Twenty years ago, a railway pushed the boundaries of engineering across the Qinghai-Xizang Plateau, crossing some of the world's highest and most challenging terrain. What was once considered impossible became reality, the Qinghai-Xizang Railway. Starting today, CGTN launches 'Beyond the Tracks', a five-part series exploring the life-changing transformations and human stories along the world's highest and longest plateau railway. Behind the profound changes the railway has brought to local communities are the technological innovations that turned the impossible into reality. Xu Xinchen travels to an altitude of more than 4,700 meters to find out more.
Situated at more than 4,700 meters above sea level, this small town of around 3,000 residents spent nearly two decades watching trains pass by, without ever having the chance to step aboard.
Xu Xinchen, Yanshiping Railway Station "But that changed on December 11, 2025, when Yanshiping Station officially opened for passenger service for the first time."
Now, hundreds of passengers board trains daily that head out for nearby towns and cities. We joined Gyaltshi as he travelled to see his children studying almost two hundred kilometers away. A trip takes more than half a day by car now 2 hours on trains.
Gyaltshi, Local Resident "It used to be hard for kids from Yanshipingzhen to go to school in Amdo county."
His children were already waiting outside the station.
Lobsang Chopel, Teacher "Transportation is much more convenient now, so parents can visit frequently. Those who can afford it come once a month on average. We also notice the students are in much better spirits."
The Yanshiping Railway Station is now the highest passenger station along the world-renowned Qinghai-Xizang Railway. Dubbed the 'Sky Road', it serves as a vital link connecting Xizang Autonomous Region with the rest of China, facilitating the movement of people and strengthening logistics. Since opening in 2006, the railway has become a landmark engineering achievement recognized around the world. Stretching 1,956 kilometers from Xining to Lhasa, the railway has carried more than 40 million passengers and transported 100 million tons of cargo over the past two decades. To understand how this massive project continues to operate and endure, we set out for on-site inspections deep along the plateau railway, with a particular focus on monitoring permafrost conditions.
He Ping, Engineer (Reporter: Did you expect such heavy snow today?) Heavy snow like this is quite common here. The altitude is high, and the weather can change rapidly at any time. (Reporter: What are your tasks for today?) Our main work includes track lifting and tamping, track realignment, ballast replenishment at the track center, manual trimming of the track bed, inspection and maintenance of permafrost roadbeds, and checks on sections with subgrade settlement. All our work is carried out on permafrost ground. (Reporter: The ground beneath us is all permafrost, right?) Yes, this area is permafrost. We also carry out renovation work where the subgrade has sunk. (Reporter: Are there any key points we need to watch out for during routine maintenance?) We must check frost-heave height, track alignment and subsidence on permafrost zones.
Snowstorms pose challenges for people, but permafrost is a far greater threat to the railway.
Liu Zhengping, Permafrost expert "We've spent 50 years conducting experiments to figure out whether to let permafrost thaw or preserve it, and the conclusion is that permanent preservation of permafrost cannot be achieved."
Large sections of the Qinghai-Xizang Railway are built on permafrost. Unlike the permafrost found in polar regions, the plateau's permafrost undergoes repeated cycles of thawing and freezing with seasonal changes, posing risks to the stability of the railway structure. Chinese engineers developed an effective solution: installing heat pipes alongside the railway tracks to stabilize the frozen ground. These devices reduce ground temperatures and help maintain the permafrost layer, a solution that has proven highly effective. Each heat pipe is filled with a volatile working medium that powers its cooling cycle.
Liu Zhengping, Permafrost expert "As long as the internal medium does not leak, the pipe will keep functioning continuously. It activates when the ambient temperature is cold enough. The pipes constantly transfer cold energy from the atmosphere down to the ground."
Conquering permafrost was just the start of the transformation. Over the past decade, the railway achieved another major upgrade: a full replacement with seamless tracks including sections over permafrost.
Wang Cheng, Engineer "Continuous welded rails deliver far smoother travel than the old short rails. Meanwhile, transport efficiency and train operating speeds are both improved."
Xu Xinchen, Nacha Station "Late-night rail maintenance on the Qinghai-Xizang Railway. We swap out worn rails for brand-new ones."
A team of 300 workers completes the replacement of 1.5 kilometers of tracks by implementing a coordinated assembly line style.
A key step uses domestically developed welding machines. The home-grown rail pressure welding heats rail ends to over 1000°C, fuses them tightly together and then cools the joint down.
The Qinghai–Xizang Railway's continuous welded rails have reduced annual maintenance costs by 30 percent while doubling the lifespan of the tracks. Full electrification is also being rolled out along the line, bringing advanced Chinese rail technology to the world's highest railway and making operations greener and more efficient. These technological upgrades are helping make travel along the route more reliable and accessible. Xu Xinchen, CGTN.
