en.Wedoany.com Reported - Recently, the "CREC 1079," a super-large diameter earth pressure balance shield machine developed by China Railway Engineering Equipment Group Tianjin Company under China Railway Group Limited, rolled off the production line in Tianjin. It will be used in the construction of the Riyadh Metro Line 2 extension project. This is China's first shield machine exported to Saudi Arabia.

The "CREC 1079" shield machine has a cutter head excavation diameter of 11.16 meters and a total machine length of 105 meters. The tunnel strata of the Riyadh Line 2 extension mainly consist of long-distance cohesive sandy soil and moderately weathered limestone, which are prone to issues such as cutter wear and mud cake formation on the cutter head during construction. Based on the project's geological conditions and the owner's requirements, the R&D team of China Railway Engineering Equipment Group equipped the machine with a radial ultra-high-pressure water injection device for the cutter head, simultaneously strengthening the wear-resistant design of the cutter head tools and the screw conveyor. It is also equipped with a new generation segment assembly process to improve equipment performance.

The total length of the Riyadh Metro Line 2 extension is approximately 8.4 kilometers, of which 6 kilometers is the shield tunneling section. The line starts from the existing King Saud University Station on the western section of Line 2, extends westward to the Diriyah Gate area, and can connect with the planned new Metro Line 7 for transfers. Once completed, the line will improve the Riyadh rail transit network, enhance urban transport capacity, alleviate road congestion, and support Riyadh's sustainable urban development.