Gaoligongshan Tunnel

Gaoligongshan Tunnel or Gaoligong Mountain Rail Tunnel^[6] (Chinese: 高黎贡山隧道) is a 34.5 km (21.4 mi)^{[Note 1]} tunnel between Nujiang Station and Longling Station on the Dali–Ruili railway in Yunnan, China.^[4] It passes through the entirety of Longling County and then into Mangshi.^[1] Upon completion, it will be the longest mountain railway tunnel in Asia.^[5]

Gaoligongshan Tunnel
高黎贡山隧道

Construction site at the end of tunnel
Overview
Line	Dali–Ruili railway
Location	Longling County, Yunnan[1]
Coordinates	24°38′57.8″N 98°49′39.4″E
Status	Under construction
System	China Railway
Crosses	Gaoligong Mountains
Start	West bank of Nu River in Longling County[1]
End	Nanwazidi (南凹子地) in Longling County[2]
Operation
Work begun	1 December 2015; 9 years ago (2015-12-01)[3]
Owner	China Railway
Technical
Design engineer	China Railway Tunnel Group[4]
Length	34.5 km[Note 1]
No. of tracks	Single-track railway[2]
Track gauge	1,435 mm (4 ft 8+1⁄2 in) standard gauge
Operating speed	140 km/h
Highest elevation	2,340 m[2]
Lowest elevation	640 m[2]
Water Depth	1,155 m[5]
Grade	23.5‰ (biggest)[2]

The tunnel is the key project of Dali–Ruili railway between Dali and Ruili.^[4]

Construction started on 1 December 2015.^[3] The tunnel boring machine "Colorful Cloud No.1"(Chinese: 彩云一号) began work on 28 August 2017.^[7] The expected completion date for 1st phase is 31 May 2022, for a cost of CN¥ 3.628 billion^[3] and 30 November 2025 for the 2nd phase.^[8]

Notes

1. The length has been reported as 34.586468 km^[2] and 34.538 km.^[4]