On 16th January 2024, the China Rail Construction Group (CRCG) unveiled its new, oversized tunnel boring machine (TBM) for the construction of high-speed rail (HSR) lines. The TBM, which was jointly developed by CRCG and China Railway Construction Heavy Industry in Changsha, is 14.60 m wide and weighs 4,350 t. It will be used to bore the 11.21 km Jintang Sea Tunnel on the 77 km Ningbo – Zhoushan HSR line currently under construction. Once completed, the Jintang tunnel will be China's first and longest sea tunnel on a HSR line, with a maximum depth of 76 m. Around 90% of the Ningbo – Zhoushan HSR line will either be elevated on 36 bridges or run underground in 17 tunnels. The new line is scheduled to open in 2026.
