Raising an Obelisk: Part 2

Our raising apparatus was a derrick of sorts, designed to reduce the pulling load required to rotate the obelisk cartwheel-fashion into its final position. Opposed, canted sets of X-braced 10x10s were tenoned at 45 degrees into a 20-ft. timber sledge framed with dovetailed ties to hold the runners parallel. Trapezoidal blocks installed between the canted arm sets increased the compressive strength of the system.

IOLO Roberts and Wyly lashed the entire structure onto the obelisk waiting on the ramp (above). Ropes encircled the belly of the 33-ton beast, then passed over the outstretched arms of our frame and to the ground. When pulled down, the obelisk would drop onto a pivot log on the lower bearing wall. Continuing the pull would bring the obelisk, rotating in its own length, down to the pedestal stone sitting on grade. In preparation, Wyly gathered the group together to pay respects to the ancient builders who had come before us. Now our hard work would be put to the test.

Mark Whitby first tried to pull the obelisk with four 2-in. ropes stretched over the derrick and down to snatch blocks attached to telephone poles lashed to two granite deadmen. Later in the day, a 31/2-ton granite counterweight was added to the system to assist the pull. Later still, a front-end loader (probable Middle Kingdom technology?) entered the picture. Ropes regularly stretched and finally broke. The obelisk persistently turned out of its intended line of rotation. Nearing the end of the day, 170 enthusiastic pullers lined up in a final attempt to rotate the stone. As the pullers tugged, inspired by traditional chants, the obelisk would rhythmically raise its head but the pivot log on which it rested continued to slide closer and closer to the edge of the bearing wall, too close to continue safely. The order was given to call it a day. That night, back at the New Cataract Hotel, the engineers decided to abort the mission. Once again the mystery of the ancient obelisk builders remained veiled. Wyly and I stood in amazement. How could we give up so easily?

At the time, I could not speak for the historical accuracy of the project, but I believed that if we gave it more time and paid attention to some critical details, this method would succeed. Mark Lehner, the Egyptologist on the scene, frequently emphasized the importance of historical accuracy in method. His vigilance and genuine interest heightened my own. My first thought was that rigorous organization must have been the rule in ancient Egypt, given the vast numbers of people needed to build. Our experience in Aswan showed the importance of carefully chosen persons for every specific task. With this in mind, I eagerly began to develop my own ideas on how to proceed.

Wyly and I visited several historic sites on our journey home. In Karnak and Luxor we saw obelisks still standing on their original pedestals. In the hall at Karnak we walked between hypostyle stone colonnades of a scale beyond belief. To build these halls, the Egyptians would literally fill the temple with earth and pull in the large stones on manmade ramps. The inclined plane and a unified workforce seem to have provided them with a sufficient method.

For several thousand years, granite was extracted from the Aswan quarry for ancient monuments and statuary. In the quarry lies an unfinished obelisk (above right) weighing over 1,000 tons, apparently abandoned when a crack in the stone was discovered. This ruin reveals the ancient method used to remove granite from the quarry. Egyptians cut the stones out of the ground using a dolerite ball, harder than the granite. Quarrymen would line up shoulder to shoulder and with the balls pulverize the stone, creating channels around the perimeter of the desired block. This painstaking process would continue until they reached the required depth. Then, by the same means, they would undercut the block until it could be levered off a narrow remaining spine.

The Egyptians produced a multitude of structures, some of the largest and most precise in history. They used natural resources: soil, stone, wood, fibers (for rope), unlimited amounts of sand and large numbers of people. Through keen observation and experience they came to know and understand how these materials would behave under certain conditions. There is no evidence of pulleys, capstans or the knowledge of iron at this time. As far as we know, they used only simple mechanical aids such as wedges, levers and rollers. And so should we.

We are all familiar with the center of gravity of the seesaw at the school playground. The apparent weightlessness of an object resting on a fulcrum is a captivating perception. In ancient times, the discovery of this physical phenomenon may have conferred near magical powers and generated sacred interpretations. Dieter Arnold's Building in Egypt (Oxford University Press, 1991) refers to evidence found in several cities and temples that workers pivoted large pillars at their center of gravity as early as the Fourth Dynasty (ca. 2600 B.C.). Once supported at its center of gravity, a large object can easily be moved by a single person. This technique will work with a seesaw at the playground, a 250-lb. timber post or a 500-ton obelisk. We chose to work with this technique as the first element in our proposed simple system.

R. Englebach in The Problem of the Obelisks (T. Fisher Unwin, 1923) suggests sliding the obelisk down a funneled earthen chamber to the top surface of the pedestal stone below, using sand somehow to stand the pillar upright. But this is the equivalent of driving an automobile through a tunnel without a steering wheel. It may be possible to get through the tunnel, but much is left to chance, and at best the obelisk would suffer some bouncing and bashing of outer surfaces on tunnel walls. This seems a crude way of handling a polished stone. Further, every obelisk in Egypt was erected on a pedestal with a pronounced radiused groove, the so-called turning groove, carved quite near one edge across its top surface (seen at the back edge of the pedestal in the drawing at left). This groove would seem to have been designed to receive the heel of the obelisk at a fairly steep angle and locate it securely while it was pulled over, or "turned," into its final upright position. Using a funneled chamber would not be a likely procedure for arriving at the precise target of the turning groove.

Nonetheless, Julia Cort believed that Englebach's sand method, adapted by Roger Hopkins in NOVA's 1994 and early 1999 efforts with a two-ton representative obelisk, provided vital information and was worth pursuing.

Dry sand flows freely. When a hole is placed low in the side of a box of dry sand, the sand will flow downward through the opening until the remaining pile reaches an angle of repose, the maximum slope at which the pile will stand without flowing and bear a load. In addition, smooth downward movement is a natural characteristic of sand-flow. Evidence in the papyrus Anastasi I, as translated by Dieter Arnold, suggests the possibility of lowering a monument into position by progressively removing the sand from the sides of a supporting pile in a chamber below: "Empty the space which has been filled with sand under the monument of thy lord."