{{short description|Mass Rapid Transit line in Singapore}} {{redirect|Circle MRT Line|other similarly named rapid transit systems in other cities|Circle Line (disambiguation){{!}}Circle Line}} {{Use dmy dates|date=August 2020}} {{Infobox rail line | box_width = width:12em; | name = Circle Line | color = {{rcr|SMRT|Circle}} | logo = Circle Line logo.svg | logo_width = 250px | image = CC29 HarbourFront MRT Platform B (Alstom Metropolis C851E) 20260417 175523.jpg | image_width = 300px | caption = Alstom Metropolis C851E trainset at {{MRT station|HarbourFront}} station | native_name = {{langx|ms|Laluan MRT Circle}}<br>{{lang-zh|地铁环线}}<br>{{langx|ta|இணைப்பு எம்ஆர்டி வழி}} | status = Operational<br>Under testing (Stage 6) | owner = Land Transport Authority | locale = Singapore | start = Dhoby Ghaut | end = HarbourFront (until Stage 6 opens)<br>Marina Bay (until Stage 6 opens) | stations = 33 (30 operational, 3 under testing) | mapcolor = {{rcb|SMRT|Circle|box}} Orange (#{{rcr|SMRT|Circle}}) | type = Rapid transit<br>Light metro | system = Mass Rapid Transit (Singapore) | routes = 3 | operator = SMRT Trains Ltd (SMRT Corporation) | depot = Kim Chuan | stock = Alstom Metropolis C830<br>Alstom Metropolis C830C<br>Alstom Metropolis C851E | daily_ridership = 450,000 (2023)<ref name="reliability">{{Cite web |title=Rail Reliability |url=https://www.smrt.com.sg/News-Room/Rail-Reliability |url-status=live |archive-url=https://web.archive.org/web/20240507062554/https://www.smrt.com.sg/News-Room/Rail-Reliability |archive-date=7 May 2024 |access-date=5 July 2024 |website=SMRT Corporation}}</ref> | yearcommenced = | planopen = {{Start date and age|df=yes|2026|07|12}} (Stage 6) | open = {{Start date and age|df=yes|2009|05|28}} (Stage 3)<br>{{Start date and age|df=yes|2010|04|17}} (Stages 1 and 2)<br>{{Start date and age|df=yes|2011|10|08}} (Stages 4 and 5)<br>{{Start date and age|df=yes|2012|01|14}} (Circle Line Extension) | close = | linelength = {{Convert|35.5|km|mi|abbr=on}} (Operational)<br>{{Convert|4|km|mi|abbr=on}} (''Under testing'') | tracklength = {{Convert|35.5|km|abbr=on}} (Operational)<br>{{Convert|4|km|abbr=on}} (''Under testing'') | tracks = | character = Fully underground | gauge = {{RailGauge|sg|allk=on}} | electrification = {{750 V DC|conductor=y}} | speed = limit of {{convert|78|km/h|mph|abbr=on}}<ref>{{Cite web|date=25 September 2025|access-date=30 September 2025|title=First JRL train arrives in Singapore; has wider doors, smaller carriages: LTA|url=https://www.straitstimes.com/singapore/first-jrl-train-arrives-in-singapore-has-wider-doors-smaller-carriages-lta |publisher=The Straits Times}}</ref> | elevation = | map_name = Maps | map = {{switcher |{{Circle Line (Singapore)|inline=yes}} |Show route diagram |{{Maplink|frame=yes|type=line|stroke-colour=#{{rcr|SMRT|Circle}}|text=Interactive Map|frame-align=center}} |Show interactive map }} | map_state = hide }} The '''Circle Line''' ('''CCL''') is a medium-capacity Mass Rapid Transit (MRT) line in Singapore. It runs in a loop from Dhoby Ghaut station in the city-centre to HarbourFront station in the south via Bishan station in the centre of the country. It also has a branch line from Promenade to Marina Bay. Coloured orange on the rail map, the fully-underground line is approximately {{convert|35.5|km|mi|abbr=on}} long with 30 stations. Travelling from one end of the line to the other takes about an hour.
The CCL was the fourth MRT line to open on the network, with its first stage, from Bartley to Marymount, commencing operations on 28 May 2009. At launch, it operated Alstom Metropolis C830 electric multiple unit (EMU) trains. The next stage to Dhoby Ghaut opened on 17 April 2010, followed by the extension to HarbourFront on 8 October 2011. A two-station extension to Marina Bay was inaugurated on 14 January 2012. The final stage, running from HarbourFront to Marina Bay with stations at Keppel, Cantonment and Prince Edward Road, is scheduled to open on 12 July 2026, at which point the line will form a complete loop.
The CCL is the second line in Singapore after the North East Line to be completely automated and driverless and is among the world's longest driverless rapid transit lines.<ref name=":1">{{cite web | url=https://www.alstom.com/press-releases-news/2002/2/ALSTOM-chosen-for-the-worlds-longest-fully-automated-metro-line-in-Singapore-20020218 | title=ALSTOM chosen for the world's longest fully automated metro line in Singapore | publisher=railway-technology.com | date=20 February 2002 | access-date=24 February 2008 | archive-url=https://web.archive.org/web/20071001143403/http://www.railway-technology.com/contractors/suburban/alstom/press5.html | archive-date=1 October 2007 | url-status=live }}</ref> It was Singapore's first medium-capacity rail line. Ridership exceeded projections for its three-car trains, resulting in overcrowding compared with high-capacity MRT lines. Following the line's opening, additional trains, including the C830C and C851E, were procured to accommodate growing demand.
==History== ===Planning=== thumb|upright=1.0|Map of the planned Marina Line|alt=A map showing the Marina Line plans as announced in October 1997. The line, coloured in orange, has five branches connecting to (clockwise from north) Kallang, Paya Lebar, Tanjong Pagar, Chinatown and Dhoby Ghaut. The Kallang and Paya Lebar branches converge into one branch, before branching out again into three branches to Tanjong Pagar, Chinatown and Dhoby Ghaut Plans for the Circle Line were first announced by Minister for Communications and Information Yeo Ning Hong. who said the line would connect Singapore’s major housing estates. However, he added that such a route would only be built once Singapore's population reached four million and new housing estates were developed farther from the city centre.<ref>{{cite web |title=Circle line 'needed with 4 million people' |url=https://www.straitstimes.com/multimedia/graphics/assets/images/ST175/NewspaperSG/1989-11-04/full.jpg |website=The Straits Times |access-date=6 October 2019 |date=4 November 1989 |first=Rav |last=Dhaliwal }}</ref> At the time, the MRT network followed a radial pattern, with lines extending outward from the city centre.{{sfn|Cheong|2012|p=33}}
In October 1994, Communications Minister Mah Bow Tan announced a proposed overground light rail system designed to serve the National Stadium, Beach Road, Marina Centre, Shenton Way, and Marina South, with interchanges at {{MRT Station|Dhoby Ghaut}} and {{MRT Station|Kallang}}.<ref>{{cite news |last1=Divyanathan |first1=Ramesh |last2=Ang |first2=Lilian |title=Marina Centre, Shenton Way to get guided transit system by 2000 |url=https://eresources.nlb.gov.sg/newspapers/digitised/article/biztimes19941012-1.2.11.3 |access-date=24 April 2026 |date=12 October 1994 |page=2|work=The Business Times|via=NewspaperSG}}{{cbignore}}</ref><ref>{{cite news |last1=Leong |first1=Chan Teik |title=Light rail train system proposed |url=https://www.straitstimes.com/multimedia/graphics/assets/images/ST175/NewspaperSG/1994-10-12/full.jpg |access-date=24 April 2026 |work=The Straits Times |date=12 October 1994 |page=1 |via=NewspaperSG}}{{cbignore}}</ref> In October 1997, the Land Transport Authority (LTA) invited companies to provide architectural and engineering services for a planned Marina Line (MRL). The proposed {{cvt|12|km}} underground line would comprise 18 stations, running from Kallang station through Marina Centre and Marina South before interchanging with the North East Line at {{MRT station|People's Park}}. A branch line from Marina Centre to Dhoby Ghaut was also proposed, while further branches and extensions to {{MRT station|Paya Lebar}} and {{MRT station|Tanjong Pagar}} were under consideration.<ref>{{Cite news |date=16 October 1997 | page=1 | url=https://eresources.nlb.gov.sg/newspapers/digitised/article/biztimes19971016-1.2.4 |title=Plans for new Marina train line are rolling |work=The Business Times |first=Jenny | last=Lam |quote=The proposed {{convert|12|km|miles|adj=on}} Marina line... is likely to start from Kallang MRT station,... (joining) People's Park (Chinatown) station (and) there will be a branch running from Marina Centre to the Dhoby Ghaut MRT station.|via=NewspaperSG}}{{cbignore}}</ref> In June 1998, Mah announced the government would proceed with the construction of the MRL, which was planned to have 20 stations and operate medium-capacity driverless trains. Construction was expected to begin in 2000 at an estimated cost of S$1.75 billion. The line was also designed with provisions to expand train capacity from four to six cars as passenger demand increased.<ref>{{cite news |title=Marina Line Gets Go-Ahead |url=https://www.straitstimes.com/multimedia/graphics/assets/images/ST175/NewspaperSG/1998-06-13/full.jpg |access-date=24 April 2026 |work=The Straits Times |date=13 June 1998 |page=1 |via=|last=Yeo|first=Geraldine}}</ref> Parsons Brinckerhoff and Mott MacDonald were appointed as architectural and engineering consultants for the MRL.<ref>{{cite news |title=Consultants for Marina Line |url=https://eresources.nlb.gov.sg/newspapers/digitised/article/straitstimes19980624-1.2.38.4 |access-date=24 April 2026 |work=The Straits Times |date=24 June 1998 |page=26|via=NewspaperSG}}{{cbignore}}</ref>
In October 1999, the LTA announced that an outer circle line would link {{MRT station|Buona Vista}} and Paya Lebar via {{MRT station|Bishan}} and {{MRT station|Serangoon}}. The number of planned stations on the MRL also increased to 24. Construction of the segment between Dhoby Ghaut and Marina Centre would be prioritised given demand along the Bras Basah corridor, while construction of the other sections would be deferred due to lack of developments in the planned Marina Downtown.<ref>{{cite news |last1=Kaur |first1=Karamjit |title=LTA Studying Paya Lebar-Buona Vista Rail Line |url=https://www.straitstimes.com/multimedia/graphics/assets/images/ST175/NewspaperSG/1999-10-28/full.jpg |access-date=25 December 2021 |work=The Straits Times |date=28 October 1999 |page=1 |archive-date=4 December 2021 |archive-url=https://web.archive.org/web/20211204083942/https://www.straitstimes.com/multimedia/graphics/assets/images/ST175/NewspaperSG/1999-10-28/full.jpg |url-status=live }}</ref> In 2001, the first six stations of the MRL from Dhoby Ghaut to {{MRT station|Boulevard}} were announced, with plans to connect the MRL from Stadium station to the Outer Circle Line at Paya Lebar. The Outer Circle Line would also loop back to Marina South via World Trade Centre.<ref>{{Cite news |last=Yeo |first=Geraldine |date=25 November 1999 |title=6 stations for Marina line's first phase |url=https://eresources.nlb.gov.sg/newspapers/digitised/article/straitstimes19991125-1.2.6.5 |access-date=24 October 2025 |work=The Straits Times |page=3 |via=NewspaperSG}}{{Cbignore}}</ref> Subsequently in April that year, communications minister Yeo Cheow Tong announced that the Marina Line would be built as the first phase of the Circle Line, alongside the announcement of the second phase that would span {{convert|5|km}} from Stadium to Upper Paya Lebar Road.<ref>{{Cite news |last=Kaur |first=Karamjit |date=29 April 2001 |title=Coming your way – MRT: Extension of Marina Line to Upper Paya Lebar Road |work=The Straits Times |page=1 |url=https://www.straitstimes.com/multimedia/graphics/assets/images/ST175/NewspaperSG/2001-04-29/full.jpg}}{{Cbignore}}</ref><ref name="LTA x567">{{cite web | title=Joint Press Release By Ministry Of Communications And Information Technology And Ministry Of Law – Circle Line And Kallang/Paya Lebar Expressway | publisher=Land Transport Authority | date=28 April 2001 | url=http://app.internet.gov.sg/scripts/lta/3_press_content.asp?start=237 | archive-url=https://web.archive.org/web/20030811132847/http://app.internet.gov.sg/scripts/lta/3_press_content.asp?start=237 | archive-date=11 August 2003 | url-status=dead | access-date=25 April 2026}}</ref>
===Construction=== thumb|Construction site of Bishan station in May 2006 thumb|Haw Par Villa under construction in December 2008 {| class="wikitable floatright" style="width:350px; font-size:90%" |+ Circle Line stations timeline ! Date !! Project !! Description |- | 28 May 2009 || Stage 3 (CCL3) || Bartley – Marymount |- | rowspan="2" | 17 April 2010 || Stage 1 (CCL1) || Dhoby Ghaut – Stadium |- |Stage 2 (CCL2) |Mountbatten – Tai Seng |- | rowspan="2" | 8 October 2011 || Stage 4 (CCL4) || Caldecott – Kent Ridge |- |Stage 5 (CCL5) |Haw Par Villa – HarbourFront |- | 14 January 2012 || Circle Line Extension (CCLe) || Bayfront – Marina Bay |- | 12 July 2026 || Stage 6 (CCL6) || Keppel – Prince Edward Road |} Industry observers anticipated that Trans-Island Bus Services (TIBS) would operate the CCL in accordance with the Singapore Government's initiative for multi-modal operators.<ref name="Koh bid"/> TIBS had partnered with Regie Autonome des Transports Parisiens (RATP) for its bid to operate the line.<ref>{{cite news |title=Tibs, French firm to jointly bid for Marina Line |url=https://eresources.nlb.gov.sg/newspapers/digitised/article/today20010213-1.2.10.2 |work=Today |date=13 February 2001 |page=5 |via=NewspaperSG|last=Chua|first=Chelsea}}{{cbignore}}</ref> However, the LTA ultimately awarded the contract to SMRT Corporation in August 2001. The LTA justified its decision based on SMRT's track record, financial strength, and customer service.<ref name="Koh bid">{{cite news |last1=Koh |first1=Leslie |title=SMRT wins bid to run $1-billion Marina Line |work=The Straits Times |date=9 August 2001 |page=3 |quote=Incumbent rail operator Singapore MRT yesterday edged out its two competitors in the race to operate the $1-billion Marina Line, despite expectations that underdog Trans-Island Bus Services would win the bid. Making this surprise announcement yesterday, the Land Transport Authority (LTA) cited SMRT's superior track record, financial strength and customer services as the main factors that knocked out Tibs and Singapore Bus Services in the close fight.}}</ref><ref name="k976">{{cite web | title=Appointment Of Operator For The Circle Line | publisher=Land Transport Authority | url= http://app.internet.gov.sg/scripts/lta/3_press_content.asp?start=315 | archive-url=https://web.archive.org/web/20030604160303fw_/http://app.internet.gov.sg/scripts/lta/3_press_content.asp?start=315 | date=8 August 2001 | archive-date=4 June 2003 | access-date=25 April 2026}}</ref>
