The Qinghai-Tibet Railway, the world's highest rail
line, is running safely and in stable condition two months after
winter descended on the Qinghai-Tibet Plateau.
"Our inspections have shown that the track bed is in stable and
accountable condition. There have been only minor changes as the
ground has frozen, which the design allows for," said Xu
Yongshuang, deputy manager of the Qinghai-Tibet Railway.
Signals and snow melting equipment along the line are all
operational, he added.
Winter safety has been a key concern for the railway. Some
1,100-kilometers of the track are at altitudes above 4,000 meters,
and the line crosses 550 kilometers of permafrost. Temperature
changes could potentially alter the shape of the permafrost,
threatening the stability of the rail bed and raising the
possibility of accidents.
Xu said problems like unstable permafrost could arise in the
railway's first winter. To offset the likelihood of an accident,
the company has drafted emergency plans in case problems occur on
the rail line during the winter months.
For example, spare locomotives positioned at major railway
stations along the line can be dispatched to replace malfunctioning
locomotives in one or two hours. Local governments will also be
involved in any rescue effort in the event of an emergency.
Since October, railway departments have stepped up inspections
and maintenance along the line to ensure trains run safely across
the world's highest plateau.
Wang Yingxian, a senior railway engineer at the Northwest
Research Institute under the China Railway Engineering Group, told
that the 550 kilometers of track sitting on top of frozen ground
were constantly being monitored with the aid of electronic
sensors.
"The tracks on frozen ground are under automatic inspection,
which means we receive around-the-clock data on weather and ground
temperature," Wang said.
The Northwest Research Institute is based in Lanzhou, in
northwest China's Gansu Province. The institute is the only
organization in the railway system that studies permafrost on the
plateau.
Before this year, observation teams surveyed the tracks three
times a day, even when temperatures dipped to -30 C, he said.
At present, teams still check for subsidence and deformities in
the rail bed.
"There are more than 70 monitoring teams along the line who work
together to inspect the rails sitting on permafrost every 15 days,"
he said.
The Northwest Research Institute has been gathering data about
permafrost conditions on the Fenghuo Mountain for the past 45
years, providing statistics for the design and construction of the
Qinghai-Tibet Railway.
"The Qinghai-Tibet Railway has many measures in place to protect
the frozen ground," he said.
For example, engineers have used stone slabs to build
embankments that cool without breaking up. They have also thrust
steel tubes into the ground along some parts of the route to
transmit heat from beneath the icy surface.
Bridges were built where the permafrost was unstable to minimize
the railway's influence on the environment.
(China Daily December 6, 2006)