Who Built the Pyramids? Posted 02. 04. 97

Well, first of all, Herodotus just claims he was told that. He said, 100,000 men working in three shifts, which raises some doubt, I guess, if you read it in the original Greek, as to whether it's three shifts of 100,000 men each or whether you subdivide the 100,000 men. But my own approach to this stems to some extent from "This Old Pyramid." [In this NOVA program, a crew attempts to build a small pyramid at Giza.] Certainly we didn't replicate ancient technology 100 percent, because there's no way we could replicate the entire ancient society that surrounded this technology. Our stones were delivered by a flatbed truck as opposed to barges; we didn't reconstruct the barges that brought the 60-ton granite blocks from Aswan. So basically what we were doing is, as we say in the film and in the accompanying book, that we're setting up the ability to test particular tools, techniques, and operations, without testing the entire building project.

One of the things that most impressed me, though, was the fact that in 21 days, 12 men in bare feet, living out in the Eastern Desert, opened a new quarry in about the time we needed stone for our NOVA Pyramid, and in 21 days they quarried 186 stones. Now, they did it with an iron cable and a winch that pulled the stone away from the quarry wall, and all their tools were iron. But other than that they did it by hand.

Even today, over 4,500 years since Khufu's time, Egyptian masons use hand tools to chip out narrow trenches in limestone to make blocks.EnlargePhoto credit: © WGBH Educational Foundation

So I said, taking just a raw figure, if 12 men in bare feet—they lived in a lean-to shelter, day and night, out there—if they can quarry 186 stones in 21 days, let's do the simple math and see, just in a very raw simplistic calculation, how many men were required to deliver 340 stones a day, which is what you would have to deliver to the Khufu Pyramid to build it in 20 years. And it comes out to between 400 and 500 men. Now, I was bothered by the iron tools, especially the iron winch that pulled the stone away from the quarry walls, so I said, let's put in an additional team of 20 men, so that 12 men become 32, and now let's run the equation. Well, it turns out that even if you give great leeway for the iron tools, all 340 stones could have been quarried in a day by something like 1,200 men. And that's quarried locally at Giza—most of the stone is local stone.

So, then, because of our mapping and because of our approach where we looked at what is the shape of the ground here, where is the quarry, where is the Pyramid, where would the ramp have run, we could come up with a figure of how many men it would take to schlep the stones up to the Pyramid. Now it's often said that the stones were delivered at a rate of one every two minutes or so. And New Agers sometimes point that out as an impossibility for the Egyptians of Khufu's day. But the stones didn't go in one after another, you see. And you can actually work out the coefficient of friction or glide on a slick surface, how much an average stone weighed, how many men it would take to pull that. And in a NOVA experiment we found that 12 men could pull a one-and-a-half-ton block over a slick surface with great ease. And then you could come up with very conservative estimates as to the number of men it would take to pull an average-sized block the distance from the quarry, which we know, to the Pyramid. And you could even factor in different configurations of the ramp, which would give you a different length.

During the making of the NOVA film "This Old Pyramid," Egyptian workers successfully pulled a large limestone block along using wooden rollers. Did the ancients use such a technique? EnlargePhoto credit: © WGBH Educational Foundation

Well, working in such ways—and I challenge anybody to join in the challenge—it comes out that you can actually get the delivery that you need. You need 340 stones delivered every day, and that's 34 stones every hour in a ten-hour day, right? Thirty-four stones can get delivered by x number of gangs of 20 men, and it comes out to something like 2,000, somewhere in that area. We can go over the exact figures. So now we've got 1,200 men in the quarry, which is a very generous estimate, 2,000 men delivering. So that's 3,200. Okay, how about men cutting the stones and setting them? Well, it's different between the core stones which were set with great slop factor, and the casing stones which were custom cut and set, one to another, with so much accuracy that you can't get a knife blade in between the joints. So there's a difference there. But let's gloss over that for a moment.

NUTS AND BOLTS

One of the things the NOVA experiment showed me that no book could is just how many men can get their hands a two- or three-ton block. You can't have 50 men working on one block; you can only get about four or five, six guys at most, working on a block—say, two on levers, cutters, and so on. You put pivots under it, and as few as two or three guys can pivot it around if you put a hard cobble under it. There are all these tricks they know. But it's just impossible to get too many men on a block. So then you figure out how many stones have to be set to keep up with this rate, to do it all in 20 years. It actually requires 5,000 or fewer men, including the stone-setters. Now, the stone-setting gets a bit complicated because of the casing, and you have one team working from each corner and another team working in the middle of each face for the casing and then the core. And I'm going to gloss over that.

"We are showing some nuts and bolts that are very useful and insightful, far more than all the armchair theorizing," Lehner says of his team's effort to understand the mechanics of pyramid-building. Here, he appears high on the Khafre Pyramid. EnlargePhoto credit: © WGBH Educational Foundation

Now, just recently I was contacted by the construction firm DMJM. The initials stand for Daniel, Mann, Johnson & Mendenhall, and it's one of the largest construction firms; they're working right now on the Pentagon. One of the senior vice presidents decided to take on for a formal address for fellow engineers a program management study of the Great Pyramid. So these are not guys lifting boilers in Manhattan; these are senior civil engineers with one of the largest construction corporations in the United States. I'm sure they'd be happy to go on record with their study, which looked at what they call "critical path analysis." What do you need to get the job done? What tools did they have?

They contacted me and other Egyptologists, and we gave them some references. Here's what we know about their tools, the inclined plane, the lever, and so on. And without any secret sophistication or hidden technology, just basically what archeologists say, this is what these folks had. DMJM came up with 4,000 to 5,000 men could build the Great Pyramid within a 20- to 40-year period. They have very specific calculations on every single aspect, from the gravel for the ramps to baking the bread.

I throw that out there, not because that's gospel truth, but because reasoned construction engineers, who plan great projects like bridges and buildings and earthworks today, look at the Great Pyramid and don't opt out for lost civilizations, extraterrestrials, or hidden technologies. No, they say it's a very impressive job, extraordinary for the people who lived then and there, but it could be done. They are human monuments.

Some of the ancient graffiti found deep inside the Great Pyramid EnlargePhoto credit: © WGBH Educational Foundation