In 2017, Chinese Academy of Engineering completed a detailed design for an 84 mile long Tunnel to Taiwan. The Academy is the largest central governmental advisory body on infrastructural construction.
Beijing included a cross-strait high-speed rail network in its then-new five-year plan. But a lot of work has been need to get a viable technical design.
There is also the political challenge. Taiwan does not want the tunnel and a majority do not want reunification with China.
The China-Taiwan tunnel would start from Pingtan, a pilot free-trade zone area set up by Beijing in Fujian province in 2013 to boost trade with Taiwan. Digging would go down nearly 200 meters (218 yards). It would cut through complex layers of rock, including extremely hard granite and avoid at least two major earthquake faults and return to the surface in Hsinchu, a coastal city near Taipei.
It would be 135 kilometers long. This is three and a half times longer than the 37.9 km Channel Tunnel between Britain and France.
The Channel Tunnel – nicknamed the “Chunnel” – took six years to build and cost the equivalent of 12 billion euros (US$13.99 billion) today.
The Taiwan-China tunnels would have three main tunnels and each would be nearly a third larger than their European counterparts. Two main tunnels would each be 10 meters in diameter.
Two main passages would be used by trains running in opposite directions. There would be a smaller service tunnel that would contain power lines, communication cables and emergency exits.
Their broader design would allow trains to travel faster and carry bulkier cargos.
Two artificial islands would have to be created in the middle of the Taiwan Strait for air treatment stations that would pipe fresh air into the tunnel.
China will spend almost US$2 billion (12 billion yuan) on a 6.8 mile (11 kilometer) long highway tunnel.
The Pingtan-Fuqing passageway, running more than 11 kilometers under the seabed, would beat the Tokyo Bay Aqua Line as the world’s longest undersea road tunnel. The Chinese road tunnel will be wide enough for three heavy cargo trucks to drive side by side in each direction.
There is a 26 million yuan feasibility assessment for building a road tunnel from Pingtan to Fuqing.
The Pingtan-Fuqing road tunnel would be a warm-up exercise for the construction of the rail tunnel from Pingtan to Hsinchu, Taiwan.
The shorter tunnel would be located in roughly the same area as the rail tunnel and require engineers to figure out how to solve similar geological and technical problems.
China may test combinations of drilling and blasting methods to build the Pingtan-Fuqing tunnel to see if costs can saved and the work can be faster.
The 5-year plan talks about completing the Taiwan rail tunnel by 2030 but current engineers indicate that the digging and other work would take from 2020 to 2050. The start date assumes the election of a pro-Chinese government in Taiwan and the negotiation of an agreement to build the tunnel.