The discovery that revealed how the Forbidden City of China was Built
In November last year, the translation of a 500-year-old document answered one of the greatest mysteries surrounding the Forbidden City in Beijing, China – how the ancient people managed to transport stones weighing more than 330 tonnes over 70 kilometres. Until now it was believed that they were transported on wheels, however, the ancient document showed that this was not the case at all.
The Forbidden City is the imperial palace that was once home to the emperors of China during the final two imperial dynasties, the Ming Dynasty and the Qing Dynasty. Built in 1406 to 1420, the complex consists of 980 buildings and covers 720,000 m 2. The palace was declared a World Heritage Site in 1987, and is listed by UNESCO as having the largest collection of preserved ancient wooden structures in the world.
The Forbidden City in China is a UNESCO World Heritage listed site. Image source: BigStockPhoto
Vast numbers of huge stones were mined and transported there for its construction, the heaviest of which weigh more than 220 tonnes and would have weighed more than 330 tonnes before they fragmented. It has been determined that the largest blocks came from a quarry 70 kilometres away and since people in China were using the wheel since around 1500 BC, it was believed that this is how the huge stones were transported.
However, Jiang Li, an engineer at the University of Science and Technology Beijing, translated a 500-year-old document and was astonished by what he read. The document described how giant stones were slid for miles on specially constructed sledges , dragged over slippery paths of wet ice by a team of men over 28 days. The workers dug wells every 500 metres to get water to pour on the ice to lubricate it, which made it easier to slide the rocks.
An historical document revealed that huge stone blocks were dragged along ice. Photo credit: Daily Mail
The researchers calculated that the transportation would have required 46 men to move a stone weighing 123 tonnes using this method, and they would have been able to move the stone about 3 inches per second, fast enough for the stone to slide over the wet ice before the liquid water on the ice froze.
The fascinating findings were published in full in the journal Proceedings of the National Academy of Sciences.
The spectacular Forbidden City. Image source: BigStockPhoto
Featured image: The Forbidden City of China. Image source: BigStockPhoto
But how is a document written a same time for historical record, wrong ? or inaccurate ?
Down a hill, they may have just let it slide down, there is probably not anything saying about those details, but i would like to see whole record to be translated, for all to read.
But upon translation, there can be no more doubt as to the details it does provide, on how stones weer moved back then. Unlike egypt that had no frozen anything, let alone ice to slide their stones, but sleds and man power did that all anyway, same with stone henge, mayan, and various others.. There still could be an egypt documentation of how they did things they did, just not found yet..
I do wonder if they moved stones at night ? More probable to move them at night with moon light to help.
And crews for day, and for night.
@Peter Harrap: I believe that you need to Go back to math class in school. One kilometer is 3,281 in feet times 70 equals 229,670 feet. That is divided by 21,600 (3ft per second=15 ft. per minute times 60 minutes = 900 feet per hour times 24 hours = 21,600) to give you 10.6328 days to move it 70 kilometers....
The men probably did not stand on the ice road to pull, but to either side in front. Pulling evenly on both sides. All you need is center line to follow, both on the stone and marked on the ice and some one on top to keep them lined up by calling out orders to each team. I'm betting the path was scouted out completely looking for the flattest way, and flatning areas that needed flatening all as the stones were being cut... Probably took yeas to move them all with teams assigned to each stone.
Good points. I'd add that if the blocks were on ice, so, presumably, were the men pulling on the ropes. Suddenly it doesn't sound quite so easy.
Also, it should be kept in mind whenever discussing the transport of large masses of stone, that although stone has an extremely high compression strength, it is weak to tension and torque, and is prone to spauling, especially on corners and finished faces. The more a stone weighs, the more likely that its own weight can cause it damage. Just setting a heavy block down on uneven ground can damage it by breaking edges of corners or chipping flat surfaces.
Moving these things isn't just about mustering the force necessary to overcome gravity and friction. That force must be wielded with finesse; there must be fine control. People yanking on ropes is not finesse.
The base of the St. Petersburg statue is often brought up as a modern example of a huge mass of stone moved by people dragging it overland with ropes. Ice was used as a means of reducing friction in that case as well, and supposedly lots of little bronze spheres acted as ball bearings to help move things along.
But that stone is just a giant boulder with no particular shape. No one cared if bits of it broke away during transport. There were no fragile corners or flattened surfaces to protect. The accounts of moving that stone are believable to me, for those reasons. Because no one was trying to build anything with it. It was a giant boulder dragged a long way to a new resting place, where it was used as...a giant boulder.
Giant blocks, which are not just dragged from A to B, but are used in the construction of a structure at B, are a problem of a different order of magnitude entirely.