Continuing to expand its subway network, Beijing is due to open three extensions to two existing lines this year and add new lines over the next three years.
According to Beijing Railway Construction and Management Co. Ltd., the western extension to the Line 6, the phase three southern extension to the Line 8, and the phase four extension to the Line 8 will open this year.
In the next three years, Beijing will put a combined 260 kilometers of new subway lines into operation, with an annual increase of 86.7 kilometers, doubling the average over the previous nine years, the authorities said.
According to the current five-year plan (2015-21), the city has launched construction on all the planned subway lines by the end of 2017, with a combined length of over 300 kilometers.
Among these lines under construction, the eastern extension of the Line 7, the southern extension of the Batong Line, the Line 17, and the Pinggu Line will link downtown Beijing with Tongzhou district, where Beijing's subsidiary administration center will be based.
In addition, the New Airport Line and the southern extension of the Changping Line (phase one) will serve Beijing's New Airport and the 2022 Winter Olympics, respectively.
The New Airport Line is designed to become the fastest subway line in China. Its construction will utilize new equipment and methods, such as the 10 domestically made shield-tunneling machines to be put into operation in the next two months. The machines will help to accelerate construction and reduce labor costs.
In addition to shield tunneling, prefabricated form is another new method applied in the construction. In the Jin'anqiao station along the western extension of the Line 6, instead of processing materials on site, prefabricated units like the roof, the platform and the wall will be assembled like piling up blocks. Data shows that this could cut the construction time by 10 percent, and reduce labor cost by 60 percent.