China's first train from Beijing to Tibet zipped past coal country and farm fields on Sunday, turning farmers' heads as it made its slow climb from the nation's capital to the forbiddingly high Tanggula Pass in the Himalayan region. Headed west at a speed of about 120 kph (75 mph), the train, which left Saturday night and was to arrive 48 hours later, raced past factories, coal mines, and squat, red mountains neatly terraced like a wedding cake and topped with plots of corn, fruit trees and bright yellow sunflowers. Farmers dug up fields by hand with wooden plows, dressed only in shorts to combat the sweltering July heat of eastern China. At Didao, a small village in Shanxi, families gathered on a dirt road near the track, seemingly to catch a fleeting glimpse of the new train that officials say was designed to be cleaner, faster and less polluting than other Chinese trains. The US$4.2 billion railway, an engineering marvel that crosses mountain passes up to 5,000 meters high, is part of government efforts to develop China's poor west and bind restive ethnic areas to the booming east. But critics warn that it will bring a flood of Chinese migrants, diluting Tibet's culture and threatening its fragile environment. Chinese officials acknowledge that few Tibetans are employed by the railway but say that number should increase. The government also says it is taking precautions to protect the environment. Railway official Zhu Zhensheng said Sunday that out of the 100,000 people who worked on building the railway between 2001 and its completion last year, only 10 percent, or about 10,000, were Tibetan. Zhu, who is vice director of the Railway Ministry's Tibetan Railway Office, said earlier that the ministry hoped to increase the opportunities for Tibetans to work on the rail in the future. Before the last leg of the journey from the far western frontier town of Golmud to Tibet's capital of Lhasa, rail staff will switch from the ordinary single locomotive to three specially imported GE-manufactured locomotives to aid the final climb up to the 5,072-meter (16,640-feet) high Tanggula Pass, Zhu said. The 1,140-kilometer (710-mile) final stretch of the line linking Golmud with Lhasa crosses some of the world's most forbidding terrain on the treeless Tibetan plateau. The railway's highest station is in Nagqu, a town at 4,500 meters in the plateau's rolling grasslands. China says this stretch of rail line is the world's highest. Chinese officials thought about building a railway to Tibet for decades. China's rail system reached Golmud, in Qinghai province nearly 3,000 kilometers (1,865 miles) from Beijing, by 1984. But railway officials said it was too difficult to extend the line to Tibet because of the region's huge swaths of permafrost and extreme temperatures. In 2001, the plan was resurrected. Engineers determined they could build elevated bridges over the most unstable tracts of permafrost. In other places, they could sink pipes with cooling elements into the ground to stabilize track embankments, ensuring they stayed frozen. Special features in the cabin include oxygen-enriched air to help passengers cope with the altitude, garbage containers with built-in compacting pressers and anti-lightning equipment on the roof. Unlike most Chinese trains which have open-hole latrines, this one has squat toilets with vacuum flush technology to collect the waste for environmental-protection purposes. Other passenger perks not usually found on Chinese trains are televisions in first-class cabins and electric sockets for charging computers and cell phones. The specially designed train cars are equipped with double-paned windows to protect against high-altitude ultraviolet radiation and outlets for oxygen masks beside every seat for passengers who need help coping with the thin air. On the train, the 500 or so passengers sipped tea and dined on hard-boiled eggs and noodles for breakfast, and were served stir-fried greens and chicken for lunch as they looked out at low, undulating hills of barren yellow sand and rock in western China's Gansu province. "I feel very comfortable," said Yue Jiang, a Beijing-born biologist who emigrated to the United States 20 years ago and who was taking the trip as a tour. "It certainly meets Western standards and it's fairly clean." Among the passengers were some 150 Chinese and foreign journalists. The train also carried about 300 rail and security staff. The railway is projected to help double tourism revenues in Tibet by 2010 and cut transport costs for goods by 75 percent. Communist troops marched into Tibet in 1950, and Beijing says the region has been Chinese territory for centuries. But Tibet was effectively independent for much of that time.