About the title

Doesn’t How the Great Pyramid Was Built sound like the ultimate in “how-to” book? It was not my original choice for a title. Early Pharaohs were considered representatives of the gods on earth; by the 4^th Dynasty, Khufu was considered divine in his own right. The pyramid was designed, not only to protect his physical remains, but to allow his soul or spirit to communicate with the gods in heaven. With this in mind, throughout the writing of the book and even on the contract I signed with Smithsonian, I called the book Stairsteps to the Gods: Building the Great Pyramid at Giza. The publisher’s marketing people, however, were concerned that with this title the book would end up shelved with books on religion in the bookstores, and so it was changed.

Color photographs

Andy Ryan, a talented professional photographer who resides in Boston, joined me on two of my trips to Egypt, where we had many interesting adventures. Andy took hundreds of superb photographs, and I planned to include at least 130 colored plates in the book. When it came time to publish, the publisher cut this number to 18, citing a desire to keep the book affordable for as broad an audience as possible. To see more of Andy’s work, including some of the unpublished Giza photographs, go to his web site at: http://www.andyryan.com/flash.html.

Comparison of Egyptian and Maya pyramids.

Pyramids evolved all over the world as a preferred form of construction in certain religious and ceremonial applications. Was this a fortuitous coincidence (after all, it does not take a lot of insight to recognize that a pyramid is the easiest, most stable way of erecting a tall structure with limited tools and materials.) But there are those who see the existence of this unique structural form sprinkled around the globe as evidence of extraterrestrial visits or migrating Egyptians. To explore this question I decided to make a study of Maya pyramids, since they have many similarities and were close and accessible. A summary report was published in Civil Engineering Magazine in April, 2004 and is reproduced here with permission. (See Khufu and Kukulcan.pdf)

What would it cost to build the Great Pyramid Today?

When the National Geographic Society asked to interview me for a new documentary they were making on the pyramids of Egypt, I was delighted to take part. “There is one catch,” the producer told me. “Besides hearing your thoughts on how the pyramids were built 4,500 years ago, we would like to know what it would cost to build the pyramid today.”

Actually, I’ve been asked this question many times before, and on occasion had started to think about it, but had not taken the time to make a detailed analysis. The query from National Geographic provided an impetus to try to answer this question. I decided to first prepare a base case for comparison with other approaches. The base case I selected was to assume that the pyramid was constructed from precast concrete blocks, as this technology is well established. I made several simplifications for the base case. First, I assumed that all of the blocks were the same size. This is definitely not true for the Great Pyramid as we know that the lowest course consists of blocks 1.5 meters high, weighing approximately 15 tons. The size of the blocks then becomes progressively smaller, decreasing from a height of 1.5 meters to 1.25 to 1.0 and so on for the next 15 to 20 courses. At this point there is another course of taller blocks, then the height of the blocks once again decreases. This pattern is repeated throughout the 200-plus courses of the actual pyramid.

For the base case I assumed that the blocks were rectangular in shape, 0.76 meters high, 1.02 meters wide, and 1.27 meters long, or 30 inches high by 40 inches wide by 50 inches long. Such a block weighs 2,360 kilograms if concrete and 2,207 kilograms if limestone. In my original research I developed several computer models for determining the number of blocks used to construct each course, the work required to install the blocks, and so on. I used these models to determine the number of concrete blocks required for the base case; 2.55 million blocks would be needed. To precast this large number of blocks it makes sense to have a batch plant at the site. Consequently I planned on a concrete batch plant with the capacity to produce 150 cubic yards of concrete per hour. This yields a theoretical block production rate of 2,800 blocks per day (3 shift operation). More realistically, around 2,600 should be possible. The batch plant would be installed at the site early and would begin stockpiling blocks.

