Gaoligongshan Tunnel
The 13th longest tunnel in the world
Gaoligongshan Tunnel or Gaoligong Mountain Rail Tunnel is a 34.5 km (21.4 mi) tunnel, currently under construction, between Nujiang Station and Longling Station on the Dali–Ruili railway in Yunnan, China. It passes through the entirety of Longling County and then into Mangshi. Upon completion, it will be the longest mountain railway tunnel in Asia. The tunnel is the key project of Dali–Ruili railway between Dali and Ruili. Construction started on 1 December 2015. The tunnel boring machine "Colorful Cloud No.1" began work on 28 August 2017. The expected completion date for 1st phase is 31 May 2022, for a cost of CN¥ 3.628 billion and 30 November 2025 for the 2nd phase.
Tunnel data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).