- 1 day ago
Category
📚
LearningTranscript
00:00It's China's most stunning palace.
00:04The Forbidden City.
00:06The greatest wonder of the medieval world.
00:09And the biggest wooden structure on earth.
00:14It's the largest complex of palace buildings anywhere in the world.
00:19Home to China's emperors.
00:21A place of staggering wealth and power filled with dazzling treasures.
00:29Only the emperor could pass along the central line.
00:39It was closed to the outside world for centuries.
00:43Now our cameras have been given access behind the palace gates.
00:48And scientists set out to solve the enduring mysteries of this engineering marvel.
00:59How was this epic megastructure created?
01:03Who built it?
01:04And how has it survived 600 years of war, upheavals, and natural disaster?
01:12Maybe we'll take one step back.
01:17The secrets of the Forbidden City can finally be revealed.
01:37The Forbidden City is a wooden wonder.
01:40History's ultimate megastructure.
01:43Dominating the heart of Beijing, it boasts a staggering 900 buildings.
01:51Opened in 1420, it is a pleasure palace.
01:55An impregnable fortress.
01:57And a seat of immense power.
02:01The most important site in the whole of Asia for the last 500 years.
02:07Economically important, politically important, and militarily important.
02:16The main entry is the Woomen, or Meridian Gate, leading into the spectacular Outer Court,
02:23with its five marble bridges that cross the man-made Golden River.
02:32The Forbidden City is ten times the size of Versailles.
02:40This is the largest palace complex in the world.
02:44And not just the largest palace complex that survives,
02:47but the largest palace complex built at any time in history.
02:53Architectural historian Jonathan Dugdale wants to master its layout.
02:58Up ahead is the Gate of Supreme Harmony.
03:02And if you think that's impressive, wait till you see what's on the other side.
03:08Three great halls dominate the Outer Court, towering over a three-tiered marble terrace.
03:16Beyond is the Inner Court, where the Emperor lived.
03:30It all covers 178 acres.
03:34With the Outer Court to the south, and the Inner Court to the north.
03:41Forbidden to any man but the Emperor, or his sons, with hundreds of structures.
03:48All surrounded by fortifications and a moat 50 meters wide.
03:55The Forbidden City originally contained 9,999 rooms.
04:01One less than the divine number of 10,000 reserved for heaven.
04:09It boasted scores of temples, gardens, and the Emperor's vast harem.
04:16With thousands of concubines and an army of eunuch guards.
04:23A hotbed of decadence and betrayal.
04:28But above all, a center of power.
04:33But at its heart, there is a mystery.
04:37In a time before industrial technology, how did a medieval society produce such a marvel?
04:48No original plans or blueprints survive.
04:51So there is no record of how it was created.
04:59To find the answer, we've gone behind closed doors.
05:03To its workshops and new research labs.
05:06With special access to its scientists and master craftsmen.
05:11To understand the palace, and the medieval superpower who built it.
05:17The Ming dynasty.
05:19From 1368, they ruled China for nearly 300 years.
05:30The Forbidden City is all the creation of one brilliant and terrifying Ming Emperor.
05:38Jungler.
05:42Warrior.
05:44Scholar.
05:46Mass murderer.
05:54The Jungler Emperor is one of the greatest emperors in Chinese history.
06:01Without him, China would be completely different.
06:04You simply would not have had a forbidden city that we see today.
06:12But Jungler was never supposed to be emperor.
06:21In 1402, he took the throne by force.
06:26After waging a brutal civil war against his nephew, the Jian Wen Emperor.
06:33It was a matter of life and death.
06:37He either rebelled and seized the throne, or he would have been eliminated himself.
06:46Jungler stormed the first Ming capital, Nanjing, and left it in flames.
06:53The genuine emperor disappeared.
06:57The genuine emperor disappeared.
06:57We do not know what happened to him.
06:59But, bodies were found burnt beyond recognition.
07:05A recognition.
07:13Jungler burnt Nanjing and declared he would build a new northern capital.
07:19A thousand kilometers away.
07:22Beijing.
07:24Jungler was a driven man, an ambitious man.
07:29And he was ruthless.
07:32He eliminated tens of thousands of officials.
07:39By building the Forbidden City at the heart of his new capital, the new emperor would create a dazzling display
07:45of power.
