Hi-tech plan cuts Line 4 subway noise

Railway noise along the new Line 4 subway has been reduced by 15 decibels thanks to new technology.

Special ladder-shaped tracks is one of many new technologies used on the new $2.2 billion line, significantly cutting down vibrations and the noise impact on local residents.

The Chinese Academy of Railway Sciences promised residents living along the brand new line a silent night.

Sun Jingjian, an engineer of the Beijing Railway Construction Company, said six new technologies were used to reduce noise and vibration on Line 4.

He said the new ideas would also be adopted on the yet-to-be-completed Line 6 and Line 9.

"In order to make the train running more quietly, we tried ladder-shaped tracks for the first time," Sun said.

Line 4 passes through areas that contain many schools, libraries, business centers, historic buildings and residential districts and the subway noise had been a concern to many. However subway noise continues to be headache for many living along the lines.

A lady surnamed Zhao, who lives in Tiantongyuan, a large community near Line 5, complained about subway noise.

"I can hardly fall asleep. It's too noisy outside and I can only keep reading until the last train passing by," she said.

She also revealed that many of her neighbors installed double-glazed windows, but the noise was still a problem.

Sun said noise reduction measures used in the Line 4 project would soon be applied to Line 5.

"We are now making changes on line 5 and the polished tracks can reduce some noise," he said.

"Moreover, we even organized an experts group to resolve these problems.

"But noise is a bottleneck of subways in every country. We need time to get better."

Sun also indicated that many property owners in Beijing and even in other cities of China are thinking different from Western people.

"People in western countries prefer living far from the downtown areas. But in Chinese cities, things are opposite," he said.

On Tuesday, Beijing's first noise map covering 12.7 sq km of north part of city was released identifying the noisiest parts of the city.

Authorities are working on a new noise map that will cover the whole city.