China's subway networks are set to enter a period of rapid expansion, with around 2 trillion yuan ($319.8 billion) being poured into constructing or expanding subways in 34 cities in the next half decade.

Liu Heming, a director from the urban construction department within the Ministry of Housing and Urban- Rural Development was quoted in the Oriental Morning Post as saying that this would be the fastest pace of urban rail development that China has ever seen, while Wang Mengshu, a vice general engineer with the China Railway Tunnel Group Co, told the Global Times that these projects would be finished in roughly three to five years, but overseas they tended to take seven to 10 years. 

However, not everyone is convinced that this kind of speed is a good thing. The country has been wracked with accidents involving collapsed land caused by subway construction, even in top tier cities like Beijing, Shanghai and Guangzhou. The fact that authorities are pushing to have the projects completed quickly is making the problem even worse.

In Harbin, Heilongjiang Province, about 20 land collapse accidents happened this summer, partly because of subway construction, sources inside subway construction companies told news magazine Caijing.

A runaway train 

More and more cities are launching subway construction projects. In September alone, the National Development and Reform Commission approved 25 rail transit projects involving 18 cities at a cost of 800 billion yuan, according to the commission's website.

According to Liu, China has about 1,700 kilometers of urban rail. The 2 trillion yuan being invested will be used to construct a further 4,300 kilometers of lines in 34 cities, 2,000 kilometers of which is already under construction. These projects would more than triple the total length of urban railway lines in China.

This speed is far beyond the pace of construction in developed countries. By 2010, London had spent 147 years constructing 408 kilometers of subway lines, and New York took 106 years to build 370 kilometers. Paris spent 110 years building just 215 kilometers, Caijing reported.

Shanghai needed just 16 years to build 420 kilometers of rail, spread over 11 lines. The Community of Metros (an international rail consortium) once said Shanghai had created "a miracle" of subway construction.

"China has to build the subways at a high speed to solve its growing traffic jams and air pollution, as well as spur consumption to boost the economy," Wang told the Global Times.

However, the frequent land collapse accidents are evidence that some cities have not sufficiently evaluated the geological environment and the associated risks.

Fatal consequences

A proper investigation into the ecological conditions for a subway project requires at least two or three years, but many officials can't wait that long, Cai Xiangmin, president of the Beijing Institute of Geological Surveys, told the Global Times

"Some officials want to reduce serious congestion in cities, while some just want impressive political performances in their terms. They have no patience," he said.

"Without sufficient investigation, subway projects will easily result in various problems such as land collapse, water or sand leakage and accidents," Cai said.

In March, 2007, six workers were killed and buried beneath rubble at the site of the Suzhoujie Station of Subway Line 10 in Beijing, after a collapse occurred. Later, a Beijing accident assessment team found the geology of the area where the accident had occurred was different from the environment listed in the original investigation report, according to a 2008 report in the Beijing Times.

During Spring Festival, Shanghai's Line 4 subway, which had been in operation for six years, was closed for an overhaul after problems with the joints between the line's tunnels. Shanghai Subway authorities had to insert 60 concrete columns that weigh 20 tons each to support the joints, the Metro Express reported.

In order to monitor these joints, Shanghai has arranged 200,000 real-time monitoring points along subway lines in the city, the report said.

In a report from the ministry's supervision teams submitted in November, six months after the ministry sent 14 supervision teams to 27 cities and investigated 85 ongoing urban rail transit projects, 737 problems were found and 171 suggestions were raised, according to Caijing.

According to the article, hidden safety risks had been found in different degrees in all the phases of subway construction, including investigation and design, quality control and construction supervision.

The magazine article also indicated that in cities such as Changsha, Hunan Province, and Changchun, Jilin Province, which are building subways for the first time, problems have been found in the original designs, with a total of 14 flawed or non-standard designs being found in the construction plan for Changchun's first subway line.

Passing the buck

These problems could be avoided through technological measures and were actually caused by the strong desire for quick success and loosened standards in relevant assessments, Dai Shiqiang, a tenured professor with Shanghai University and also an expert in urban rail transit, was quoted by Caijing as saying.

The ministry organizes one overhaul every two years and many of its staff in the supervising team have complained about the way subway companies work, the article said.

"They don't follow the ministry's suggestions at all," a source close to the team told Caijing. "Only when accidents occur and some officials are removed from their posts, do they realize the seriousness of the problems."

"Building a subway is a large and complicated project and we can't avoid all the problems," Li Hongchang, an associate professor with the School of Economics and Management at Beijing Jiaotong University, told the Global Times.

Frequent collapse accidents are also related to a shortage of experienced workers in the industry, Li said.

Currently, China needs an additional 100,000 talented professionals in the industry, which also has problems when related professionals from other industries come to work in China despite lacking the necessary training, Li said.

Fortunately, many schools and universities have opened urban rail transit majors or lessons, Sun Zhang, a rail expert with Tongji University told the Global Times, noting that the human-capital situation will improve gradually in the future. "The development of urban rail transit is a continuing trend, and so is fostering relevant talents," he said.