Senefru's Fouth Pyramid Complex

FOURTH PYRAMID OF SENEFERU

2605 BCE

King Seneferu constructed his fourth pyramid complex one mile north of his earlier pyramid at Dahshur and titled it Khai , which meant Glorious (the same name as his other pyramid complex in Dahshur). This was the third geometrically true, smooth sided pyramid in Egypt. The core was constructed with very large, finely shaped limestone blocks that contained a high amount of iron, which had a reddish tint caused by the oxidation of iron. During the Old Kingdom, the core was covered with polished, white casing stones, and the pyramid was stark white. It had a gentle angle of 44 degrees from top to bottom, so it seems slightly flat compared to other pyramids, but it is quite elegant. Its dimensions are 720 feet square (almost as wide as Khufu’s pyramid) and 324 feet high. It had a rain catchment potential of 446, 900 gallons of water per inch of rainfall.

The catchment basin was paved with fine limestone blocks that were joined with mortar. It averaged 65 feet in width from the base of the pyramid. The width of the basin was significantly reduced compared to Seneferu’s earlier pyramid at Dahshur. The narrower basin was more practical because it caused the water level to become higher, which improved its efficiency. At some point, the width was reduced even further to about 40 feet on the east side of the pyramid. The earlier wall preserved because it made an excellent wind barrier. The narrow basin caused the water in the channel to become higher, which create mass and made the water flow more efficiently towards the aqueduct. This essentially pushed the water out of the basin and into the aqueduct more efficiently than a shallow basin, which drained slowly. In the wider basins, the water rested too long, which caused a certain amount of evaporation to occur. The water might also leak. Huni pioneered the concept of the narrow basin for his small step-pyramids because it was more advantageous for a small pyramid. However, Seneferu assumed that a wider basin was more advantageous for his first mega-pyramid. His assumption was incorrect, and he reacted by building a much narrower basin for his second mega-pyramid. The new basin had a rain catchment potential of 85,000 gallons of water per inch of rainfall. After Seneferu’s reign, narrow catchment basins became standard for all pyramid complexes of the Old Kingdom.

     The enclosure wall of the basin was built with fine limestone blocks that were polished and mortared. It was 25 feet high and 15 feet wide.

     The first known WMB (water management building) was constructed at a pyramid complex. It resembled a pavilion-like structure composed of eighty stone pillars supporting a stone roof made of monolithic blocks of limestone. It was 90 feet by 100 feet, and completely open on all sides except the west (the pyramid side). Thus, it would have been an airy, shaded environment with an opening in the roof for light. It contained a large colonnaded open-air courtyard as well as four stone courtyards with rectangular cisterns. Its function was to receive rainwater on its roof as water descended from the east side of the pyramid.  There were inlets in the roof  (perhaps eight to sixteen) that allowed rainwater to drain into four courtyards that contained cisterns. Each of the courtyards in the east half of the building contained a large, rectangular stone cistern. The stout walls of the cisterns provided additional support for the roof, which otherwise would have been held up entirely by pillars. When the cisterns reached capacity and began to overflow, the excess water spilled over the walls and fell onto the pavement to the catchment basin. The pavement was about 15 inches higher than the catchment basin, which ensured that rainwater would not accumulate around the cisterns. Most likely, this was a work area where water jars were filled. The pavement declined from the pyramid to the aqueduct so that rainwater would naturally flow to the aqueduct’s entrance.

     The walls of the aqueduct were attached to the enclosure walls of the catchment basin, near the center of the eastern wall. The channel’s width was about 6 feet. The aqueduct may have been extremely short compared to others, and this may be why most of the stone blocks are missing. It is likely that this early aqueduct did not have had a roof.

     Egyptologists have not determined the location of the WCB, although it may have been built on a flat, rectangular area of land about 550 feet NE of the enclosure wall of the pyramid. This area appears to have been artificially raised, and it would have been a suitable size for a WCB (approximately 130 feet by 245 feet). This location would have placed the structure at the end of a long canal that once joined the Nile River. 

