Photo taken on Dec 23, 2018 shows a construction site on the Lhasa-Nyingchi section of the Sichuan-Tibet Railway in Southwest China's Tibet autonomous region. (Photo/Xinhua)
Construction on the last pivotal tunnel for the Lhasa-Nyingchi section of the Sichuan-Tibet railway was completed on Tuesday, marking huge progress for the mammoth project, according to the country's top railway operator.
The Milin tunnel, located in Milin county of Nyingchi, Southwest China's Tibet autonomous region, is 11,560 meters long with an average elevation of 3,100 meters above sea level. It's the 47th and last tunnel being finished in the section, the company said on Tuesday.
The tunnel is considered the "hardest nut to crack" for railway constructors, and its success will provide valuable reference for the Ya'an-Nyingchi railway - the intricate section of the Sichuan-Tibet railway - which is expected to begin construction this year, it said.
At present, all 47 tunnels on the section have been completed, and 119 of its 120 bridges have finished construction as well. It will also finish track-laying work by the end of this year, the company added.
The Lhasa-Nyingchi section is 435 kilometers long, 75 percent of which are bridges and tunnels. The electrified railway section is designed for trains running at an average speed of 160 kilometers per hour and is scheduled to be operational in 2021.