On January 22, the large-diameter dual-mode shield tunneling machine "CREC No. 749" successfully completed acceptance at the Zhengzhou base via online video and live streaming. The equipment will be used in the Cefalù section of the railway tunnel from Messina to Palermo on the southern Italian island of Sicily. This is also the first time China's dual-mode shield tunneling machine has been applied to overseas railway tunnel construction.

The Cefalù railway section is located on the beautiful island of Sicily in southern Italy. The strata are mainly argillaceous sandstone, siltstone, and quartz sandstone. The tunnel is designed as a single-track, double-tube tunnel, with each tube about 6.7 km long, a maximum burial depth of about 300 m, and a maximum water pressure exceeding 5 bar. Because the equipment's tunneling section is long, some strata are located in sand-gravel strata, clay, clayey limestone, sandstone, sandstone fracture zones, and other complex strata. The equipment also needs to pass through historical and cultural relics in the Cefalù area, all of which place extremely high demands on the overall performance of the tunneling machine.

The equipment has an excavation diameter of 9.98 meters, an overall length of about 146 meters, and a total weight of about 1,650 tons. To enable mode change inside the tunnel, the equipment innovatively designed a main drive telescopic partition to achieve the telescoping of the main machine belt conveyor and the transfer of the muck discharge structure at the back of the cutterhead under dual modes through the material transport channel, thereby effectively improving the mode-change efficiency and saving time on mode switching. At the same time, the entire machine is designed in terms of safety protection, escape passages, fluid systems, and electrical systems in accordance with CE standards and local Italian standards.

The Cefalù railway tunnel project is one of the sections of the Palermo-Messina railway line, with a design speed of 200 km/h. This railway line is an important part of the European TEN-T railway network and is a rapid corridor running through the heart of Europe, with major international significance. It is worth mentioning that it is one of four strategic infrastructure projects in Italy belonging to the European TEN-T railway network. The arrival of "CREC No. 749" will accelerate the construction of transportation facilities in Italy, bring more convenience to this Mediterranean country with a long history, and contribute Chinese strength to the improvement of the European railway network.