20th May, 2012
PYRAMID CONSTRUCTION
The Great Pyramid at Giza is the only remaining Wonder of the Ancient World. It is unique in that over 40 centuries after its construction, Scientists, Egyptologists, Engineers, Mathematicians and Architects cannot agree about how exactly it was made. Like many other aspects of Ancient Egypt, it is not readily yielding of its mysteries.
If it did not exist for all to measure, photograph and analyse, there would almost certainly be a body of opinion to maintain that this great wonder could not have been constructed during that period of history, or that its dimensions had been exaggerated. But the Great Pyramid at Giza is resplendently real, just a bus ride from Cairo centre, and invites us to theorise.
There is no reliable information from the Egyptian Old Kingdom which details the construction method, but the age, size and phenomenal accuracy of the structure has intrigued many and sparked numerous investigations into how and why it was built. Some have measured every possible feature, looking for hidden relationships or codes. Others have examined the materials used and postulated likely methods which might have been employed. Artefacts from the period have been studied, which include measuring sticks, plumb bobs and wooden cradles.
All of this has provided a body of information, but not a viable or complete theory of the actual construction process.
The Great Pyramid today is without its smooth white limestone casing, leaving stones which were behind the casing, exposed as steps at each course level. The unromantic truth about this is that thousands of years after the Pyramid Age, the citizens of early Cairo simply took the white casing stone for other building projects. All pyramids became a ready-made quarry, and the stone removed, was used to build the Mosques, bridges and walls of Cairo.
The statistics relating to the movement of material to build a pyramid should provide a perspective for understanding what might have taken place. To complete the Great Pyramid in 4000 days for example, would have meant delivering and placing each day 650 cubic metres of stone weighing 1700 tonnes. Simultaneously 25 metres of casing would have to be laid so accurately that all would eventually meet at a single point at the apex, almost 150 metres above the base.
However, some modern examples of average work rates are also impressive. During World War II, Liberty Ships weighing thousands of tonnes were completed at the rate of one ship every three days. Assembling the 102 storey Empire State Building from steel sections prefabricated 300 miles away, was at the rate of one storey per day and took less time to complete than the predicted 18 months. It is reported that some of the steelwork was still warm when it arrived on site. It is obvious that to produce the results in each of these examples, an organised and appropriate production system had been prepared and was being applied.
Other achievements and without machinery, include Vietnamese underground guerrilla bases; one with over 350 kilometres of interconnecting tunnels (220 miles) all dug by hand. In the 19th C, when the track gauge was changed on the Great Western Railway, the whole work from London to Bristol (107 miles) was completed in one weekend and in the USA, 10 miles of railroad track was laid from scratch in one day. Railway construction provides other good examples in non-mechanised civil engineering. A cutting at Tring on the London to Birmingham line is 4 kilometres in length and 20 metres deep and the volume of material removed to form the Chalk Farm cutting in north London, is more than the volume of the Great Pyramid. This was achieved by a workforce of 20000 over a 5 year period and their work rate tallies with that of a 'good navvy' from the period who would be expected to move up to 20 tonnes of 'muck' up and into a wagon each day.
The Great Pyramid is the largest and most well known of all the pyramids, but others constructed during the same period are also large and accurate, even though each has a slightly different shape or dimensions. It follows that any solution to the mystery of the construction processes employed in the Great Pyramid must also apply to all others and clearly demonstrate how a work rate can be achieved, with the materials and tools known, to create the structures with the shapes found.
To focus only on the moving of large blocks for example is not enough as this aspect is only one of the many inter-related processes in the completion of the design.
It is necessary to show, not only how the Ancient Egyptians might have moved typical blocks of stone, but what was done with them when they arrived at a pyramid and why.
Some believe that a solution cannot be found or too readily accept an incomplete answer. Latterly this topic has attracted all kinds of theories which exploit this lack of a complete and practical solution and allowed authors to introduce ideas, which have no basis in either fact or logic and at the very least add confusion to the topic.
