Suzy Bennett, in the Telegraph, takes the ten-day Beijing to Lhasa rail tour.

The final 15 hour, 710 mile (1143 km) stretch from Golmud in China’s western Qinghai province to Lhasa, the capital of Tibet, was only opened last July 1st. The carriages are pumped full of oxygen, and a supplementary supply is available by tube, since the route reaches a height of 16,640ft (5072 meters). As Bennett writes, breathlessly:

There are no crampons or ice picks in our gear. Instead we – a band of 77 rail enthusiasts, retirees and foreign journalists – have crammed altitude-sickness pills, painkillers and oxygen supplies into our bags in the hope of combating the effects of our journey across the roof of the world. We are the first group of Western holidaymakers to take Tibet’s new Sky Train and, although carriages will be pumped with supplementary oxygen, no one – not even the doctor who is accompanying us -knows whether it will be enough. At best we have been told to expect breathlessness, tiredness and headaches; at worst, pulmonary oedema or death.

If the railway causes a headache for its passengers, it has proved a chronic migraine for the engineers. A constantly freezing and melting permafrost along the route has meant that a network of pipes has had to be driven into the ground to pump liquid nitrogen and cold air beneath the track to keep it frozen all year round. Just four weeks after the line opened, the Chinese government admitted that global warming had raised temperatures faster than expected and that the foundations had begun sinking into the permafrost. The day before our group boarded the train, one of the dining cars derailed 250 miles from Lhasa. No one was hurt, but it sparked fears about what would have happened if the oxygen supply to the 600 passengers had been cut off.