The Great Pyramid of Giza has seen 4,600 years of history, flourishing empires and fallen dynasties. Built to serve as the tomb of Pharaoh Khufu, it nevertheless remains shrouded in mystery: how did the Egyptians of the Old Kingdom manage to erect such a stone monster without steel, without wheels for heavy transport and without sophisticated pulleys? Let’s put aside the theory of extraterrestrial construction: how did men achieve such a miracle?
Computer engineer Vicente Luis Rosell Roig has just proposed a very concrete response, based on digital models rather than fantasies. It starts from a simple observation: the classic hypothesis of a large rectilinear ramp allowing 2.5 tonne blocks to be hoisted to the top poses enormous practical problems. To remain sufficiently gentle, this ramp would have had to be gigantic, and only allowed one team to move at a time, which would have considerably slowed down the construction site. The spiral versions, accepted by many Egyptologists, improve traffic, but involve an exterior structure that should have left visible archaeological traces.
Rosell Roig proposes a variant, detailed in an article in Popular Mechanics: a spiral ramp integrated into the very interior of the pyramid, along its edges, then gradually covered by the facing blocks as the elevation progresses. Once the work was completed, there would be nothing left to dismantle, and almost no direct trace of this ramp would be visible from the outside. To test this idea, the researcher designed an algorithm which aimed to find the most efficient geometry: ideal angle, width of the corridors, number of ramp segments, without weakening the structure. Too many repetitions in the spiral would, according to him, have compromised the integrity of the pyramid.
The constraints to be respected were tight: the base of the Great Pyramid measures approximately 230 meters on each side, for a height of approximately 147 meters, and it is estimated that it is made up of approximately 2.3 million blocks. To build it within the window of 20 to 27 years of Khufu’s reign, it was necessary on average to place a block every three minutes over the duration of the construction site. The algorithm therefore had to not only propose a plausible ramp, but also show that such a pace was achievable with the technology of the time.
The crucial role of the Nile and its floods
In his article published in NPJ Heritage Science, Rosell Roig recalls that the builders of the Old Kingdom had copper chisels, water-lubricated sleds, ropes, levers, earth embankments and barges on the Nile, but neither iron tools, nor wheeled carts for heavy loads, nor complex pulley systems. He incorporated these limitations into his model by setting bounds on the slope percentage, the width of the ramp lanes and the possible friction forces. The software then calculated the minimum time between two blocks deposited, depending on the number of teams, to manage to stay within the famous window of 20-27 years.
To fill in certain gray areas – how exactly did the blocks reach the foot of the monument? – the researcher relied on a rare and precious source: Merer’s diary, also called the “Jarf papyrus”, discovered in an ancient port on the Red Sea. These documents relate the daily work of an inspector responsible for transporting blocks of limestone by boat, taking advantage of the floods of the Nile to the Giza site. They confirm the existence of fluid logistics, structured into teams named by hieroglyphs, which shared the transport of materials.
Rosell Roig extrapolates: if several teams divided the four sides of the pyramid, each could climb their blocks up a segment of gently sloping ramp, covering a quarter of the turn before giving way to another. Widened areas at the corners would have allowed maneuvers without traffic jams, while frontal access to each section reduced the towing distance. As other experiments have shown, simply sprinkling sand in front of the sleds can greatly reduce friction, making moving massive loads much more realistic.
One of the advantages of the model is its flexibility: the phases of setting up the bases and storing the blocks could have lasted more or less long without invalidating the whole thing, as long as the average block throughput remained sufficient. Rosell Roig also suggests that geophysical studies could, in the future, test certain very concrete aspects of his hypothesis: mapping possible areas of wear at the corners or even checking certain internal anomalies already detected by imaging, which could correspond to the old route of the ramps.
Far from definitively closing the debate, this work above all offers a transparent, reproducible simulation framework to confront major construction hypotheses with realistic physical and logistical constraints. But it has the merit of showing that with barges, sleds, ropes and good organization, the builders of Cheops had no need of extraterrestrial help to hoist 6 million tons of stone into the sky.