Construction of the CCL officially began on 5 March 2002 with a groundbreaking ceremony at Bras Basah Park.<ref>{{cite news |first=Karamjit |last=Kaur |title=Work on Circle Line starts |work=The Straits Times |date=6 March 2002 |page=3 |quote=At the ground-breaking ceremony for the Circle Line yesterday, Transport Minister Yeo Cheow Tong said that commuters would not be the only ones to benefit when the line was ready.}}</ref><ref name="NAS x874">{{cite web | title=Speech by Mr Yeo Cheow Tong Minister for Transport at the Groundbreaking Ceremony for the Circle Line at Bras Basah Park on Tuesday, 5 March 2002 at 10.10AM | website=National Archives of Singapore | url=https://www.nas.gov.sg/archivesonline/data/pdfdoc/2002030502.htm | access-date=25 April 2026}}</ref> At the ceremony, Yeo announced that the {{convert|34|km|adj=on}} CCL would be built in five stages and completed by 2010.<ref name="NAS x874"/> Stage 3 of the CCL (CCL3), which comprises five stations from {{MRT station|Bartley}} to {{MRT station|Marymount}}, was announced in January 2003.<ref name="o893">{{cite web | title=Circle Line Stage 3 | date= 20 January 2003| publisher=Land Transport Authority | url=http://app.internet.gov.sg/scripts/lta/3_press_content.asp?start=662 | archive-url=https://web.archive.org/web/20030811092013/http://app.internet.gov.sg/scripts/lta/3_press_content.asp?start=662 | archive-date=11 August 2003 | url-status=dead | access-date=25 April 2026}}</ref> The 13 stations of CCL Stages 4 and 5 (CCL4 and CCL5) from {{MRT station|Thomson}} to HarbourFront were announced in December 2003.<ref>{{cite news |first=Joy|last=Frances|title=Completing the Circle via Holland V |url=https://eresources.nlb.gov.sg/newspapers/Digitised/Article/today20031213-1.2.3 |work=Today |date=13 December 2003 |page=1 |via=NewspaperSG }}{{cbignore}}</ref><ref name="Stages 4 and 5">{{Cite web |date=16 November 2005 |title=Stages 4 & 5 of Circle Line |url=http://www.lta.gov.sg/projects/proj_rail_ccl4n5.htm |url-status=dead |archive-url=https://web.archive.org/web/20040616041703/http://www.lta.gov.sg/projects/proj_rail_ccl4n5.htm |archive-date=16 June 2004 |access-date=21 September 2020 |publisher=Land Transport Authority}}</ref> This segment included three planned shell stations – {{MRT station|Caldecott}}, {{MRT station|Bukit Brown}} and {{MRT station|Haw Par Villa}}.{{efn|Caldecott was initially named Thomson, and Haw Par Villa was initially named West Coast. Both were renamed through a naming poll.<ref>{{Cite web |title=Annex 1: Final Station Names |url=http://www.lta.gov.sg/data/apps/news/press/2009/2009-06-16_Annex1_StationNaming-FINAL.pdf |url-status=dead |archive-url=https://megalodon.jp/2026-0227-1146-47/https://eresources.nlb.gov.sg:443/webarchives/wayback/20160425111553/http://www.lta.gov.sg/data/apps/news/press/2009/2009-06-16_Annex1_StationNaming-FINAL.pdf |archive-date=25 April 2016 |access-date=27 February 2026 |publisher=Land Transport Authority}}</ref><ref>{{cite news |title=Haw Par Villa, Caldecott named as Circle Line stations |url=https://eresources.nlb.gov.sg/newspapers/digitised/article/today20090617-1.2.7.10 |access-date=30 April 2026 |work=Today |date=17 June 2009 |page=12|via=NewspaperSG}}{{cbignore}}</ref>}} These station were to be opened only when their surroundings were more developed.<ref name="Stages 4 and 5"/>{{sfn|Cheong|2012|p=46}}
On 20 April 2004, the tunnels linking to Nicoll Highway station caved in along with a {{cvt|100|m|ft|adj=on}} stretch of the Nicoll Highway. The collapse of a tunnel retaining wall caused soil subsidence,<ref name="Technical brief">{{Cite web |title=Incident at Nicoll Highway – Technical Brief |url=http://www.lta.gov.sg/projects/doc/Nicoll%20Highway%20Collapse-Technical%20Brief.pdf |url-status=dead |archive-url=https://web.archive.org/web/20070717184318/http://www.lta.gov.sg/projects/doc/Nicoll%20Highway%20Collapse-Technical%20Brief.pdf |archive-date=17 July 2007 |access-date=17 July 2007 |publisher=Land Transport Authority<!-- |website=lta.gov.sg -->}}</ref> creating a hole 100 metres long, 130 metres wide, and 30 metres deep (328 by 427 by 98 ft).{{sfn|Cheong|2012|p=82}} Four people were killed and three were injured.<ref name="Local Major Incidents 2015">{{cite web |title=Nicoll Highway Cave-In |publisher=Singapore Civil Defence Force |date=30 September 2011 |url=https://www.scdf.gov.sg/content/scdf_internet/en/general/information/local-major-incidents/nicoll_highway_cave-in.html |archive-url=https://web.archive.org/web/20150419032600/https://www.scdf.gov.sg/content/scdf_internet/en/general/information/local-major-incidents/nicoll_highway_cave-in.html |archive-date=19 April 2015 |url-status=dead |access-date=7 February 2022}}</ref><ref name="station wreck">{{Cite news |date=21 April 2004 |title=MRT worksite wrecks Nicoll Highway |page=1 |work=The Straits Times |url=https://www.straitstimes.com/multimedia/graphics/assets/images/ST175/NewspaperSG/2004-04-21/full.jpg |url-status=live |first1=Sharon |last1=Loh |access-date=3 January 2022 |archive-date=3 December 2021 |archive-url=https://web.archive.org/web/20211203111148/https://www.straitstimes.com/multimedia/graphics/assets/images/ST175/NewspaperSG/2004-04-21/full.jpg}}</ref><ref>{{Cite web |title=Friday's fatal mishap among worst worksite accidents since 2004 Nicoll Highway tragedy |url=https://www.todayonline.com/singapore/fridays-fatal-mishap-worst-worksite-accident-2004-nicoll-highway-tragedy |access-date=17 April 2020 |website=TODAYonline |publisher=Mediacorp |archive-url=https://megalodon.jp/2026-0221-1524-38/https://www.todayonline.com:443/singapore/fridays-fatal-mishap-worst-worksite-accident-2004-nicoll-highway-tragedy |archive-date=21 February 2026 |url-status=live |first1=Louisa |last1=Tang}}</ref> The LTA halted work at 16 of the 24 CCL excavation sites for review.{{sfn|Cheong|2012|p=82}}<ref>{{Cite news |date=24 April 2004 |title=Main contractor told to stop all excavation work |page=H3 |work=The Straits Times }}</ref> A Committee of Inquiry (COI) concluded that the incident was caused by human error and organisational failures.<ref name="Ministry of Transport (MOT) 2005">{{Cite web |date=11 May 2005 |title=Government Response To The Final Report Of The Committee Of Inquiry Into The Nicoll Highway Collapse |url=https://www.mot.gov.sg/news-centre/news/Detail/Government%20Response%20To%20The%20Final%20Report%20Of%20The%20Committee%20Of%20Inquiry%20Into%20The%20Nicoll%20Highway%20Collapse/ |archive-url=https://web.archive.org/web/20210422120313/https://www.mot.gov.sg/news-centre/news/Detail/Government%20Response%20To%20The%20Final%20Report%20Of%20The%20Committee%20Of%20Inquiry%20Into%20The%20Nicoll%20Highway%20Collapse/ |archive-date=22 April 2021 |access-date=23 April 2021 |publisher=Ministry of Transport <!-- |website=mot.gov.sg --> |url-status=<!--live-->dead}}</ref> The strut-waler support system was poorly designed and weaker than it should have been, with a lack of monitoring and proper management of data.<ref name="COI Report">{{Cite web |title=Committee of Inquiry concludes string of critical design errors (that) caused (the) collapse at Nicoll Highway |url=https://www.nas.gov.sg/archivesonline/data/pdfdoc/20050513987.pdf |url-status=live |archive-url=https://web.archive.org/web/20210422120652/https://www.nas.gov.sg/archivesonline/data/pdfdoc/20050513987.pdf |archive-date=22 April 2021 |access-date=23 April 2021 |website=National Archives of Singapore |publisher=Ministry of Manpower |date=13 May 2005}}</ref> Although the LTA initially said that the collapse happened without warning,<ref>{{Cite news |date=22 April 2004 |title=It happened without warning: LTA |page=1 |work=The Straits Times |url=https://www.straitstimes.com/multimedia/graphics/assets/images/ST175/NewspaperSG/2004-04-22/full.jpg |url-status=live |last1=Tan |first1=Christopher |access-date=3 January 2022 |archive-date=3 December 2021 |archive-url=https://web.archive.org/web/20211203111107/https://www.straitstimes.com/multimedia/graphics/assets/images/ST175/NewspaperSG/2004-04-22/full.jpg}}</ref> the COI report revealed that there were already "warning signs", such as excessive wall deflections and surging inclinometer readings, which were not addressed seriously.<ref name="COI Report" /><ref>{{Cite news |date=11 September 2004 |title=Critical warning signs 'overlooked' |page=8 |work=The Straits Times |last1=Goh |first1=Chin Lian}}</ref> The report pointed out a lack of safety culture at the site and made several recommendations to improve the safety of construction projects,<ref name="COI Report" /> which the government accepted.<ref name="Ministry of Transport (MOT) 2005" /><ref>{{cite web |last1=Popatlal |first1=Asha |title=Nicoll Highway Inquiry: Govt accepts broad thrust of committee's recommendations |url=http://www.channelnewsasia.com/stories/singaporelocalnews/view/106445/1/.html |website=Channel NewsAsia |publisher=Mediacorp |access-date=29 January 2022 |archive-url=https://web.archive.org/web/20050506130127/http://www.channelnewsasia.com/stories/singaporelocalnews/view/106445/1/.html |archive-date=6 May 2005 |date=13 September 2004}}</ref> Nicoll Highway station was rebuilt {{cvt|100|m}} south of the original site along Republic Avenue, with a new tunnel alignment between the Millenia and Boulevard stations.<ref>{{Cite news |date=5 February 2005 |title=Nicoll Highway MRT to be built at new site |work= The Business Times |page=9}}</ref> Due to the tunnels' collapse, the completion date of CCL Stage 1 was delayed from 2007 to 2009.<ref name="CCL delayed">{{cite web |date=4 December 2004 |title=Circle Line stage one likely to be delayed by 2 years: Yeo |url=http://www.channelnewsasia.com/stories/singaporelocalnews/view/120604/1/.html |url-status=dead |archive-url=https://web.archive.org/web/20050507235545/http://www.channelnewsasia.com/stories/singaporelocalnews/view/120604/1/.html |archive-date=7 May 2005 |access-date=30 January 2022 |website=Channel NewsAsia |publisher=}}</ref>
In March 2004, the LTA launched a public polling exercise to name the stations along the CCL, marking the first time the general public was invited to participate in the naming process to foster a greater sense of community ownership.<ref name="LTA s014">{{cite web |date=26 March 2004 |title=LTA Seeks Your Views On Names For Circle Line Stations |url=http://app.lta.gov.sg/corp_press_content.asp?start=986 |url-status=dead |archive-url=https://web.archive.org/web/20110926210939/http://app.lta.gov.sg/corp_press_content.asp?start=986 |archive-date=26 September 2011 |access-date=26 April 2026 |publisher=Land Transport Authority}}</ref><ref>{{Cite news |date=27 March 2004 |title=You can name an MRT station |url=https://eresources.nlb.gov.sg/newspapers/digitised/article/today20040327-1.2.6.6 |access-date=26 April 2024 |work=Today |page=3|via=NewspaperSG}}{{cbignore}}</ref><ref>{{cite news |title=Circle Line stations: Go ahead and suggest names |url=https://eresources.nlb.gov.sg/newspapers/digitised/article/straitstimes20040329-1.2.23.4.4 |work=The Straits Times |date=29 March 2004 |page=3 |via=NewspaperSG |url-access=subscription}}{{cbignore}}</ref> The public could choose between two LTA-proposed names for each station or suggest their own, provided the names accurately reflected the area's locality, history, and multi-cultural heritage.<ref name="LTA s014"/> The names for the CCL Stages 1 to 3 stations were finalised in July 2005.<ref name="LTA finalised CCL 1 to 3">{{cite web |title=LTA announces finalised names for Circle Line Stages 1–3 stations and seeks views on names for Circle Line Stages 4 and 5 stations |url=http://app.lta.gov.sg/corp_press_content.asp?start=1292 |publisher=Land Transport Authority |access-date=26 April 2026 |archive-url=https://web.archive.org/web/20110926205917/http://app.lta.gov.sg/corp_press_content.asp?start=1292 |archive-date=26 September 2011 |date=6 July 2005 |url-status=dead}}</ref><ref>{{cite news |title=Next stop, Dakota |url=https://eresources.nlb.gov.sg/newspapers/digitised/article/straitstimes20050707-1.2.48.17 |access-date=26 April 2026 |work=The Straits Times |date=7 July 2005 |page=5 |via=NewspaperSG |url-access=subscription}}{{cbignore}}</ref> A subsequent naming poll for the CCL4 and CCL5 stations attracted 634 respondents – 152 more than the previous poll. These station names were finalised in December 2005.<ref>{{cite news |first1=Ching Li |last1=Tor |title=Polling for station names |url=https://eresources.nlb.gov.sg/newspapers/digitised/article/today20051108-1.2.11.7 |access-date=26 April 2026 |work=Today |date=8 November 2005 |page=8 |via=NewspaperSG}}{{cbignore}}</ref><ref name="LTA v916">{{cite web | title=Station Names For Circle Line Stages 4 And 5 | publisher=Land Transport Authority | date=20 July 2005 | url=http://app.lta.gov.sg/corp_press_content.asp?start=1419 | archive-url=https://web.archive.org/web/20110926205933/http://app.lta.gov.sg/corp_press_content.asp?start=1419 | archive-date=26 September 2011 | url-status=dead | access-date=26 April 2026}}</ref>
