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00:01The ancient Egyptians built the Great Pyramid in 20 years,
00:06cut miles of underground tombs,
00:09and razed this towering obelisk, all 320 tons of it,
00:14with nothing more than manpower.
00:17Walking in their footsteps,
00:19this team of engineering experts
00:21is on a mission to investigate.
00:24The Egyptians left nothing to chance.
00:27Explore.
00:29Insert a wedge, and that section of rock,
00:31it will come away really easily.
00:33And decode construction.
00:35A little bit low.
00:37The way the ancients did it.
00:3946 centuries after the first pyramid rose from the desert,
00:43they will discover how the Egyptians dreamt the impossible,
00:48and then built it.
00:59across three continents.
01:07A team who solve engineering challenges every day,
01:10are on an extraordinary quest.
01:12To think, work, and build like Egyptians.
01:16Steve Burrows is one of the world's top structural engineers.
01:22He builds stadiums and skyscrapers,
01:26so he's used to building big.
01:28But one thing he'd still like to understand,
01:31is how ancient Egyptian structures were built.
01:34The task for architectural designer, Charlie Luxton,
01:38is to look at the big picture.
01:40Deconstruct these buildings from their plans and blueprints.
01:44While over 6,500 miles away,
01:47at the University of Louisiana at Lafayette,
01:49Dr. Chris Carroll has set up a field lab.
01:52A civil engineer and construction expert,
01:54with a whole class of would-be pyramid builders at his command,
01:57he's going to put the analysis to the test.
02:01There's a little bit, whoa!
02:02There is something about building tall.
02:08People have been doing it since the dawn of history.
02:11And for nearly 4,000 years,
02:14the undisputed world champions were the ancient Egyptians.
02:18For Steve and the team, it all starts here.
02:22This is the prototype for every Egyptian pyramid.
02:26But it's more than that.
02:31It's the oldest major stone construction on Earth.
02:36It's called the Step Pyramid.
02:42Because it sits alone in the desert,
02:44it's hard to gauge just how big the Step Pyramid is.
02:48But if you picked it up and dropped it in a 21st century city,
02:52it'd take up most of a block.
02:55And it's as tall as a 20-story high-rise.
02:59Just the scale of the building.
03:04Not just the entire building itself, but every piece of it.
03:07Every stone is large.
03:08There's no way that one man can pick up one of those stones.
03:11That it was teamwork.
03:12There must have been thousands of people working on this.
03:14Steve knows that this building evolved
03:17from what had been a traditional Egyptian tomb,
03:20a single-story building with the body buried beneath it.
03:23To gain height, the builders added smaller and smaller versions
03:27of the same design, one on top of another.
03:30It's just a pile of stones, but it's enormous.
03:36And I wonder whether it was like some large experiment
03:39in the idea of building tall.
03:41To architectural designer Charlie Luxton, the plans tell a remarkable story.
03:48At first glance, you'd be forgiven for thinking that this is a very simple, almost crude building.
03:56It's just a pile of stones.
03:58But in fact, it is anything but.
04:00This is an incredibly complex building.
04:04Buried under the steppe pyramid, there are miles of tunnels.
04:09Archaeologist Dr. Zahi Hawass takes Steve on a tour.
04:14It's about three miles of tunnels and corridors.
04:17Wow.
04:18That was the vision of the ancient Egyptians, how they imagined the afterlife.
04:24The netherworlded Osiris is sitting in the burial chamber waiting for the king to go through
04:29all these dark tunnels and corridors.
04:32Well, what an achievement to dig three miles of tunnels.
04:36And this rock is really soft as well.
04:38Yeah.
04:39So quite dangerous.
04:42The idea that you build a pyramid by putting one layer of stone,
04:46putting a smaller one on top and a smaller one on top of that,
04:49it seems relatively simple.
04:51You know, we could teach a four-year-old child to build a pyramid out of building blocks.
04:57Then ask that child to put a tunnel underneath that pyramid.
05:01And the complexity is huge.
05:03And I start to wonder, how did they explain that to the workforce?
05:08After 20 minutes of walking, they find themselves in a hidden chamber, directly beneath the center of the pyramid.
