China Plans To Build World's Longest Underwater Tunnel

Chinese engineers unveiled a plan to connect the cities of Dalian and Yantai via a rail tunnel underneath the Bohai Sea.

China Plans To Build World's Longest Underwater Tunnel
Flickr / dcmaster

Chinese engineers just unveiled plans to build the world's longest undersea tunnel.

State-run newspaper China Daily first reported the mammoth engineering project, which is estimated to cost $36 billion. The paper noted plans for this tunnel were first given the green light by local authorities in 2011, and will be submitted to the central government this April.

The 76-mile tunnel will house a rail line connecting the cities of Dalian and Yantai by tunneling under the Bohai Sea. The tunnel could shave around 800 miles off of the current travel route between the two cities, and it would provide a vital link for a high speed rail-line connecting China's north and south provinces. (Via Google Earth)

Xinhua notes the tunnel's trains are planned to run at almost 140 mph, meaning the tunnel could be traversed in 40 minutes. Currently, traveling between Yantai and Dalian takes about eight hours by ferry.

And Bloomberg writes building the tunnel would be the latest in a series of massive construction projects undertaken by China in recent years. "The world’s second-largest economy has poured billions in past years to build infrastructure to spur growth, which may be more critical with gross domestic product forecast by economists to expand this year at the slowest pace since 1990."

Of course, building a massive rail tunnel underneath an ocean isn't without risks — especially given China's vulnerability to earthquakes.

The Telegraph reports China's planned tunnel crosses across two major fault lines. A university researcher working on the project told the paper, "The government is being cautious about the project. ... We proposed this idea of a tunnel 20 years ago and many research teams have been looking at it since."

If China decides to go ahead with the project, work could begin in 2015 or 2016. The earliest completion date for the tunnel is 2026.