THE PYRAMIDS OF KING SENEFERU

THE PYRAMIDS OF KING SENEFERU

King Seneferu was one of the greatest pyramid builders of the age. Not only did he build three pyramids as well as remodeling another, he also developed the pyramid complex dramatically. Essentially, he took the knowledge of his father’s experiences (King Huni) and took it to new heights. He built the first smooth sided pyramid in the world and he was the first to build an entire pyramid complex with stone blocks instead of mudbrick— as his father had done. When Seneferu came to power, the concept of the aqueduct had just been introduced, and the technology was crude. By the time he left power, the stone built aqueduct was highly refined.

     His first pyramid complex was built in the high cliffs behind the town of Seila, which was in the Faiyum Region upriver from the capital of Memphis. This town was developing rapidly and it needed a rain harvester for their clean water needs. The best place to construct it was in the hills because that area was prone to flash flooding. Thus, the placement of the harvester solved two problems—where to harvest the maximum amount of rainwater, and how to stop the flash flooding. The aqueduct was built in the gulley where flooding was concentrated and the pyramid with its catchment basin was built where floods concentrated before they careened down the gulley. The pyramid itself was rather small compared to Jzoser’s Step Pyramid, but it was a significant structure (100 feet square and 65 feet high). It could harvest about 7,000 gallons of water per inch of rainfall. It also captured flood water and diverted it to the aqueduct. The aqueduct was essentially a modified gulley that was paved with basalt blocks. It may have had sidewalls of limestone blocks, but they may have been mudbrick as well. Huni preferred to make the sidewalls of the aqueduct out of mudbrick coated with plaster, but Seneferu chose to use stone blocks so that it was permanent. The aqueduct at Seila was about 2000 feet long and it led down to a cistern at the base of the cliffs. The only remnant of the cistern is its basalt pavement.

     Seneferu’s second pyramid was built at Dahshur, right across from Memphis. The plateau he built it on was nearly a mile from the Nile, so he dug a canal almost a mile long to connect to the cistern of the pyramid complex. The pyramid was built extremely well from well-shaped limestone blocks that were very large and sturdy. The casing stones are still on the pyramid, and this is a testament to the remarkable construction techniques of the time. Unfortunately, two things went wrong with this extremely large pyramid (330 feet high and 619 feet square). One—the angle was too steep, so when the pyramid reached about half way, it was realized that the tip of the pyramid would be narrow and unstable. The second problem was that the rock plateau was composed of rather soft limestone, so the base of the pyramid began to sink. This caused internal cracking within the chambers of the pyramid, so the decision was made to lower the angle of the second half to the pyramid, which meant that the angle bent inward. Thus, it is called the Bent Pyramid.

At it completion, it was the most massive stone structure ever created and it had a rain catchment potential of 354,300 per inch of rainfall. The aqueduct was the first highly sophisticated aqueduct of the Old Kingdom. It was built entirely out of stone blocks and it reveals a complete understanding of the problems associated with transferring and containing water. In this revolutionary design, the aqueduct became an extension of the catchment basin around the pyramid. It was capable of holding tons of water for long durations of time without leaking, which meant that a greater amount of water could be captured as the catchment basin drained.     The WCB was 75 feet wide, 135 feet long, and approximately 25 to 30 feet tall. The walls were made with fine, white limestone blocks. The roof was made with very large, fine limestone blocks, and it covered the north and south ends of the building. A rectangular courtyard in the middle of the building was left open to the sky. The entrance to the WCB was accessed through the stone basin on the south side of the building. This entrance led to a narrow hallway than ran between four large rain catchment rooms. These cisterns were designed to receive rainwater from the roof above them as it drained in through water inlets. The water was stored until it was needed. When the rooms reached capacity, the excess water on the roof overflowed into a drain that led to the interior courtyard of the WCB. The stone-paved courtyard received water from three sources, which include the sky, the roof over the north area, and the aqueduct. Thus, a lot of water accumulated in this area. As a result, it was probably used as a place to fill water jars. The excess water in the courtyard was released to the stone basin on the south side of the building. The north end of the building contained five small cubicles that once held statues of Seneferu. Ten monolithic square pillars stood in front of the statue area, and these held up a stone roof that protected the statues.  Rainwater collected on this roof and then drained through water inlets that led to the interior courtyard. The WCB was surrounded by a pavement that was approximately 40 feet wide on all sides (as measured from the walls of the WCB). The pavement was enclosed by a plastered mudbrick wall that was approximately 10 feet high. The wall was built on a stone foundation, which helped stabilize it. It also prevented water erosion at the base. The purpose of the pavement was to create a buffer between the WCB and the landscape, which prevented sand from entering the area. The wall also captured any excess rainwater around the WCB. The water on the pavement was drained through an opening that led to the overflow tunnel, where it drained to the harbor. 

An architectural drawing of the WCB.

An overflow tunnel was built from the east wall of the WCB for the purpose of removing excess water from the WCB. The water was delivered to a harbor about 460 feet away. The tunnel had a rather steep angle of approximately 20 degrees. Its walls were made with mudbrick and they were 10 feet thick. They supported a vaulted roof which prevented sand from entering the water channel. This may have been the first aqueduct-type structure to contain a roof, which was needed because part of it was built below ground level. This was unusual, but it was necessary to maintain a constant declination to the harbor. The inner channel was 8 feet wide. The floor of the channel was concave like a pipe so that the water in the channel would flow to the center and drain efficiently. The interior walls were coated with plaster four different times, which indicates that the structure was used for about forty years (ten years per plastering).  Undoubtedly, it was eroded by the swift moving water and recoated regularly. According to the ancient Decree of Pepi I, it was still in use after 300 years of service. This is certain because the water it supplied was still being taxed. Thus, it is likely that all of the old layers of plaster were completely removed about every 50 to 60 years, which would mean that the actual number of years in which it was used would be greatly increased. The next two pyramids of King Seneferu will be discussed in the next blog entry.

The overflow tunnel stone that led to the harbor.