China completes construction of high-speed railway tunnel beneath Yangtze River

China has completed the excavation of a high-speed railway (HSR) tunnel beneath the Yangtze River, the longest river in China and the third longest in the world. This was reported by Xinhua News Agency, a partner of TV BRICS.

The total length of the tunnel is 14.25 km, of which 11.18 km runs beneath the river. It connects the Chongming District in Shanghai with the city of Taicang in Jiangsu Province, Eastern China. Once the tunnel becomes operational, high-speed trains will be able to cross the river underwater at speeds of up to 350 km/h.

The tunnel is a key project in the construction of the Shanghai–Nanjing section of the Shanghai–Chongqing–Chengdu high-speed railway. In the future, it will form part of China’s unified high-speed rail network, which consists of eight vertical (north–south) and eight horizontal (east–west) corridors.

The successful implementation of the project aligns with the country’s broader strategy for the accelerated development of high-speed rail. The first such railway opened in 2008, linking Beijing and Tianjin. By 26 December 2025, with the launch of the Xi’an–Yan’an line in Shaanxi Province, the total operational length of China’s high-speed railways exceeded 50,000 km.

According to Yu Jian, an expert at the China Railway Economic and Planning Research Institute, the development of high-speed rail has significantly improved transport accessibility across the country. Journeys within urban agglomerations (up to 500 km) now take 1–2 hours; travel between major cities (around 1,000 km) is possible in four hours; and distances exceeding 2,000 km can be covered within a single day.

China also plans to expand the length of high-speed railways to approximately 60,000 km by 2030 and 70,000 km by 2035.

China is also working to increase train speeds. In December 2024, a prototype of the world’s fastest train, designed to operate at 400 km/h, was unveiled in Beijing. During testing, the train covered 300,000 km – half of the distance required before commercial operation – and reached a speed of 453 km/h. In December 2025, Chinese researchers accelerated a one-tonne magnetic levitation (maglev) test train to 700 km/h in just two seconds.