Pyramid Construction Theory

Article by Daniel Gerardo

The pyramids, a monument of human strength and intelligence, have caused awe and curiosity among men at all times. Cheops's Pyramid - also called the Great Pyramid -, which was raised on the Gizeh plateau during the ancient Egyptian Empire, is the masterpiece of builders. The construction techniques applied for carrying out this work and the explanation of the reasons for its unique inner layout are both vast and debatable matters.

In this article I shall refer to two issues which have attracted the attention of archaeologists from Borchardt's time to our days:

a) the method used for lifting the blocks of stone;
b) the purpose of the Grand Gallery.

Traditionally, the two questions have been analysed separately without ever gathering enough evidence in either case. I shall briefly outline the existing scientific views on each one of them and will then formulate a different approach whose uniqueness lies in the fact that the two are assumed to be related.

The Purpose of the Grand Gallery

Flinders Petrie was the first archaeologist to express the opinion that the Grand Gallery had been used for storing the three granite blocks blocking the upward corridor - where they had been placed after the Pharao´s funeral (see Fig. 1).

Borchardt shares this idea, yet he points out that it can explain neither the slots carved in the lower part of the third row of stones on the side-walls of the gallery, nor the blocks mounted on each one of the twenty-eight holes carved in the wall benches at regular intervals (see Fig. 2). He also believes that the blocks of stone on the floor of the gallery might have hindered the funeral procession, and postulates that they were placed on a wooden platform mounted on the side-wall slots which was supported by logs embedded in the bench holes. He completes his hypothesis with the theory of the successive stages of the construction, based on the assumption that during the building process three changes were made in the layout plan. This might cast a new light on the existence of three chambers in the pyramid. According to Lauer, the second layout plan provided that the intermediate chamber would act as a chapelle ardente while the gallery would be built as a dead-end hall for storing the large granite blockswhich would obstruct the whole upward corridor. In the end, this idea might have been discarded by the builders. The upper- and antechambers were furnished with a built-in blocking system which provided sufficient safety for the upper storey, so the builders may have deemed it unnecessary to obstruct the whole upward corridor and thus limited the number of blocks to three. The remaining granite stones were used for building the upper chamber. They mounted a scaffolding akin to the one formulated by Borchardt - and consistent with the various details found in the gallery - in order to raise the blocks of stone to the upper chamber.

Techniques for Lifting the Stone Blocks

The average weight of the blocks of stone in Cheops's Pyramid amounts to 2,500 kilogrammes - except for the huge slabs on the 68-metre-high roof of the granite chamber and its outlet rooms, near the centre of the building. There was but one way in which ancient Egypcians could lift those enormous slabs: the use of the straight ramp made of bricks and earth. Considering that vestiges of ramps were found during archaeological explorations, the straight ramp theory formulated by Borchardt and completed by Lauer was unanimously accepted at that time. However, the use of a straight sloping path proves extremely laborious when it comes to reaching heights like those in this pyramid, as the volume of the material on the ramp could only be compared with that of the pyramid itself.

The use of a spiral ramp might have helped overcome this difficulty. Even though no archaeological evidence has confirmed it, the spiral ramp theory has been widely accepted among scientific circles.

J.F. Lauer, an archaeologist who has greatly helped elucidate this issue, suggested a variant to his straight ramp model. He postulates that ramps of increasing steepness were placed one on top of the other, taking into account both the gradual average-height decrease in the courses as they approached the peak, and the fact that the huge stone slabs are not found above the height of 68 metres in this pyramid. Furthermore, superimposed ramps make it possible to limit their length from the foot of the pyramid to 300 metres. The great advantage of this system is that the ramps in the lower levels of the pyramid are extremely wide, providing vast building surfaces. Their width decreases slightly as each new row of stones is placed. The outer path, on the other hand, lengthens towards the south and towards the north, where a system of large counterbalance baskets filled with sand, descending along the face of the building, may have helped lift the heavier blocks of stone.

