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Great Pyramid of Giza
Great Pyramid of Giza
Great Pyramid of Giza was the world's tallest building from ~2570 BC to ~1300 AD.*
Preceded by Red Pyramid of Sneferu, Egypt
Surpassed by Lincoln Cathedral
Location Giza, Egypt
Constructed ~2570 BC
Roof 138.8 m, 455.2 ft (Formerly height: 146.6 m, 480.9 ft)
* Fully habitable, self-supported, from main entrance to rooftop; see world's tallest structures for other listings.
Great Pyramid of Giza from a 19th century stereopticon card photo.
The Great Pyramid of Giza (29°58?44.68?N, 31°08?02.58?E) is the oldest and only remaining member of the Seven Wonders of the World. Most Egyptologists agree the pyramid was constructed over a 20 year period concluding around 2560 BC. It is generally believed the Great Pyramid was built as the tomb of Fourth dynasty Egyptian pharaoh Khufu (Cheops), after the person who created it, it is sometimes called Khufu's Pyramid or the Pyramid of Khufu. Khufu's vizier, Hemon, is credited as the architect of the Great Pyramid.
The Great Pyramid is the oldest and largest of the three pyramids in the Giza Necropolis bordering what is now Cairo, Egypt in Africa. It is the main part of a complex setting of buildings that included two mortuary temples in honor of Khufu (one close to the pyramid and one near the Nile), three smaller pyramids for Khufu's wives, an even smaller "satellite" pyramid, a raised causeway connecting the two temples, and small mastaba tombs surrounding the pyramid for nobles. One of the small pyramids contains the tomb of queen Hetepheres (discovered in 1925), sister and wife of Sneferu and the mother of Khufu. There was a town for the workers of Giza, including a cemetery, bakeries, a beer factory and a copper smelting complex. More buildings and complexes are being discovered by The Giza Mapping Project.
A few hundred metres south-west of the Great Pyramid lies the slightly smaller Pyramid of Khafre, one of Khufu's successors who is also commonly considered the builder of the Great Sphinx, and a few hundred metres further south-west is the Pyramid of Menkaure, Khafre's successor, which is about half as tall. In modern day, the pyramid of Khafre is the tallest of the three pyramids since the Great Pyramid has lost about 8 metres of material from its tip. In ancient times, King Khufu's pyramid was indeed taller, but even then, Khafre's pyramid appeared taller because its sides are at a steeper angle than Khufu's pyramid and it was constructed on higher ground.
Mainstream Egyptologists believe that it was constructed in approximately 20 years. Their generally accepted estimated date of its completion is c. 2500 BC. Although this date contradicts radiocarbon dating evidence it is loosely supported by a lack of archaeological findings for the existence prior to the fourth dynasty of a civilization with sufficient population or technical ability in the area.
RJ or RL-shaped supports possibly used to raise several-ton stone blocks.
Materials and workforce
Many varied estimates have been made regarding the workforce needed to construct the Great Pyramid. Herodotus, the Greek historian in the 5th century BC, estimated that construction may have required 20,000 workers for 20 years. Recent evidence has been found that suggests the workforce was in fact paid , which would require accounting and bureaucratic skills of a high order. Polish architect Wieslaw Kozinski believed that it took as many as 25 men to transport a 1.5-ton stone block. Based on this, he estimated the workforce to be 300,000 men on the construction site, with an additional 60,000 off-site. 19th century Egyptologist William Flinders Petrie proposed that the workforce was largely composed not of slaves but of the rural Egyptian population, working during periods when the Nile river was flooded and agricultural activity suspended. Egyptologist Miroslav Verner posited that the labor was organized into a hierarchy, consisting of two gangs of 100,000 men, divided into five zaa or phyle of 200 men each, which may have been further divided according to the skills of the workers. Some research suggests alternate estimates to the accepted workforce size. For instance, mathematician Kurt Mendelssohn calculated that the workforce may have been 50,000 men at most, while Ludwig Borchardt and Louis Croon placed the number at 36,000. According to Verner, a workforce of no more than 30,000 was needed in the Great Pyramid's construction.
A construction management study (testing) carried out by the firm Daniel, Mann, Johnson, & Mendenhall in association with Mark Lehner and other Egyptologists, estimates that the total project required an average workforce of 14,567 people and a peak workforce of 40,000. Without the use of pulleys, wheels, or iron tools, they surmise the Great Pyramid was completed from start to finish in approximately 10 years. Their critical path analysis study reveals estimates that the number of blocks used in construction was between 2-2.8 million (an average of 2.4 million), but settles on a reduced finished total of 2 million after subtracting the estimated area of the hollow spaces of the chambers and galleries. Most sources agree on this number of blocks somewhere above 2.3 million. The Egyptologists' calculations suggest the workforce could have sustained a rate of 180 blocks per hour (3 stones/minute) with ten hour work days for putting each individual block in place. They derived these estimates from construction projects that did not use modern machinery. This study fails to take into account however, especially when compared to modern third world construction projects, the logistics and craftsmanship time inherent in constructing a building of nearly unparalleled magnitude with such precision, or among other things, the use of up to 60-80 ton stones being quarried and transported a distance of over 500 miles.
In contrast, a Great Pyramid feasibility study relating to the quarrying of the stone was performed in 1978 by Technical Director Merle Booker of the Indiana Limestone Institute of America. Consisting of 33 quarries, the Institute is considered by many architects to be one of the world's leading authorities on limestone. Using modern equipment, the study concludes:
"Utilizing the entire Indiana Limestone industry's facilities as they now stand [for 33 quarries], and figuring on tripling present average production, it would take approximately 27 years to quarry, fabricate and ship the total requirements."
Booker points out the time study assumes sufficient quantities of railroad cars would be available without delay or downtime during this 27 year period and does not factor in the increasing costs of completing the work.
Theentire Giza Plateau is believed to have been constructed over the reign of five pharaohs in less than a hundred years. In the hundred years prior to Giza, beginning with Djoser who ruled from 2687-2667 BC, three other massive pyramids were built - the Step pyramid of Saqqara (believed to be the first Egyptian pyramid), the Bent Pyramid, and the Red Pyramid. Also during this period (between 2686 and 2498 BC) the Wadi Al-Garawi dam which used an estimated 100,000 cubic meters of rock and rubble was built.
The accepted values by Egyptologists bear out the following result: 2,400,000 stones used ? 20 years ? 365 days per year ? 10 work hours per day ? 60 minutes per hour = 0.55 stones laid per minute.
Thus no matter how many workers were used or in what configuration, 1.1 blocks on average would have to be put in place every 2 minutes, ten hours a day, 365 days a year for twenty years to complete the Great Pyramid within this time frame. This equation, however, does not take into account among other things the designing, planning, surveying, and leveling the 13 acre site the Great Pyramid sits on.