Coloured orange on the rail map, the fully-underground line is approximately 35.5 kilometres (22.1 mi) long with 30 stations.

[20][21] Due to the collapse, the station was relocated to a new site two-thirds the size of the original 100 metres (330 ft) away.

[20] The first section of the line, Stage 3, a 5 kilometres (3.1 mi) five-station segment stretching from Bartley to Marymount, opened on 28 May 2009.

[38][39] The extension will connect commuters between the HarbourFront to Marina Bay stations and expand the rail network to the southern edge of the Central Business District.

Structures were erected to protect the railway station's facade and interior, and monitoring instruments were installed to watch out for any building settlement.

[53] A criminal inquiry found the main contractor Nishimatsu Construction Company and joint venture partner firm Lum Chang Construction Company and their officers, as well as key Land Transport Authority officers responsible for the collapse.

[53] As a result of this accident, the first phase of the Circle Line, previously scheduled to open in 2008, was completed in 2009 instead.

The affected station has been shifted about 100 metres (330 ft) away from the accident site and is now located at Republic Avenue.

This accident also resulted in stricter safety regulations for the construction of all future MRT lines.

[54] On 16 August 2007, the Building and Construction Authority (BCA) issued a stop-work order and revoked the contractor's tunnelling permit after a 7-metre (23 ft) stretch of two lanes close to the junction of Telok Blangah Road and Alexandra Road sank about 20 centimetres (7.9 in) that evening.

[56] On 20 September 2011, a power fault disrupted train services at all 16 stations on the Circle Line.

It was reported that leaks and a damaged electrical cable along the Circle Line were the cause of the disruption.

[58] Investigations were carried out, and the fault was traced back to a faulty cable beneath the platform level at Dakota station.

[59] 27,000 passengers were affected by the disruption during the four hour delay, with bus bridging services plying the Circle Line route.

[60] In late August 2016, intermittent signal interference led to a five-day series of train disruptions.

Power was restored by 6.05pm, and SMRT staff had to manually drive the stalled trains to their next stations, causing delays of about 30 minutes,.

[65][66] Investigations show that the disruption was first caused by a circuit breaker that tripped in the Traction Safety Shutdown System (TSSS) cubicle.

After the incident, SMRT said that the procurement of a replacement TSSS cubicle with enhanced features, is being expedited.

[citation needed] The 35.5-kilometre (22.1-mile) Circle Line forms an incomplete loop from Dhoby Ghaut in the Central Region of Singapore, north to Serangoon and Bishan, and south to HarbourFront, with a branch from Promenade to Marina Bay station which will be extended to HarbourFront in 2026.

From Promenade station, the line goes northwards and towards the east, passing beneath the Kallang Basin.

Legend List The Circle Line's numbering scheme reserves station code "CC18" for future use.

The rolling stock for the Circle Line uses electric multiple unit (EMU) trains operating in a three-car configuration, with four doors per side on each carriage and can accommodate of up to 931 passengers in each trainsets.

Train Data Management System (TDMS) which concentrate and dispatch the rolling stock information with fixed equipment.

Automatic platform screen doors supplied by Westinghouse provide safety for commuters, offering protection from arriving and departing trains.