Using the technology
available, I suspect that you have perhaps two practical strategies. This is clearly one of them and definitely applies
to this part of china. The second is to
actually float it along somehow by building a barge around the block and then
either constructing a canal or using one available. Such a canal could even be temporary and be
simply moved along.
Both methods bring
manning levels down to reality.
Wheels require a secure
weight bearing roadbed with rigid wheels and sticky hubs. The necessary construction is likely to be
huge while an ice road means a partial roadbed build.
China's Forbidden City
Built with Giant 'Sliding Stones'
By
Charles Q. Choi,
The
heaviest of the Forbidden City's giant boulders, named the Large Stone Carving
(shown here), now weighs more than 220 tons (200 metric tons) but once weighed
more than 330 tons (300 metric tons).
Credit: Jiang Li.
The
Forbidden City, the palace once home to the emperors of China, was built by
workers sliding giant stones for miles on slippery paths of wet ice,
researchers have found.
The emperors
of China lived in the Forbidden City,
located in the heart of Beijing, for nearly 500 years, during China's final two
imperial dynasties, the Ming Dynasty and the Qing Dynasty. Vast numbers of huge
stones were mined and transported there for its construction in the 15th and
16th centuries. The heaviest of these giant boulders, aptly named the Large
Stone Carving, now weighs more than 220 tons (200 metric tons) but once weighed
more than 330 tons (300 metric tons).
Many of the largest
building blocks of the Forbidden City came from a quarry about 43 miles (70
kilometers) away from the site.
People in China had been using the spoked wheel since about 1500 B.C., so it
was commonly thought that such colossal stones would've been transported on
wheels, not by something like a sled.
However,
Jiang Li, an engineer at the University of Science and Technology Beijing,
translated a 500-year-old document, which revealed that an especially large
stone — measuring 31 feet (9.5 meters) long and weighing about 135 tons (123
metric tons) — was slid over ice to the Forbidden City on a sledge hauled by a team
of men over 28 days in the winter of 1557. This finding supported previously
discovered clues suggesting that sleds helped to build the imperial palace.
To
discover why sleds were still used for hauling
gigantic stones 3,000 years after the development of the
wheel, Li and her colleagues calculated how much energy it would take for
sleds to accomplish this goal.
"We
were never sure quite what we would learn," said study co-author Howard
Stone, an engineer at Princeton University.
The
ancient document Li translated revealed that workers dug wells every 1,600 feet
(500 meters) or so to get water to pour on the ice to lubricate it. This made
the ice even more slippery and, therefore, easier upon which to slide rocks.
The
researchers calculated that a workforce of fewer than 50 men could haul a
123-ton stone on a sledge over lubricated ice from the quarry to the Forbidden
City. In contrast, pulling the same load over bare ground would have required
more than 1,500 men.
Moreover,
the researchers estimated that the average speed of a 123-ton stone hauled on a
sled on wet ice would be about 3 inches (8 centimeters) per second. This would
have been fast enough for the stone to slide over the wet ice before the liquid
water on the ice froze.
All
in all, the researchers suggested that workers preferred hauling stones on
smooth, flat, slippery, wet ice rather than on a bumpy ride on a wheeled cart.
The ancient document Li translated revealed there were debates over whether to
rely on sledges or wheels to help build the Forbidden City — sledges may have
required far more workers, time and money than mule-pulled wagons, but sledges
were seen as a safer and more reliable means for slowly transporting heavy
objects.
"It
is humbling to think about a big project like this taking place 500 to 600
years ago, and the level of planning and coordination that was needed for it to
occur," Stone told LiveScience.
Li,
Stone and their colleague Haosheng Chen detailed their findings online Nov. 4
in the journal Proceedings of the National Academy of Sciences.
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