On 14 June 2005, the LTA announced plans for the Downtown Extension (DTE), which was intended to be a branch of the CCL.<ref name="ST CCL">{{Cite news |last1=Tan |first1=Christopher |date=15 June 2005 |title=Circle Line extends to Marina South |url=https://www.straitstimes.com/multimedia/graphics/assets/images/ST175/NewspaperSG/2005-06-15/full.jpg |url-status=live |archive-url=https://web.archive.org/web/20220130061244/https://www.straitstimes.com/multimedia/graphics/assets/images/ST175/NewspaperSG/2005-06-15/full.jpg |archive-date=30 January 2022 |access-date=6 January 2023 |work=The Straits Times |page=1}}</ref> Comprising five stations from Milennia (now Promenade) to Chinatown,<ref>{{Cite news |last1=Tor |first1=Ching Li |date=15 June 2005 |title=Joining the hot spots |work=Today |page=2 |url=https://eresources.nlb.gov.sg/newspapers/digitised/page/today20050615-1.1.2 |via=NewspaperSG}}{{cbignore}}</ref><ref name="DTE LTA">{{cite web |date=14 June 2005 |title=Expanding The Rail Network With Downtown Extension |url=http://app.lta.gov.sg/corp_press_content.asp?start=1268 |archive-url=https://web.archive.org/web/20070927182445/http://app.lta.gov.sg/corp_press_content.asp?start=1268 |archive-date=27 September 2007 |access-date=30 August 2019 |publisher=Land Transport Authority}}</ref><ref>{{cite news |last=Shankari |first=Uma |date=15 June 2005 |title=Marina Bay to get new MRT line by 2012 |newspaper=The Business Times |page=10}}</ref> it would serve the development of the Downtown at Marina Bay, a planned business and financial hub.<ref name="DTE LTA" /> Yam Ah Mee, the then-chief executive of the LTA, also stated that the agency was studying further extensions to the DTE, including an eastward extension to Kim Chuan Depot and a westward extension linking the line to the Bukit Timah Line{{sfn|Cheong|2012|p=17}} In 2007, transport minister Raymond Lim announced that the DTE would instead be incorporated into the Downtown Line (DTL).<ref>{{Cite news |last1=Tan |first1=Christopher |date=15 March 2007 |title=Five stops planned for first phase of Downtown MRT line |url=https://www.straitstimes.com/multimedia/graphics/assets/images/ST175/NewspaperSG/2007-03-15/full.jpg |url-status=live |archive-url=https://web.archive.org/web/20221108084438/https://www.straitstimes.com/multimedia/graphics/assets/images/ST175/NewspaperSG/2007-03-15/full.jpg |archive-date=8 November 2022 |access-date=8 November 2022 |work=The Straits Times |page=1}}</ref> Another branch to Marina Bay station via Bayfront was announced in April that year.<ref name="web.archive.org 2007">{{cite web |title=Government Approves Building Of The Downtown Line|publisher=Land Transport Authority|date=27 April 2007|url=http://app.lta.gov.sg/corp_press_content.asp?start=1763|archive-url=https://web.archive.org/web/20120302024844/http://app.lta.gov.sg/corp_press_content.asp?start=1763|archive-date=2 March 2012|url-status=dead|access-date=8 November 2022}}</ref>
Construction of the CCL platforms at Dhoby Ghaut required stabilising the existing underpass above linking the North East Line (NEL) and North–South Line platforms. Seven caisson piles were installed to enhance the support of the underpass and capping beams were then constructed to form the supporting system.{{sfn | Cheong| 2012 | p=46}} At {{MRT station|Esplanade}}, the arterial routes of Bras Basah Road and Nicoll Highway had to be diverted through more than 10 phases.{{sfn | Cheong | 2012 | p=60}} The station was constructed using the top-down method to minimise the impact of noise and dust pollution on the surrounding developments. Diaphragm walls were built to minimise ground movement. With the roof constructed first, construction could proceed under all weather conditions while allowing the early reinstatement of Bras Basah Road and War Memorial Park.{{sfn | Cheong | 2012 | p=57}} Two East–West Line viaduct piers at Paya Lebar station had to be underpinned. Using concrete walls, beams, and a powerful jacking system, they transferred the weight of the viaduct so they could safely cut away the old piles.{{sfn | Cheong | 2012 | p=61}}<ref name="brouchre">{{Cite web|title=Lum Chang Technical Brochure|url=http://www.lumchang.com.sg/docs/default-source/default-document-library/downloads/downloads/lum-chang-technical-brochure.pdf?sfvrsn=2|website=www.lumchang.com.sg|access-date=19 August 2020|archive-date=10 July 2021|archive-url=https://web.archive.org/web/20210710185139/http://www.lumchang.com.sg/docs/default-source/default-document-library/downloads/downloads/lum-chang-technical-brochure.pdf?sfvrsn=2|url-status=dead|page=28}}</ref>
During excavation of the CCL tunnels beneath Serangoon station, contractors encountered significant groundwater seepage, causing ground settlement and the NEL station to sink by {{convert|1|cm}}.<ref name="LTA safety edition">{{cite web | title = Safety News, Special Edition, July 2006 | url = http://www.lta.gov.sg/projects/doc/LTA_Special_Edition_LR.pdf | access-date = 30 September 2008 | archive-url = https://web.archive.org/web/20081031072521/http://www.lta.gov.sg/projects/doc/LTA_Special_Edition_LR.pdf | archive-date = 31 October 2008 | url-status = dead |website=lta.gov.sg |publisher=Land Transport Authority }}</ref> Works were suspended while water was pumped out, and NEL trains were required to slow when entering or leaving the station.<ref name="MRT damage">{{cite news | last1=Goh |first1= Chin Lian| title = More claims of MRT work damage | work= The Straits Times | date = 8 June 2005|page=4}}</ref> The tunnel was subsequently redesigned, with jet grouting and enhanced monitoring introduced to detect further settlement.<ref name="LTA safety edition"/>{{sfn | Cheong | 2012 | p=54}} At {{MRT station|Holland Village}}, the excavation pit was only {{cvt|6|m}} away from the Willyn Ville Condominium, requiring vigilant ground testing and wall deflection monitoring to ensure the building's safety.{{sfn | Cheong | 2012 | p=76}} Similarly, {{MRT station|Pasir Panjang}} was dug in soft ground just {{convert|10|m}} from a road viaduct and in close proximity to residential homes and shophouses.{{sfn | Cheong | 2012 | p=77}}
The Building and Construction Authority halted tunnelling works near Telok Blangah in August 2007 following the ground settlement of two road lanes near the junction of Telok Blangah Road and Alexandra Road.<ref name="ST k136">{{cite web |last=Rajan |first=T. |date=22 August 2007 |title=Tunnel work stops at Circle Line site after road sinks |url=http://www.straitstimes.com/Free/Story/STIStory_150531.html |url-status=dead |archive-url=https://web.archive.org/web/20080609193530/http://www.straitstimes.com/Free/Story/STIStory_150531.html |archive-date=9 June 2008 |access-date=30 April 2026 |website=The Straits Times}}</ref> A section of Cornwall Gardens Road near Holland Road caved in on 24 May 2008 during tunnelling works between Holland and Farrer Road stations. While no one was injured, the sinkhole led to the disruptions of utilities in the area.<ref name="CNA j670">{{cite web |date=24 May 2008 |title=Road above Circle Line construction site caves in |url=http://www.channelnewsasia.com/stories/singaporelocalnews/view/349771/1/.html |url-status=dead |archive-url=https://web.archive.org/web/20080526221930/http://www.channelnewsasia.com/stories/singaporelocalnews/view/349771/1/.html |archive-date=26 May 2008 |access-date=30 April 2026 |website=CNA}}</ref><ref name="Tunnels and Tunnelling e977">{{cite web |date=11 June 2008 |title=Subsidence at Singapore Circle Line |url=https://www.tunnelsandtunnelling.com/news/subsidence-at-singapore-circle-line/ |access-date=15 May 2026 |website=Tunnels and Tunnelling}}</ref>
===Opening=== ''The Straits Times'' reported that the CCL3 stations were "in advanced stages of completion" in September 2007, with architectural, engineering, and mechanical works being carried out and expected to be finished by mid-2008. In January 2008, the CCL3 stations' completion date was moved earlier from 2010 to mid-2009.<ref>{{Cite news |last=Almenoar |first=Maria |date=26 January 2008 |title=More trains, shorter waits |work=The Straits Times |page=H10}}</ref><ref>{{Cite news |date=26 January 2008 |title=We're getting super connected |work=The New Paper |pages=16–17 }}</ref> Two of the planned shell stations – Thomson and West Coast – would also be fitted out and opened with the other CCL stations.<ref name="NAS w811">{{cite web | title=Speech by Mr Raymond Lim, Minister for Transport, at the Visit to Kim Chuan Depot, 25 January 2008, 9.00 AM | website=National Archives of Singapore |date=25 January 2008 | url=https://www.nas.gov.sg/archivesonline/data/pdfdoc/20080125985.htm | access-date=30 April 2026}}</ref> The LTA started conducting test runs on the CCL3 stations, with the expected commencement date set for June 2009.<ref>{{Cite news |last=Tan |first=Christopher |date=23 April 2008 |title=Stage 3 of Circle Line set for Nov completion |work=The Straits Times |page=H3 }}</ref> In February 2009, transport minister Raymond Lim announced that CCL3 would open on 30 May,<ref>{{Cite news |last=Yeo |first=Ghim Lay |date=13 February 2009 |title=Five stations on Circle Line to open in May |url=https://www.straitstimes.com/multimedia/graphics/assets/images/ST175/NewspaperSG/2009-02-13/full.jpg |work=The Straits Times |page=1 |quote=Circle Line Stage 3, which has five stations, will open on May 30 instead of June, Transport Minister Raymond Lim announced in Parliament during yesterday's debate on his ministry's budget. }}</ref> though it was later moved to 28 May.<ref>{{Cite news |last=Leong |first=Wee Keet |date=17 April 2009 |title=Faster and cheaper |url=https://eresources.nlb.gov.sg/newspapers/digitised/article/today20090417-1.2.6.3 |access-date=24 October 2025 |work=Today |page=3 |via=NewspaperSG }}</ref><ref>{{cite web |title=Early Opening for Circle Line from Bartley to Marymount |url=http://www.lta.gov.sg/content/dam/ltaweb/corp/PublicTransport/files/Early-Opening-for-CCL-from-Bartley-to-Marymount.pdf |url-status=dead |archive-url=https://web.archive.org/web/20140401194609/http://www.lta.gov.sg/content/dam/ltaweb/corp/PublicTransport/files/Early-Opening-for-CCL-from-Bartley-to-Marymount.pdf |archive-date=1 April 2014 |access-date=16 April 2019 |website=Land Transport Authority }}</ref> An open house was held for the CCL3 stations on 23 May,<ref>{{cite web |title=Circle Line Open House on Saturday, 23 May 2009 |url=http://app.lta.gov.sg/corp_press_content.asp?start=2134 |publisher=Land Transport Authority |access-date=29 April 2026 |archive-url=https://megalodon.jp/2026-0429-2129-51/tiny.cc/l6k2101 |archive-date=29 April 2026 |date=23 May 2009 |url-status=dead}}</ref> before operations commenced on 28 May.<ref name="CNA News">{{cite web |last=Lim |first=Cheryl |date=28 May 2009 |title=Part of Circle Line opens today |url=http://www.channelnewsasia.com/stories/singaporelocalnews/view/432074/1/.html |archive-url=https://web.archive.org/web/20090528095244/http://www.channelnewsasia.com/stories/singaporelocalnews/view/432074/1/.html |archive-date=28 May 2009 |access-date=28 May 2009 |website=Channel NewsAsia }}</ref> An opening ceremony was held at Bishan station, presided by deputy prime minister Teo Chee Hean.<ref>{{cite news |last1=Yeo |first1=Ghim Lay |title=Circle Line trains start rolling today |url=https://eresources.nlb.gov.sg/newspapers/digitised/page/straitstimes20090528-1.1.3 |access-date=29 April 2026 |work=The Straits Times |date=28 May 2009 |page=3 |via=NewspaperSG |url-access=subscription |quote=Deputy Prime Minister Teo Chee Hean, who opened the stations in a ceremony at Bishan MRT yesterday, said: 'It will open up multiple new connections for residents in the north and the north-east.'}}{{cbignore}}</ref>{{sfn|Cheong|2012|pp=94–95}}
