Workers lay tracks for a high-speed railway linking Beijing and Shanghai on Monday. The 1,318-km line will cut the travel time between Beijing and Shanghai by more than half to less than five hours. Liu Wen / Xinhua

BEIJING:Construction workers on Monday began to lay tracks for a high-speed railway linking Beijing and Shanghai, the Ministry of Railways said.

The ministry's Beijing-Shanghai high-speed railway construction headquarters held a ceremony in Xuzhou city, East China's Jiangsu province, to mark the beginning of the track-laying process.

The headquarters said the 1,318-km track will be completed by the end of the year.

The 220.9-billion-yuan ($32.5 billion) railway line, which began construction in 2008, is scheduled to start operation in 2012.

The line will span three municipalities - Beijing, Tianjin and Shanghai - and pass through Hebei, Shandong, Anhui and Jiangsu provinces, the ministry said.

Twenty-one stations will be set along the line, which will also connect the Bohai Sea Rim and the Yangtze River Delta, two major economic zones in the country, it added.

Nearly a quarter of the country's population resides around the railway line, the ministry said.

According to earlier reports, the operating speed of the railway is expected to be 350 km per hour, with a maximum speed of 380 km per hour.

The average commercial speed between Beijing and Shanghai will be 330 km per hour.

Once completed, the line will cut the travel time between Beijing and Shanghai by more than half to less than five hours.

More than 1,060 km, or 80.5 percent of the line, will be laid on 244 bridges.

The 164 km viaduct between Danyang and Kunshan in Jiangsu province will be the longest bridge in the world.

The line will also include 22 tunnels, totaling 16.1 km, according to ministry officials.

With the completion of this line, by 2012 China will have a railway network of 110,000 km, 13,000 km of which will be high-speed rail, the ministry said.

The ministry has predicted that an estimated 220,000 passengers will use the trains each day, almost doubling the current capacity, while the annual passenger capacity of the line is estimated to be 160 million.

While the project is a work of cutting-edge technology and has a host of top Chinese railway technicians working on it, some experts remain concerned about the line's operational safety due to its high speed.

"It is theoretically possible that some unpredictable safety problems may arise with the increase in speed," said Yang Hao, a professor at the school of traffic and transportation, Beijing Jiaotong University.

"But I'm convinced that China's railway technology and construction capabilities are mature enough and reliable," he told China Daily.

Zhao Jian, a professor at the school of economics and management at the same university, said he is not satisfied with the energy consumption and profitability of the railway line.

"I doubt the new railway will return the government's investment any time soon, since it is inclined to become an energy-consuming line. The fare may also be expensive and unaffordable to many ordinary commuters," he said.

"The government may need to subsidize the railway in the first few years of its operation. And when passenger volume starts to increase, only then will the line reach its planned objectives," Yang said.

By Zhao Lei (China Daily)

Xin Dingding and Xinhua contributed to this story.

Editor Yu Meng