The world's highest tunnel for high-speed trains in northwest China became operational today at an altitude of 3,607.4 metres.
The 16.3-km-long was completely linked up, operationalising the line linking Gansu Province and Xinjiang provinces.
With altitudes of up to 3,607.4 metres, the tunnel passes through the Qilian Mountains with two sections and a bridge.
The construction began in 2009.
The tunnel's complete joining means the most difficult part for the Lanxin high-speed railway has been solved, state-run Xinhua reported, quoting an official in charge of the tunnel project.
The 1,776-km Lanxin high-speed railway links Lanzhou, capital of Gansu, with Urumqi, capital of Xinjiang and runs across Gansu and Qinghai provinces to Xinjiang, traversing the Gobi Desert.
The line is planned to be put into use at the end of this year.
It is designed for trains running at over 200 km per hour and will cut the train travel time between Lanzhou and Urumqi to eight hours from about 20 hours.