07:47His ambition is reflected in its sheer scale.
07:53Without his vision of making this as a capital, China would simply not have the central role that it does
08:03in the modern world today.
08:06It's a vision of one man, but it's actually the genius of the entire Chinese people.
08:13So vast, its construction even shaped the landscape itself.
08:19This hill gives us an amazing aerial view of the Forbidden City.
08:25What's more incredible is that prior to the construction, this hill didn't even exist.
08:30It was actually built using the earth excavated from the moat.
08:37Building on such an epic scale faced huge obstacles.
08:43The environment and the climate was bad.
08:47They still suffered from floods and famines here and plagues of locusts.
08:51So all of this was an enormous undertaking.
08:55All the labor and materials had to be brought to Beijing.
09:05Today, the fruits of that labor can be seen up close in structures such as Tai Miao Temple.
09:16It was first built in 1420 by Yongle to honor his ancestors.
09:25Yongle came to this spectacular temple to assert his connection with his predecessors in the Ming Dynasty.
09:37The importance of Tai Miao is reflected in its vast size and ornate decoration.
09:47The 13-meter-tall columns sparkle as if speckled with gold.
09:53It's a chance for master carpenter Richard Weiborg to see a rare Ming interior up close.
10:00Look at this magnificent column, so round and so smooth.
10:06Imagine how big the tree was that this came from.
10:11In fact, we have 68 columns in total for this hole and they're supporting the structure.
10:19And they look good for us as well.
10:21This is a single log of a Nanmu tree, the rarest of all Chinese woods.
10:29It's straight, dense and resistant to rot.
10:34But Nanmu can only be found deep in forests, over 1800 kilometers from Beijing.
10:46And the sheer quantity of wood required is staggering.
10:49The latest high-tech laser scans show the Forbidden City's biggest hall contains thousands of timbers.
10:57It has an effect to be turned into the office floor.
11:04The roof area alone is revealed as a forest of complex beams, joints and trusses.
11:11Above, the huge roofs are covered with thousands of heavy glazed tiles and figurines.
11:21This amazing edifice in front of us brings up a huge number of questions.
11:26How did they build it?
11:28Where did the resources come from to create something so vast?
11:37To supply this vast building site,
11:39huge quantities of specialized materials were imported from across the whole empire.
11:47Over 100,000 Nanmu logs from 1800 kilometers to the southwest.
11:54Golden floor tiles from 1000 kilometers south.
11:5980 million bricks, each weighing 24 kilograms.
12:06Gold leaf from Nanjing.
12:10And food for the million workers and vast garrison.
12:24But to get everything to Beijing, Yongle's builders had to dream up another engineering marvel.
12:33China's Grand Canal.
12:37The Grand Canal is both longer and older than the Panama Canal and the Suez Canal.
12:46They really solved a very large problem of canal engineering at the time.
12:53Rebuilding a canal that runs over 1700 kilometers.
12:58From commercial Hangzhou in the south,
13:00it then links China's lifeblood rivers, the Yangtze and the Yellow.
13:07Right up to Beijing.
13:09The water flow is controlled from Nanwang.
13:13Here we are at the center of the Nanwang water diversion project as part of the Grand Canal system.
13:22Here at Nanwang, a whole river was diverted to feed the canal.
13:28Today, it is dry.
13:29But this is what it would have looked like in Yongle's rain.
13:37But the hilly terrain blocked the canal.
13:40So engineers devised a vast system of locks.
13:48To raise the ships, the canal is fed from the one river.
13:53And three huge lakes were dug as storage tanks.
13:57Barges travel up the canal to Nanwang, where they enter a series of locks, over five kilometers long.
14:06The river water pours in to raise the ships in the lock, so they can then proceed.
14:12Huge sluices then empty the water into the specially made lakes, ready for the next vessels.
14:22For just this section of the canal, there was 300,000 laborers conscripted, working for a period of 200 days
14:31constantly.
14:32And they created this with only the most rudimentary hand tools.
14:39The Grand Canal allowed engineers to float the Nanmu logs north, to Beijing.
14:47Along with a fleet of 20,000 barges, manned by the army to carry 420 million liters of grain to
14:54feed the Beijing building site.
14:57Every year.
