Prefabrication of immersed tube E23 of Shenzhen-Zhongshan highway underwater tunnel completed

A staff member maintains a device loading immersed tube E23 of Shenzhen-Zhongshan highway underwater tunnel at an immersed tube smart factory of CCCC Fourth Harbour Engineering Co., Ltd. on Niutou Island, Zhuhai, south China's Guangdong Province, Jan. 30, 2023. (Xinhua/Liu Dawei)

The prefabrication of E23, the last immersed tube (non-standard tube, including the final joint) of an underwater tunnel, a section of highway linking Shenzhen and Zhongshan in Guangdong, was completed on Tuesday. After being poured concrete, the 164.5-meter steel-shelled tube weighs about 80,000 tonnes.

With a total length of 6,845 meters, the underwater tunnel consists of 5,035-meter-long prefabricated immersed tubes, including 32 ones and a final joint.

The Shenzhen-Zhongshan highway, which is scheduled to open to traffic in 2024, is expected to cut the travel time between the two cities from two hours to about 20 minutes. 

Staff members prepare the outfitting of immersed tube E23 of Shenzhen-Zhongshan highway underwater tunnel at an immersed tube smart factory of CCCC Fourth Harbour Engineering Co., Ltd. on Niutou Island, Zhuhai, south China's Guangdong Province, Jan. 30, 2023. (Xinhua/Liu Dawei)

Staff members manipulate a machine to pour concrete to immersed tube E23 of Shenzhen-Zhongshan highway underwater tunnel at an immersed tube smart factory of CCCC Fourth Harbour Engineering Co., Ltd. on Niutou Island, Zhuhai, south China's Guangdong Province, Jan. 30, 2023. (Xinhua/Liu Dawei)

Staff members prepare the outfitting of immersed tube E23 of Shenzhen-Zhongshan highway underwater tunnel at an immersed tube smart factory of CCCC Fourth Harbour Engineering Co., Ltd. on Niutou Island, Zhuhai, south China's Guangdong Province, Jan. 30, 2023. (Xinhua/Liu Dawei)

Staff members check immersed tube E23 of Shenzhen-Zhongshan highway underwater tunnel at an immersed tube smart factory of CCCC Fourth Harbour Engineering Co., Ltd. on Niutou Island, Zhuhai, south China's Guangdong Province, Jan. 31, 2023. (Xinhua/Liu Dawei)

This aerial photo taken on Jan. 30, 2023 shows immersed tube E23 of Shenzhen-Zhongshan highway underwater tunnel and a vessel for its transport and installation at an immersed tube smart factory of CCCC Fourth Harbour Engineering Co., Ltd. on Niutou Island, Zhuhai, south China's Guangdong Province. (Xinhua/Liu Dawei)

This aerial photo taken on Jan. 30, 2023 shows immersed tube E23 of Shenzhen-Zhongshan highway underwater tunnel at an immersed tube smart factory of CCCC Fourth Harbour Engineering Co., Ltd. on Niutou Island, Zhuhai, south China's Guangdong Province.  (Xinhua/Liu Dawei)

A staff member lays out pipelines before pouring concrete to immersed tube E23 of Shenzhen-Zhongshan highway underwater tunnel at an immersed tube smart factory of CCCC Fourth Harbour Engineering Co., Ltd. on Niutou Island, Zhuhai, south China's Guangdong Province, Jan. 31, 2023. (Xinhua/Liu Dawei)

Staff members lay out pipelines before pouring concrete to immersed tube E23 of Shenzhen-Zhongshan highway underwater tunnel at an immersed tube smart factory of CCCC Fourth Harbour Engineering Co., Ltd. on Niutou Island, Zhuhai, south China's Guangdong Province, Jan. 31, 2023. (Xinhua/Liu Dawei)

A staff member maintains a device loading immersed tube E23 of Shenzhen-Zhongshan highway underwater tunnel at an immersed tube smart factory of CCCC Fourth Harbour Engineering Co., Ltd. on Niutou Island, Zhuhai, south China's Guangdong Province, Jan. 30, 2023. (Xinhua/Liu Dawei)