Recently, three hard rock TBMs, designed and made by China Railway Engineering Equipment Group Co., Ltd. (CREG), rolled off the production line and were ready for the Yangtze-to-Hanjiang River Water Diversion Project. With the total tunnelling length of 123km, this project will use ten hard rock TBMs. Within the next six months, CREG will supply additional three TBMs for this project.

This project is characterized with deep overburden, long mileage and large tunnel diameter. During the construction, there are also many challenges, including strong rockburst, mud and water gushing, large fault, soft rock deformation, high temperature and poisonous and harmful gases, caused by high geostress, high water pressure, high rock strength, many faults, rich groundwater and other geological difficulties.

The single shield TBM "CREC 1463" was the first hard rock TBM for the project. This 12.23m-diameter TBM is about 160m long in total and has the advantages of probe drilling, intelligent tunnelling, safety and reliability. Besides, the machine is equipped with lots of innovative technologies, such as comprehensive geological prediction system and cutter condition monitoring system.

The double shield TBM "CREC 1468" was the second one rolling off the production line. This 11.93m-diameter TBM is about 180m long in total and is equipped with the self-developed TBM SMART system in addition to TBM jamming warning system, cutter condition monitoring system and other innovative technologies. This SMART system can automatically evaluate the geological condition and machine health, and set best TBM tunnelling parameters to ensure the safety and efficiency of TBM tunnelling.

The single shield TBM "CREC 1466" was the third one with the diameter of 12.23m and total length of 227m. It can adapt to the minimum curve radius of 800m and the maximum gradient of 10%. Potential construction risks are greatly minimized by adopting a double-speed reducer, shield structure resistance reduction design and TBM jamming warning and evaluation system.

The Yangtze-to-Hanjiang River Water Diversion Project is a follow-up water source project of the South-to-North Water Diversion Middle Route Project, which aims at diverting water from the Three Gorges Reservoir to the Danjiangkou Reservoir. The implementation of the project will make the South-to-North Water Diversion Project and the Three Gorges project closely linked, connect the Yangtze River Basin, the Hanjiang River Basin and North China's Beijing and Tianjin to form a new water network pattern and guarantee water resources for the Hanjiang River Basin and North China's Beijing and Tianjin.