05:20Oh.
05:21Fantastic.
05:22It's amazing.
05:23This is just a huge chamber.
05:27It's disorienting.
05:35The ceiling, way above them, is in fact only at ground level.
05:40It's the base of the pyramid.
05:42Above that is another 200 feet of rock.
05:46What we've got here is a sort of iceberg of a building.
05:50That is to say that you can see a small amount of the step pyramid above ground.
05:54But below ground, there's just this huge amount of construction that's taking place.
05:59It's a phenomenon, below ground and above.
06:03It's hard to imagine mankind ever building anything else which lasts as long as the pyramids.
06:10The first challenge for construction expert Dr. Chris Carroll is to discover what keeps them standing over 4,000 years after they were built.
06:19Craig, hold right there, hold right there.
06:21And he's in for a big surprise.
06:31The monuments of ancient Egypt are among the most enduring man-made structures on Earth.
06:36And our team of construction specialists wants to know how they have stood for so long.
06:42At the field lab in the University of Louisiana at Lafayette,
06:46Dr. Chris Carroll and his team are about to conduct an experiment to examine the durability of a pyramid.
06:53They're laying the foundation for a giant concrete box.
06:58When it's ready and filled with sand, they're hoping it'll pass for the shifting desert sands of Egypt.
07:05Chris and his team work with all types of buildings.
07:09But no one around here has ever built anything like this.
07:14So we were curious to see what a pyramid would do with an instability, so we decided to build one.
07:19Now this is a little bit different in scale than what you would see in Egypt.
07:22If you saw an Egyptian pyramid on this scale, it would probably be about two feet tall.
07:25But we decided to build it a little bit taller just so we could magnify the effect of that instability.
07:30Now the one thing that makes the pyramid the most stable shape is the fact that the center of gravity is low with respect to where its base is.
07:37The center of gravity on a solid pyramid is a quarter of the way up.
07:44One side of the sandbox is a wooden panel hinged like the tailgate of a truck.
07:50For an Egyptian pyramid to suddenly collapse, the earth would have to move beneath it.
07:55Here, Chris's student, Craig Girard, is going to use his truck to create a landslide.
08:02You're going backwards first, and I'm going to inch you.
08:04Okay?
08:05Okay.
08:17Okay, so it's starting to shift just a few degrees.
08:26Most modern buildings could never lean this far.
08:30Shift it a little bit more.
08:35All right, so it's starting to shift just a little bit more.
08:38So you're looking at about 15, 20 degrees right there.
08:49The pyramid's leaning more than 30 degrees now, and it's still standing.
08:56Okay, it's continuing to go.
08:58Looks like it's about to topple.
09:00There it goes, there it goes.
09:02A little bit more, a little bit more, a little bit more.
09:04And there it goes.
09:07So the full failure, the whole thing.
09:10And that is a little surprising.
09:11I was not expecting it to last that long at all.
09:14All right, good job, Craig.
09:15The foundation started to go on one side of it, and the pyramid started to shift.
09:22As it started to shift, you start increasing the pressure on the front, which causes it to shift more.
09:28And then the sand starts moving a little bit more.
09:30The pyramid shifts a little bit more, and it just keeps going.
09:33It's kind of like a chain reaction.
09:34Once it starts going, it's kind of hard to stop it.
09:36So you can see that with an instability in the foundation, the structure's just not going to stand.
09:42And if we had built a model with a perfectly square block, the center of gravity would have been higher, and that process would have went much, much quicker.
09:49You know, even though this one has collapsed, this is why pyramids have withstood for thousands of years, is because they keep a uniform pressure on their foundations by being perfectly plumb or perfectly vertical.
10:00The team has demonstrated exactly why the step pyramid still stands, and its success inspired the Egyptians to even more ambitious builds.
10:13While this was still brand new, they were drawing up the plans for something over twice the height, over 500 feet.
10:21Steve is staggered by this leap in scale and wants to see it for himself.
10:26Well, if you can make one pyramid twice as high as the next, it takes eight times the volume of rock, and it's four times the engineering complexity.
10:37They were making big step changes in technology when they went from one size to the next.
10:43But it's not just bigger, it's the weirdest shape.