15:02The cost was paid by Yongla's subjects in money, materials, and lives.
15:09Tens of thousands of people starved to death.
15:12He worked convicts, he worked the military, he worked ordinary peasants.
15:18He squeezed as much as he could out of the taxes.
15:24Their sacrifice was building a palace unrivaled anywhere on earth.
15:32But what was going on behind the opulent walls of the Forbidden City?
15:45Beijing's Forbidden City Palace was built nearly 600 years ago, for a man who stole the throne, Ming Emperor Yongla.
15:59A typical day in Yongla's life could cover much of his private city, the Danai, or Great Within.
16:10This courtyard and the palace behind me is the most sacred location in the entire Forbidden City.
16:18The Palace of Heavenly Purity.
16:23And every morning he would rise at about four o'clock and he would come down this central pathway.
16:31Only he could pass along the central line for the dawn audience.
16:41At dawn, thousands of eunuch mandarins would gather here in silence to kowtow before his majesty.
16:51Filling the courtyard in front of the city's grandest structure.
16:56The Hall of Supreme Harmony.
17:01In the very centre is the throne.
17:06On either side you can see dragons.
17:10And the dragons have five claws.
17:15That is the imperial dragon.
17:17Only the emperor could have five clawed dragons.
17:23And above you have the symbol of the heavens.
17:28And the throne is directly underneath their heaven.
17:33Why?
17:34Because the emperor is the son of heaven.
17:39Yongla must constantly prove he has the mandate of heaven.
17:44And demonstrate he is worthy to rule by maintaining a careful balance in the cosmos.
17:50Through daily rituals and ceremonies.
17:58One of which was ensuring the safety of the palace.
18:04The Yongla emperor would have come out from this gate here in his private quarters.
18:10Walked down these steps.
18:13And probably if it was winter, he would have come to these great cauldrons.
18:19Which are now brass but originally covered in gold leaf.
18:23And put his hand inside to make sure that there was no ice.
18:29They must be full of water.
18:31As these are the Forbidden City's fire extinguishers.
18:34In a wooden palace, any spark can lead to disaster.
18:41But the Forbidden City is not only made from wood.
18:46Many of the key halls and palaces sit on layers of marble terracing.
18:52Huge blocks, quarried over 60 kilometers outside Beijing.
19:04One of the city's most impressive features is Emperor Yongla's grand staircase.
19:10Inlaid with dragons.
19:13Hand carved from a single vast block of the finest marble.
19:17More than 16 meters long.
19:20It weighs over 300 tons.
19:23More than 125 Land Rovers.
19:26It's the largest stone sculpture in the Forbidden City.
19:30Showing nine dragons playing in the clouds.
19:34Just touching them led to a death penalty.
19:39But how was it transported from the quarry over 60 kilometers away?
19:46Scientists are investigating a new theory that might explain how it got from the quarry to the Forbidden City.
19:56Every winter, Beijing freezes over.
19:59And Ming court records describe the creation of great ice roads.
20:04Modern science suggests they may have moved the blocks on ice.
20:15Professor Rob Dwyer-Joyce is a tribologist, a friction and lubrication engineer.
20:22He wants to discover how many men would be needed to shift the marble.
20:27What we have is a wooden sled.
20:30We've loaded it with stone weighing about a tonne, 1,000 kilograms or 2,200 pounds.
20:36And we're going to do an experiment to try to pull this along by hand on the ice.
20:40This is going to be quite difficult because it's...
20:46Nope, we can't get shifted.
20:48Nope.
20:49Can't do it.
20:50I think we're going to need some help.
21:00Even the whole ice hockey team struggled to get it moving.
21:06Whoa!
21:09So how much force does it take to start a one-ton sled sliding across the ice?
21:16Remembering that the marble block of the Forbidden City's Grand Dragon Stairs weighs 300 tons.
21:23The challenge is to get it started.
21:27Ming sources say wells were dug along these ice roads.
21:31Could water help get it going?
21:33I'm going to put some water down there and see how many we need when we've slightly wetted the ice.
21:39Go on, pull it, pull the ice.
21:44The water acts as a lubricant, making the sled easier to start moving over the ice.
21:51This is exactly what happens with an ice skater's blade.