Due to the Nicoll Highway collapse, the expected opening date for CCL1 was delayed by two years from 2007 to 2009.<ref name="CCL delayed"/> In August 2009, transport minister Lim announced that CCL1 and 2 would open by the first half of 2010;<ref>{{Cite news|url=https://eresources.nlb.gov.sg/newspapers/digitised/article/today20090831-1.2.4?qt=%22tai%20seng%22,%20station&q=%22tai%20seng%22%20%22station%22|title=10-Month Countdown for 11 Circle Line Stations|last=Leong|first=Wee Kat|date=31 August 2009|page=1|access-date=29 November 2025|work=Today}}</ref><ref>{{Cite news|title=More Circle Line Stations to Open in April|last=EE|first=Samuel|date=27 January 2010|page=10|work=The Business Times}}</ref> this was later announced to be 17 April.<ref>{{Cite news|title=Round Trip Travel|last=Tan|first=Suan Chiang|date=6 February 2010|pages=|work=The Straits Times|page=E10}}</ref><ref>{{cite web |url=http://app.lta.gov.sg/corp_press_content.asp?start=kpt8zx9w8ik53wi33gr59p754348fsj35b9glldouy8ndlh7kb |title=Circle Line from Bartley to Dhoby Ghaut to Open 17 April |access-date=26 January 2010 |url-status=dead |archive-url=https://web.archive.org/web/20110621220756/http://app.lta.gov.sg/corp_press_content.asp?start=kpt8zx9w8ik53wi33gr59p754348fsj35b9glldouy8ndlh7kb |archive-date=21 June 2011 |date=21 July 2011|website=|publisher=Land Transport Authority}}</ref> An open house was held on 5 April 2010.<ref>{{Cite news|url=https://eresources.nlb.gov.sg/newspapers/digitised/page/today20100405-3.1.8|title=Free Rides for 52,000|last=Ramesh|first=S.|date=5 April 2010|pages=11|access-date=29 November 2025|work=Today}}</ref><ref>{{Cite news|title=Track Stars / Natural Lighting|last=Tay|first=Suan Chiang|date=27 March 2010|pages=F8–9|work=The Straits Times}}</ref> CCL1 and CCL2 commenced operations on 17 April 2010,<ref>{{Cite news|title=Another Stretch of Circle Line Opens|last=Chee|first=Glenn|date=17 April 2010|page=15|work=The Business Times}}</ref><ref>{{Cite news|title=11 Circle Line Stations Open Today|last=Alemenoar|first=Maria|date=17 April 2010|page=A4|work=The Straits Times}}</ref> with transport minister Lim holding an opening ceremony at Bras Basah station the day before.<ref name="NAS l236">{{cite web | title=Speech by Mr Raymond Lim, Minister for Transport and Second Minister for Foreign Affairs, at Opening of the Circle Line (Dhoby Ghaut to Bartley), 16 April 2010, 7:30 PM at Bras Basah Station | website=National Archives of Singapore | url=https://www.nas.gov.sg/archivesonline/data/pdfdoc/20100423004.htm | access-date=30 April 2026}}</ref>
Tunnelling works for the CCL were completed in August 2009,<ref name="CCL delayed" /> marked by a tunnel breakthrough ceremony at Farrer Road.<ref>{{cite web |date=17 August 2009 |title=Circle Line: The longest dig |url=http://www.straitstimes.com/Breaking%2BNews/Singapore/Story/STIStory_417858.html?vgnmr=1 |archive-url=https://web.archive.org/web/20090821173820/https://www.straitstimes.com/Breaking%2BNews/Singapore/Story/STIStory_417858.html?vgnmr=1 |archive-date=21 August 2009 |publisher=The Straits Times}}</ref><ref>{{Cite news|url=https://eresources.nlb.gov.sg/newspapers/digitised/page/today20090818-1.1.12|title=Right on Track|date=18 August 2009|access-date=29 November 2025|work=Today|page=12}}</ref> As announced by transport minister Lui Tuck Yew during his visit to the CCL 4 and CCL 5 stations on 1 August 2011,<ref>{{Cite web |url=http://www.mot.gov.sg/news-centre/highlights/detail/circle-line-from-marymount-to-harbourfront-to-open|date=1 August 2011|title=Circle Line from Marymount to HarbourFront to open|publisher=Ministry of Transport|language=en|access-date=28 April 2020|archive-date=19 November 2020|archive-url=https://web.archive.org/web/20201119125715/https://www.mot.gov.sg/news-centre/highlights/detail/circle-line-from-marymount-to-harbourfront-to-open|url-status=live}}</ref><ref name="lta.gov.sg 2017">{{cite web |title=12 Circle Line Stations, from Marymount to HarbourFront, to Open on 8 October – Press Room – Land Transport Authority|publisher=Land Transport Authority|date=1 August 2011|url=https://www.lta.gov.sg/apps/news/page.aspx?c=2&id=pharbnd879bjz9ota7rrl6r7150ytjs8g7wf2n00qbcz29b005|archive-url=https://web.archive.org/web/20171017151218/https://www.lta.gov.sg/apps/news/page.aspx?c=2&id=pharbnd879bjz9ota7rrl6r7150ytjs8g7wf2n00qbcz29b005|archive-date=17 October 2017|url-status=dead|access-date=10 February 2022}}</ref> the segment began revenue service on 8 October of that year.<ref>{{Cite web |title=Speech by Mr Tharman Shanmugaratnam at the Circle Line Opening Ceremony on 7 Oct 2011|date=7 October 2011|url=http://www.mot.gov.sg/news-centre/news/Detail/Speech%20by%20Mr%20Tharman%20Shanmugaratnam%20at%20the%20Circle%20Line%20Opening%20Ceremony%20on%207%20Oct%202011/|publisher=Ministry of Transport|language=en|access-date=1 May 2020|archive-date=1 May 2020|archive-url=https://web.archive.org/web/20200501111937/https://www.mot.gov.sg/news-centre/news/Detail/Speech%20by%20Mr%20Tharman%20Shanmugaratnam%20at%20the%20Circle%20Line%20Opening%20Ceremony%20on%207%20Oct%202011/|url-status=dead}}</ref><ref>{{cite web |last1=Almenoar|first1=Maria|title=Circle Line opens on Saturday after 10-year wait|url=http://www.straitstimes.com/BreakingNews/Singapore/Story/STIStory_721203.html|website=The Straits Times|access-date=9 February 2022|archive-url=https://web.archive.org/web/20120625100627/http://www.straitstimes.com/BreakingNews/Singapore/Story/STIStory_721203.html|archive-date=25 June 2012|date=8 October 2011|url-status=dead}}</ref> The Circle Line extension (CCLe) to Marina Bay opened on 14 January 2012, with an official opening ceremony held on the day before.<ref name="MOT speech">{{Cite web |title=Speech by Mr Lui Tuck Yew at the Opening Ceremony of the Circle Line Extension on 13 January 2012 |date=13 January 2012 |url=http://www.mot.gov.sg/news-centre/news/Detail/Speech%20by%20Mr%20Lui%20Tuck%20Yew%20at%20the%20Opening%20Ceremony%20of%20the%20Circle%20Line%20Extension%20on%2013%20January%202012/ |archive-url=https://web.archive.org/web/20200904091109/https://www.mot.gov.sg/news-centre/news/Detail/Speech%20by%20Mr%20Lui%20Tuck%20Yew%20at%20the%20Opening%20Ceremony%20of%20the%20Circle%20Line%20Extension%20on%2013%20January%202012/ |archive-date=4 September 2020 |url-status=dead |access-date=21 April 2020|publisher=Ministry of Transport|language=en}}</ref><ref>{{Cite web |url=http://www.smrt.com.sg/Announcements/articleid/630|title=The extension on Circle Line opens with two events held concurrently at Bayfront Station and Esplanade Xchange|publisher=SMRT Corporation|access-date=22 April 2020|archive-url=https://web.archive.org/web/20200422010155/http://www.smrt.com.sg/Announcements/articleid/630|archive-date=22 April 2020|url-status=live|date=14 January 2012}}</ref><ref>{{cite news |last1=Almenoar|first1=Maria|title=Marina Bay, Bayfront stations open|work=The Straits Times |date=14 January 2012|page=|url=http://www.straitstimes.com/The-Big-Story/The-Big-Story-3/Story/STIStory_755544.html|archive-date=20 March 2012|access-date=20 March 2012|url-status=dead|archive-url=https://web.archive.org/web/20120320140627/http://www.straitstimes.com/The-Big-Story/The-Big-Story-3/Story/STIStory_755544.html}}</ref>
=== Tunnel strengthening works === In 2023, routine inspections by the LTA and train operators found that a stretch of the CCL tunnel between Promenade and Nicoll Highway stations was subjected to greater pressure. Although no safety risks were identified, precautionary strengthening works, including the installation of steel supports, were carried out between June and July to ensure the tunnel’s long-term integrity.<ref name="ST s064">{{cite web |last=Lee |first=Nian Tjoe |date=24 May 2023 |title=MRT services at 7 CCL stations including Dhoby Ghaut to be affected by tunnel strengthening works |url=https://www.straitstimes.com/singapore/mrt-services-at-7-ccl-stations-including-dhoby-ghaut-to-be-affected-by-tunnel-strengthening-works |access-date=16 May 2026 |website=The Straits Times}}</ref> To facilitate these strengthening works, only one platform remained in operation from 9 pm daily for the segment between Stadium and Dhoby Ghaut, and on the CCLe between Bayfront and Marina Bay.<ref name="LTA t240">{{cite web |date=24 May 2023 |title=Service Adjustments for Seven Stations Along Circle Line |url=https://www.lta.gov.sg/content/ltagov/en/newsroom/2023/5/news-releases/service_adjustments_for_seven_stations_along_CCL.html |access-date=16 May 2026 |publisher=Land Transport Authority}}</ref>
The LTA announced in December 2025 that the tunnels between Mountbatten and Paya Lebar would be closed from January to April 2026 to facilitate tunnel strengthening works.<ref name="tunnel squatting">{{cite web |title=Train Service Adjustments to Circle Line for Tunnel Works |url=https://www.lta.gov.sg/content/ltagov/en/newsroom/2025/12/news-releases/train-service-adjustments-to-circle-line-for-tunnel-works.html |website= |publisher=Land Transport Authority |access-date=17 January 2026}}</ref> Following scans conducted after earlier works in 2023, the LTA identified three localised sections of the CCL tunnels that were more affected by tunnel squatting<ref>{{Cite web |title=Annex A: Further Information on Tunnel Strengthening Works |url=https://www.lta.gov.sg/content/dam/ltagov/news/press/2025/251201-CCL-Train-Service-Adjustments-annex-a.pdf |publisher=Land Transport Authority}}</ref> – the deformation of tunnel linings due to compression of marine clay.<ref name="CNA r825">{{cite web |last=Ganesan |first=Natasha |date=2 December 2025 |title=CNA Explains: What is 'tunnel squatting' and how does it affect MRT operations? |url=https://www.channelnewsasia.com/singapore/circle-line-tunnel-squatting-train-operations-cna-explains-5522091 |access-date=16 May 2026 |website=Channel NewsAsia}}</ref> Shuttle trains ran on a single platform at 10-minute intervals connecting the Mountbatten, Dakota and Paya Lebar stations, while peak-hour frequencies between HarbourFront and Paya Lebar were raised from two to three minutes.<ref name="ST m700">{{cite web |last=Chelvan |first=Vanessa Paige |date=1 December 2025 |title=What you need to know when taking the Circle Line from January to April |url=https://www.straitstimes.com/singapore/transport/askst-what-you-need-to-know-about-circle-line-service-adjustments-from-jan-17-to-april-19-2026 |access-date=16 May 2026 |website=The Straits Times}}</ref><ref name="ST f326">{{cite web |last=Chelvan |first=Vanessa Paige |date=1 December 2025 |title=Longer waits for CCL trains from Jan 17 to April 19 due to tunnel works between three stations |url=https://www.straitstimes.com/singapore/transport/longer-waits-between-ccl-trains-from-jan-17-to-april-19-due-to-tunnel-works-between-three-stations |access-date=16 May 2026 |website=The Straits Times}}</ref><ref name="CNA k990">{{cite web |last=Ong |first=Justin (Guang-Xi) |date=19 January 2026 |title=Planned Circle Line disruption: Station staff, shuttle buses keep peak-hour crowds under control |url=https://www.channelnewsasia.com/singapore/circle-line-planned-service-disruption-mrt-stations-crowd-control-5867596 |access-date=16 May 2026 |website=Channel NewsAsia}}</ref> Shuttle buses were also deployed to supplement the disrupted services.<ref name="ST f326" /><ref>{{cite web |last=Ong |first=Justin (Guang-Xi) |title=Commuters urged to plan alternative routes ahead of scheduled 3-month Circle Line disruption |url=https://www.channelnewsasia.com/singapore/circle-line-scheduled-closure-jeffrey-siow-shuttle-bus-5854666 |publisher= |access-date=17 January 2026 |date=13 January 2026|website=Channel NewsAsia}}</ref>
The strengthening works involved installing an estimated 300 steel rings made from plates fabricated in China. Each plate, weighing about {{Convert|800|kg}}, was positioned using a robotic arm and temporarily secured with mechanical bolts before being permanently fixed with epoxy-based chemical bolts, welding, and grouting. Installation of the steel rings in the HarbourFront-bound tunnel was completed in February 2026.<ref name="ST Feb 2026 v063">{{cite web |last=Chelvan |first=Vanessa Paige |date=10 February 2026 |title=Circle Line tunnel-strengthening works on track to finish by April 19 |url=https://www.straitstimes.com/singapore/transport/ccl-tunnel-strengthening-works-nearly-50-complete-on-track-to-finish-by-april-19 |access-date=16 May 2026 |website=The Straits Times}}</ref> The strengthening works were completed ahead of schedule, and regular CCL services resumed on 11 April.<ref>{{cite web |last=Loi |first=Esther |title=CCL tunnel work to finish early; shorter weekend rail service from April 11 to May 17 for Stage 6 tests |url=https://www.straitstimes.com/singapore/transport/ccl-tunnel-work-to-finish-early-shorter-weekend-rail-service-from-april-11-may-17-for-stage-6-tests |publisher= |access-date=27 March 2026 |date=26 March 2026|website=The Straits Times}}</ref><ref name="MOT n216">{{cite web |date=26 March 2026 |title=Transcript of Acting Minister for Transport Jeffrey Siow's Remarks at Dakota MRT Station Visit on Circle Line Tunnel Strengthening Works and Service Adjustments |url=https://www.mot.gov.sg/news-resources/newsroom/transcript-of-acting-minister-for-transport-jeffrey-siow-s-remarks-at-dakota-mrt-station-visit-on-circle-line-tunnel-strengthening-works-and-service-adjustments/ |access-date=16 May 2026 |website=Ministry of Transport}}</ref><ref name="CNA k150">{{cite web |last=Jacob |first=Charmaine |date=26 March 2026 |title=Shorter Circle Line weekend services from Apr 11 ahead of final three station openings |url=https://www.channelnewsasia.com/singapore/circle-line-mrt-shorter-hours-weekends-6017886 |access-date=16 May 2026 |website=Channel NewsAsia}}</ref>