10:50This is the bent pyramid, and for Steve, it just doesn't make sense.
10:57Looking at the bent pyramid, the first reaction has got to be, why?
11:01I mean, why did they change the angle? Why is it bent at the top?
11:05Is it some massive mistake, or was it designed like this?
11:09If they had continued at their original angle, they'd have produced an immense building, taller than anything that would be seen on Earth for around the next 4,000 years.
11:22But the builders clearly had a change of heart, and Steve wants to know why.
11:28To form a theory, he needs a close-up look.
11:34With his guide, Egyptologist Melinda Hartwig, he steps inside the pyramid.
11:40And there's an immediate shock.
11:42Oh wow, look, almost as soon as we go in.
11:45Unbelievable, look at that.
11:46I mean, there's this huge gap between stones.
11:48Yeah, now that doesn't look natural, does it?
11:50I mean, it looks like there's been some movement up there.
11:53How deep do these cracks go?
11:56They move further into the pyramid to investigate.
12:00A little bit higher here.
12:02Oh wow, look at this.
12:04And we've got a big, big crack.
12:07Look at that.
12:09It looks dangerous.
12:12And it's getting worse the further down they go.
12:15It's amazing.
12:16This is really recent.
12:18It shows there's still movement taking place in the pyramid.
12:21That's not good.
12:23Could these cracks explain how the bent pyramid got its shape?
12:35Leading structural engineer Steve Burrows and his team are on a mission to decode Egypt's ancient structures.
12:43Steve is inside the bent pyramid on a hunt for clues which may reveal how and why it's bent.
12:50Yeah, figure out what's going on here.
12:52So you can see that these plates here, see these pieces of rock?
12:56Mm-hmm.
12:57Only about an inch wide.
12:58They've just sheared off.
12:59So there's been a lot of movement taking place here.
13:01And it's much larger than it is.
13:03It is.
13:04Much bigger than it.
13:05At the beginning, yeah.
13:06Yeah, yeah.
13:07And I'm guessing as we go further down we're going to find...
13:08They're going to get larger.
13:09Yeah, I think so.
13:10But let's go down the tunnel and have a look.
13:12They need to know if the pyramid's strange shape was deliberate or the result of an experiment gone wrong.
13:24The cracks might be significant.
13:26Okay.
13:27Staircase here.
13:29Wow.
13:30We've got to be right in the middle of the pyramid now.
13:35Okay, big space up here.
13:39That's a relief.
13:41It's amazing.
13:43Just like the step pyramid, the interior of the bent pyramid opens out into a huge central chamber.
13:53Okay, look at it.
13:54Come and have a look at this.
14:01This is a sheer crack.
14:03So what we've got here is that this section of rock is stable and this one is moving.
14:08This section's moving down into that staircase area we've just come up.
14:12This is really recent.
14:13It shows there's still movement taking place in the pyramid.
14:17You can feel by the sharp edges.
14:18That's not good.
14:19They erode with time and get much smoother on the edges.
14:22So this one, this one is very fresh.
14:25So how fresh, how fresh is this crack?
14:27Ah, very recent.
14:29Maybe a day, maybe a few months, but not much longer than that.
14:34So there's still movement taking place in the pyramid, even today.
14:39It's quite a scary thought, isn't it?
14:41Yeah.
14:42Built on sand foundations, the bent pyramid is moving.
14:47So the first cracks probably didn't worry anybody.
14:53You know, they just expected them.
14:54They had cracks all the time.
14:56Some of the stones, they settled and they moved around and they absorbed the load as the load was piled on top.
15:01But of course, normally those cracks, after they happen, the movement becomes less and less over time.
15:07I think what they saw with the bent pyramid is that the movement got worse.
15:13Probably a big meeting took place and a complete redesign.
15:16And they said, well, you know, they understood why the problems were occurring.
15:20Let's try and find a way to, to solve them.
15:24The sudden change in angle is the answer.
15:28Reduce its height, reduce the volume, reduce the weight of stone bearing down and threatening disaster.
15:35Steve believes the engineers realized that a radical compromise was their only option.
