Deep beneath the waters off eastern China, engineers are carrying out one of the most demanding stages of construction on a high-speed railway tunnel.
The Jintang undersea tunnel, part of the Ningbo-Zhoushan high-speed railway in Zhejiang Province, has completed the inspection and replacement of 104 shield cutting tools after 21 days of work under intense water and soil pressure.
The 16.18-kilometre tunnel is set to become the world’s longest undersea high-speed rail tunnel, linking Ningbo with Zhoushan and cutting the journey between the two cities from as much as two hours to about 26 minutes.
The latest operation also tested a domestically developed saturation hyperbaric system adapted from deep-sea diving technology.
The achievement comes as China continues pushing high-speed rail construction through challenging underwater environments, including the recently completed shield-machine crossing beneath the Yangtze River, another major engineering milestone highlighted by China’s State Council Information Office.






