China’s Sichuan-Tibet rail project at full steam – with fans and ice as machines melt, workers wilt
- Boiling heat from the Earth’s crust forces engineers to cool things down to continue the most challenging railway construction in history
- 70 tunnels, including one over 40km long, will navigate some of the world’s most remote and hostile terrain
A significant proportion of its route involves tunnelling through rock too hot for humans or machines to bear, with ground temperatures of up to 89 degrees Celsius (192 degrees Fahrenheit) – the highest on record for a transport infrastructure project, according to geologists.
When the Tibetan plateau was created by a collision between the Eurasian plate and the Indian subcontinent, with the tectonic force giving rise to the Himalayas, an enormous amount of heat was trapped inside the elevated crust.
The 1,543km (959-mile) Sichuan-Tibet railway has to cross more than 40 major fault lines, more than attempted by any previous rail project.
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“The underground heat sources spread upwards along the fault zone and generate random local heat spots, causing frequent geothermal disasters,” said geophysics professor Lan Hengxing and his colleagues with the Institute of Geographic Sciences and Natural Resources Research, in a paper published last week in the domestic peer-reviewed publication Journal of Engineering Geology.