15:43This imperfect pyramid was discarded, abandoned, never used by the Pharaoh for whom it was intended.
15:51But perhaps they had to get it wrong here in order to get it right in the future.
15:56The Step Pyramid and the Bent Pyramid were extraordinary monuments in their own right.
16:06Revolutionary.
16:08But what they learned here led the Egyptians on the path to perfection.
16:13The most talked about building ever constructed.
16:17It's the Great Pyramid, the biggest pyramid ever built.
16:21It's obvious the Egyptians were going for size here.
16:27It's 130 feet taller than the Bent Pyramid and over twice the volume.
16:33The scale is awe-inspiring.
16:36If you look, the last pyramid that we can see there, that is the pinnacle of pyramid engineering.
16:42It is the last standing monument of the Seven Wonders of the World.
16:47And today it is 481 feet high.
16:50So at that sort of height, it was the tallest building in the world for quite some time?
16:54If you can believe it, it was the tallest building for 3800 years.
16:58The big question for me is how did they actually build it?
17:03756 foot along each side of its base, rising to a height of 481 foot.
17:11Built of about 2.3 million different blocks of stone, each weighing an average of 2.5 tons.
17:17That's more than 6 million tons of rock.
17:21Built over a 20-year period, which means that a block of stone had to be going into place every five minutes throughout the day and night of that entire period.
17:31And then it was capped with an alloy of gold and silver.
17:34I mean, not only is this the most audacious, incredible piece of architecture, it is a miracle of logistics.
17:44And for Steve, it's a treasure trove of engineering mysteries.
17:53Wow.
17:55You tend to think of the Great Pyramid as a solid mass.
17:59And you realise that inside there's just an incredible amount of space.
18:05It's a three-dimensional stone maze.
18:10These passageways, they go up at an inclination and they turn through angles.
18:15It would have looked like an incredibly complex puzzle to the people who are building it.
18:19There are many different theories as to how the Great Pyramid was actually built.
18:26But nearly all of them involve some kind of ramp.
18:31You have a right-angled triangle and you just drag stuff up the longest side.
18:37Simple.
18:38But on this scale, it's anything but.
18:42Sounds like a challenge for Dr Chris Carroll and the team in Louisiana.
18:47Build a ramp, move some stone.
18:50Of all the theories of how the Great Pyramid was built,
18:54the one that is best known and so beloved by Hollywood is a single ramp theory.
18:59And it's incredibly simple.
19:01It's just a great big ramp made of mud brick or sand
19:05with an army of people dragging the stones up it.
19:10And as the pyramid gets bigger, the ramp gets bigger as well.
19:15It's been argued that any construction ramp would have an ideal incline of between 7 and 9 degrees.
19:23Any steeper and stone hauling becomes unmanageable, even with a large team.
19:28But as the ramp gets bigger, the need to preserve this angle is going to cause problems.
19:33Because the gradient of the ramp is so slight, you'd have had to build a huge length of material on the new ramp,
19:42another 3 feet higher, before you could bring one single stone onto the side.
19:47And Chris has identified another problem.
19:51Now, when we're building the ramp, we had to slope the sides.
19:54Because if we didn't, the ramp would be unstable.
19:58This is similar to what the Egyptians would have done, just to have stability in the ramp.
20:02So you really couldn't have a sheer face on each side of the ramp.
20:06And basically what you're having to do is you're having to build a whole other pyramid,
20:09even with the Egyptians using mud bricks.
20:11You have to build another pyramid just to get up to the actual pyramid.
20:13Take this problem and scale it up for a pyramid reaching 480 feet in the air.
20:20And Chris's doubts about the single ramp theory look right.
20:25So here's the Great Pyramid, over 400 feet high.
20:29And a ramp at 7 degrees would have stretched a mile out into the desert in this direction.
20:33It couldn't have vertical sides because it's impossible.
20:35So the sides would have had to have been ramped.
20:38Making the ramp, the volume of the ramp bigger than the volume of the pyramid itself.
20:42So I don't believe the theory of a single ramp.
20:45I just think it's impossible that a ramp of that scale could have been used to construct this pyramid.
20:50While Steve ponders the alternatives, Chris has a new challenge to contend with.
