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The world’s oldest, tallest extant wooden pagoda

WANG NAN | 2020-08-07
(Chinese Social Sciences Today)

A measured drawing of the Pagoda of Fogong Temple by Liang Sicheng Photo: FILE

The Pagoda of Fogong Temple, a wooden pagoda in Ying County, Shanxi Province, is the oldest, tallest and also most complex surviving wooden structure in the world. It was built in 1056 during the Liao Dynasty (916–1125), measuring 67.31 meters tall, a height equivalent to a 22-story modern building. 
The pagoda has survived earthquakes and wars over the past 900 years. When China sank into a morass of warlord politics during the 1920s, the pagoda was hit by over 200 artillery shells, leaving many holes, but it still stood firm. When the earthquake on July 28, 1976, razed the industrial city of Tangshan (with a magnitude of 7.5), this pagoda withstood the earthquake, despite a seismic intensity scale of 4 measured in the locality. 
It is the complicated structure of brackets (dou gong, a traditional Chinese bracket set consisting of a group of wood blocks known as dou and short beam-arms known as gong, cut so they interlock and form a unit when stacked up together) that enables the pagoda to survive. Brackets allow for a large structural unit to be formed of many small pieces of wooden blocks, joined by innumerable mortises and tenons (without using any nails). An earthquake may easily destroy a large structure, but brackets consist of many small pieces with spaces between them, which act as an energy-absorbing cushion or a damper in technical terms. There are 54 types of brackets installed in different parts of the wooden pagoda, each consisting of a different function. This represents China’s greatest achievement in the application of brackets. 
The pagoda adopts a dual-barrel structure—each story is supported by an interior and an exterior circle of wooden columns, while between the two circles of columns are many brackets and crossbeams that form a strong supporting framework—an outstanding architectural design widely adopted by modern skyscrapers. All the stories have a similar structure, where the two circles of columns define an outer aisle (wai cao) and a central area (nei cao). The outer aisle is built with stairs, a cloister and a surrounding terrace balcony (ping zuo) for sightseeing. Within the octagonal central area there are many fine Buddha statues. The pagoda is considered an architectural gem for its unique design and wonderful construction techniques. 
The pagoda is currently facing an ongoing crisis: It leans slightly at an angle, and there is an obvious tilt in the columns of the second and third floors. There are multiple reasons for this problem: Its own weight, wind, earthquakes and wars. However, much of the blame should be borne by human beings. 
The pagoda seems to have only five stories, yet its interior reveals that it has nine stories in all—between each outer story of the pagoda is a mezzanine layer. For example, the height of the second story is equivalent to that of a standard story and a half, because above the second outer story is a mezzanine layer, which can only be found from the inside. The structures of the outer stories and the mezzanine layers are quite different. The outer stories are propped up only by vertical columns and horizontal beams, while there are added diagonal supports on the radial direction of each mezzanine layer, forming many rigid triangle frameworks. These triangle frameworks are similar to the trusses used in modern buildings that span a long distance, such as barns and terminal buildings for airports. The only difference is that the trusses of modern buildings are made of steel while the pagoda is a fully wooden structure. This architectural design explodes the statement that the ancient Chinese were unable to use triangle structures in construction. In fact, ancient Chinese builders often adopted this type of structure, which was usually installed in the mezzanine layers of intricate wooden buildings. 
These mezzanine layers function similar to a ring beam in modern constructions, performing as horizontal supports to the pagoda. There used to be wall structuring similar to the mezzanine layers on each outer story, blocking some sunlight but playing a vital role in supporting the pagoda. Unfortunately, during the 1930s, the local landed gentry, who had no idea of the function of the wall structuring, tore these down to allow more light into the stories. 
Today, the four stories above the first story of the pagoda, without the previous wall structuring (with the diagonal supports inside), have more light and space. However, this distinct change in its physical appearance is at the cost of the stability of the structure. 
The Chinese architect Liang Sicheng (1901–1972) was the first person who found this tilting problem and issued warnings about the danger of the structure. However, his warnings didn’t reach the public until recent years, as Liang’s report, finished around 1935, was lost due to the Japanese invasion in 1937. Several years after the publication of The Complete Works of Liang Sicheng (published in 2001 in commemoration of the 100th anniversary of Liang’s birth), the original report was found by the Chinese Academy of Cultural Heritage. 
Liang Sicheng, Lin Huiyin 
Liang Sicheng and his wife, Lin Huiyin (1904–1955), were the most remarkable partners in exploring China’s architectural past. At that time, in order to develop measurement records of Chinese ancient architecture, architects had to climb up to the roofs of those buildings. Lin even climbed up the brackets and crossbeams wearing a cheongsam. 
Lin didn’t take part in the field investigation of the Ying County wooden pagoda in 1933. She published letters about Liang’s measurement progress in Ta Kung Pao (the oldest active Chinese language newspaper in China founded in Tianjin in 1902). In those letters, Lin depicted how Liang was obsessed by the pagoda before he saw it with his own eyes: “Since Sicheng heard about the pagoda, this building has overwhelmed everything in his daily life. ‘It might not be too hard to get to Ying County,’ he often murmured when washing his face in the morning.” In fact, Liang hadn’t seen the pagoda at that time, not even its photos. So he wrote a letter for “the best photo studio in Ying County” to request a photo of the pagoda. He didn’t know who he could ask for help. He put a silver dollar in the envelope and hoped for the best. Later, Liang received a photo from a studio. What was more interesting was that the studio didn’t take the silver dollar. Instead, it asked for some writing paper with drawings from Beijing as payment. 
Liang and his colleague Mo Zongjiang spent two weeks measuring the pagoda. The workload was heavy. Behind their architectural drawings was a thick book of measurements and sketches. Tens of thousands of components were carefully measured one by one. Even so, the real challenge was to measure the top of the pagoda, an approximately 11-meter-high tasha (sōrin). They had to climb up on to the roof without any safety equipment. 
Mo Zongjiang recalled that when they arrived at the roof of the pagoda, the wind was strong enough to blow them off. But the only way to measure the tasha was to climb the iron chain dropping from the top of the tasha. “That was a 900-year-old iron chain. It may have been rusty or broken. It scared me, but Mr. Liang climbed it bravely. So we followed him. That was how we measured the tasha,” Mo said. 
In addition to their commitment to science, an important reason why Liang and his colleagues did such risky work was to compete with their Japanese peers. At that time, Japan was ahead of China in the research of Chinese ancient architecture. When the Japanese architect Itō Chūta came to China for field investigations in 1901, Liang had just been born. In one of his speeches, Itō suggested leaving all field investigation to Japanese experts while the Chinese experts did the auxiliary paperwork. Therefore, Liang, Lin and their colleagues did their best to investigate every case since the beginning of their studies of the Song Dynasty Yingzao Fashi (Treatise on Architectural Methods) in 1932. 
This article was edited and translated from Guangming Daily. Wang Nan is the deputy curator of the Memorial Museum for the Society for the Study of Chinese Architecture at the School of Architecture at Tsinghua University. 
edited by REN GUANHONG