The repair rate of hollow watchtower on the Great Wall in Yanqing has reached 85%

The magnificent Great Wall [Photo by Zhang Shunyan]

Recently, the repair and reinforcement works of No.2 watchtower in Dazhuangke Township and No.66 and No.90 watchtowers in Badaling Town were completed, marking the successful completion of the Great Wall repair and protection project in 2020. Up to now, 82 of the 96 hollow watchtowers on the 26.6km long Great Wall in our district have been repaired, and the repair rate has reached 85%.

It is understood that the three watchtowers which have been repaired and reinforced are not open to the public, in a state of nature. The repair project of the three watchtowers is not only the key work in the three-year action plan for the protection and development of the Great Wall in Yanqing District (2020-2022), but also one of the important parts of this year's Great Wall Cultural Belt construction project in Beijing.

The watchtower that located at the junction of Xiangtun Village of Dazhuangke Township and Huairou District is the No.1watchtower. The No.2 watchtower of Xiangtun village is to the west of the mountain. Between the No.1 and No.2 watchtower, this section of the Great Wall is engraved with the words "right chariot troop". The wall is winding and magnificent，it is the essence of the Great Wall of Yanqing, attracting large numbers of tourists to visit each year. This section of the Great Wall has never been repaired before. It is out of repair for a long time and its structure is unstable.

The No.66 watchtower, which was reinforced this year, belongs to the east section of the ancient Great Wall. The No.65 watchtower connected to its east side has been repaired last year. The reinforcement work of no.67-69 watchtowers and side wall on the west side is also under implementation.

The No. 90 watchtower is located in Shixia Village, Badaling Town, only one tower away from the Great Wall of Hebei Province on its west side. It is also the worst preserved watchtower in this renovation work. The existing part is less than half of the overall structure.

In the Ming Dynasty, Badaling was a transportation hub and military defense center in the northwest of the capital at that time, while Dazhuangke Great Wall was an important military barrier to guard the Ming mausoleum. Therefore, its architectural specifications were relatively high, mostly built of brick and stone. Among them, the most representative one is the diamond shaped watchtower. In addition, there are a large number of  6-eye, 5-eye, 4-eye and 3-eye watchtowers. The No.90 watchtower strengthened this time is a 6-eye watchtower, No.66 is a 3-eye watchtower, and No. 2 is a 4-eye watchtower.

The three watchtowers repaired this time are all masonry structures, and these are facing the same dangerous situations such as wall cracking and collapse, structural instability, and so on. Based on the principle of minimum and effective intervention, the staff focused on solving the problems of risk elimination, collapse repair, and stabilization. They made rational use of scattered raw materials, strictly control the number of new materials and the overall workload, to ensure that the existing style is maintained under the condition of structural safety.

In this emergency protection project, in addition to the repair and reinforcement of the three watchtowers and the wall of the Great Wall of about 30 linear meters on both sides of the No.90 watchtower, part of the collapsed vaulting was built back with old bricks to ensure the stability of the support structure on the top of the vaulting.

They properly patched up the missing wall bricks which endangered the safety of the door and window vaulting hole structure, blocked the cracks, repaired the top surface waterproof system, and did the drainage work.

According to presentations, due to the distance between the three watchtowers and the ground, it is difficult to transport materials. They have to rely on the cross transportation of manpower, machinery and livestock, which also brings difficulties to the repair work. The staff overcame numerous difficulties and successfully completed the emergency repair work as scheduled by erecting scaffolding around the watchtower, clearing the dust on the brick surface and repositioning the loose bricks. After the renovation, the danger coefficient of the current No.2, No.66 and No.90 watchtowers have been greatly reduced. The three watchtowers stand on the top of the mountain with more dignity.

Yu Haikuan, deputy director of Yanqing District Cultural Relics Management Institute, said, "Next year, we will continue to carry out in-depth protection of the Great Wall and its affiliated cultural relics, focusing on the repair project of the ancient Great Wall in Badaling, and the repair and reinforcement of xiwanghuaying beacon towers and jiangjiapu beacon towers, as well as the environmental remediation work." (Xu Xiaoxin)