20:56Moving the building blocks on rollers.
21:00But will he pull it off?
21:05It's still one of the biggest puzzles on the planet.
21:14Just how did the ancient Egyptians lift the six and a half million tons of stone that make up the Great Pyramid?
21:22Our team of construction specialists, architects and engineers is taking a fresh look at the problem.
21:29They're studying the evidence on the ground, putting themselves in the place of the men who designed this structure,
21:35and trying some Egyptian-style construction for themselves.
21:39Okay, so basically what we have right here is a 4,000-pound block of concrete,
21:43which is equivalent to what the weight of sandstone probably is.
21:46And what we're going to do is we're going to place it on the rollers.
21:49And then we're going to pull it up the ramp in just a second.
21:55For this transport system to work, every element has to be perfectly engineered.
22:01Every surface perfectly smooth.
22:05Okay, so by placing it on the rollers, we're able to pull directly on the block, and then it can roll all the way up the ramp.
22:10So we'll take one roller from the back, place it in the front, and then as the block rolls off of them, we'll keep taking one from the back and put it in the front.
22:17Go ahead, back up.
22:22If the block slides off the rollers, it'll crush whatever it lands on.
22:27It'll also be stuck there.
22:29And if a ramp was used to build the pyramids, dozens of teams were working on it at the same time.
22:36So one mistake, and the whole system grinds to a halt.
22:38We're getting ready to try to pull the block up the ramp, and we're going to start off by using two guys.
22:44Let's start pulling, see if you can get it to move.
22:47Come on.
22:49As the guys pull, it's worth remembering that the average ancient Egyptian stood just a few inches over five feet tall.
22:59All right, maybe we need one more person.
23:01Toby, come here, jump in here.
23:03Jump in here.
23:04One.
23:07All right, come on, guys. Let's try this.
23:09Three.
23:10Let's go, man.
23:11Let's go, man.
23:13Woo!
23:15Woo!
23:17Let's get one more.
23:19Kalen, come on. Let's try. Let's get one more.
23:21See if we can do it with four.
23:23Hustle, man. Hustle up here.
23:25Will they have any luck with four?
23:27All right, guys. You ready? Let's go.
23:31Come on, man.
23:34All right, hold up, hold up, hold up, hold up.
23:40Let it back easy.
23:42Let it back easy.
23:44All right, guys, let's try it with all eight people and see what we can do.
23:50All right, Harrison, Craig, and Hayden, let's go ahead and try it with all eight and see what happens.
23:55Will doubling the manpower make a difference?
24:07Finally, they get the momentum they need.
24:12But they lose the control.
24:15Oh.
24:16Uh-oh.
24:17Disaster strikes.
24:21Uh-oh.
24:25Well, we lost part of the concrete.
24:26Okay, so we got going a little bit too fast on our rollers, and we weren't fast enough to get the rollers back in front.
24:37And by doing that, the rollers came out the back, and the block fell down, and we actually broke our block.
24:43Now, if you're in Egypt, this is a sandstone block that's taken months and months to carve.
24:46So this block becomes useless, and we have to start all over again.
24:49Now, the problem is this block's no longer on the rollers, so how do you get it off the ramp, and how do you start over again?
24:56The Egyptians must have used extremely tight tolerances because the process just doesn't work unless you're basically perfect with everything that you're doing.
25:04I mean, it just gives me that much more respect for Egyptian engineers.
25:08The team's investigation is leading Steve to examine another ramp theory,
25:12one which may finally explain how the pyramids were built.
25:17And it's based on versatility.
25:20So I think that ramps were definitely used in the lower third of the pyramid, the one-third of its heights.
25:25The ramps that were there would have come perpendicular from the face of the pyramid, all in the low levels.
25:32There were at least four ramps.
25:34Four smaller ramps would require a quarter of the materials of a single ramp all the way to the top,
25:39and there'd be another big advantage.
25:42We know that the angle of the ramp's incline has to be preserved.
25:46But this way, three of the ramps can remain in use while one is being worked on.
25:52You could be raising one of the ramps while you went up the other, so it gave continuous access to the working platform,
25:58such that you could keep the men employed, you could keep the stone arriving,
26:02and you could be building up ramps that you needed for the next level as you go.
