Costly, but not safer

Many cities now spend money on subway equipment that consumes energy and pushes up construction costs, but doesn't improve safety, according to Wang Mengshu, of the Chinese Academy of Engineering. Wang, who participated in the design of the country's first subway line, said that 1 km of subway cost about 400 million yuan several years ago, but the cost has soared in the intervening years. The record is currently held by Xi'an, capital of Shaanxi province, where 1 km of subway costs 800 million yuan.

One reason behind the spiraling cost is that builders blindly seek size and luxury in most cities, said Wang. "When the first subway line was built in Beijing, the platforms were smaller than 8,000 square meters. Now, none of the new platforms is smaller than 12,000 square meters," said Wang.

Wang also noted that recently built subway lines include more than 20 components, some of which he couldn't even name. "But if you look at high-speed railways, which operate faster trains and require more-sophisticated technologies, they include fewer than 10 components," said Wang.

Many of components are added out of "unnecessary safety concerns", he said, citing the example of the shield doors that have been widely adopted in newly built subway stations. The doors, which prevent access to the track from the platform, completely seal the train from the outside environment, resulting in much higher power consumption for ventilation. The shield doors are meant to prevent passengers from jumping onto the track, but such incidents have been rare in recent years.

One of the drawbacks of the complex systems is that they use too much energy, with the power to drive the engines accounting for just 30 percent of total energy consumption.

The unnecessary facilities also pose potential hazards to subway operations. "Once a small problem occurs, the whole line is halted," added Wang.

This is partly because decisions about subway construction in many cities are not made by professionals. "Since the construction of subways in most cities is guided by the government, officials often have the final say in design and construction, instead of the experts," said Wang.

The November 2008 collapse of a subway construction site in Hangzhou, Zhejiang province, that killed 21 workers is a good example of the situation, he said. The local government blamed violations of construction regulations and technical failures. "But I think the accident exposed the serious consequences that can result from excessive interference by government officials in subway construction," said Wang, who inspected the accident scene.

"It normally takes three years to build a subway station of that size, but the construction period for that line was reduced by one-half by the city government," he said, adding that local government saw the completion of the subway line as an achievement of its tenure and thus attempted to reduce the construction period.

The CPPCC's Chen believed that the construction boom has resulted in a shortage of professionals: "Construction teams in many cities were scrambled to meet a deadline and untrained workers were hired. Safety cannot be guaranteed."

He suggested that the requirements for subway construction approval should be upgraded. Even if some cities meet the basic requirements, they should not be given the green light if they have problems raising funds or are able to solve traffic congestion by other means, such as improving the existing road network.

Moreover, the decision-making procedure involving subway construction should be more open and the public should be involved to prevent the plans being hijacked by parties with a vested interest, he said.

Contact the writers at xindingding@chinadaily.com.cn, wangxiaodong@chinadaily.com.cn, shiyingying@chinadaily.com.cn