North South Line

North South Line
Choa Chu Kang MRT Station
Choa Chu Kang MRT Station
Type Mass Rapid Transit (MRT)
Station Count 26 (Operational)
1 (Under construction)
Line length 44 km
Termini Jurong East
Marina South Pier
Depot Bishan Depot
Ulu Pandan Depot
Operational Data
Operators SMRT Trains
Rolling stock Kawasaki Heavy Industries C151 
Siemens C651 
Kawasaki-Nippon Sharyo C751B 
Kawasaki-Sifang C151A
Kawasaki-Sifang C151B
Electrification 750 V DC third rail
Track gauge Standard Gauge (1435mm)
Opened Nov 1987 – Nov 1989 (Yishun – Marina Bay)
Mar 1990 (Branch Line)
Feb 1996 (Woodlands Extension)
Jan 2012 (Marina South Pier)
Year 2019 (Canberra)

The North South Line (NSL) is a high capacity MRT line and the first MRT line in Singapore to enter service, connecting the northern and southern regions of the island through Central Singapore. It is currently operated by SMRT.

The NSL is 44km long with 26 stations, running from Jurong East (NS1) in the West to Marina South Pier (NS28) in the South, via Woodlands (NS9) in the North, with station codes NS6 reserved for future use and NS12 for Canberra station (currently under construction). The line runs on elevated viaducts along more than half of its length, and goes underground within the Central Area (between Bishan and Marina South Pier) and along other short sections of its route.

Trains on the North South Line operate in a six-car formation, based out of Ulu Pandan and Bishan Depot. The rolling stock is also used on East West Line, which joins the North South Line at Jurong East and Raffles Place / City Hall.

Currently, train services operate between Jurong East and Marina South Pier.

Timeline & History

Detailed: History of the North South Line
  • 7 Nov 1987: Yio Chu Kang to Toa Payoh stations opened, the very first section of MRT to commence operations in Singapore
  • 12 Dec 1987: Extended south to Raffles Place. Train services would then switch to the East West Line and continue on to Tanjong Pagar and beyond.
  • 20 Dec 1988: Extended north to Yishun
  • 4 Nov 1989: Extended south to Marina Bay, formal separation of North South Line and East West Line operations
  • 10 Mar 1990: Jurong East to Choa Chu Kang opens, as part of the Branch MRT Line
  • 10 Feb 1996: Extended north from Yishun to Choa Chu Kang, taking over the Branch Line and terminating at Jurong East
  • 23 Nov 2014: Extended south to Marina South Pier
  • Year 2019: Canberra station opens

The original North South Line opened in stages between 1987 to 1989. Yio Chu Kang to Toa Payoh first opened on 7 November 1987, the first section of MRT to open in Singapore. A month later, the line extended south to Raffles Place, where southbound train services would switch lines between City Hall and Raffles Place, and continue along on the East West Line. The line extended north to Yishun in 1988, and finally extended south to Marina Bay in 1989, with formal separation of North South Line and East West Line operations that same day.

In 1990, Jurong East to Choa Chu Kang stations opened as part of the Branch Line, which were eventually assimilated into the North South Line in 1996 when the Woodlands Extension opened between Yishun and Choa Chu Kang. North South Line services between Jurong East and Marina Bay continued until the opening of the Marina South Pier extension in 2014, although many train services continued to turn around at Marina Bay.

Canberra station is expected to open in Year 2019, the second time a station is added to an operational MRT line after Dover station on the East West Line.

Alignment

The North South Line starts from the western side of Singapore at Jurong East, runs north via Woodlands and turns south via Yishun and through Central Singapore, terminating at Marina Bay in the South. It passes through major residential towns such as Bukit Batok, Choa Chu Kang, Woodlands, Sembawang, Yishun, Ang Mo Kio, Bishan and Toa Payoh.

Running on a mix of elevated viaducts, at-grade sections and underground tunnels, the line goes underground within the Central Area (between Bishan and Marina South Pier) to avoid building tracks at surface level. A short tunnel between Bukit Batok and Bukit Gombak cuts through a hill, and another short tunnel between Kranji and Marsling cuts underneath Woodlands Avenue 3. At-grade sections of track lie between Bukit Gombak and Choa Chu Kang, and between Khatib and Yio Chu Kang, the later being between the longest distance between any two MRT stations in Singapore. The only at-grade station on the MRT network is Bishan station, along this line.

Constructed alongside the East West Line (NSL) in the 1980s, both the NSL and EWL share similar technology and rolling stock. Both lines are connected by crossovers at Jurong East and in tunnels between Raffles Place and City Hall. Apart from pre-1989 through-train operations, peak hour NSL through-train services crossing over to eastbound EWL at Jurong East have since been discontinued.

Improvement works

Engineering works are being carried out throughout the North South Line to improve service. Timber sleepers on overground sections of track are approaching the end of their lifespan, and being replaced by concrete sleepers, with work completed by April 2015. The third rail, which provides electricity to trains since 1987, is gradually being replaced. Finally, re-signalling works costing $195 million will upgrade the NSL to a Communications-Based Train Control (CBTC) system supplied by Thales, expected to reduce the minimum interval between trains from the current 120 seconds to 100 seconds.

Testing of the new system began in the late hours of 28 March 2017, during the last hour of revenue service, when all trains were stopped at around 11pm to facilitate the switch to the new system. These tests were carried out across a few days. Full-day weekend testing of the system commenced on 16 April 2017 (Sunday) and continued every Sunday till End-May. Full-day weekday testing of the system commenced on 29 May 2017 (Monday).

The system is expected to be fully operational later in 2017.

As part of SMRT’s efforts to speed up improvement works, early closures along sections of the line and later train service start times on Sundays have been implemented. Noise barriers along certain stretches of elevated track near residential areas have also been constructed, expected to be completed by 2019.

Train Stations

Rolling Stock

Five batches of rolling stock operate on the NSL, namely the Kawasaki Heavy Industries C151Siemens C651Kawasaki-Nippon Sharyo C751BKawasaki-Sifang C151A and Kawasaki-Sifang C151B from oldest to newest, which are also operated on the East West Line. Trains are maintained at Bishan Depot and Ulu Pandan Depot.