26:05Steve's theory is dependent on a discovery explained by Dennis Stocks, an expert in ancient Egyptian construction.
26:14Between some of the pyramid blocks, there appears to be some kind of dried paste.
26:19It's a type of mortar.
26:21But before it dried, it had another vital role.
26:24Dennis demonstrates how it was used to make the blocks slide.
26:28It's so easy!
26:29It's so easy!
26:30Well, there you are, you see, Melinda, the gypsum mortar does do the job.
26:35Probably about five times less force needed...
26:38Yes.
26:39...than it was dried.
26:41With this information, Steve realizes that the blocks have been worked so smoothly
26:46that once they're at the correct height, they can be slid with comparatively little effort.
26:51So then all that's needed is the simplest of lifting devices.
26:56So I've got this building where in the bottom levels I've got mud brick ramps
27:00and I can raise the stones up and I can lift them about 150 feet.
27:03But as the pyramid gets smaller at the top, I need a different technique to actually lift the stones up.
27:09Steve believes that for the Egyptian engineers, there was an obvious answer.
27:12One that sprang, like so much of ancient Egyptian life, from the Nile River.
27:19There are techniques already employed in Egypt at this time for lifting loads.
27:25There was an instrument called a shadoof.
27:27And what it involved was two pieces of wood, top one balanced on a lower one.
27:32And they used it, I could pivot, to lift water out of the Nile.
27:36Shadoofs are the most basic kind of crane used by the ancient Egyptians
27:40and still in use today.
27:43So if they can lift water, why couldn't the Egyptians use them to lift stone?
27:49Get some wood, it's fairly scarce, but I only need to build a few of these primitive cranes.
27:54Create a vertical pole with a horizontal section.
27:58I can lift a two-ton stone with half a ton of men on the other end of that piece of wood.
28:03That's eight to ten men can lift that stone very easily.
28:06The way I do it is, I bring in the stone, connect some ropes around it, and I just lift it vertically.
28:13And I hold it up in place.
28:15I bring the next stone in below that stone, and I can lower it back down at the upper level, and I can slide it off sideways.
28:22So I have a team that all day long, all they do is lift stones.
28:26And I have two other teams, one bringing the stones in, another one taking the stones away.
28:31And that's how I think they did it.
28:33The team's investigation has uncovered answers to some of the key pyramid building questions.
28:39But for Steve, there's still one more engineering mystery here that he wants to crack.
28:44How did they raise this 320-ton obelisk?
28:58Our team of experts is unearthing the engineering secrets of the men who built ancient Egypt.
29:06Architectural designer Charlie Luxton is analyzing the buildings from their plans and blueprints.
29:11Dr. Chris Carroll and his crew are putting construction theory into practice.
29:20And Steve Burrows, one of the world's leading engineers, is on the ground in Egypt.
29:26Guided by Egyptologist Dr. Melinda Hartwig, he's come here to see what may be one of the largest religious complexes ever built on Earth.
29:36Karnak.
29:37So, Steve, here we are. This is the Temple of Amun-Ra at Karnak.
29:42You've got 1500 years of history here of construction, of destruction and also of reconstruction.
29:48And inside you have got pillars, you have columns, you have shrines, you've got courts and it's huge.
29:55It's essentially a mile long and it is two-thirds of a mile wide.
29:59You can't think of Karnak as a single building.
30:06It was built over 1300 years with different builders and pharaohs adding layer upon layer to create the complex that we see today.
30:13Over the years, most of the complex has decayed.
30:17But one structure remains intact. Built to honor the sun god Ra, it is inscribed in hieroglyphs with declarations of love and devotion.
30:31It's an obelisk.
30:34The obelisk is incredible, but primarily because it's the tallest thing on the site at Karnak.
30:39So it stands above everything else.
30:41And the question is, when you look at it as a single piece of stone, I mean, how on earth did they, did they make it and raise that obelisk?
30:47Most Egyptian obelisks have been broken up or carted off, but this one, built by Queen Hatshepsut, has never been touched.
30:57That may be because it's a single 320 ton piece of granite, 97 feet tall.
