French architect Jean-Pierre Houdin thinks he’s got the answer to the age-old question of how the ancient Egyptians built the Great Pyramid. He suggests an external ramp was used to create the bottom third of the pyramid, but the rest was built using an internal spiral ramp and a system of counterweights for lifting the 2.5 ton blocks.
He believes workers used an outer ramp to build the first 43 metres (47 yards) then constructed an inner ramp to carry stones to the apex of the 137m pyramid. [...]
Mr Houdin said that an outer ramp all the way to the top of the pyramid would have blocked sight lines and left little room to work, while a long, frontal ramp would have used up too much stone.
Further confusing matters, there is little evidence left of external ramps at the site of the Great Pyramid.
Houdin’s theory also explains how the immense 60 ton granite beams were erected above the King’s Chamber, something none of the other theories can account for.
You can get a glimpse of Houdin’s 3D model in this news clip:
For the full story, there’s a really good pdf here, complete with excellent graphics and detailed explanations of competing theories as well as Houdin’s: ‘Khufu Revealed’ pdf.
If you don’t mind installing a 3D plugin (it took me about 3 minutes in Firefox, plus a few more to load the model), you can take the complete Houdin-guided CGI tour of his theory. I highly recommend it. It’s frikking amazing.