China is planning to build the world’s longest underground tunnel, running beneath the Bohai Sea, by 2026 for an estimated $26 billion, the state-run China Daily reports.
The 123-kilometer tunnel would connect the port cities of Dalian in Liaoning Province and Yantai in Shandong Province with a rail line, knocking off 800 miles and cutting the travel time between the two places from eight hours to 40 minutes. Authorities hope that the plan will stimulate economic growth by connecting the north with the wealthy eastern coast.
“Once approved, work could begin as early as 2015 or 2016,” said Wang Mengshu, a tunnel and railway expert at the Chinese Academy of Engineering who has been working on the plan since 2012.
Although China has a history of large-scale engineering projects – from the Great Wall to the world’s largest high-speed railway network, several long bridges and tall skyscrapers – the underground tunnel will pose many challenges. Engineers would have to drill three tunnels for cars, trains, and maintenance through hard rock 100 feet below the sea bed.
Some have expressed concerns over safety since the proposed tunnel would run across two earthquake fault lines. In 1976 a 7.5 magnitude earthquake hit the industrial city of Tangshan in Hebei province, which lies between Shandong and Liaoning. The official death toll was 242,000, but some estimates outside of China are as high as 655,000.
A leading researcher on the tunnel at East Shandong University who asked not to be named told The Telegraph that the Chinese government “is being very cautious about the project.”
“We set up a special group to study the Channel Tunnel. In fact, every undersea tunnel engineer in the world has learned from the Channel Tunnel because it is the best example in the world. We learned some construction techniques and also some ways of financing our tunnel,” the researcher added.
Despite the reassurances, others have cast doubt on the safety of the project.
“In general, though, one can say tunnels are not unsafe in earthquake areas, all depending on the geology, tunnel depth and other local conditions,” Matthias Loftsson, director of geology for Iceland’s Mann-vit, told the China Daily.
The final decision of whether the tunnel will be built or not lies with the State Council, which will examine the blueprints in April.