China approved plans for the country’s first underwater tunnel for high-speed trains, CNN reports.
The ¥25.2 billion (or $3.7 billion) project will be a part of the 77-kilometer Yong-Zhou Railway plan, linking the port city of Ningbo with Zhoushan, an archipelago. Most of the line will be newly built, with 16.2 kilometers (10 miles) running underwater. It’s expected to be finished by 2025.
The high-speed trains, traveling at 250 km/h (155 mph), are intended to boost tourism and decrease commute times. The new route will connect to China’s existing high-speed train network, CNN reports, allowing travel between Hangzhou (the capital city of Zhejiang) and Zhoushan in 80 minutes. By car, the journey can take up to three hours.
Train speeds do lag behind those of high-speed trains in France and Japan—both of which can reach 320 km/h (198 mph)—but this is because China reduced its maximum speeds following a fatal crash in 2011.
France’s and Japan’s trains both run through longer underwater tunnels as well, the World Economic Forum reports: Japan’s Seikan Tunnel has 23 kilometers (14 miles) underwater and the Channel Tunnel connecting the UK and France has 38 kilometers (24 miles) underwater. China has some long-term plans to change this, however, with a train tunnel passing under the Bohai Strait, with 90 kilometers (56 miles) underwater.