The Train to Tibet.

On an evening in late December, amid the chaos of Beijing West Railway Station, I stood in line for a train that looked little different from any of the other long-distance services shuffling into the vast Chinese hinterland. And yet the train I was about to board, the new Chinese service from Beijing to Lhasa, in Tibet, runs on the highest railroad in the world. Traversing a region known for earthquakes, low temperatures, and low atmospheric pressure, the railroad, which cost $4.2 billion to build, is an extraordinary feat of modern engineering--perhaps even, as the former Chinese premier Zhu Rongji has claimed, "an unprecedented project in the history of mankind." In two days, the train brings you to a region that thwarted some of the boldest travellers and explorers of the past.

The route's prospect encourages the laziest kind of armchair fantasy--of great expanses of the "roof of the world" rolling into view with silky black yaks grazing in the grasslands and prayer flags fluttering from gold-topped temples. The train is meant only partly for seekers of Tibet's romance, however. Beijing claims that the railroad between Golmud, in Qinghai Province, and Lhasa, which began operation on July 1st last year, will help speed up the modernization of the country's second-largest region, one of the remotest and least developed. Many critics, meanwhile, have denounced the railroad as a means for the Chinese authorities to strengthen their hold on Tibet, further settling the region with China's ethnic majority, the Han Chinese, and eroding indigenous Tibetan culture. Tibet, which is almost as big as Texas, California, and New York State combined, also holds vast reserves of copper, iron, lead, zinc, and other minerals vital to China's economic growth.

In the long, disorderly line for the train, there were hardly any foreign tourists. I noticed several Chinese officials cutting ahead, dressed in Western suits and trailed by armed soldiers. Polite uniformed coach attendants stood rigidly at attention outside the pine-green cars, but no one asked to see my expensively acquired permit for travel in Tibet.

Once aboard, I found my "soft sleeper" cabin, the ticket for which had cost about twelve hundred yuan, or some hundred and sixty dollars. Containing four bunk beds, it seemed very cramped. The introduction of luxury rolling stock is scheduled for the end of this year; the cars will feature private suites measuring a hundred square feet, and tickets will cost a thousand dollars a day. Meanwhile, it seemed that any impulse to luxury, or even basic comfort, had been squeezed out of my compartment. Flat-panel televisions, headphones, and a solitary white plastic rose in a narrow glass vase only highlighted its bleak functionalism. The ceiling was very low, and the space between the lower berths was barely wide enough for one person to stand up in, let alone four passengers struggling with severe altitude sickness.

To my relief, no one showed up to share my cabin. Indeed, despite subsidized fares and Chinese claims that four hundred and fifty thousand people took the train in its first two and a half months of operation, the train seemed far from full. I changed into my nightclothes, and hurried to the toilet at the end of the railcar; squat-style, it did not promise to stay clean for long. Back in the compartment, an attendant brought a thermos of hot water and then a rubber tube wrapped in a plastic packet. Wordlessly, he showed me how to attach it to the oxygen valve above my berth. The extra oxygen was a necessary precaution--the air in the mountains of Tibet contains thirty-five to forty per cent less oxygen than at sea level--but made the compartment look like a mobile clinic.

As the train slid away from Beijing, a P.A. system came to life. After a long speech in Chinese, a deep voice with a strange American accent unctuously intoned, "Dear passengers," and began to relay impressive statistics about the seven-hundred-mile railroad extension from Qinghai to Tibet: laid by a hundred thousand workers over five years, it traverses three hundred and forty miles of permafrost, often at altitudes between thirteen and sixteen thousand feet. Chinese pride in the railroad is intense, as I knew from a three-hour documentary that had been broadcast on the state-run CCTV channel in 2006. It had detailed the history of successive efforts by Chinese leaders to build the railway, and the struggles and sacrifices of construction workers, and had also asserted China's commitment to bringing "modern civilization" to Tibet, which it described as "a once remote and backward place." It claimed that Tibetans had been "yearning for decades" for the rail link to Lhasa, and showed Tibetans singing, in Mandarin, of their love for the Chinese motherland.

Such propaganda notwithstanding, the greatest rail construction ventures in history, in the American West and the Siberian East, do not come close to matching the technical achievement of the railroad to the Tibet Autonomous Region (as the land previously ruled by the Dalai Lama has been officially called since 1965). Laying rail tracks across Tibet's permafrost is especially risky, because the surface is prone to melt as temperatures rise. Chinese engineers faced this challenge with innovative cooling strategies. They elevated tracks; they put in a network of pipes to circulate liquid nitrogen and cold air beneath the rails in order to keep them frozen throughout the year; they installed metal sunshades in south-facing locations to deflect warmth from the sun. Although the carriages of the train looked old to me, they had UV-resistant coatings and an eco-friendly wastewater-storage system, and their underbellies were enclosed to protect wiring from snowstorms and sandstorms. A complex mechanism drew in outside air and released nitrogen and other gases while pumping oxygen-enriched air through the train.