===Circle Line Stage 6=== thumb|Construction site of Cantonment in 2020 Stage 6 of the CCL (CCL6), which LTA said would "close the circle" by linking HarbourFront to Marina Bay,<ref name="LTA LTMP 2013"/> was first announced by transport minister Lui in January 2013 as part of the 2013 Land Transport Master Plan.<ref name="LTA LTMP 2013">{{cite web |title=Two New Rail Lines and Three New Extensions to Expand Rail Network by 2030 |url=https://www.lta.gov.sg/content/ltagov/en/newsroom/2013/1/2/two-new-rail-lines-and-three-new-extensions-to-expand-rail-network-by-2030.html |publisher=Land Transport Authority |access-date=28 February 2026 |archive-url=https://web.archive.org/web/20200515135133/https://www.lta.gov.sg/content/ltagov/en/newsroom/2013/1/2/two-new-rail-lines-and-three-new-extensions-to-expand-rail-network-by-2030.html |archive-date=15 May 2020 |date=17 January 2013 |url-status=dead}}</ref><ref name="Ministry of Transport (MOT) 2013">{{Cite web |date=17 January 2013 |title=Speech by Mr Lui Tuck Yew at Visit to DTL1 Chinatown Station on 17 January 2013 |url=https://www.mot.gov.sg/news-centre/news/Detail/Speech%20by%20Mr%20Lui%20Tuck%20Yew%20at%20visit%20to%20DTL1%20Chinatown%20Station%20on%2017%20January%202013/ |url-status=live |archive-url=https://web.archive.org/web/20200226205104/https://www.mot.gov.sg/news-centre/news/Detail/Speech%20by%20Mr%20Lui%20Tuck%20Yew%20at%20visit%20to%20DTL1%20Chinatown%20Station%20on%2017%20January%202013/ |archive-date=26 February 2020 |access-date=7 February 2021 |publisher=Ministry of Transport}}</ref> Details of the CCL6 were finalised in October 2015.<ref>{{Cite web |last=Lim |first=Adrian |date=25 May 2016 |title=Three new stations to close loop for Circle Line |url=http://www.straitstimes.com/singapore/transport/three-new-stations-to-close-loop-for-circle-line |url-status=dead |archive-url=https://web.archive.org/web/20160525230418/http://www.straitstimes.com/singapore/transport/three-new-stations-to-close-loop-for-circle-line |archive-date=25 May 2016 |access-date=25 May 2016 |website=The Straits Times}}</ref> The {{cvt|4|km}} segment would include three stations – {{MRT station|Keppel}}, {{MRT station|Cantonment}} and {{MRT station|Prince Edward}}, and was expected to be completed by 2025. The project also includes the expansion of Kim Chuan Depot.<ref name="LTA 2015 CCL full circle">{{cite web | title=News Room – News Releases – Joint Release by the Land Transport Authority (LTA) & SLA – Circle Line 6 – Becoming A Full Circle | publisher=Land Transport Authority | date=29 October 2015 | url=https://www.lta.gov.sg/content/ltagov/en/newsroom/2015/10/2/joint-release-by-the-land-transport-authority-lta-sla---circle-line-6--becoming-a-full-circle.html | access-date=30 October 2020 | archive-date=15 May 2020 | archive-url=https://web.archive.org/web/20200515132905/https://www.lta.gov.sg/content/ltagov/en/newsroom/2015/10/2/joint-release-by-the-land-transport-authority-lta-sla---circle-line-6--becoming-a-full-circle.html | url-status=dead }}</ref><ref name="CNA CCL6">{{cite web |last1=Khamid |first1=Hetty Musfirah Abdul |title=With final 3 stations, Circle Line will come 'full circle' by 2025 |url=http://www.channelnewsasia.com/news/singapore/with-final-3-stations/2225168.html |website=Channel NewsAsia |access-date=19 May 2026 |date=29 October 2015 |url-status=dead|archive-url=https://web.archive.org/web/20151029204238/http://www.channelnewsasia.com/news/singapore/with-final-3-stations/2225168.html|archive-date=29 October 2015}}</ref> Prince Edward station was renamed to Prince Edward Road following a naming poll held in 2017.<ref>{{Cite web|url=https://www.lta.gov.sg/apps/news/page.aspx?c=2&id=5cf30fa9-12bd-463d-a481-120c410dcb99|title=LTA Invites Public to Suggest MRT station Names for Circle Line 6 stations | publisher=Land Transport Authority|language=en|access-date=18 September 2017|archive-url=https://web.archive.org/web/20170918201927/https://www.lta.gov.sg/apps/news/page.aspx?c=2&id=5cf30fa9-12bd-463d-a481-120c410dcb99|archive-date=18 September 2017|url-status=dead|date=15 May 2017}}</ref><ref>{{cite web| url=http://www.channelnewsasia.com/news/singapore/wanted-names-for-3-new-circle-line-stations-8847558| website=Channel NewsAsia| access-date=15 May 2017| title=Wanted: Names for 3 new Circle Line stations| date=15 May 2017| archive-url=https://web.archive.org/web/20170516182519/http://www.channelnewsasia.com/news/singapore/wanted-names-for-3-new-circle-line-stations-8847558| archive-date=16 May 2017| url-status=dead}}</ref><ref name="ST excavation">{{Cite news|url=https://www.straitstimes.com/singapore/transport/excavation-for-circle-line-6-to-start-in-middle-of-next-year|title=Excavation for Circle Line 6 to start in middle of next year|date=28 September 2018|work=The Straits Times|access-date=13 October 2018|language=en|archive-url=https://web.archive.org/web/20181013211735/https://www.straitstimes.com/singapore/transport/excavation-for-circle-line-6-to-start-in-middle-of-next-year|archive-date=13 October 2018|url-status=live}}</ref>
To facilitate construction works of Cantonment station, the old train platform canopy structures were relocated to a restoration yard nearby in November 2017.<ref name="LTA 2018 CCL6 factsheet">{{cite web |title=Factsheet: Circle Line 6 Construction to go into Full Swing| publisher=Land Transport Authority|date=29 March 2018|url=https://www.lta.gov.sg/content/ltagov/en/newsroom/2018/3/2/factsheet-circle-line-6-construction-to-go-into-full-swing.html|access-date=30 October 2020|archive-date=30 October 2020|archive-url=https://web.archive.org/web/20201030034445/https://www.lta.gov.sg/content/ltagov/en/newsroom/2018/3/2/factsheet-circle-line-6-construction-to-go-into-full-swing.html|url-status=dead}}</ref> Tunnelling works for the CCL6 began on 25 July 2019 with the launch of the Tunnel Boring Machine (TBM) at Keppel station. The TBM would tunnel from Keppel to HarbourFront station.<ref name="LTA 2019">{{cite web |title=Joint News Release by the Land Transport Authority (LTA) & SMRT – Upgrading the Circle Line in Preparation for Circle Line 6 |publisher=Land Transport Authority |date=25 July 2019|url=https://www.lta.gov.sg/content/ltagov/en/newsroom/2019/7/2/joint-news-release-by-the-land-transport-authority-lta-smrt---upgrading-the-circle-line-in-preparation-for-circle-line-.html|access-date=31 October 2020|archive-date=31 October 2020|archive-url=https://web.archive.org/web/20201031035510/https://www.lta.gov.sg/content/ltagov/en/newsroom/2019/7/2/joint-news-release-by-the-land-transport-authority-lta-smrt---upgrading-the-circle-line-in-preparation-for-circle-line-.html|url-status=dead}}</ref> To construct the tunnels between Keppel and Cantonment, the Keppel viaduct was underpinned with new micro piles. Three bored piles were removed for the tunnelling works.<ref name="LTA 2022">{{cite web |title=Factsheet: Completion of Circle Line 6 Tunnelling Works |publisher=Land Transport Authority |date=12 January 2022|url=https://www.lta.gov.sg/content/ltagov/en/newsroom/2022/1/news-releases/Completion_CCL6_tunnelling_works.html|access-date=12 January 2022|archive-date=12 January 2022|archive-url=https://web.archive.org/web/20220112050732/https://www.lta.gov.sg/content/ltagov/en/newsroom/2022/1/news-releases/Completion_CCL6_tunnelling_works.html|url-status=live}}</ref> During tunnelling between the Cantonment and Prince Edward Road stations, structures were erected to protect the Tanjong Pagar railway station's facade and interior, and monitoring instruments were installed to watch out for any building settlement.<ref name="CNA 2022">{{cite web |title=Circle Line 6 tunnelling works complete, 3 new stations set to open in 2026|website=Channel NewsAsia|date=12 January 2022|url=https://www.channelnewsasia.com/singapore/circle-line-6-extension-tunnelling-complete-keppel-cantonment-prince-edward-road-2429691|access-date=12 January 2022|archive-date=12 January 2022|archive-url=https://web.archive.org/web/20220112053403/https://www.channelnewsasia.com/singapore/circle-line-6-extension-tunnelling-complete-keppel-cantonment-prince-edward-road-2429691|url-status=live}}</ref> CCL6 tunnelling works were completed on 12 January 2022, with a final tunnel breakthrough from Prince Edward Road into Cantonment.<ref name="Auto 2022">{{cite web |last=Tan|first=Christopher|title=Tunnelling works for Circle Line MRT extension completed|website=The Straits Times|date=12 January 2022|url=https://www.straitstimes.com/singapore/transport/tunnelling-works-for-circle-line-mrt-extension-completed|access-date=12 January 2022|archive-date=12 January 2022|archive-url=https://web.archive.org/web/20220112025858/https://www.straitstimes.com/singapore/transport/tunnelling-works-for-circle-line-mrt-extension-completed|url-status=live}}</ref><ref name="CNA h279">{{cite web | last=Yeoh | first=Grace | title=Circle Line 6 tunnelling works complete, 3 new stations set to open in 2026 | website=Channel NewsAsia | date=12 January 2022 | url=https://www.channelnewsasia.com/singapore/circle-line-6-extension-tunnelling-complete-keppel-cantonment-prince-edward-road-2429691 | access-date=1 May 2026}}</ref><ref name="Tunnels and Tunelling m912">{{cite web | title=Breakthrough marks completion of Singapore Circle Line 6 tunnelling | website=Tunnels and Tunnelling | date=12 January 2022 | url=https://www.tunnelsandtunnelling.com/news/breakthrough-marks-completion-of-singapore-circle-line-6-tunnelling-9397995/ | access-date=15 May 2026}}</ref>
From January to April 2024, one platform at the Telok Blangah and HarbourFront stations were closed to facilitate track integration works with the CCL6 stations.<ref name="ST a658">{{cite web |last=Lee |first=Nian Tjoe |date=3 April 2024 |title=Regular service at some Circle Line stations to resume from April 6 with early completion of works |url=https://www.straitstimes.com/singapore/transport/regular-service-at-3-circle-line-stations-to-resume-from-april-6-with-early-completion-of-works |access-date=30 April 2026 |website=The Straits Times}}</ref> A new Integrated Supervisory Control System (ISCS) – which monitors and manages power supply, communications and station facilities on the CCL – has also been installed in 2025.<ref name="LTA w874">{{cite web | title=Circle Line Stage 6 Moves to Next Phase of Works Ahead of Opening in 1H2026 | publisher=Land Transport Authority | date=12 August 2025 | url=https://www.lta.gov.sg/content/ltagov/en/newsroom/2025/8/news-releases/ccl6_next_phase_works_ahead_1h2026_opening.html | access-date=1 May 2026}}</ref><ref name="CNA o730">{{cite web | title=Circle Line train services to end early and start later on selected days from Sep 5 to Dec 28 | website=CNA | date=12 August 2025 | url=https://www.channelnewsasia.com/singapore/circle-line-ccl-timings-start-late-end-early-weekends-5289691 | access-date=14 May 2026}}</ref> Final system integration testing works occurred in April and May 2026.<ref name="ST d392">{{cite web | last=Loi | first=Esther | title=Circle Line MRT service to finish early | website=The Straits Times | date=26 March 2026 | url=https://www.straitstimes.com/singapore/transport/ccl-tunnel-work-to-finish-early-shorter-weekend-rail-service-from-april-11-may-17-for-stage-6-tests?ref=inline-article | access-date=1 May 2026}}</ref><ref name="ST w526">{{cite web | last=Diviyadhaarshini | first=BNB | title=Shuttle buses for Circle Line late opening | website=The Straits Times | date=7 April 2026 | url=https://www.straitstimes.com/singapore/two-shuttle-bus-services-to-be-rolled-out-to-accommodate-late-opening-of-circle-line | access-date=1 May 2026}}</ref>
Due to delays caused by the COVID-19 pandemic, the completion date of CCL6 was shifted to 2025,<ref>{{Cite web |title=Speech by Minister For Transport Mr Ong Ye Kung at MOT Committee of Supply Debate 2021 on A Tale of Three Connections |url=http://www.mot.gov.sg/news-centre/news/Detail/speech-by-minister-for-transport-mr-ong-ye-kung-at-mot-committee-of-supply-debate-2021-on-a-tale-of-three-connections/ |url-status=live |archive-url=https://web.archive.org/web/20210414222045/https://www.mot.gov.sg/news-centre/news/Detail/speech-by-minister-for-transport-mr-ong-ye-kung-at-mot-committee-of-supply-debate-2021-on-a-tale-of-three-connections/ |archive-date=14 April 2021 |access-date=2021-03-08 | publisher=Ministry of Transport}}</ref> then to the first half of 2026.<ref>{{Cite news |last=Kok|first=Yufeng|date=6 December 2024|title=Hume MRT Station to Open in Q2 2025; Circle Line Stage 6 to Be Ready in First Half of 2026|url=https://www.straitstimes.com/singapore/transport/hume-mrt-station-to-open-in-q2-2025-circle-line-stage-6-to-be-completed-in-first-half-of-2026-chee|access-date=6 December 2024|work=The Straits Times|archive-date=6 December 2024|archive-url=https://web.archive.org/web/20241206111213/https://www.straitstimes.com/singapore/transport/hume-mrt-station-to-open-in-q2-2025-circle-line-stage-6-to-be-completed-in-first-half-of-2026-chee|url-status=live}}</ref><ref name="MOT t025">{{cite web |date=12 February 2026 |title=Update on Progress of Train Lines Under Extension and Construction |url=https://www.mot.gov.sg/news-resources/newsroom/update-on-progress-of-train-lines-under-extension-and-construction/ |access-date=16 May 2026 |publisher=Ministry of Transport}}</ref> In April 2026, the opening was delayed a final time to the middle of the year.<ref>{{cite news |last1=Chevlan |first1=Venessa Paige |title=Normal MRT service on CCL to resume on April 10; shorter rail service on weekends till May 17 |url=https://www.straitstimes.com/singapore/transport/normal-mrt-service-on-ccl-to-resume-on-april-10-shorter-rail-service-on-weekends-till-may-17 |access-date=10 May 2026 |work=The Straits Times |date=9 April 2026}}</ref> In May, transport minister Jeffrey Siow announced that the CCL6 stations would open on 12 July 2026. A preview of the stations will be held on 4 July.<ref name="ST y795">{{cite web | last=Hamzah | first=Aqil | title=Keppel, Cantonment, Prince Edward Road MRT stations on Circle Line to open on July 12 | website=The Straits Times | date=14 May 2026 | url=https://www.straitstimes.com/singapore/transport/keppel-cantonment-prince-edward-road-mrt-stations-on-circle-line-to-open-on-july-12 | access-date=14 May 2026}}</ref><ref name="CNA c689">{{cite web | last=Kuek | first=Renee | title=3 new Circle Line MRT stations to open on Jul 12, completing its loop | website=CNA | date=14 May 2026 | url=https://www.channelnewsasia.com/singapore/3-new-circle-line-mrt-stations-open-jul-12-6121571 | access-date=15 May 2026}}</ref>