21:55The friction creates a very thin layer of water between the blade and the ice, allowing grace and movement.
22:06The Ming dug the wells every 500 meters to create the ice road and then lubricate it.
22:14Scaled up, our experiment proves just 180 men could move the 300-ton marble block.
22:26And it wasn't just the marble that had to be brought over great distances.
22:35What strikes visitors, along with the Forbidden City's sheer scale, is the vast array of colors.
22:42The turquoise, blues and greens.
22:48Now new evidence is emerging of efforts made to source the very best materials.
22:56At the Hall of Mental Cultivation, Dr Lei's restoration team are working to identify the precise pigments used to color
23:05the paints.
23:07Over the centuries, layer upon layer of paint has built up.
23:12Making the task of identifying the minerals very difficult.
23:26They're using the latest technology, a portable X-ray fluorescent spectrometer, to make some startling discoveries.
23:37At his lab, Dr Lei combines the X-RF scan data with the microscopic examination of paint fragments, to identify
23:46the colorful elements.
23:49In China, the orange paint is usually used to use the silver.
23:55The silver is made by grinding down the mineral ore, azurite.
23:59But this doesn't look like azurite.
24:03But this doesn't look like azurite.
24:03This is very complicated.
24:08It's a slightly smaller weight.
24:15Dr Lei's analysis identifies the compound.
24:27it's a remarkable find this blue is smolt and only comes from Europe further analysis shows the
24:37pigments used to create the Paris green and ultramarine paints are also unique to Europe
24:53the analysis ensures the correct pigments are used in the restoration but also proves that to decorate the
25:00forbidden city no expense was spared in all it took over a million laborers to build
25:13Yongla's Forbidden City and over a hundred thousand skilled craftsmen and carpenters from across the
25:21Empire to build a wooden structure unsurpassed in scale even to this day but once built how did
25:32the palace survive nature's most devastating force earthquakes in December 1420 Emperor Yongla's
25:49Forbidden City was complete his vast palace was ready to face the world diplomats and dignitaries arrived
25:57for its grand opening ceremony they're overwhelmed by just the physical space this statement of power
26:07political power the power of the dynasty but also the power of the Emperor visiting ambassadors
26:14described 300,000 guests 2,000 musicians and dancers and as many armed guards this constant visual
26:26campaign of political persuasion that I am the most powerful man in the world now it was complete the
26:37Forbidden City became the beating heart of the Ming Dynasty the place where the Emperor Yongla lived and
26:43the headquarters from which he commanded his empire but over the centuries his palace has faced a series of
26:53man-made threats revolution civil war and invasion but one of the greatest threats of all was natural disaster
27:11Beijing sits in a very active seismic zone
27:16with dangerous fault lines that spread over a thousand kilometers
27:33Dr. Joe is the Forbidden City's resident seismologist
27:47In its 600 years the Forbidden City has withstood over 200 devastating quakes including the deadliest
27:56earthquake of the 20th century in 1976 centered around 150 kilometers east of the capital it was magnitude 7.8
28:17In just 15 seconds it killed a quarter of a million people
28:25Tangshan city was obliterated
28:41So how has the Forbidden City survived so many quakes?
