khufu just ascended the throne of Egypt when 40, he is no longer a chicken of the year, he participated with his 3 brothers in the administration of the kingdom, probably he was part of the expeditions of his father Snefrou to Lebanon and Sinai.
Elder of the siblings, he was destined to inherit the kingdom, his younger brother Nefermaat first vizier there had important functions, maybe there was as often rivalries to have the right to eternity? Maybe he had to “elbow up” to maintain his primacy? We’ll never know.
According to the Egyptologists he was 10 years old when his grandfather Houni was buried in his pyramid as a young child he saw the end of the building, he witnessed from A to Z the erection of the red pyramid (or bent?) In which he just buried his father Snefrou.
He received the education of a king and therefore initiated to all the secrets of the knowledge of the times, he knows what is possible and what is not, he knows the whole team of scientists and engineers who made the pyramid of his father, there is a great probability that upon his accession to power, the plans of his pyramid were already more than sketched, his location spotted, logistics supply of wood, copper, precious stones was already in place for the pyramid of his father, he only has to “put feet under the table”, the “free lunch” was served.
In his family they have a healthy life, they live a long time for the period, nevertheless at 40 years he knows he must do quickly to build his pyramid, no one is safe from a devastating tooth abscess, or of a bad hunting accident, the pyramid must be built quickly.
We are told that he chose Hemiunu, the son of Nefermaat, his younger brother as architect, his half-brother Ankhaf as project leader, both younger than him, and probably full of energy.
However Hémiunu will not survive the pyramid, he made his last breath in the nineteenth year of the reign of Cheops and the pyramid was not over yet if we believe the deciphering by P.Tallet papyri found on the site Waadi el-Jarf ancient port on the red sea of copper supply logistics and precious stones of “Akhet Khufu” Cheops horizon, then given name to this pyramid.
According to P.Tallet, these documents testifying to an activity of supplying Turah’s quarry stones, date from the last years of the reign, it is therefore that the pyramid was not yet completed.
Thus, 20 years for the construction time of the pyramid is eligible.
In my study, the goal of the project is to deliver the pyramid in 20 years.
However, the operations of extraction and assembly of the building stones, do not come the day after the decision to start the work, it took time to choose the site to analyze its geology to validate the quarries, probe the bedrock to make sure of its stability, to go from sketches of plans, to final plans or more likely to a fonctionnal mockup aimed at giving the building instructions, to complete and finish the calculations of lifts which innovate compared to those of dad, to make models, prototypes, to test, to correct.
Soon it was necessary to start the construction of the city of the workers, its supply logistics with its port, the link with the Nile, the channel, the locks, the harbor basin …
Moving from the final design file, to the manufacturing file, not only the pyramid, but also the tools, then build up the tools, test them to move to mass production.
Then it was necessary to trace the first furrow which delimits the base of the pyramid, to carve the small hill which covers then this site, for at the same time to extract the first blocks, those of the base, the biggest ones, which for my study is the starting point for manufacturing operations and assembly blocks in series itself.
I evaluate the duration of this phase to 1/3 of the total delay of 20 years.
There will therefore remain 5,000 days to manufacture the pyramid itself.
In an arbitrary way, I take 12 hours of work a day, the average duration of the day in the year under the thirtieth parallel, and consider that the site worked 365 days a year, thus allocating 60,000 hours to make this mountain of stones.
By doing so I am aware of all the arbitrariness of these choices, nevertheless within +/- 3 years on 20 years, orders of magnitude are there and the nature of the problem to solve does not change, only the fine tuning can be questioned.
In my study there is another zone of approximation, the physical characteristics of the stones, which despite all the work that was done on this pyramid (and the others) remain unpublished, were they ever measured?
The density of the stones and their compressive strength directly determine the energy to be expended for extraction and elevation and have a direct influence on the workforce and therefore on the time.
I was therefore forced to taking for the stones the known characteristics of certain quarries extracting stones of the same composition, of the same geological nature.
However, specialists know well that on a given site, the rock is not homogeneous and one can have considerable variations of resistance from one place to another on the bedrock and probably even more for a different quarry . Nothing will replace the direct measurement!
Anyway, anyone who has had to lead large multi-year projects involving thousands of people (this is my experience) knows that any project has its hazards, that of this pyramid has had his own that we will never know .
So 5,000 days, 60,000 hours for the duration of the phase of extraction and assembly of blocks.
For large-scale calculations, it is customary to go through the notion of average block, which is an abstraction, but which makes it possible to grasp the large numbers in an easy to understand way.
What to take for average block in this pyramid?
F.Petrie who did an admirable job of measurements in this pyramid established all the heights of the 201 sitting still present which constitute the pyramid:
The average block should have a thickness of 0.7 m, having a volume of 1 M³ looks reasonable, so for the following I will give this block these dimensions height 0.7 m length 1.3 m, width 1.1 m, volume 1 M³ , weight 2.4 t.
The pyramid is made up of 4 essential parts, the base, the filling, the casing and the masonry of the rooms and corridors.
In terms of volume, this last part will be assimilated to the filling stones, this is an approximation which simplifies the calculations without distorting the reality.
For the casing which is the “skin” of the pyramid, I take a thickness of 2 m at the base and 1 m at the top, which gives a volume of skin of 106 000 M³ to withdraw from the total volume and to consider separately, because it is the object of a different process, the quarry being 20 KM further south of the Giza plateau on the banks of the Nile.
Finally the original rock mount on which the pyramid was erected was evaluated by Petrie at 6 m height and 140 m square, this volume spared to quarry out and assemble some stones.
This results in 2.4 million M³ for the filling blocks, ie 2.4 million filling blocks and 100,000 casing blocks.
It is obviously the number of filling blocks that size the bulk of the workforce to quarry out and assemble.
The average pace over 5,000 days will be 480 blocks per day of 12 hours so 40 blocks per hour, one block every 90 seconds.
This average daily rate of 480 average blocks will be the average production objective of the site.
An important aspect of the site is its energy balance:
Excavations in the workers’ city led to an estimate of between 1,600 and 2,000 of the number of “hard” workers.
These workers, the NFRW (hear neferou), “the young”, the “effective”, selected as a team of professional athletes today, well fed, well motivated. Intrinsically for a long time with daily repetition, they could deliver without burning out an average power of 80 W or an energy of 1 KWH per day.
The site therefore had a total “human” power of between 130 and 160 KW or a daily energy capacity of 1,600 to 2,000 KWH.
Raising 480 average stones of 2.4 t of 40 m consumes an energy of 125 KWH, which “cost” only 125 NFRW in average necessary staff, it was not the sea to drink!
But these stones had to be quarried out before making a trip of the order of one kilometer to reach their final location. Admittedly, in order to fix the idea that 20% of the workforce was doing something other than quarrying and moving the stones, there remained only between 1100 and 1400 NFRW for these two tasks, ie about 2.6 KWH per average block energy available for these two processes.
As we will see later, the builders had a very efficient method to quarry out the ready to use blocks, but it was nevertheless necessary to spend 2.4 KWH per block.
There was then only 0.2 KWH left to move the blocks from the quarry to their last place, an average path of 1 KM, which limits to 700 N the effort to move a 2.4 t stone horizontally. This is the equivalent of a coefficient of friction no more than 3%, which eliminates the use of sleds slipping on ramps to move stones, because then the coefficient of friction would have been of the order of 20%.
It can thus be seen from the outset that the job / resource energy balance of the site makes it feasible, provided that the builders have tools and methods that have an energy efficiency very close to ONE.