==Network and operations== ===Services=== The CCL is a medium-capacity line operated by SMRT Trains.{{sfn|Kumarasamy|2017|p=24}}<ref name="Rail network">{{Cite web |title=Getting Around{{snd}}Public Transport{{snd}}Rail Network |url=https://www.lta.gov.sg/content/ltagov/en/getting_around/public_transport/rail_network.html |url-status=live |archive-url=https://web.archive.org/web/20191101093543/https://www.lta.gov.sg/content/ltagov/en/getting_around/public_transport/rail_network.html |archive-date=1 November 2019 |access-date=27 April 2021 |publisher=Land Transport Authority}}</ref><ref name=":2">{{Cite web |date=15 July 2016 |title=SMRT Trains and SMRT Light Rail to Transit to New Rail Financing Framework |url=https://www.lta.gov.sg/content/ltagov/en/newsroom/2016/7/2/smrt-trains-and-smrt-light-rail-to-transit-to-new-rail-financing-framework.html |url-status=dead |archive-url=https://web.archive.org/web/20210424032354/https://www.lta.gov.sg/content/ltagov/en/newsroom/2016/7/2/smrt-trains-and-smrt-light-rail-to-transit-to-new-rail-financing-framework.html |archive-date=24 April 2021 |access-date=14 April 2026 |publisher=Land Transport Authority}}</ref> Since October 2016, the CCL has been part of the New Rail Financing Framework (NRFF).<ref>{{Cite web |last=Tan |first=Christopher |date=15 July 2016 |title=LTA to buy $1b of SMRT assets under new rail financing framework |url=http://www.straitstimes.com/singapore/transport/government-and-smrt-reach-agreement-on-new-rail-financing-framework |url-status=dead |archive-url=https://web.archive.org/web/20160717203403/http://www.straitstimes.com/singapore/transport/government-and-smrt-reach-agreement-on-new-rail-financing-framework |archive-date=17 July 2016 |access-date=14 May 2026 |website=The Straits Times}}</ref> Previously, the operator (the owner of the rail assets) had to bear the cost of maintaining and upgrading trains and signalling. Under the NRFF, the LTA will take control of its operating assets and SMRT will operate the line under a 15-year licence which will expire on 30 September 2031. The LTA and SMRT will share the profits and financial risks in operating the line.<ref name=":2" /><ref>{{Cite web |last=Chew |first=Hui Min |date=15 July 2016 |title=New rail financing framework: 9 things to know about agreement between SMRT and Govt |url=http://www.straitstimes.com/singapore/transport/new-rail-financing-framework-9-things-to-know-about-agreement-between-smrt-and |url-status=dead |archive-url=https://web.archive.org/web/20160717205722/http://www.straitstimes.com/singapore/transport/new-rail-financing-framework-9-things-to-know-about-agreement-between-smrt-and |archive-date=17 July 2016 |access-date=17 July 2016 |website=The Straits Times}}</ref>
On weekdays and Saturdays, the first CCL train leaves HarbourFront at 5:30{{nbsp}}am;<ref name="SMRT Journeys2">{{cite web |title=HarbourFront – First & Last Train|website=SMRT Journeys|url=http://journey.smrt.com.sg/journey/station_info/harbourfront/exits/|access-date=31 December 2021|archive-url=https://ghostarchive.org/archive/p2vAV|archive-date=14 May 2026|url-status=live}}</ref> the last train leaves Dhoby Ghaut at 12:10{{nbsp}}am.<ref name="SMRT First and Last">{{Cite web |title=Dhoby Ghaut – First & Last Train|url=http://journey.smrt.com.sg/journey/station_info/dhoby-ghaut/first-and-last-train/|access-date=23 September 2021|website=SMRT Journeys|archive-date=22 February 2026|archive-url=https://ghostarchive.org/archive/Y0I7i|url-status=live}}{{cbignore}}</ref> Trains on the line run every 2.5 to 5 minutes.<ref name="LTA frequencies">{{Cite web |date=6 May 2020 |title=Transport Tools – MRT/LRT |url=https://www.lta.gov.sg/content/ltagov/en/map/train.html |url-status=live |archive-url=https://web.archive.org/web/20191101093932/https://www.lta.gov.sg/content/ltagov/en/map/train.html |archive-date=1 November 2019 |access-date=19 June 2020 |publisher=Land Transport Authority}}</ref> Similar to the NEL, the CCL initially had a higher fare than the North–South and East–West lines due to greater operating costs.<ref>{{Cite news |last=Yeo |first=Ghim Lay |date=17 April 2009 |title=Circle Line fares to match those of NEL |work=The Straits Times |page=4 |quote=CIRCLE Line trains will start rolling on May 28 - two days early - and fares will be identical to those on the North-East Line (NEL), the Public Transport Council (PTC) said yesterday. The Circle Line's fare structure, while widely anticipated by those who stand to save on travel time by taking its trains, was not surprising. Both the NEL and Circle Line are fully underground and automated, which makes them 2.5 times more costly to run and maintain than the older rail lines, explained the PTC.}}</ref> On 30 December 2016, fares on the CCL were lowered to match the other lines with a "purely distance-based approach". This revision, made after a fare review by the Public Transport Council, was intended to minimise commuter confusion.<ref>{{Cite web |last=Abdullah |first=Zhaki |date=10 October 2016 |title=Public Transport Fares May Be Standardised |url=https://www.straitstimes.com/singapore/public-transport-fares-may-be-standardised |url-status=dead |archive-url=https://web.archive.org/web/20190406131955/https://www.straitstimes.com/singapore/public-transport-fares-may-be-standardised |archive-date=6 April 2019 |access-date=6 April 2019 |website=The Straits Times |language=en}}</ref><ref name="PTC 2016">{{Cite web |date=26 October 2016 |title=PTC Reduces Bus and Rail Fares |url=http://www.ptc.gov.sg/newsroom/news-releases/newsroom-view/ptc-reduces-bus-and-rail-fares |url-status=dead |archive-url=https://web.archive.org/web/20210827063736/https://www.ptc.gov.sg/newsroom/news-releases/newsroom-view/ptc-reduces-bus-and-rail-fares |archive-date=27 August 2021 |access-date=27 August 2021 |publisher=Public Transport Council}}</ref>
The CCL will have four main services once CCL6 opens: the Anticlockwise Loop and Clockwise Loop for continuous travel,<ref name="a172">{{cite web |title=CCL Wayfinding: The Anticlockwise Loop |url=https://www.lta.gov.sg/cclwayfinding/education/loop |access-date=29 May 2026 |publisher=Land Transport Authority}}</ref> and Anticlockwise and Clockwise services that would serve the spur on the Dhoby Ghaut branch and terminate at Prince Edward Road station.<ref name="LTA e895">{{cite web |title=CCL Wayfinding: Serving the spur — Anticlockwise |url=https://www.lta.gov.sg/cclwayfinding/education/spur |access-date=29 May 2026 |publisher=Land Transport Authority}}</ref> As the idea of a train line running in a continuous loop is new in Singapore, the LTA launched a survey in March 2025 survey to improve wayfinding on the CCL,<ref>{{Cite news |date=2025-03-14 |title=Public feedback invited on new way-finding signs in Circle Line stations |url=https://www.straitstimes.com/singapore/transport/public-feedback-invited-on-new-wayfinding-signs-in-circle-line-stations |access-date=2026-05-30 |work=The Straits Times |language=en |issn=0585-3923}}</ref> which found that respondents preferred the terms "clockwise" and "anticlockwise" over alternatives such as "inner loop" and "outer loop".<ref name="CNA o190">{{cite web |last=Ong |first=Justin (Guang-Xi) |date=29 May 2026 |title=Circle Line to show clockwise, anticlockwise directions when full loop completed in July |url=https://www.channelnewsasia.com/singapore/circle-line-ccl-signs-clockwise-anti-6148741 |access-date=29 May 2026 |website=Channel NewsAsia}}</ref><ref>{{Cite news |date=2026-05-29 |title=Circle Line signs to show clockwise and anticlockwise directions |url=https://www.straitstimes.com/singapore/transport/new-circle-line-signs-installed-to-show-clockwise-and-anticlockwise-train-directions |access-date=2026-05-30 |work=The Straits Times |language=en |issn=0585-3923}}</ref> The LTA has also launched a web app to explain these service changes, which are “difficult to convey through posters alone” in May 2026.<ref>{{Cite web |title=CCL Wayfinding |url=https://www.lta.gov.sg/cclwayfinding/ |access-date=2026-05-30 |website=www.lta.gov.sg}}</ref>
Transport minister Lui Tuck Yew projected that the CCL would serve 400,000 passengers daily upon the completion of CCL Stages 4 and 5 in 2011.<ref>{{Cite news |last=Musifrah |first=Hetty |date=2 August 2011 |title=Train crowding expected to ease with full opening of Circle Line: Lui |url=https://eresources.nlb.gov.sg/newspapers/digitised/page/today20110802-1.1.1 |access-date=21 May 2016 |work=Today |pages=1, [https://eresources.nlb.gov.sg/newspapers/digitised/page/today20110802-1.1.2 2]}}</ref> Prior to their opening, the CCL recorded average daily ridership of 230,000 on weekdays and 150,000 on weekends. Following the opening of the 12 new stations, commuters interviewed by ''The Straits Times'' reported that the line had already become more crowded,<ref>{{Cite web |date=12 October 2011 |title=SMRT tweaks waiting times on Circle Line |url=http://www.straitstimes.com/BreakingNews/Singapore/Story/STIStory_722446.html |url-status=dead |archive-url=https://web.archive.org/web/20111012055652/http://www.straitstimes.com/BreakingNews/Singapore/Story/STIStory_722446.html |archive-date=12 October 2011 |access-date=21 May 2026 |website=The Straits Times}}</ref> with Bishan station also experiencing heavy congestion.<ref>{{Cite web |date=19 October 2011 |title=Pictures: Transport Minister Lui Tuck Yew seen at Circle Line station |url=http://www.straitstimes.com/BreakingNews/Singapore/Story/STIStory_724977.html |url-status=dead |archive-url=https://web.archive.org/web/20111019201200/http://www.straitstimes.com/BreakingNews/Singapore/Story/STIStory_724977.html |archive-date=19 October 2011 |access-date=21 May 2026 |website=The Straits Times}}</ref> Daily ridership on the CCL reached 300,000 in November 2011, more than double of SMRT's projections,<ref>{{Cite news |last=Tan |first=Christopher |date=5 November 2011 |title=Circle Line trips up 60% a month after full opening |url=http://www.straitstimes.com/BreakingNews/Singapore/Story/STIStory_730798.html |url-status=dead |archive-url=https://web.archive.org/web/20111105191008/http://www.straitstimes.com/BreakingNews/Singapore/Story/STIStory_730798.html |archive-date=5 November 2011 |access-date=21 May 2026 |work=The Straits Times}}</ref> and rose to 398,000 in May 2015.<ref>{{Cite web |title=Four more trains for Circle Line as ridership rises (27 June 2015)|url=https://www.mot.gov.sg/docs/default-source/news-centre/transport-news/st-four_more_trains_for_circle_line_as_ridership_rises.pdf |url-status=dead|access-date=28 December 2020 |website=The Straits Times |language=|archive-url=https://web.archive.org/web/20191014155540/https://www.mot.gov.sg/docs/default-source/news-centre/transport-news/st-four_more_trains_for_circle_line_as_ridership_rises.pdf|via=Ministry of Transport|last=Lim|first=Adrian|archive-date=14 October 2019}}</ref> As of 2025, the CCL records an average daily ridership of 463,000.<ref name="reliability" />
The CCL is the least reliable line on the network in terms of mean kilometres between failures (MKBF) from 2023 to 2025, only achieving 1.069 million train-km in 2025.<ref name="ST reliability 2025 t302">{{cite web |last=Lee |first=Nian Tjoe |date=5 September 2025 |title=MRT reliability falls to lowest level since 2020; LRT network improves |url=https://www.straitstimes.com/singapore/transport/mrt-reliability-falls-to-lowest-level-since-2020-lrt-network-improves |access-date=16 May 2026 |website=The Straits Times}}</ref> Reliability of the CCL improved in July 2025, and has reached 2.36 million train-km in April 2026.<ref name="ST May 2026 v610">{{cite web |last=Chelvan |first=Vanessa Paige |date=15 May 2026 |title=MRT reliability hits highest since November 2024 |url=https://www.straitstimes.com/singapore/transport/mrt-reliability-in-april-at-highest-level-since-november-2024-all-lines-improved-except-ccl |access-date=16 May 2026 |website=The Straits Times}}</ref> In July 2024, SMRT chief executive Ngien Hoon Ping attributed the CCL breakdowns to upgrading works integrating the line's existing systems with CCL6, and pledged that the line's reliability "will go straight up" upon the completion of CCL6.<ref name="SMRT CEO d029">{{cite web |last=Lee |first=Nian Tjoe |date=31 July 2024 |title=Reliability of Circle Line will 'go straight up' after full line is complete: SMRT CEO |url=https://www.straitstimes.com/singapore/transport/reliability-of-circle-line-will-go-straight-up-after-full-line-is-complete-smrt-ceo |access-date=16 May 2026 |website=The Straits Times}}</ref>
===Route=== 500px|thumb|Geographically accurate map of the Circle Line|alt=Refer to caption.
