On January 22, 2021, a 9.98m diameter dual-mode (EPB / single shield) TBM designed and manufactured by CREG for the Cefalù tunnel, Italy completed its live FAT at Zhengzhou, China, the headquarters of CREG. The Cefalù railway tunnel project is one of the tender sections of the Palermo-Messina railway line and an important part of the European TEN-T railway network.
The project is designed as a single line with two bores. The length of each tunnel is about 6.7km, the maximum overburden is 300 meters, and the maximum water pressure exceeds 5 bar. The geology features sandy gravel in some parts, clay, clay limestone, sandstone, sandstone fracture zone, etc. And it will go through many historical and cultural monuments. All these put extremely high requirements on the overall performance of the equipment.
CREC 749, the dual-mode (EPB / single shield) TBM, has an excavation diameter of 9.98 meters, a total length of about 146 meters, and a total weight of about 1,650 tons. In order to realize rapid mode switching in the tunnel, CREG innovatively designed the bulkhead for the main drive and the material transportation channel, making that the main machine belt conveyor can work with the cutter head back slag structure, thereby effectively improves the efficiency of mode change and saves the construction period.