LIGHTNING SPEED: The Beijing-Tianjin inter-city railway adopts a number of advanced technologies to realize top speed and absolute safety

When an array of emerging modern railways bring immediate benefits to China's mountainous and isolated regions, no one doubts that the country is moving on a fast track toward prosperity. But building railways in China can never be an easy job given its complex geological conditions and a growing need for faster and easier transportation. What it takes to tunnel through towering mountains and lay tracks in vast deserts goes far beyond the toil of construction workers. By flexing its scientific and technological muscles, China has raced ahead of most other countries in the competition of railway engineering.

Mission impossible

The Qinghai-Tibet Railway, a link to the "roof of the world," is one of the country's pioneering scientific feats that stunned the world. Running higher than any other railway in the world, it passes through remote regions of Tibet and covers more than 500 km of permafrost, which may melt when temperatures rise and destabilize the roadbeds. Intensifying global warming has even defied a batch of routine counter-measures such as raising embankments and paving the track with heat-insulating materials.

MAKING CONNECTIONS: Workers build the technologically advanced Beijing-Shanghai high-speed railway in 2009

After decades of research, Chinese scientists and engineers have come up with a set of roadbed-cooling measures to prevent the permafrost from thawing. Among them, the most important is thermosyphons, steel pipes filled with an easily vaporizable liquid such as ammonia. As the liquid boils, the devices, embedded beneath the embankments, could absorb heat from the permafrost and transfer it into the air.