A Different Proposal

It is clear that one of the objectives of pyramid builders was to increase the height of their constructions. In the case of Cheops's Pyramid they achieved the maximum height of 147 metres - surpassing by far that of the proceeding South Pyramid (103 metres) and North Pyramid (92 metres) of the Dahshur Group. This remarkable increase in height entailed growing difficulties. Builders had to solve a number of structural problems which were apparent both in Meidum and in the South Pyramid, and they also had to confront ever-increasing difficulty when raising the blocks of stone to much higher positions.

Most probably, as construction evolved the block-lifting techniques also varied. Thus, the difficulties that the old construction methods entailed could finally be overcome. Coinciding with the unprecedented height of Cheops's Pyramid there is also an unprecedented feature in its inner layout: the Grand Gallery.

Let us consider that both phenomena are connected, that is to say, that the remarkable increment in height has been achieved by applying a block-lifting method which calls for the existence of an inner ramp with the characteristics of the Grand Gallery.

In order to clarify my thesis, I shall adopt the hypothesis that the gallery was used as an inner ramp whereon a counterweight would slide (see Fig. 3). To illustrate the practical application of the method I am postulating, let us imagine that the pyramid has been built up to the height of 100 metres; its upper surface is a square platform where the next row of blocks is about to be placed. Inside the building, the sloping gallery is divided by a wooden platform mounted on the existing slots along the third tapering of the side-walls. Under this platform a counterweight container filled with small stones is sliding along the wooden rails fixed to the benches. The holes at regular intervals make it possible to fit the logs to the benches by means of wooden pegs, while the blocks embedded in the walls, acting as bumpers, halt the counterbalances at intermediate positions.

A vertical conduit connects the south wall of the gallery with the upper surface of the building. The effect resulting from the counterweights sliding movement is transferred by means of ropes and lubricated props thus helping lift the blocks of stone outside. By the time a block has been lifted, the counterweight reaches the end of its run, next to the north wall of the gallery, where it is unloaded. A group of men standing on the platform in the gallery raise the unloaded counterweight back to its initial position in the upper part of the gallery by means of ropes. Once the counterbalance has been loaded again, another block of stone can be lifted. As we can see, the apparently inexplicable details and features in the gallery can now be explained in the light of the roles they have been assigned. The greatest virtue of this new way of visualising this Question is that it is susceptible of proof. As a matter of fact, in order to describe the method I am postulating I assumed that there existed a vertical conduit connecting the south wall of the gallery with the building platform, and that this conduit made it possible to transfer the kinetic energy generated during the sliding movement of the counter-balance to the building platform outside. Let us now imagine that the construction of the pyramid - including the surfacing - has been completed.

The next task to be performed is the obstruction of the vertical conduit. If we assume that this conduit did exist and that it was obstructed by means of small blocks, evidence of this should necessarily be found in the upper lock of the building. Fig. 4 shows a drawing of the upper lock made by E.W.Laner a professional draftsman, in his work "Exhaustive Description of Egypt" (British Museum, add. MS. 34,083, f.24) -first published in C.W. Ceram´s book "In Search of the Past". Three small blocks of stone placed one next to the other can be seen on the east face of the building, near the centre of the platform (see arrow).

I shall point out two facts that can prove the existence of the aforementioned obstruction. In the first place, the size of these three blocks differs from that of the rest of the stones in the platform. Secondly, the stones which still remain from the previous course are placed along the edge of those small blocks and do not form the lock, as one would suppose they should. This detail, which will be analysed in due course, makes it possible to prove in one way or another the alternative theories I have formulated.

The Chephren Pyramid was built right after Cheops's Pyramid and is slightly lower in height; it is logical to deduce that its inner layout should be similar to the one we have just analysed, as suggested by different archaeologists. In short, the use of an inner counterweight during the construction may have helped lift the blocks of stone to unprecedented heights, thus supplementing the existing building methods. Furtbermore, it makes it possible to explain both the use and the unique characteristics,of the Grand Gallery.

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