China’s self-developed world’s largest diameter high-speed rail tunnel boring machine, “Linghanghao” (Navigator), has successfully begun its second phase of excavation. This milestone follows its groundbreaking journey across the Yangtze River and a 41-day deep maintenance period.
Renewed Journey Towards World Record
On September 9th, the “Linghanghao” machine re-commenced its tunneling operations from Shaft 2 of the Chongtai Yangtze River Tunnel. This marks a significant step as the machine embarks on the land-based section of its journey, aiming to achieve a new world record for single-face tunneling by an ultra-large diameter shield machine. The target is to excavate 13.2 kilometers, pushing the boundaries of current technological capabilities in tunnel boring.
The Chongtai Yangtze River Tunnel Project
The Chongtai Yangtze River Tunnel is a monumental infrastructure project spanning 14.25 kilometers, designed to connect Shanghai’s Chongming Island with Taicang in Jiangsu Province. It is a crucial component of the new Shanghai-Nanjing-Hefei high-speed railway, part of China’s national “eight vertical and eight horizontal” high-speed rail network. The tunnel includes a 13.2-kilometer segment to be constructed using the shield tunneling method, comprising 11.3255 kilometers underwater and 1.8755 kilometers on land.
“Linghanghao”: A Technological Marvel
The “Linghanghao” machine itself is an engineering marvel. It boasts a cutter head diameter of 15.4 meters, a total length of 148 meters, and weighs approximately 4,000 tons, making it the largest diameter high-speed rail tunnel boring machine in the world to date. Its recent restart after deep maintenance signifies advancements not only in the machine’s capability but also in the techniques for its upkeep and operational readiness.
Innovations in Tunneling and Maintenance
This second start-up is particularly noteworthy as it integrates several key technological breakthroughs: comprehensive deep equipment maintenance, confined underground starting procedures, and ultra-long distance tunneling. These advancements underscore China’s self-reliant innovation capabilities across the entire chain of ultra-large diameter shield equipment, tunnel construction, and intelligent operation and maintenance.
Project Timeline and Future Impact
According to the construction schedule, the Chongtai Yangtze River Tunnel is expected to be fully completed by the end of 2026. Once operational, it will be a transformative development for Shanghai’s Chongming Island, ending its history of being without a railway connection. High-speed rail passengers will be able to travel from Chongming to Shanghai Baoshan Station via Taicang in a mere 17 minutes, significantly enhancing connectivity and travel efficiency.
The successful crossing of the Yangtze River and the subsequent restart of the “Linghanghao” machine represent a significant achievement in China’s high-speed rail infrastructure development, demonstrating the nation’s prowess in advanced engineering and large-scale tunneling projects.