The {{convert|35.7|km|miles|adj=on}}{{Efn|The original CCL was {{cvt|33.3|km}}.{{sfn|Cheong|2012|p=35}} The CCL extension from Promenade to Marina Bay is {{cvt|2.4|km}}.<ref name="factsheet ccl">{{cite web |title=Factsheet on Circle Line Extension |publisher=Land Transport Authority |url=http://app.lta.gov.sg/apps/news/page.aspx?c=2&id=289gjpnks1d1xue5op98xv06ulyy4b1cnrc6eyyj89e413p2r7 |url-status=dead |archive-url=https://eresources.nlb.gov.sg/webarchives/2012-12-02%2017:36:38.000/wp/details/http%3A%2F%2Fapp.lta.gov.sg%2Fapps%2Fnews%2Fpage.aspx%3Fc%3D2%26id%3D289gjpnks1d1xue5op98xv06ulyy4b1cnrc6eyyj89e413p2r7 |archive-date=2 December 2012 |date=28 November 2011 |via=Web Archive Singapore }}</ref>}} CCL forms an incomplete loop that begins in Dhoby Ghaut in the Central Region of Singapore and passes through the eastern, northern and western areas of Singapore before terminating south at HarbourFront.<ref name="CCLLTA">{{Cite web|url=https://www.lta.gov.sg/content/ltagov/en/getting_around/public_transport/rail_network/circle_line.html|title=Circle Line|access-date=29 April 2020|archive-date=1 November 2019|archive-url=https://web.archive.org/web/20191101093906/https://www.lta.gov.sg/content/ltagov/en/getting_around/public_transport/rail_network/circle_line.html|url-status=live|publisher=Land Transport Authority}}</ref> A branch, known as the Circle Line extension (CCLe), extends south from Promenade to Marina Bay station.<ref name="factsheet ccl"/><ref name="CCLLTA" /><ref name="CCL Plan">{{Cite web |title=CCL Plan |url=http://www.lta.gov.sg/projects/images/CCL%20plan.pdf |url-status=dead |archive-url=https://web.archive.org/web/20111027170124/http://www.lta.gov.sg/projects/images/CCL%20plan.pdf |archive-date=27 October 2011 |access-date=8 May 2026 |publisher=Land Transport Authority}}</ref> The line is coloured orange on official maps.<ref name="LTA system map">{{Cite web |last= |first= |date= |title=MRT System Map |url=https://www.lta.gov.sg/content/dam/ltagov/getting_around/public_transport/rail_network/pdf/sm-20-03-en-exp.pdf |url-status=live |archive-url=https://web.archive.org/web/20200821064838/https://www.lta.gov.sg/content/dam/ltagov/getting_around/public_transport/rail_network/pdf/sm-20-03-en-exp.pdf |archive-date=21 August 2020 |access-date=21 August 2020 |publisher=Land Transport Authority}}</ref><ref name="ST j190">{{cite web | last=Chia | first=Laura | title='For the record, it's orange, not yellow': LTA unveils new Circle Line trains in signature colour | website=The Straits Times | date=11 April 2026 | url=https://www.straitstimes.com/singapore/commuters-can-look-forward-to-new-circle-line-trains-from-april-13 | access-date=14 May 2026}}</ref>
The CCL begins at Dhoby Ghaut station, where it interchanges with the NSL and NEL.<ref name=":1" /> From there, the line runs eastwards, paralleling Bras Basah Road.<ref>{{Cite web |title=Circle Line 1 |url=http://www.lta.gov.sg/projects/images/ccl1-loc.pdf |url-status=dead |archive-url=https://web.archive.org/web/20070717182429/http://www.lta.gov.sg/projects/images/ccl1-loc.pdf |archive-date=17 July 2007 |access-date=8 May 2026 |publisher=Land Transport Authority}}</ref> The line turns north at Promenade station, where it joins with the CCLe and interchanges with the DTL.<ref name="CCL Plan" /><ref name="SMRT Promenade u703">{{cite web |title=Promenade{{snd}}Map |url=https://journey.smrt.com.sg/journey/station_info/promenade/map/ |url-status=live |archive-url=https://ghostarchive.org/archive/mfOQ0 |archive-date=22 February 2026 |access-date=26 February 2026 |website=SMRT Journeys}}</ref> After turning east toward Nicoll Highway, the CCL passes underneath the Kallang Basin. Between the Stadium and Dakota stations, the line parallels Stadium Boulevard and Old Airport Road.<ref name="CCL Plan" />
The line continues northwards and parallels Paya Lebar Road and Upper Paya Lebar Road between the Paya Lebar and Tai Seng stations.<ref name="CCL Plan" /><ref>{{Cite web |title=Circle Line 2 |url=http://www.lta.gov.sg/projects/images/ccl2-loc.pdf |url-status=dead |archive-url=https://web.archive.org/web/20111111233215/http://www.lta.gov.sg/projects/images/ccl2-loc.pdf |archive-date=11 November 2011 |access-date=8 May 2026 |publisher=Land Transport Authority}}</ref> Reception tracks between Tai Seng and Bartley connect the CCL to Kim Chuan Depot.<ref name="CCL Plan" /> Briefly paralleling Bartley Road at Bartley, the line runs in a general westward direction, interchanging with the NEL at Serangoon and the NSL at Bishan.<ref name=":1" /><ref name="CCL Plan" />
Turning south to Marymount, the CCL interchanges with the Thomson–East Coast Line (TEL) at Caldecott,<ref name="SMRT Journeys">{{cite web |title=Caldecott - Map|website=SMRT Journeys|url=https://journey.smrt.com.sg/journey/station_info/caldecott/map/|access-date=29 November 2020|archive-date=8 May 2026|archive-url=https://ghostarchive.org/archive/uAnzQ|url-status=live}}</ref> before continuing in a general southwest direction between Caldecott and Kent Ridge.<ref name="CCL Plan" /> The line also interchanges with the DTL at Botanic Gardens and the EWL at Buona Vista. After Kent Ridge station, the line curves eastwards, paralleling West Coast Highway, Pasir Panjang Road and Telok Blangah Road, before terminating at HarbourFront station, where it interchanges with the NEL.<ref>{{Cite web |title=Circle Line 5 |url=http://www.lta.gov.sg/projects/images/ccl5-loc.pdf |url-status=dead |archive-url=https://web.archive.org/web/20111111174915/http://www.lta.gov.sg/projects/images/ccl5-loc.pdf |archive-date=11 November 2011 |access-date=8 May 2026 |publisher=Land Transport Authority}}</ref>
With the completion of CCL6, the line will continue eastwards from HarbourFront, paralleling Keppel Road and Ayer Rajah Expressway, and joins the CCLe at Marina Bay.<ref>{{Cite web |title=Location Maps and Station Entrances of CCL6 |url=https://www.lta.gov.sg/content/dam/ltaweb/corp/PublicTransport/files/Location%20maps%20and%20station%20entrances%20(CCL6).pdf |url-status=dead |archive-url=https://web.archive.org/web/20160822122101/https://www.lta.gov.sg/content/dam/ltaweb/corp/PublicTransport/files/Location%20maps%20and%20station%20entrances%20(CCL6).pdf |archive-date=22 August 2016 |access-date=8 May 2026 |publisher=Land Transport Authority |page=8}}</ref> The CCLe from Marina Bay to Promenade station generally parallels Bayfront Avenue.<ref name="CCL Plan" /> At Bayfront station, the CCLe passes underneath Marina Bay Sands and has a cross-platform interchange with the DTL.<ref name="LTA DTL 2013">{{Cite web |date=21 December 2013|title=News Room – News Releases – Downtown Line|url=https://www.lta.gov.sg/content/ltagov/en/newsroom/2013/12/2/downtown-line.html|archive-url=https://web.archive.org/web/20210131070042/https://www.lta.gov.sg/content/ltagov/en/newsroom/2013/12/2/downtown-line.html|archive-date=31 January 2021|access-date=8 February 2021|publisher=Land Transport Authority|url-status=dead}}</ref><ref>{{cite web |url=http://journey.smrt.com.sg/journey/station_info/bayfront/map/|title=Bayfront – Map|author=<!--Not stated-->|website=SMRT Journeys|publisher=SMRT Corporation|access-date=3 October 2021|archive-url=https://ghostarchive.org/archive/AwKY8|archive-date=22 February 2026|url-status=live}}</ref>
===Stations=== The line has 30 operational stations. Twelve stations connect to other MRT lines.<ref name="CNA c689"/><ref name="CCLLTA"/><ref name="LTA system map"/> A reserved station, Bukit Brown, would be built in tandem with future developments.<ref name="Stages 4 and 5" />
{| class="wikitable" style="border-collapse: collapse; font-size: 95%" |- ! scope="col" style="color: black; background:#{{rcr|SMRT|Circle}}" | Station code ! scope="col" style="color: black; background:#{{rcr|SMRT|Circle}}" | Station name ! scope="col" style="color: black; background:#{{rcr|SMRT|Circle}}" | Images ! scope="col" style="color: black; background:#{{rcr|SMRT|Circle}}" | Interchange;<br><small>Adjacent transportation</small> ! scope="col" style="color: black; background:#{{rcr|SMRT|Circle}}" | Opening |- |scope="row"|{{SMRT code|CC|1|NS|24|NE|6}}||Dhoby Ghaut||120px||{{rbox|North–South Line|North–South Line (Singapore)|#{{rcr|SMRT|NS}}|White}}<br>{{rbox|North East Line|North East Line|#{{rcr|SMRT|NE}}|White}}||rowspan="11"|{{center|17 April 2010;<br>{{Years or months ago|2010|04}}}} |- |scope="row"|{{SMRT code|CC|2}}||Bras Basah||frameless|120px||rowspan="2" {{sdash}} |- |scope="row"|{{SMRT code|CC|3}}||Esplanade||120px |- |scope="row"|{{SMRT code|CC|4|DT|15}}||Promenade||120x120px||{{rbox|Downtown Line|Downtown Line|#{{rcr|SMRT|DT}}|White}}<br>―<br>15px|link=Marina Centre |- |scope="row"|{{SMRT code|CC|5}}||Nicoll Highway||120x120px||rowspan="4" {{sdash}} |- |scope="row"|{{SMRT code|CC|6}}||Stadium||120px |- |scope="row"|{{SMRT code|CC|7}}||Mountbatten||120px |- |scope="row"|{{SMRT code|CC|8}}||Dakota||120px |- |scope="row"|{{SMRT code|CC|9|EW|8}}||Paya Lebar||120px||{{rbox|East–West Line|East–West Line (Singapore)|#{{rcr|SMRT|EW}}|White}} |- |scope="row"|{{SMRT code|CC|10|DT|26}}||MacPherson||120px||{{rbox|Downtown Line|Downtown Line|#{{rcr|SMRT|DT}}|White}} |- |scope="row"|{{SMRT code|CC|11}}||Tai Seng||120px||rowspan="2" {{sdash}} |- |scope="row"|{{SMRT code|CC|12}}||Bartley||120px||rowspan="5"|{{center|28 May 2009;<br>{{Years or months ago|2009|05}}}} |- |scope="row"|{{SMRT code|CC|13|NE|12}}||Serangoon||120px||{{rbox|North East Line|North East Line|#{{rcr|SMRT|NE}}|White}}<br>―<br>15px|link=Serangoon |- |scope="row"|{{SMRT code|CC|14}}||Lorong Chuan||120px||{{sdash}} |- |scope="row"|{{SMRT code|CC|15|NS|17}}||Bishan||120px||{{rbox|North–South Line|North–South Line (Singapore)|#{{rcr|SMRT|NS}}|White}}<br>―<br>15px|link=Bishan |- |scope="row"|{{SMRT code|CC|16}}||Marymount||120px||{{sdash}} |- |scope="row"|{{SMRT code|CC|17|TE|9}}||Caldecott||frameless|120px||{{rbox|Thomson–East Coast Line|Thomson–East Coast Line|#{{rcr|SMRT|TE}}|White}}||{{center|8 October 2011;<br>{{Years or months ago|2011|10}}}} |- |scope="row"|{{SMRT code|CC|18}}||''Bukit Brown''||frameless|120px||{{sdash}}||{{TBA}} |- |scope="row"|{{SMRT code|CC|19|DT|9}}||Botanic Gardens||120px||{{rbox|Downtown Line|Downtown Line|#{{rcr|SMRT|DT}}|White}}||rowspan="11"|{{center|8 October 2011;<br>{{Years or months ago|2011|10}}}} |- |scope="row"|{{SMRT code|CC|20}}||Farrer Road||120px||rowspan="2" {{sdash}} |- |scope="row"|{{SMRT code|CC|21}}||Holland Village||120px |- |scope="row"|{{SMRT code|CC|22|EW|21}}||Buona Vista||120px||{{rbox|East–West Line|East–West Line (Singapore)|#{{rcr|SMRT|EW}}|White}}<br>―<br>15px|link=Buona Vista<br>15px|link=Ghim Moh |- |scope="row"|{{SMRT code|CC|23}}||one-north||120px||{{sdash}} |- |scope="row"|{{SMRT code|CC|24}}||Kent Ridge||120px||{{rbox|Jurong Region Line (East)|Jurong Region Line|#{{rcr|SMRT|JR}}|White}} (early-2040s) |- |scope="row"|{{SMRT code|CC|25}}||Haw Par Villa||120px||rowspan="4" {{sdash}} |- |scope="row"|{{SMRT code|CC|26}}||Pasir Panjang||120px |- |scope="row"|{{SMRT code|CC|27}}||Labrador Park||120px |- |scope="row"|{{SMRT code|CC|28}}||Telok Blangah||120px |- |scope="row"|{{SMRT code|CC|29|NE|1}}||HarbourFront||120px||{{rbox|North East Line|North East Line|#{{rcr|SMRT|NE}}|White}}<br>―<br>15px|link=HarbourFront |- ! colspan="5" |Stage 6 |- |scope="row"|{{SMRT code|CC|30}}||Keppel||120px||rowspan="2" {{sdash}}||rowspan="3"|{{center|12 July 2026;<br>{{Years or months ago|2026|06}}}} |- |scope="row"|{{SMRT code|CC|31}}||Cantonment||120px |- |scope="row"|{{SMRT code|CC|32}}||Prince Edward Road||120px||15px|link=Shenton Way |- ! colspan="5" |Circle Line Extension |- |scope="row"|{{SMRT code|CC|33|NS|27|TE|20}}||Marina Bay||120px||{{rbox|North–South Line|North–South Line (Singapore)|#{{rcr|SMRT|NS}}|White}}<br>{{rbox|Thomson–East Coast Line|Thomson–East Coast Line|#{{rcr|SMRT|TE}}|White}}||rowspan="2"|{{center|14 January 2012;<br>{{Years or months ago|2012|01}}}} |- |scope="row"|{{SMRT code|CC|34|DT|16}}||Bayfront||120px||{{rbox|Downtown Line|Downtown Line|#{{rcr|SMRT|DT}}|White}} |- ! colspan="5" |''Continues onto'' {{SMRT code|CC|4|DT|15}} Promenade. |}
