"This is the first time globally that a 15-meter-diameter shield machine has achieved continuous tunneling exceeding 10,000 meters in a single drive," said Li Bin, chief engineer of the project.

According to China Railway Tunnel Group Co, the project's contractor, the single-tunnel double-track structure has established multiple records.

In addition to marking the longest single-drive tunneling distance of 11.32 km, the project has achieved the highest global design speed for an underwater tunnel at 350 km per hour and the greatest depth for a Yangtze River tunnel at 89 meters.

"The machine incorporates an advanced tunneling system, which enables autonomous operation through intelligent analysis and decision-making," said Wang Yi, deputy equipment manager of the project.

"Drawing from hundreds of historical datasets and machine-learning models, the system's capabilities enable efficient manned supervision along with unmanned operation," he said.