Beijing plans to import 10 robots this year to check hazards in the city's drainage system, following a sewage pipe leakage accident that caused cave-in on a major urban road.

"The US-made robots will be imported by the Beijing Drainage Group, which imported two such robots last year. Each costs around hundreds of thousands of yuan (around 8.1 yuan equals US$1 US)," said Jiao Zhizhong, director of the Beijing Water Authority (BWA).

Equipped with video cameras, the robots will enable technicians in the control room to carry out real-time monitoring of the pipes.

"There are poisonous gas in the sewage pipes. Robots are more safer than humans to undertake such tasks," said Qi Jingjun, an official with the BWA.

A sewage pipe near a subway construction site cracked on Jan. 3, pouring out large amounts of sewage and caused section of a major road to cave in. Traffic was blocked for several days.

Analysts say lack of complete information about the layout and conditions of underground pipes, including sewage pipes, rain water drainage pipes and water supply pipes, and their conditions is partly to blame for the accident.

The underground pipes of Beijing were built in various periods, with many dating back to the 1950s. Design charts of many pipes have been lost.

Following the road cave-in accident, Beijing Mayor Wang Qishan has ordered the BWA to use robots to probe the drainage pipes and establish a complete data bank about the underground pipe system.

"A wise child should not fall on the same spot again," said Wang.

Beijing's drainage conduits run a total length of 3,800 kilometers, nearly half of which is for carrying sewage.

(Xinhua News Agency January 18, 2006)