31:06Wow, impressive.
31:09Up close and personal.
31:11This is one of the few monuments in Egypt which is actually giving us a little bit of the history about how it was quarried and how it was moved.
31:22So how long did it take to quarry it? Is there anything on here that tells us about that?
31:26Yes, we're told on the inscription on the north side that it was seven months in the quarry to get two of them out, not one.
31:32Seven months?
31:33Seven months to get this in its mate, which was across the main axis.
31:37Is there anything on here that tells us about how it might have been erected and lifted?
31:40No, that's the big mystery. They're silent about that.
31:43They tell us about where it came from and why it's here, but not how it got here.
31:52Perhaps the best way to work out how it was done is to give it a try.
31:57At the University of Louisiana, Dr. Chris Carroll and his team are preparing to do just that.
32:03All right, so we've built an obelisk. Ours is concrete, not granite, and not nearly to the scale of the Egyptians,
32:08but we are going to try to raise our obelisk the way we think that they did it.
32:12Once an obelisk is standing, it can stand for centuries.
32:17But getting it vertical in the first place is a risky business.
32:21The danger is that as it's raised, it starts to bend. And when it bends, it can crack.
32:28And that crack will then spread from the bottom of the obelisk right the way through and snap in half.
32:32Chris knows the obelisk must not be allowed to bend. He needs to find a way to lift one end while supporting the body of the stone and guiding the base precisely into position.
32:45And both the bottom of the obelisk and the plinth on which it sits have to be completely smooth and completely flat.
32:55The key component is actually the platform itself. It has to be perfectly level, and we have to have a way for the obelisk to catch on.
33:01So we'll check to see if it's level.
33:05It looks pretty good in both directions.
33:06Now, in addition to that, we also have a little ledge at the front of the pedestal that we're going to use for the obelisk to catch on.
33:13And from that point, we'll actually tilt up the obelisk.
33:18The solution Chris and Steve decide on will involve precision from the whole team.
33:24It will also rely on the one thing the Egyptians had plenty of.
33:29Sand.
33:31They're building a sandbox eight feet deep.
33:33If their plan works, the obelisk will slide into place under its own weight.
33:43Many archaeologists believe that the obelisk was hauled vertical by an army of laborers.
33:49If this is true, it involved a superhuman piece of organization.
33:55I find it amazing the idea that it was men pulling on ropes that pulled it vertical.
34:00Yeah, I think you have to worry of the factor here is manpower leverage.
34:05You could use one man for maybe for about a half a ton.
34:08And so you just have to extrapolate from that.
34:10And you've got thousands of bodies, I guess, yanking on one end of several ropes to be able to get it up.
34:16The problem is that this is a 320 ton rock as tall as a 10 story building.
34:22And brute force just isn't enough.
34:26For Steve, the big question is, where's the precision?
34:30Let's say it was brought in horizontally and you've got a group of men and said, I want to lift this obelisk off the floor.
34:37It would involve thousands of people all to be coordinated.
34:40You know, one, two, three, pull wouldn't do it.
34:44There's no doubt it's an incredible feat.
34:47But is it one that Chris can replicate even on this small scale?
34:52Can he get the obelisk up and in the right place without breaking it?
34:57Pull that way, just a hair.
34:58Dr. Chris Carroll and his team are building like the ancient Egyptians.
35:14They're going to try to replicate one of the high points of Egyptian engineering.
35:20Concrete is standing in for red granite as they try to build and then raise one of these.
35:26An obelisk.
35:30Engineering expert Steve Burrows believes that the best way for the Egyptians to position the obelisk was to let gravity do the work.
35:38They could first lay the foundation on which it would rest, then build a chamber around it.
35:43A kind of well filled with sand.
35:46It would be approached on one side by a ramp.
35:50If you were to take a bird's eye view of the site on lifting day,
35:53on one side there would be a huge ramp that runs a long way that they can actually drag this huge weight up the ramp and then much steeper on the other.
36:04For the purposes of this experiment, Queen Hatshepsut's army of loincloth clad workers is replaced by Craig and his truck.
36:13OK, that's good. That's perfect. All right.