28:55To find the answer specialist carpenters are building a unique scale model to replicate the classic Forbidden City structure
29:06To be as accurate as possible it is being made using traditional carpentry tools and techniques the scale is one
29:14to five a fifth of the original size
29:18Engineers have built it on a shake table to simulate earthquake forces calibrated to the size and weight of the
29:26scale model
29:35The scale model is based on the traditional timber frame core as used at the palace of longevity and health
29:45What you immediately notice is this huge golden roof that curves outwards away from the building in a way that
29:54you just don't see in European architecture
29:57Looking up here what we have is these elegantly colored cross beams decorated with imperial dragons and phoenixes
30:06And they're there to support these huge red columns that bear the structural load of that massive roof
30:15These beams and columns are the structural core of all the Forbidden City's buildings
30:23If you look up here in between the cross beams and the roof underneath that mesh
30:29There's these flower-shaped brackets and they're called dogong
30:36A dogong is a complex bracket that supports the huge roof
30:43At first glance it looks like an elaborate decorative feature
30:47But the unique design is the structural key to every Forbidden City building
30:54Dogong brackets are extremely versatile
30:57They've been used throughout East Asian architecture
31:00For literally thousands of years
31:02We see examples of them used in Buddhist temples
31:06Palatial architecture down to simple houses
31:11Dogong date back at least 2,000 years
31:15But they reach their zenith in the Forbidden City
31:19Carpenter Richard Weiburg finds it's easy to take one apart
31:25But harder to assemble
31:28Now, after taking a deep breath
31:31We'll try and put this back together again
31:33And amazingly, there are no nails or glue
31:38Nothing holding it together other than sheer ingenuity
31:42You can see this isn't even for somebody who's done it a few times
31:46It's complicated
31:49One piece goes in the front here
31:52There you have it, a bracket set
31:54So you can see it's a little bit flexible
31:59It's very strong pressing down
32:01It can take a tremendous amount of weight
32:04It ties together with other parts of the building
32:07And is a beautiful, creative feature of Chinese architecture
32:15The complicated Dogong brackets extend to the exterior
32:19To support the eaves as well as the roof
32:22They sit on the large beams supported by the tall columns
32:27But the columns are not founded in the earth
32:29And are free standing
32:31All these structural parts bear the roof's immense weight
32:35For a large hall that is 1800 tons
32:40Engineers highlight areas that are vulnerable
32:43During the most powerful quakes
32:44The earth's movement could snap the columns
32:47Fracture the beams or joints
32:49Or topple the roof
32:51It seems a tremor would be catastrophic
32:54So how does it survive quakes?
33:02Now, in a series of unique tests
33:05The Forbidden Cities seismologist Dr. Joe
33:08Will subject the scale model to a series of simulated quakes
33:12To discover how the Forbidden Cities intricate parts react
33:16And see what magnitude of quake they can survive
33:24It's test day
33:29Wow, the roof is so big
33:31It's amazing
33:34Dr. Joe is joined by Richard Weiborg
33:50The shake table will replicate the energy of quakes
33:54In increasing orders of magnitude
33:58How strong a quake will it take
34:00To bring down the structure?
34:09An earthquake's strength
34:10Is defined by its magnitude
34:12The amount of energy released
34:17Each tremor lasts 30 seconds
34:21As the magnitude rises
34:234
34:244.5
34:26Then 5
34:27These are massive increases
34:30A magnitude 5 has 10 times the energy of a 4
34:36It begins to strain the dogon
34:38It begins to strain the dogon
34:40Maybe we'll take one step back
34:51Magnitude 7.5 is over a thousand times stronger than the initial test quake of 4
35:13This shows that the brick walls have no structural role
35:18And the timber frame does all the work
35:22But how long can the frame resist the force of nature?
35:30So a 9.0
35:32This is like a very, very big earthquake
35:38The test now moves beyond magnitude 9.5
35:42The largest recorded quake in history
35:45The equivalent energy to well over 2 billion tons of TNT
35:51The equivalent energy to well over 2 billion tons of TNT
36:18We wanted to break this building, and it wouldn't break, so, wonderful test.
36:24When Dr. Joe and Richard examine the model, they find clues to how it survived the quakes.
36:30This is why the columns are not found in deep into the stone bases.
36:46If they were, they could only break, if overwhelmed by the energy of the quake.
36:52By being left free to move, they ride out the earthquake.
37:03The design secret can be summarized in one word, flexibility.
37:09The wooden parts work both as individual units and together.
37:13The Dogon acts like a shock absorber in a car, and there's both friction and rotation that
37:20absorbs the energy from the earthquake.
37:24The test also explains the effect of the heavy roof.
37:28It acts as a counterweight, pushing down so the flexible parts can ride the quake.
37:35What was most surprising to me was how much the building could move, how flexible it was.
37:42Nothing was damaged, and it could survive a 10.1 earthquake.
37:45This is a fabulous proof of the genius of Chinese traditional architecture.
37:57It has allowed the Forbidden City to survive one great force of nature.
38:03But there was one enemy it couldn't resist forever.
38:06Not earthquakes.
38:07Not earthquakes.
38:08But fire.
38:10Fire.
38:17For nearly 600 years, Beijing's vast Forbidden City has suffered from a recurring threat.
38:26Fire.
38:27Fire.
38:28Fire.
