.
But the empire was fading.
Justinian knew that if he didn't make his mark in some grand way, he would be just a footnote in history.
He wanted to be great.
He was determined that as well as being something massive, his cathedral was going to be something completely new.
So he didn't go to the master builders of his age.
He went to mathematicians.
He depends upon these experts of math and geometry and science to go in a new direction, to create something that no one had ever seen before.
To understand it, we need to start with the dome.
The dome is the most impossible achievement.
It's 102 feet across and 180 feet high.
It's huge.
It's broader than the dome of the capitol building, and that was built 1,300 years later.
But the most amazing thing is that the dome doesn't seem to be resting on anything solid.
Essentially you have this massive dome, which seems to just rest lightly on these 40 windows so it's something that's ethereal, almost light about it.
And for a dome to be built on a square base rather than a round one was something completely new.
For the Romans to achieve this was truly remarkable.
These four piers are essentially building supports, and in the hagia Sophia, they're huge.
They were built to support the dome.
Well, four arches were built on top of the columns.
Then, the spaces in between were filled with masonry.
They fill in the upper corners of the space and so form a circular support for the dome.
This was a giant leap in architecture.
It must have been incredible then, because today it still looks awe-inspiring.
Hagia Sophia is huge, about 65,000 square feet, but the speed of its building was impossible, too.
Normally, cathedrals took decades to build.
The construction of notre dame hundreds of years later took over a century.
And just the dome of the capitol building took 11 years.
This is a large structure that's built in a mere five years.
That is incredible.
To give a modern comparison, the Burj Khalifa in Dubai, which is the tallest building in the whole world, took six years, and that's with all the modern technology that we now have.
That is a tribute to Justinian's vision to make this engineering miracle happen.
Some of the biggest builds of the ancient world were factories and places of industry.
And, just like today, some of the most impressive of these were built because of our insatiable desire for precious metal.
The Romans' need for copper and silver brought them here, to rio tinto in Spain.
And for 2,000 years, the mine held a dark secret deep beneath the surface.
This is the Rio Tinto mine in the heart of andalucia in Southern Spain.
It's absolutely vast, almost 20 square miles.
The first people to start exploiting metals in these hills were over 5,000 years ago.
In Roman hands, this mine became the single greatest mining complex in the whole of the ancient world.
And it was here, in 1919, that an astonishing discovery was made a huge wooden wheel buried deep in the ground.
Further investigation revealed that it was almost 2,000 years old.
But what was it for? The answer is almost impossible to believe.
A clue was found here, at a gold mine in Dolaucothi in Southern wales-- a similar wheel and well- preserved enough for a scaled-down replica to be made.
Remains of that wheel were found 150 foot down, so far down that it's reasonable to expect that more than one wheel were used.
And this is a replica of what one of those wheels may have looked like.
It became clear that the wheel was used to lift water to prevent the mine from flooding.
Water from the bottom was scooped up and then fell out at the top into a channel that drained it away.
And someone must have stood deep underground turning the wheel.
What a horrendous job.
A human hamster in near pitch- black conditions.
The Romans were masters of waterwheel technology, but with a waterwheel, normally moving water turns the wheel.
At both Dolaucothi and at Rio Tinto, what the Romans did was turn that concept on its head.
They used manpower to turn the wheels, and then the wheels moved the water.
Move the water, drain the mine, miners work.
Genius.
But could a large wooden wheel really have been any use here at Rio Tinto? This mine is massive, and the Roman shafts went deep into the earth.
We now know that at Rio Tinto, the use of these wheels was taken to impossible extremes-- underground caverns, carved by hand from the earth, and inside? Eight pairs of huge waterwheels powered by slaves, walking the wheels.
To a modern engineer it would seem incredible.
To the ancients, it must have seemed impossible.
But it was an impossible task that the Romans faced and mastered.
This was ancient engineering on a massive scale, and it made the impossible possible.
The wheels were probably prefabricated and constructed within the mine.
Building a whole series of these huge waterwheels underground is almost beyond belief.
Today it would be incredible.
2,000 years ago, simply impossible.
As the slaves trod the wheels, the water was channeled from one pair to the other, eventually rising over 100 feet before being drawn to the surface by a huge Archimedes screw.
This wasn't hell on earth.
It was hell deep within the earth, dark, hot and working with toxic, mineral-soaked water.
The slaves who operated these waterwheels had the worst job in the whole mine.
Their life expectancy once they got down here was about 12 to 16 months.
It was that poisonous, and they were constantly coated in the water.
And when they finally died, which they inevitably did, the Romans didn't even bother taking their bodies to the surface.
But whatever the terror of the wheels, they were truly an ancient wonder, an incredible, fantastic construction.
Unbelievable structures built with techniques thousands of years ahead of their time, the biggest builds of the ancient world were as astonishing and awe-inspiring as anything built today, a world of wonder, of terror, and of the impossible made real.