     The WCB of this complex was mentioned on a stone tablet found in the ruins of the pyramid town called Djed. This tablet contained a decree by Pepi I which essentially exempted the townspeople from paying taxes for water-related facilities. It stated that the residents would not be taxed for anything related to the use of water, which included trees, garden ponds, private wells, and the two WCB structures that were associated with Seneferu’s pyramid complexes. The decree referred to the pyramid complexes as the double pyramid complexes. These structures were approximately 300 years old when the decree was written, which implies that the two WCB structures were still being used as cisterns long after Seneferu died. Most likely, they had been maintained diligently by the local people who were exempted from taxes.
 

     Seneferu’s ambition to build four major pyramid complexes was not the result of his need to design a perfect pyramid for his burial. His father, Huni, had also built multiple step-pyramids, and only one of them contained chambers (the one at Meidum). Menkaurai built two pyramid complexes at different sites. These kings built multiple pyramids because they needed to provide their newest settlements with large rain catchment systems. Southern Memphis was located across the Nile River from Dahshur and it had a burgeoning  population. Therefore, it needed two RCS. Every pyramid complex Seneferu built required tremendous effort to construct and a vast expenditure of resources. It can be assumed that these projects had the enthusiastic support of everyone because these projects benefited thousands of individuals, including the king. Prior to Seneferu’s reign, there were very few giant RCS complexes in Egypt. The technology of the aqueduct-type pyramid complex had just been invented prior to his reign. He experimented with the design of the pyramid complex until his death, and most of his innovations became vital to later pyramid complexes.

  

SENEFERU • PLAN OF FOURTH PYRAMID COMPLEX • DAHSHUR

Third Pyramid of Seneferu

THIRD PYRAMID OF SENEFERU

2615 BCE

King Seneferu rebuilt and enlarged the step-pyramid complex of Huni at Meidum approximately fifteen years after it had been constructed. As part of the renovation, he transformed the step-pyramid into a smooth-sided (non-stepped), geometrically true pyramid. This was his third pyramid project.

     The ancient title of this pyramid complex is unknown, but it may have been the same title given to Seneferu’s nearby pyramid town called Djed  , which meant Endurance. It was similar to many other titles of the Old Kingdom pyramid complexes, including two of Seneferu’s, which were titled with a single hieroglyphic word (Glorious  ).

When Seneferu rebuilt the earlier step-pyramid, he filled in the steps and formed a smooth surface. Essentially, he covered the outer surface with a new layer of casing stones and gave it the appearance of a geometrically true pyramid. His engineers applied the casing stones over the earlier casing stones on Huni’s step-pyramid, which was a risky construction technique because the earlier casing stones were not a suitable underlay for the new casing stones (the core that is visible today is actually the finished exterior of the step-pyramid of Huni). The lower courses of the casing stones were not capable of supporting the casing stones above, and this eventually caused them to collapse. However, it is evident from the rubble around the base of the pyramid that the collapse was evenly distributed, so it appears that all of the sides fell during a single event, such as an earthquake. An observatory structure was uncovered in the rubble, and it was in excellent condition, so it may have been buried by the collapse before it could be used (the stele were never inscribed). Thus, it is possible that a collapse occurred during the renovation.

     The decision to alter the step-pyramid was based on the realization that rainwater would cascade down the pyramid’s sides more efficiently if there were no steps interfering with its descent. The builders stacked small stone blocks on the steps for support and then covered them with polished limestone casing stones that were mortared together. The new casing stones enlarged the original step-pyramid by about twenty percent to form a new base that was 475 feet square. The new height was 300 feet. The surface of the pyramid had a rain catchment potential of 225, 180 gallons of water per inch of rainfall.

