China’s largest domestically built tunnel boring machine rolls off line in Zhengzhou

TREE NEWS update: The ‘Zhongtie 1662’, China’s largest self-developed tunnel boring machine to date, rolled off the production line in Zhengzhou, Henan province on September 15. Jointly developed by China Railway Tunnel Group, China Railway No. 4 Engineering Group and China Railway Engineering Equipment Group, the slurry shield machine has an excavation diameter of 16.68 metres, a total length of 125 metres and weighs about 4,800 tonnes.