AThe CNN reported that the 435-kilometer (250-mile) rail line connecting Tibetan capital Lhasa with the city of Nyingchi entered into service on June 25, giving all 31 provincial-level regions of mainland China access to high-speed train travel.
47 tunnels, 121 bridges
Building a high-speed railroad in Tibet, dubbed the "roof of the world," was no easy feat.
Some 90% of the route, which took six years to construct, sits higher than 3,000 meters above sea level.
The Lhasa-Nyingchi line features 47 tunnels and 121 bridges - which account for about 75% of the whole route. This includes the 525-meter-long Zangmu Railway Bridge, the largest and highest arch bridge of its kind in the world.A staggering RMB 36.6 billion ($5.6 billion) was spent to build the line, which is serviced by the Fuxing series of high-speed electric trains developed and operated by the state-owned China State Railway Group.
Traveling at high altitudes, the Fuxing trains are equipped with automated oxygen supply systems, which keep oxygen levels at a constant 23.6% - slightly higher than the 21% average found in normal atmospheres.
The trains' windows are equipped with a special layer of glass designed to withstand the region's high UV levels.
The Fuxing trains deployed on the nine-station Lhasa-Nyingchi line are powered by both internal combustion and electric engines. The dual-power engine allows them to achieve smooth traction throughout the 2.5-hour journey on both electrified and non-electrified railroads.
They operate at about 160 kilometers per hour -- far slower than the maximum speeds of 350 kph (217 mph) travelers experience on many of China's other lines.