Seneferu paved the bare bedrock that originally formed the floor of the basin with mudbrick and then plastered it. Apparently, he was trying to level out the old basin to help it drain properly. He did not pave the basin with stone blocks. He expanded the size of the original catchment basin and built a new enclosure wall made with large limestone blocks. The older fieldstone wall was removed. The basin was about 150 feet wide, from the pyramid’s base. This was much wider than later catchment basins around pyramids. The extreme width was ideal for harvesting a great amount of rainwater. However, it was inefficient because the water level would have been too shallow, which meant that it would drain very slowly to the aqueduct. This delay could allow some of the water to evaporate or leak. A wide basin was difficult to maintain because it had excessive surface area, which is probably why Seneferu paved it with plaster instead of stone blocks. The expansive basin would have required an enormous amount of stone blocks to create, and an incredible amount of mortar for the joints. Additionally, it would have required extensive  maintenance. It had a rain catchment potential of 84, 750 gallons per inch of rainfall. The width of later catchment basins was less than half the width of the one at this pyramid complex. Nearly all the catchments basins after Seneferu’s reign were paved with polished, fine-grained stone blocks.

     The gate to the aqueduct was located in the center of the eastern enclosure wall. Its remains indicate that it was a stop log water gate that contained wooden planks, which were lowered or raised to determine the speed of the flow of water as it was released to the aqueduct.

  

A small, rectangular structure (30 feet square and 10 feet high) was built against the east face of the pyramid (within the catchment basin). It was made of fine limestone blocks. A stone enclosure wall surrounded the structure on three sides, with the fourth side being formed by the face of the pyramid. It was entered through a stone portal that led to a zigzag hallway, which led to a small open-air courtyard at the foot of the pyramid. There was just enough room inside the courtyard for two large, upright rectangular slabs of fine limestone. They were never inscribed, and this may indicate that they were used as gnomons.

     When it rained on the pyramid, the water cascaded to the courtyard and flooded it. The water then drained through the zigzag corridor and spilled into the catchment basin. As the catchment basin filled with water, the structure was partly submerged. This did not affect the building because it was made entirely of stone. The structure may have functioned as an observatory for the purpose of calculating the seasons as well as determining the timetables for planting crops. It would have been possible to determine the solstice with two gnomons that faced eastward. The stones would have cast their shadows against the smooth surface of the pyramid and they could also be used to tell the time of day. A person could stand under the roof of the structure and make observations of the shadows on the pyramid. The zigzag corridor, which was behind the observer, prevented light from entering the chamber. This helped maintain a cool temperature within the structure. There is a very similar gnomon structure at the second pyramid complex of Seneferu, which was built just prior to this one.

King Huni constructed a satellite pyramid on the south side of the main pyramid prior to the Seneferu’s rebuilding phase. Seneferu incorporated the satellite into the new catchment basin when he redesigned the complex. It was approximately 90 feet square and 55 feet high. It’s purpose was to capture rainwater and store it below its base. The enclosure wall of the new complex was built around it. Presumably, the satellite continued to capture rainwater during light rainstorms.

     

The new aqueduct was one of the first ones constructed entirely out of stone blocks. It was 500 feet long and 10 feet wide. It coursed nearly due east on a channel that was carved directly into the bedrock. The interior channel was 4 feet wide. Its walls were 3 feet wide and 7 feet high. They were constructed with very large limestone blocks. The earlier aqueduct, which had mudbrick sidewalls, was the last one ever built with mudbrick elements (except for Shepseskaf’s) during the Old Kingdom. This is because the aqueduct walls had to be replaced and repaired too often. Stone walls endured much longer in a watery environment. The aqueduct did not contain a roof. When the aqueduct was first excavated, archaeologists discovered that the water channel was layered with mudbrick that had been placed over the stone pavement. This was probably done long after the RCS stopped functioning in order to provide a better surface for pedestrian traffic (when the memorial monument was visited during the New Kingdom). 

White limestone blocks and part of a granite doorway for the WCB were discovered near the banks of the ancient Nile River. Unfortunately, the structure lies below the water table so it cannot be excavated without considerable expense and technology. A long mudbrick wall was discovered near the end of the aqueduct, and this may be part of the enclosure wall of the WCB.  

 

SENEFERU • PLAN OF THIRD PYRAMID COMPLEX