Some proposals for example, have suggested that pyramids incorporate star alignments, which represent key elements of an Ancient Egyptian religion, but without explaining how these supposed features were actually formed within the pyramid.
Others have begun with an assumption that all blocks are of equal size, and simply investigated the ways that these 'average' blocks might have been moved. In fact the visible blocks on the exterior of the Great Pyramid for example, vary in weight from 20 tonnes at the base to less than one tonne in the majority of courses and even these are not representative of the whole structure.
Those theories which focus on shaping a pyramid fall into several groups. 'Rise and Run' is a method, which proposes that each exterior casing block is marked or shaped with a face slope, based on its chosen profile. When these blocks are carefully placed on a level and straight course of blocks below, this would allow the faces of the pyramid to rise to the chosen height, with all four sides and corners eventually meeting at a single point at the top. However, blocks from pyramids which have had their slope angle measured on a level surface have been found to differ from their pyramid slope to such an extent that some would fit better on other pyramids with a different slope. It is suggested that these deviations in slope angles, plus or minus, would have been automatically 'self correcting' during construction
An alternative method is for the builders to check the pyramid face slope during construction by measuring inwards at specific heights, an amount which corresponds to the height : half base ratio. Backsighting is proposed as an additional aid which suggests that the pyramid shape is controlled by visually comparing blocks as they are laid with those already in place, with an aim of ensuring that the pyramid faces and corner edges follow straight lines. A variation of this method, proposes that an internal core structure is constructed first with a pole eventually planted on top at the apex position, thus providing a single point to which the corner edges and sides of the casing can also be visually aligned. However visual sighting does not provide any help in constructing accurately and at best would only provide a means for identifying errors after the event which are then impossible to correct.
A skilled bricklayer for example, would find it impossible to build a wall of any kind using visual alignment only to keep it straight and vertical.
None of these methods satisfactorily explains how the straightness of a course of blocks is maintained when there is no physical guide. Each wrongly assumes that a pyramid shape can be accurately formed by carefully placing marked blocks, which might already contain errors and without an opportunity for making adjustments until later. They would have to rely entirely on the straightness of an earlier course of blocks as the only guide for placing the blocks of a subsequent course.
If it were in fact possible to build a large solid pyramid using any of these 'rise and run' techniques then it would have been more reasonable for the Ancient Egyptians to have simply cut or marked all their casing blocks with vertical faces and then tilted the course so that the face matched the desired 'rise and run' angle. Significantly, not one of the methods proposed for controlling the shape of a large pyramid is able to describe how the corner edges are formed where the pyramid faces meet.
Some pyramids with their casing sufficiently intact, show face slope angles which vary on each side and some have faces which are not completely flat. However all have corner edges running straight to their apex, where an error of only one degree at the base of the tallest, would have caused them to miss by over five metres at the top.
It is the difficulties and limitations identified in implementing any of these construction processes to form pyramids, which has forced ever more exotic proposals to be devised for the delivery of material to them. These range from complex ramp systems both inside and outside the pyramid, to steps and slides using levers and winches of various designs to move usually an 'average' block. As these pyramids approach the apex their delivery and alignment problems magnify.
The Virtual Apex Method detailed in my book 'Building Egyptian Pyramids- Achieving the Impossible', describes a construction process that can be applied to form any solid pyramid accurately. Delivering material to a pyramid using this design can be made using an effective platform and ramp system which provides access to the exterior at all heights including the apex.
With over 100 drawings, diagrams and photographs I illustrate how The Ancient Egyptians, who discovered the method, applied it in its simplest form to build all their massive pyramids.
Photographs courtesy of Jon Bodsworth
www.egyptarchive.co.uk
Photograph John and Moreton Edgar
If you would like to investigate more about the Pyramid Age you will find many fascinating pieces of evidence at Ancient Wisdom