Formidable mountain barriers
Unstable permafrost & swampy wetlands
A Fragile Ecosystem
How do you think Chinese build a railway across these mountains to China’s most remote province, Tibet?
Kunlun Mountain Range: This is the legendary “Mother of Thousands of Mountains.” American writer Paul Theroux once prophesied that this “formidable mountain range that divides Tibet from the rest of China would guarantee that a train to Lhasa – which China has dreamed of since the 1950s – will never be built.” About 85 percent of the entire rail track is located in the “Forbidden Zone.“ This is also known as the “Death Zone” because of thin air, harsh and unpredictable weather, fierce sandstorms and high UV radiation. Annual average temp is minus zero. Temp drops to as low as -45 degree C. Average altitude of rail track here is 13,500 feet above sea level. The highest point is 16,700 feet making it the world’s most elevated track. When constructing the Fenghuo Mountain Tunnel – 16,000 ft above seal level – workers had to be equipped with oxygen cylinders. An oxygen-producing station to “feed” the tunnel was built. Seventeen such stations were built along the railway line equipped with high-pressure oxygen cabins for workers to recover. There were 17,000 ft-high mountains to climb, 12 kilometre-wide valleys to bridge, hundreds of kilometres of perennial ice and slush that could never support tracks and trains. How could anyone tunnel through rock at -40C, or lay rails when the least exertion sends you gasping for oxygen in the thin air?
Unstable Permafrost: There is a total of 550 km of permafrost along the rail route. Permafrost is soft and wet soil in summer, hard and expanding in winter – a nightmare for all railroad engineers. The most viable solution is the building of stone embankments for the railroad foundation. In some places, engineers bury ventilation pipes in the ground to allow cold air to circulate underneath the rail-bed. In other spots, a pipe called a thermosiphon is sunk 15 feet into the ground and filled at the bottom with ammonia. The ammonia becomes gas at low temperatures, giving off a vapour that draws heat from the bottom of the tube and flushes it out the top. Building a bridge over the permafrost. This has the least impact on the area, but is also the most expensive. E.g., The 11.7km Qingshuihe Bridge is the world-longest bridge built on permafrost. A round-the-clock monitoring system has been installed to keep tab on the temperature change along the 550 km permafrost stretch of the route.
Environmental protection of Fragile Ecosystem: Some RMB 2.54 billion was invested by Chinese authorities in the environmental protection in the project. Protection of the ecological environment has been an essential concern in the design. The routes were selected so that they would keep away fro m the major habitats of wild animals. E.g, the original route was abandoned because it passed through the reserves of black-necked cranes. While in some other places like the section cutting through the Hohxil, Qumar and Soga nature reserves, the planners minimized disturbance to the nature reserves for endangered Tibetan antelope and wild ass by building 25 passageways for wild animals based on their migration habit. Reducing adverse impact on ecological environment to the minimum during rail construction. All the train cars are installed with environment-friendly toilets, wastewater deposit tanks and garbage treatment facilities to protect the environment along the route.
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