On June 5, Red Star News learned from Yangtze River Coastal Railway Group Chongqing Co., Ltd. that the first tunnel on the entire Chengdu-Chongqing Middle Line High-Speed Railway — the Huanglianbao Tunnel — was successfully holed through today, marking that tunnel construction along the entire line has entered a critical stage.

As an important component of the Yangtze River corridor of China's "Eight Vertical and Eight Horizontal" high-speed rail network, the Chengdu-Chongqing Middle Line High-Speed Railway starts from Chongqing North Station in the Chongqing hub, runs westward through Yubei District, Shapingba District, Bishan District, Tongliang District and Dazu District of Chongqing Municipality, and Ziyang City and Chengdu City of Sichuan Province, before entering Chengdu Station in the Chengdu hub. The main line has a total length of 292 kilometers and a design speed of 350 kilometers per hour.

The Huanglianbao Tunnel is located within Dazu District, Chongqing Municipality, and was constructed by China Railway No. 5 Engineering Group. The tunnel has a total length of 821 meters and is a single-tube double-track tunnel, characterized by a large excavation cross-section and shallow cover. According to Wu Yueguang, manager of the No. 3 Bid Project Department of China Railway No. 5 Engineering Group, since last year all tunnels in the bid section have commenced construction, with 16 of 17 bridges and 9 of 15 sections of interval subgrade works started.

According to Huang Chenghua, commander of the Dazu Command Post of Yangtze River Coastal Railway Group Chongqing Co., Ltd., four construction contractors are distributed along the Chongqing section, and project construction is progressing smoothly, with overall progress at 35 percent. Once the project is completed, it will connect with the already completed and operational Xi'an-Chengdu High-Speed Railway and Zhengzhou-Chongqing High-Speed Railway, as well as multiple lines under construction, including the Xining-Chengdu High-Speed Railway, Chengdu-Dazhou-Wanzhou High-Speed Railway, Xi'an-Chongqing High-Speed Railway, Chongqing-Kunming High-Speed Railway and Chongqing-Wanzhou High-Speed Railway. By then, the road network structure in the Chengdu-Chongqing region will be further improved, travel time between Chengdu and Chongqing will be further reduced, and travel for people along the line will become more convenient.