Construction work on Shanghai's Metro Line 7 gained full steam today as workers began to lay noise-reducing tracks and install electric machinery, eastday.com reported today.

Major construction on Line 7 will be completed this year. The line will start trial operations next year, the report said.

Several noise-reducing technologies worth 120 million yuan (US$17.14 million) have been introduced on the 35-kilometer line, according to China Railway No. 3 Engineering Group Co, the project's builder.

The technology has never been used on the eight existing subway lines, the report said.

Moreover, Japanese-made ladder-shaped tracks will be laid on two trial sections of the line, the report said.

The measures will considerably reduce the noise that disturbs nearby residents, the report said.

Line 7 will stretch from Chentai Road near the Outer Ring Road in Baoshan District to Fangdian Road near Longyang Road in Pudong New Area, home to the world’s first commercially run Maglev line.

Line 7 will include 28 stations and connect to the city's 14 existing and future subway routes, the report said.

Shanghai plans to build 10 new Metro lines between 2005 and 2012, stretching 389 kilometers. The subway network is expected to span 510 kilometers by 2012.