A drone photo taken on Jan. 10, 2024 shows an unveiling ceremony of the tunnel boring machine (TNM) Dinghai at an industrial park of China Railway Construction Heavy Industry Corporation Limited in Changsha, central China's Hunan Province. With a diameter of 14.57 meters and a total weight of 4,350 tonnes, the TNM Dinghai will be used in the construction of Jintang undersea tunnel linking the Jintang islet of Zhoushan and the coastal area of Ningbo. (Xinhua/Chen Sihan)

A drone photo taken on Jan. 10, 2024 shows the tunnel boring machine (TNM) Dinghai at an industrial park of China Railway Construction Heavy Industry Corporation Limited in Changsha, central China's Hunan Province. With a diameter of 14.57 meters and a total weight of 4,350 tonnes, the TNM Dinghai will be used in the construction of Jintang undersea tunnel linking the Jintang islet of Zhoushan and the coastal area of Ningbo. (Xinhua/Chen Sihan)

The tunnel boring machine (TNM) Dinghai is seen at an industrial park of China Railway Construction Heavy Industry Corporation Limited in Changsha, central China's Hunan Province, Jan. 10, 2024. With a diameter of 14.57 meters and a total weight of 4,350 tonnes, the TNM Dinghai will be used in the construction of Jintang undersea tunnel linking the Jintang islet of Zhoushan and the coastal area of Ningbo. (Xinhua/Chen Sihan)

Workers record the tunnel boring machine (TNM) Dinghai at an industrial park of China Railway Construction Heavy Industry Corporation Limited in Changsha, central China's Hunan Province, Jan. 10, 2024. With a diameter of 14.57 meters and a total weight of 4,350 tonnes, the TNM Dinghai will be used in the construction of Jintang undersea tunnel linking the Jintang islet of Zhoushan and the coastal area of Ningbo. (Xinhua/Chen Sihan)

Workers attend an unveiling ceremony of the tunnel boring machine (TNM) Dinghai at an industrial park of China Railway Construction Heavy Industry Corporation Limited in Changsha, central China's Hunan Province, Jan. 10, 2024. With a diameter of 14.57 meters and a total weight of 4,350 tonnes, the TNM Dinghai will be used in the construction of Jintang undersea tunnel linking the Jintang islet of Zhoushan and the coastal area of Ningbo. (Xinhua/Chen Sihan)

The tunnel boring machine (TNM) Dinghai is seen at an industrial park of China Railway Construction Heavy Industry Corporation Limited in Changsha, central China's Hunan Province, Jan. 10, 2024. With a diameter of 14.57 meters and a total weight of 4,350 tonnes, the TNM Dinghai will be used in the construction of Jintang undersea tunnel linking the Jintang islet of Zhoushan and the coastal area of Ningbo. (Xinhua/Chen Sihan)

A drone photo taken on Jan. 10, 2024 shows an unveiling ceremony of the tunnel boring machine (TNM) Dinghai at an industrial park of China Railway Construction Heavy Industry Corporation Limited in Changsha, central China's Hunan Province. With a diameter of 14.57 meters and a total weight of 4,350 tonnes, the TNM Dinghai will be used in the construction of Jintang undersea tunnel linking the Jintang islet of Zhoushan and the coastal area of Ningbo. (Xinhua/Chen Sihan)

The tunnel boring machine (TNM) Dinghai is seen at an industrial park of China Railway Construction Heavy Industry Corporation Limited in Changsha, central China's Hunan Province, Jan. 10, 2024. With a diameter of 14.57 meters and a total weight of 4,350 tonnes, the TNM Dinghai will be used in the construction of Jintang undersea tunnel linking the Jintang islet of Zhoushan and the coastal area of Ningbo. (Xinhua/Chen Sihan)