36:17The obelisk has been placed very carefully into position.
36:21And the idea is that you would bring the obelisk up and let it project out, and this is where the enterprise gets really risky, and then use its weight to allow it to tip against the face without breaking.
36:33The sand is there to control this movement. By slowly releasing it, digging it out, the team can dictate exactly when and how quickly the obelisk falls.
36:47They open two gates in the side of the box. The sand begins to flow, and the guys begin to dig. 18 tons of sand for a one and a half ton obelisk.
37:03Of course, Hatshepsut's obelisk was over 200 times heavier. Slowly, a void grows beneath the stone. Its base is now balanced on a thin ridge of sand, and it's just a matter of time.
37:16There it goes. There it goes.
37:22As the obelisk continues to subside, the challenge for the team lies in safely removing the sand from underneath.
37:29There we go.
37:34Right now, we're holding the entire weight of the obelisk on a rope that's supported by a truck.
37:39And you have to think that ours is only about 3,000 pounds. If you scale it up to an Egyptian obelisk, think about how many people that would actually take to hold it.
37:46I think that is possible with enough people, but it takes a lot of coordination as well.
37:50I see daylight coming through the hole, H. That's good.
37:52I mean, how much is left?
37:56All right, there's not too much sand left.
37:58All right, well, let's brush it off.
37:59All right, let's brush it off. Let's do this. Let's set it down.
38:01All right.
38:02All right.
38:03It's pretty clear. There's nothing to snag on, so let's go ahead and do this.
38:07You ready, Craig?
38:09All right.
38:10Everybody keep the ropes taut.
38:22Just a little bit. Whoa.
38:24A little bit more.
38:26Whoa.
38:28All right.
38:29We need to pull that way.
38:30Let off a little bit on this side.
38:32Pull a little bit.
38:33Hold a little bit.
38:34Hold right there. Hold right there.
38:36All right, we're good.
38:38All right, a little bit more.
38:43Hold.
38:44A quick look to check it straight.
38:47All right, hold right there. Hold right there.
38:49We're on it.
38:51All right, good job.
38:53You go through such an incredibly long process of excavating the stone, bringing it to site,
39:02raising it in place, and it's only in that final moment that it's either right or wrong.
39:08If you raise the obelisk and it's slightly out of position or it twists or it's not vertical,
39:13there's really not a lot you can do.
39:15You're not going to pull as tight as they do, but you're going to kind of let it, okay?
39:19You're going to kind of let it go, all right?
39:21But you've got to keep it from going all the way.
39:23Go ahead and pull it just a little bit.
39:27Okay, a little bit more.
39:30There's no taking it back down and trying again.
39:32You get one shot at this and you've got to get it right.
39:36I think we're good. Set.
39:38They've done it.
39:41That's it.
39:50Don't touch it.
39:51Hey, come look at it. Check it out, guys.
39:53And that's how you raise an obelisk using rope, sand, and human ingenuity.
40:01The engineers of ancient Egypt didn't build like anyone else then or now.
40:08Investigating their remarkable legacy has given the team a new perspective
40:13on what these men thousands of years ago were trying to achieve.
40:20Quite often the brief for tall buildings around the world is that they will have a life of 60 years.
40:25I know that doesn't seem very long.
40:27Maybe they'll last 100 years, but it's quite a defined period of time.
40:32Compare that to the pyramids where the brief was for the buildings to last forever.
40:37And what we're looking at are structures that have lasted 5,000 years already.
40:44The team has examined and recreated ancient construction techniques
40:48and now understands the ingenuity, the ambition, and the effort involved.
40:55It seems like the Egyptians are doing something that we just, we just can't replicate.
41:00I mean, you know, we're using modern tools, we're using bubble levels, things like that.
41:06And we just can't get our tolerances that tight.
41:09You know, I think it's possible, but is it probable for us to do it? No, I don't think so.
41:13It just gives me that much more respect for Egyptian engineers.
41:20These men devoted their lives to glorifying their kings and queens, honoring them for eternity.
41:27In doing so, they created buildings that will stand long after we've gone,
41:32and achieving for themselves and their rulers a kind of immortality.
41:39At all, we should have tested999.