North-South Line of the Singapore MRT is a 44 km long mass rapid transit train line that forms a semi-circle through Singapore. At time of writing (May 2010), the line has 25 stations, NS1 to NS27 (there are no NS6 or NS12 station).
The North-South Line is colour-coded red. The line has interchanges with the East-West Line at Jurong East, City Hall and Raffles Place. These are cross-platform transfers. It also interchanges with the North East Line at the Dhoby Ghaut station, connected via linkway. The North-South Line also interchanges with the Circle Line at the Bishan and Dhoby Ghaut stations, connected by linkway.
Background information on the North-South Line
The North-South Line first opened on 7 November 1987, between Yio Chu Kang and Toa Payoh. It extends to Outram Park on 12 December 1987, then from Yio Chu Kang to Yishun on 20 Decmber 1988. Separately, the City Hall to Marina Bay section was opened on 4 November 1989. Another section from Jurong East to Choa Chu Kang, initially operated as a fork off the East-West Line, opened on 10 March, 1990. On 10 February 1996, the Yishun to Choa Chu Kang section was completed.