A revolutionary undersea tunnel costing £20bn could slash an eight-hour journey between two Chinese cities to just 40 minutes. The Bohai Strait Tunnel, stretching 76 miles (123km), will be the world's longest when completed, with 56 miles submerged beneath the sea.
The tunnel will link Dalian and Yantai, two industrial powerhouses in China, using high-speed trains running at over 150mph. This will reduce travel time by nearly 90%, outpacing Eurostar services which only reach 100mph in the Channel Tunnel.
Engineers are incorporating advanced earthquake-resistant technology as the tunnel passes through several fault zones. Design features include longitudinal ventilation shafts, dozens of cross-passages between twin tunnels, and hundreds of emergency refuge areas to manage safety over the vast distance.
The current budget is estimated at £20bn, and while no completion date has been set, a Chinese government representative stated in 2018 that authorities were eager to launch the project 'as soon as possible.' Construction is expected to take 10 to 15 years, with the first train potentially running in the late 2030s.
When finished, the tunnel will dwarf existing rivals like the 31-mile Channel Tunnel and Japan's 33.5-mile Seikan Tunnel. However, environmental campaigners have raised concerns about the impact on wildlife, particularly the spotted seal, a protected species that breeds in the region.
