Egyptians apparently used elevators to build pyramids
Ancient Egyptian builders may have used hydraulics as early as 4700 years ago to transport tons of stone to build pyramids. Scientists are speculating about the origin of the water used for this purpose.
French scientists have discovered structures in the Step Pyramid of Djoser and its surroundings that suggest a hydraulic system was used to construct it. The team, led by Xavier Landreau from the private French research institute Paleotechnic, suggests that the nearby Gisr el-Mudir, the oldest known stone structure, may have served as a water reservoir from the higher-lying hinterland, according to the journal PLOS One.
The Step Pyramid of Djoser in Sakkara, located about 20 kilometers south of Cairo, was the first structure to feature two important innovations, as the study authors write: "a pyramid shape for the pharaoh's tomb and the exclusive use of fully dressed stones for the masonry."
Lifting stone masses through targeted flooding?
Another innovation may have been the use of a shaft within the pyramid as a kind of hydraulic lifting device to transport stones. The inner shaft was connected to an outer shaft.
The approximately 200-meter-long pipe between the two shafts lay at a depth of about 27 meters. When the shaft in the pyramid was flooded from the outer shaft, the water rose to the height of the water in the outer shaft - this is the principle of communicating vessels. This could have lifted a raft with stones to a certain height.
However, this alone may not have been enough to bring stones to the top of the more than 62.5-meter-high pyramid. Therefore, the group offers another explanation: a high scaffold with a platform on top could have stood on the raft in the inner shaft. This could have been secured in the masonry of the shaft with beams. With this setup, the builders could have reached higher levels as well.
Where did the water come from in the Sahara region?
The researchers also suggest that ramps were used to transport the stones. The pyramid is made of limestone - like the ground it stands on. Therefore, some of the stones may have come from quarries dug around the pyramid. Some of these quarries may have served to clean the water from the Abusir Lake, which was located west above the pyramid site at the time. Sediments could have settled in several basins of the quarry, making the water gradually clearer over time.
The water may not have been used only as drinking water, but also to supply the outer and inner pyramid shafts. However, where did the water of the Abusir Lake come from? Since the town of Sakkara is located above the Nile plain on the edge of the Sahara.
The team speculates that there was significantly more rainfall in the area 4700 years ago than there is today. Aerial photographs even show an dried-up riverbed: the Abusir Wadi. It may have filled the Abusir Lake from time to time with rainfall.
Retention basins and kilometer-long canals
Between the Abusir Wadi and the Abusir Lake lies the rectangular Gisr el-Mudir. Researchers believe it served as a retention basin: Rainwater from the Abusir Wadi, containing sand and small stones, was largely filtered out of the water through this retention basin.
However, it is uncertain whether the water from the Abusir Wadi was sufficient for the hydraulic system of the Djoser Pyramid. Scientists suspect that water from the Taflah Wadi, which flows into the Nile plain two kilometers south of Sakkara, was also channeled into the Abusir Lake.
"This work opens up a new direction of research: the use of hydraulic power for the construction of the massive monuments of the Pharaohs," the study authors write. Their findings are based on combining insights from archaeology with knowledge from other disciplines such as hydrology, hydraulics, geotechnology, or paleoclimatology.
The team's discovery of hydraulic structures in the Step Pyramid of Djoser supports the theory that ancient Egyptian builders may have utilized hydraulics extensively in the construction of their architectural wonders, such as the pyramid itself. Furthermore, the PLOS One study suggest that the nearby Gisr el-Mudir could have functioned as a water reservoir, providing the necessary hydraulic power for the monumental construction projects.
