BEIJING, June 26 -- The new Qinghai-Tibet Railway line the highest on earth will endure the harsh conditions along the "Roof of the World" thanks to new technology and constant monitoring.

    Vice-Minister of Railways Sun Yongfu said: "It is a railway we've made a whole lot of innovations and breakthroughs with. No other country could build a railway on as high permafrost as this."

    With most of the new 1,110-kilometre track being laid at altitudes above 4,000 metres, the line crosses 550 kilometres of permafrost.

    Based on preparatory work carried out over the past four decades, Chinese engineers have used stone slabs to build embankments that cool without breaking up, and thrust steel tubes into the ground along some parts of the route, to transmit heat from beneath the icy surface.

    "We built bridges rather than causeways on extremely unstable permafrost regions," Sun told China Daily.

    "Construction on the permafrost regions appears to be of excellent quality. During our trial runs this month, trains have been rattling by at up to 100 kilometres an hour, much faster than trains on railways in permafrost regions in other countries, which can only travel at up to 70 kilometres an hour."

    Despite the current stability of the recently completed track, the Qinghai-Tibet Railway Corp, the railway's sole operator, will have to work to ensure the line endures standing on the permafrost in the long term, he said.

    A long-term permafrost monitoring system has been installed to check for changes in ground temperature and any deformities in the rail bed, according to Zhang Luxin, a senior expert with the Chinese Academy of Sciences.

    Contingency measures have also been put in place to protect the track from the worst hazard affecting the plateau global warming, said Sun.

    "We have taken account of the impact of global warming, but if the temperature rises too much, extra solutions will have to be found," he conceded.

    Sun also said his ministry would spare no effort in addressing the railway's environmental repercussions.

    The ministry is determined to prove that the new line is "harmonious with the ecology." For one thing, no waste will be discharged along the road from the trains, according to Sun.

    Lakes, plants and desertification along the route will be monitored, as will animal populations, he said.

    Asked about the hazard of natural disasters such as earthquakes, which are frequent on the plateau, Sun said the route had been designed to avoid regions with active seismic activity.

    In the vulnerable regions that the track has to pass through, constructors used rail beds rather than tunnels and bridges, and retrofitted structures to minimize the effects of any possible tremors, he said.

    Sun said that from February, the Qinghai-Tibet Railway Corp has been deploying staff along the new route. The company has employed 450 people for station and train services.

    An additional 1,000 work on telecommunications and power supply on the railway, he said.

    "All the workers have undergone medical check-ups to make sure they can react and adapt to high altitude conditions and effective measures have been taken to improve working and living conditions on the plateau," said Sun.

    Monument

    Sun, 65, who has directed the construction of a dozen railways since 1962, said the Qinghai-Tibet Railway was the one that impressed him most.

    He said he was proud no workers died of altitude sickness during construction, a testimony to the ministry's precaution measures.

    Sun revealed that the ministry is considering building a commemorative structure on the Tanggula Mountain Pass, bearing the inscription: "Altitude 5,072, the world's highest railway."

    (Source: China Daily)