State contractors have once again showcased their edge in infrastructure construction with the recent completion of a tunneling project on a major railway under construction. China Railway 24th Bureau Group Corp Ltd (CR24), which is building the Shanghai-Chongqing-Chengdu High-speed Railway together with other major infrastructure builders, including units from China Communications Construction Co Ltd and China Railway Group Ltd, said its construction teams completed the tunneling project on the railway on Thursday. As the first tunnel over one kilometer long that has been dug on the railway, the maximum burial depth of the two-rail Dangyang Tunnel reaches 86 meters, going through many fault areas in the mountainous region of Hubei province. (....)