Once the site is graded and leveled, 4 tower cranes would be set up in each quadrant of the pyramid. (Figure 1.) The hoist speed for the crane for a 4 metric ton load is 113 meters per minute.[1] To hoist to the top (146 meters) therefore requires 1.3 minutes (say 2 minutes to account for hook/unhook time.) However, the weighted average lift height is about 50 meters, which would take about 1 minute hoist time. With 4 cranes and 3-shift operation, hoisting the blocks would take 2 years. The Liebherr 420 ECH tower crane has a hook radius of 75 meters (246 feet), which is sufficient to reach the center of the pyramid as well as most of the outer perimeter. One mobile crane would be dedicated to placing blocks on a few locations on the lower courses that cannot be reached by the tower cranes. A dedicated railroad track runs from the batch plant, around the perimeter of the pyramid to several lift points, and back. The train system includes flat cars equipped with steel precasting forms for making the blocks. The forms have removable sides so that once the concrete has cured the sides can be knocked down and the blocks are easily hoisted. After the concrete is poured, the cars are moved to a staging area while the concrete cures. Next they are transported to the site. The tower cranes can lift blocks directly from the flat cars.

 

Figure 1 Liebherr Tower Crane

 

Before the first course of blocks is placed it is necessary to excavate the descending corridor and the subterranean chamber located 100 feet below the base of the pyramid. This is done using a tunnel boring machine. Once the subterranean chamber is complete, the construction of the pyramid itself can begin. The descending corridor rises to up through the pyramid body to a height of 11.7 meters (course 15). Above grade, the descending corridor is framed with pre-cast elements as the construction proceeds.

Blocks are put in place up to course 28, (21.2 meters above grade), which corresponds to the floor of the Queen’s Chamber. At this level a horizontal corridor is constructed and the Queen’s Chamber is erected. Once this is done, the Grand Gallery is constructed, in parallel with raising the pyramid to course 56, (elevation 43 meters), where the King’s Chamber is located. The Grand Gallery leading up to the King’s Chamber is constructed from precast concrete sections. After the King’s Chamber is complete, the construction is continued to course 96 (elevation 73.2 meters), at which point there is a tie point and then the tower cranes are extended to their maximum height. From this position construction continues until course 192 (elevation 146.6 meters) is reached. When all of the blocks have been placed, a heavy lift helicopter removes the tower cranes.

In reality, we know that the Great Pyramid was constructed of limestone blocks with granite beams and slabs where additional structural strength was required. In order to estimate the cost of limestone construction, I contacted several large limestone quarries and obtained prices for limestone blocks the same size as the concrete blocks used in the base case. I also obtained prices for granite beams.[2] Limestone blocks would be pre-cut and delivered to the site by rail or truck. They are taken from a staging area to a point where they are hoisted into position using the tower and mobile cranes. Blocks are predrilled with a hole for use in lifting with a device called a Lewis pin. For the limestone case, there is no requirement for a batch plant or a rail system to deliver materials. Blocks can be brought directly by rail or truck to the site and off-loaded for installation.

For both the concrete base case and the limestone case, some concessions to modern design are included in the pyramid. There is lighting in the corridors and chambers, a ventilation system provides two changes of air per hour, and a security system includes remotely operated surveillance cameras to monitor the interior spaces of the construction. A man lift, extending from the King’s Chamber to the apex of the pyramid, provides a means for post-construction inspection and access to the top. It is placed in an annulus in the construction. The pyramidion is fabricated from stainless steel and has 4 removable panels that can be opened for inspection purposes. Also included in the cost estimate is a small visitor’s center, access roads, and parking and other minimal necessary infrastructure. I assumed that the basic utility services are available at the boundaries of the site, i.e., water, power, sewer, and rail and highway access.

 

Work force and Cost Estimate

The total labor days expended in the construction of the pyramid in 2006 is 40,350. The construction schedule for completing the pyramid is 4 years for either the base case or the limestone case. This is predicated on the throughput of the batch plant for the base case and it is assumed that sufficient limestone quarrying capacity can be found within a reasonable distance of the site to maintain a similar delivery rate of several thousand blocks per day.

The cost for the base project assuming the pyramid is built using concrete blocks is $1 billion.[3] This estimate includes a 15 percent contingency. The construction cost includes site development, infrastructure work, necessary equipment and labor and all materials to complete the pyramid and develop the site. It does not include any allowance for the cost of land, of which approximately 20 acres is required. Using the same assumptions, the cost of building the pyramid limestone blocks and granite beams is $4 billion. The price tag is higher primarily because of the cost of cutting and delivering limestone. By way of comparison, these costs are equivalent to $395 per cubic meter ($301 per cubic yard) for the base case using concrete blocks and $1,621 per cubic meter ($1,236 per cubic yard) for the limestone case.