Songshan Line (Taipei Metro)

Songshan–Xindian Line
Gongguan Station Platform
Overview
Other name(s)	Green Line
Type	Rapid transit
Locale	Taipei and New Taipei, Republic of China
Termini	Songshan Taipower Building, Xindian
Stations	20
Operation
Opened	November 11, 1999
Operator(s)	Taipei Rapid Transit Corporation
Character	Underground
Depot(s)	Xindian Depot
Technical
Line length	21.5 km (13.4 mi)
Number of tracks	2
Track gauge	1,435 mm (4 ft 8 1⁄2 in)
Electrification	Third rail (750 volts DC)
Operating speed	80 km/h

Songshan–Xindian Line or Green Line (G as identifier) is a line of Taipei Metro. Parts of the line runs under the Roosevelt Road, following the route of the former TRA Xindian Line—which ceased service in 1965— on its southern section.

Initial plans for the line originally called for another station between Zhongshan and Beimen stations (at Chien-Cheng Circle). However, the Circle was suffering from economic concerns, as well as engineering feasibility and effectiveness problems. Coupled with problems with landowners regarding joint developments and two of the entrances/exits, plans for the station were shelved on May 1, 2007. The station would have been a five-level underground station with stacked, split platforms.

It was originally estimated that its opening will take place in 2013.

Shield tunneling was used to construct most of the tunnels on the line, except for a few locations. Tunneling beneath Dacheng St. crosses existing Taiwan Railway Administration and Taiwan High Speed Rail tunnels. Common utility ducts were constructed in sync with the Metro line, carrying water pipes, gas pipes, and cables. Over 200 homes were demolished or relocated to make way for Metro land use.

Construction of the line was divided into three civil engineering section contracts and one electrical/mechanical system-wide contract. The contract for construction on the eastern end of the line (including Nanjing Sanmin and Songshan) was awarded to Da Cin Construction Co., Ltd. on March 2, 2006. The 3.02 km (1.88 mi)-long section includes a crossover section, a tail-track work shaft, and three shield tunnels. Construction of the line was completed in late 2014.

In 2008, steel price increases threatened to delay construction plans due to the price doubling over the previous two years. The Ministry of Economic Affairs ordered that exports of other steel products be strictly supervised to ensure a steady local supply and to keep prices down.