As the massive cutterhead slowly rotated, on August 31, the CRSH No. 0061 dual-mode shield machine successfully launched in the section from Bainikeng Station to No. 1 Working Shaft of Baida in the Fourth Work Area of the Shenzhen–Dayawan Intercity Railway. The charge was officially sounded for construction of the 6-kilometer double-line shield tunnel section, marking a further acceleration in the construction of the Shenzhen–Dayawan Intercity Railway project and laying a solid foundation for speeding up the realization of rapid rail transit interconnection in the Guangdong–Hong Kong–Macao Greater Bay Area.

The left line of the section from Bainikeng Station to No. 1 Working Shaft of Baida on the Shenzhen–Dayawan Intercity Railway project runs from chainage 3085.545 meters, and the right line runs from chainage 3079.9 meters, with a total section length of 6165.445 meters. After leaving Bainikeng Station, the alignment successively passes beneath important structures and buildings such as the Bainikeng building complex, the Pingyan Railway, the Paibang Interchange, the subgrade section of the Hangzhou–Shenzhen Railway, and the Yantian Tunnel before reaching No. 1 Working Shaft. The section has an overburden thickness of 16 to 105 meters, a maximum longitudinal slope of 27‰, and a minimum horizontal curve radius of 1300 meters. The tunnel body mainly passes through completely weathered quartz sandstone, slightly weathered quartz sandstone, moderately weathered quartz sandstone, slightly weathered siltstone, and moderately weathered siltstone. The rock mass compressive strength exceeds 100 MPa, and a single construction run reaches 3 kilometers, with large burial depth and downhill excavation, making construction relatively difficult.

In response to the above issues, CRSH, together with sister units, invited experts from various parties to discuss and analyze the shield technical parameters. Taking comprehensive account of the actual construction conditions of the tunnel on the Shenzhen–Dayawan project, they optimized the design of the shield machine model in a targeted manner. After more than eight months, the design and manufacture of Baolian No. 1 (No. 0061), a φ9130 mm EPB/TBM dual-mode shield machine, was finally completed, and it rolled off the production line at the Zhongshan manufacturing base on July 15.

The shield has an excavation diameter of 9.13 meters, a total length of about 113 meters, and a weight of about 1500 tons. It has earth pressure balance functions and open TBM excavation functions, adopts split launching, and uses battery locomotives together with gantry cranes for muck removal. It is tunnel excavation equipment suitable for possible soft rock and hard rock composite stratum engineering geological conditions. When formation and geological conditions change, by switching the excavation mode and muck removal method, it causes little interference to supporting construction and can effectively reduce engineering risks.

To ensure the smooth launch of the shield, CRSH technical personnel carried out extensive deployment and preparation work, overcame problems such as a small site, cross-operation, and equipment entry, and successfully completed the lowering, assembly, and debugging of the shield machine. By August 30, the launch conditions had been met and the assembly of three negative rings had been completed, sounding the assembly call for the smooth launch of the shield and for the next step of accelerating shield construction and completing construction milestones with quality and quantity guaranteed.