An aerial drone photo taken on Dec. 18, 2024 shows workers debugging a tunnel boring machine at an industrial park in Changsha, central China's Hunan Province, Dec. 18, 2024. (Xinhua/Chen Sihan)

Jointly developed by the China Railway Construction Heavy Industry Co., Ltd. (CRCHI) and China 15th Metallurgical Construction Group Co., Ltd., the tunnel boring machine rolled off the production line in Changsha, central China's Hunan Province on Dec. 18 (Wednesday). It is about 130 meters long and approximately 800 tonnes in weight, with an excavation diameter of 5.63 meters. It will be exported to Zambia for mining tunnel construction.

A worker debugs a tunnel boring machine at an industrial park in Changsha, central China's Hunan Province, Dec. 18, 2024. (Xinhua/Chen Sihan)

Workers debug a tunnel boring machine at an industrial park in Changsha, central China's Hunan Province, Dec. 18, 2024. (Xinhua/Chen Sihan)

A tunnel boring machine performs an operational demonstration at an industrial park in Changsha, central China's Hunan Province, Dec. 18, 2024. (Xinhua/Chen Sihan)

A tunnel boring machine rolls off the production line at an industrial park in Changsha, central China's Hunan Province, Dec. 18, 2024. (Xinhua/Chen Sihan)