38:30Fire.
38:32Fire.
38:33Fire.
38:34Fire.
38:34Fire.
38:35Fire.
38:36Fire.
38:36Fire.
38:37Fire.
38:38Fire.
38:40Fire.
38:41actually been rebuilt seven times and each time it gets rebuilt it gets rebuilt with the technology
38:47of the day rebuilding and restoring the forbidden city remains an ongoing task
38:56today work is being carried out on the gates courtyards walls and ceilings
39:03in the gate of heavenly purity many of the precious golden tiles have lost their shine
39:11da bing is a master craftsman from the department of restoration skills at the forbidden city
39:32the forbidden city has thousands of these gold leaf tiles but the gold has faded or eroded
39:42restoration is a delicate process each tile takes two weeks
39:50a piece of paper and black chalk is used to copy the intricate tile pattern
40:01it's essential the design is exactly the same as the original
40:05this five-claw dragon signifies the emperor reserved only for him
40:13the
40:27once the tile has been copied and painted it is ready to be brushed with the precious gold leaf
40:39pure gold is melted and mixed with bronze that adds a red sheen the alloy is still 98 pure gold
40:51it's not the same as it is the same as it is the same as one five-hundredth the diameter
41:02of a hair
41:04it is cut up and carefully placed between sheets of bamboo paper
41:10the forbidden city's restoration needs over 10 million pieces
41:16after days of work the master craftsman is ready to apply the gold leaf
41:21the gold leaf
41:38finally it's impressive enough for the emperor himself
41:53the restoration work is still unveiling new surprises
42:00hidden beneath centuries of dust
42:04researchers have uncovered rare evidence of the original ming decorations in the hall of mental
42:10cultivation's loft
42:31over 500 years old this is an extremely unusual find
42:37it is classic ming dynasty artwork with unique flower blooms petals
42:44and an exquisite attention to detail
42:47in the context of the general common nature
42:50its region in the hall of Probation
42:54the oldest structure was created
42:54the end of the когда-to-ги
42:56the last bit of theIEе is theließen
42:58the second part is-bye
42:58its respect to the free-canning
43:07In that situation, this painting will be more
43:11fondly and more
43:13beautiful.
43:17From the gorgeous paintwork and brilliant gold leaf
43:22to the giant wooden columns and monumental marble staircases,
43:27the Forbidden City was the ultimate expression of
43:29Yongle's ambition and power.
43:33But his enjoyment of his pleasure palace
43:36was short-lived.
43:39In 1424, just four years after its completion,
43:43the emperor died whilst on campaign.
43:48In his last years, he still was determined
43:52against opposition of his officials
43:54to go out and fight the wars.
43:57And he was brought here to be buried
44:00in great pomp and circumstance.
44:05Yongle was laid to rest at this tranquil mountainside
44:09near Beijing.
44:11This magnificent hall remains as he built it.
44:17It stands as a symbol of Ming architectural genius
44:21and the 22-year reign in which he changed China forever.
44:32The legacy of Yongle, on the one hand, is the physical legacy,
44:38the great Forbidden City that we see today.
44:40But on the other hand, it was his establishment
44:44of the foundations of the empire that has survived down to this day.
44:53For nearly 500 years after Yongle's death,
44:57just 23 other emperors ruled China from the Forbidden City.
45:03Until the last emperor, the boy, Pu Yi,
45:07abdicated in 1912 during a nationalist revolution.
45:12He ended his days tending the palace gardens.
45:25In 1925, a palace once forbidden to all
45:29opened its doors to the public.
45:32The epic edifice had devoured goods from the vast Ming Empire
45:37and beyond.
45:42Had demanded extraordinary logistics on land.
45:48Water.
45:51And ice.
45:54Had cost countless lives,
45:56but became medieval China's greatest creation.
46:03More for tomorrow.
46:05Unearthing more Chinese history
46:06following on from the first discovery in 1974.
46:09The secrets of the Terracotta Warriors
46:10takes us even deeper tomorrow night at 9.
46:13Back to 4 tomorrow with house builders making record profits.
46:16Why are so few affordable homes available?
46:18Secrets of Britain's new homes.
46:20Channel 4 dispatches investigates at 8.
46:22The Handmaid's Tale is next.
Comments