== Infrastructure == === Rolling stock === The CCL's rolling stock consists of three-car driverless trains that can accommodate up to 931 passengers per trainset.{{sfn|Champaud|2005|p=3}}{{sfn|Cheong|2012|p=126}}<ref name="Fast Facts CCL">{{cite web |title=Fast Facts |url=https://www.lta.gov.sg/content/ltaweb/en/public-transport/projects/circle-line/fast-facts.html |publisher=Land Transport Authority |access-date=17 May 2026 |archive-url=https://web.archive.org/web/20170118134321/https://www.lta.gov.sg/content/ltaweb/en/public-transport/projects/circle-line/fast-facts.html |archive-date=18 January 2017 |url-status=dead}}</ref> As part of Contract C830,{{sfn|Cheong|2012|p=126}}<ref name=":0">{{cite web |title=Award of Electrical and Mechanical Systems Contract 830 for the Marina Line |url=http://app.internet.gov.sg/scripts/lta/3_press_content.asp?start=172 | publisher=Land Transport Authority |access-date=29 May 2022 |archive-url=https://web.archive.org/web/20010701062516fw_/http://app.internet.gov.sg/scripts/lta/3_press_content.asp?start=172 |archive-date=1 July 2001 |date=28 December 2000}}</ref> Alstom supplied 40 Alstom Metropolis trains for the CCL.{{sfn|Champaud|2005|p=3}} An additional 24 second-generation Alstom Metropolis C830C<ref>{{cite web |title=Contract 751C and 830C – Schedule of Tenders Received |url=https://www.lta.gov.sg/data/apps/tender/doc/484/751C_830C_Tender_Schedule_Financial.pdfr_Schedule_Financial.pdf |publisher=Land Transport Authority |access-date=17 May 2026 |archive-url=https://web.archive.org/web/20161130153902/https://www.lta.gov.sg/data/apps/tender/doc/484/751C_830C_Tender_Schedule_Financial.pdf |archive-date=30 November 2016 |date=3 November 2011 |url-status=dead}}</ref> trains were delivered to Singapore beginning in June 2014.<ref name="shorter waits">{{cite web | title=From Next Year – Shorter Waits and More Comfortable Rides on Circle Line and North East Line | publisher=Land Transport Authority | date=23 July 2014 | url=https://www.lta.gov.sg/content/ltagov/en/newsroom/2014/7/2/from-next-year---shorter-waits-and-more-comfortable-rides-on-circle-line-and-north-east-line.html | access-date=27 August 2021 | archive-date=27 August 2021 | archive-url=https://web.archive.org/web/20210827105340/https://www.lta.gov.sg/content/ltagov/en/newsroom/2014/7/2/from-next-year---shorter-waits-and-more-comfortable-rides-on-circle-line-and-north-east-line.html | url-status=dead }}</ref><ref name="The Straits Times 2014">{{Cite web |last=Sim |first=Royston |date=23 July 2014 |title=First New Circle and North East Line Trains Arrive |url=https://www.straitstimes.com/singapore/transport/first-new-circle-and-north-east-line-trains-arrive |url-status=live |archive-url=https://web.archive.org/web/20220817013531/https://www.straitstimes.com/singapore/transport/first-new-circle-and-north-east-line-trains-arrive |archive-date=17 August 2022 |access-date=17 August 2022 |website=The Straits Times}}</ref> An additional 11 third-generation Alstom Metropolis C851E trains were ordered in April 2018,<ref name=":3">{{Cite web |last=Lim |first=Adrian |date=30 April 2018 |title=Alstom to Supply 17 New MRT Trains for North East Line and Circle Line |url=https://www.straitstimes.com/singapore/transport/alstom-to-supply-17-new-mrt-trains-for-north-east-line-and-circle-line |url-status=live |archive-url=https://web.archive.org/web/20211116060126/https://www.straitstimes.com/singapore/transport/alstom-to-supply-17-new-mrt-trains-for-north-east-line-and-circle-line |archive-date=16 November 2021 |access-date=16 November 2021 |website=The Straits Times}}</ref><ref>{{Cite web |title=Alstom to Supply 17 Additional Metropolis Trains for Singapore Circle Line and North East Line |url=http://www.fccsingapore.com/publications/alstom-supply-17-additional-metropolis-trains-singapore-circle-line-and-north-east-line |url-status=dead |archive-url=https://web.archive.org/web/20180809063339/http://www.fccsingapore.com/publications/alstom-supply-17-additional-metropolis-trains-singapore-circle-line-and-north-east-line |archive-date=9 August 2018 |access-date=9 August 2018 |website=The French Chamber of Commerce in Singapore |language=en}}</ref><ref name="Cost">{{Cite web|url=https://www.lta.gov.sg/data/apps/tender/doc/13026/851E_Schedule.pdf|title=851E Schedule | publisher=Land Transport Authority |access-date=15 September 2018|archive-date=15 September 2018|archive-url=https://web.archive.org/web/20180915143942/https://www.lta.gov.sg/data/apps/tender/doc/13026/851E_Schedule.pdf|url-status=live}}</ref> and 12 more trainsets were ordered in July 2019.<ref name="CCL tunnelling o944">{{cite web | last=Tan | first=Christopher | title=Tunnelling starts on Circle Line's final stage, existing line to be upgraded | website=The Straits Times | date=25 July 2019 | url=https://www.straitstimes.com/singapore/transport/tunnelling-starts-on-circle-lines-final-stage-circle-line-6 | access-date=18 May 2026}}</ref> Built in Barcelona,<ref name="Alstom in Singapore">{{Cite web| url=https://www.alstom.com/sites/alstom.com/files/2018/07/16/country_sheet_singapore_2018_final.pdf| archive-url=https://web.archive.org/web/20191208035114/https://www.alstom.com/sites/alstom.com/files/2018/07/16/country_sheet_singapore_2018_final.pdf| url-status=dead| archive-date=8 December 2019| title=Alstom in Singapore| date=8 December 2019| access-date=8 December 2019|website=Alstom}}</ref> the first C851E trainset arrived in Singapore in March 2022 and officially entered passenger service on 13 April 2026.<ref name="ST j190"/><ref>{{Cite news |title=New train for Circle Line MRT arrives in Singapore; first of 23 to be shipped here |url=https://www.straitstimes.com/singapore/transport/new-train-for-circle-line-mrt-arrives-in-singapore-first-of-23-to-be-shipped-here |website=The Straits Times |date=11 March 2022 |access-date=16 March 2022 |archive-date=14 March 2022 |archive-url=https://web.archive.org/web/20220314125340/https://www.straitstimes.com/singapore/transport/new-train-for-circle-line-mrt-arrives-in-singapore-first-of-23-to-be-shipped-here |url-status=live }}</ref> In May 2026, transport minister Jeffrey Siow said the LTA is studying plans for the refurbishment of the C830 trains.<ref name="MOT t602">{{cite web | title=Refurbishment Plans for First-Generation C830 Circle Line Trains | publisher=Ministry of Transport | date=7 May 2026 | url=https://www.mot.gov.sg/news-resources/newsroom/refurbishment-plans-for-first-generation-c830-circle-line-trains/ | access-date=17 May 2026}}</ref>
The CCL trains are controlled by an operations control centre (OCC) at Kim Chuan Depot.{{sfn|Cheong|2012|p=70}} Powered by 750V DC third rail,{{sfn|Champaud|2005|p=6}} the trains have a top speed of {{convert|90|km/h|abbr=on}} but with a maximum operational speed of {{convert|80|km/h|abbr=on}}.{{sfn|Cheong|2012|p=126}} Each train is {{convert|70|m}} in long, {{convert|3.21|m}} wide and {{cvt|3.68|m}} in high, with a weight of {{cvt|122.49|tonnes}}.{{sfn|Champaud|2005|p=6}} The trains are fitted with 146 seats, two wheelchair spaces, and four doors on each side of every carriage.{{sfn|Cheong|2012|p=126}} The doors are {{convert|1.4|m}} wide.{{sfn|Champaud|2005|p=6}} Large windows at the front and rear of the trains provide passengers with clear views of the tunnels.<ref name="Fast Facts CCL"/> In emergencies, detrainment doors at both ends of the trains can be opened to deploy evacuation ramps. The trains also have smoke and heat detectors with an emergency ventilation system and a fully redundant train management system.{{sfn|Cheong|2012|p=126}}
The C830C trains feature additional straphangers and platform gap fillers to reduce the space between the train and platform edge. Dynamic Route Map Displays positioned above each door show the train's current location, route information, and the side on which the doors will open at the next station.<ref>{{Cite web |date=3 August 2015 |title=Factsheet: Shorter Waits with 24 New Circle Line Trains by Mid-2016 |url=https://www.lta.gov.sg/content/ltagov/en/newsroom/2015/8/2/factsheet-shorter-waits-with-24-new-circle-line-trains-by-mid-2016.html |url-status=dead |archive-url=https://web.archive.org/web/20210617091155/https://www.lta.gov.sg/content/ltagov/en/newsroom/2015/8/2/factsheet-shorter-waits-with-24-new-circle-line-trains-by-mid-2016.html |archive-date=17 June 2021 |access-date=18 May 2026 |publisher=Land Transport Authority}}</ref> The C851E trains are equipped with sensors on the current collector shoes to detect any dislodgement while drawing power from the third rail. Two trainsets are also fitted with an Automatic Track Inspection (ATI) system, allowing real-time monitoring of running rails, track equipment and sleepers during operation.<ref name="ST j190" /><ref name=":3" /> ===Depot=== Kim Chuan Depot, located at Hougang Avenue 3 and Kim Chuan Road, houses the line's fleet.{{sfn|Cheong|2012|p=70}} The depot was constructed by a joint venture between Hock Lian Seng Infrastructure Pte Ltd and Hock Chuan Ann Construction Pte Ltd for S$296.55 million (US${{ToUSD|296.55|Singapore|y=2002|r=1}} million).<ref name="KCD contract award">{{cite web |title=Award Of Contracts For Circle Line |url=http://app.internet.gov.sg/scripts/lta/3_press_content.asp?start=525 |publisher=Land Transport Authority |access-date=19 May 2026 |archive-url=https://web.archive.org/web/20030604073847/http://app.internet.gov.sg/scripts/lta/3_press_content.asp?start=525 |archive-date=4 June 2003 |date=28 June 2002 |url-status=dead}}</ref> Spanning {{convert|11|ha|acre|abbr=on}}, the underground depot could accommodate up to 77 three-car trains.<ref>{{cite news|url=http://www.channelnewsasia.com/stories/singaporelocalnews/view/413013/1/.html|title=World's largest underground depot opens in Singapore|first=Shereena |last=Sajeed|date=4 March 2009| work=Channel NewsAsia|access-date=17 June 2022|archive-date=19 October 2012|archive-url=https://web.archive.org/web/20121019005133/http://www.channelnewsasia.com/stories/singaporelocalnews/view/413013/1/.html|url-status=dead}}</ref> It also houses the line's Operations Control Centre (OCC), which oversees the statuses of trains and other equipment on the CCL,{{sfn|Cheong|2012|p=124}} as well as the Depot Control Centre, which runs trains within the depot.{{sfn|Cheong|2012|p=70}} The depot also features an Automatic Storage and Retrieval System, Singapore's tallest underground automated warehouse at {{cvt|23|m}} high. Serving as the central warehouse for the CCL, it can store up to 24,000 train spare parts.{{sfn|Cheong|2012|p=131}}<ref>{{cite web |title=Kim Chuan Depot |url=http://www.lta.gov.sg/projects/proj_kim_chuan.htm |publisher=Land Transport Authority |access-date=19 May 2026 |archive-url=https://web.archive.org/web/20110605114919/http://www.lta.gov.sg/projects/proj_kim_chuan.htm |archive-date=5 June 2011 |url-status=dead}}</ref> The train washing facilities at Kim Chuan are also fully automated.{{sfn|Cheong|2012|p=129}}
Before the completion of Gali Batu Depot, a temporary OCC for the DTL was established at the depot,{{sfn|Feng|2017|p=127}} where the DTL trains were also temporarily stabled.{{sfn|Feng|2017|p=115}} After the relocation of the NSL and EWL OCC to Kim Chuan Depot in 2019.<ref name="Tan 2019">{{cite web |last=Tan |first=Christopher |date=24 April 2019 |title=New Rail Facility in Tuas Aims to Reduce MRT Line Testing Closures |url=https://www.straitstimes.com/singapore/transport/new-rail-facility-will-aim-to-reduce-mrt-line-testing-closures |url-status=live |archive-url=https://web.archive.org/web/20210321234259/https://www.straitstimes.com/singapore/transport/new-rail-facility-will-aim-to-reduce-mrt-line-testing-closures |archive-date=21 March 2021 |access-date=21 March 2021 |website=The Straits Times }}</ref><ref name="MOT y910">{{cite web | title=Speech by Minister Khaw Boon Wan at the visit to SMRT's New North-South and East-West Line (NSEWL) Operations Control Centre (OCC) at Kim Chuan Depot | publisher=Ministry of Transport | date=24 April 2019 | url=https://www.mot.gov.sg/news-resources/newsroom/speech-by-minister-khaw-boon-wan-at-the-visit-to-smrt-s-new-north-south-and-east-west-line-nsewl-operations-control-centre-occ-at-kim-chuan-depot/ | access-date=19 May 2026}}</ref> the OCC for the three lines were consolidated into the Rail Operations Centre.<ref name="SMRT q077">{{cite web | title=Rail Operations Centre envisions integration of SMRT's transport network operations | publisher=SMRT Corporation | date=24 April 2019 | url=https://www.smrt.com.sg/news-publications/newsroom/media-releases/rail-operations-centre-envisions-integration-of-smrt-s-transport-network-operations/ | access-date=19 May 2026}}</ref> A new Maintenance Engineering Centre, which monitors and controls the maintenance activities of the NSL, EWL and CCL, was established at Kim Chuan in April 2023.<ref name="ST MEC x164">{{cite web | last=Lee | first=Nian Tjoe | title=SMRT's noise monitoring system cuts time needed to probe complaints from three days to one | website=The Straits Times | date=19 June 2023 | url=https://www.straitstimes.com/singapore/transport/smrt-s-noise-monitoring-system-cuts-time-needed-to-probe-complaints-from-three-days-to-one | access-date=19 May 2026}}</ref> In June 2024, the SMRT Rail Safety Experiential Centre (SRSEC) was commissioned at Kim Chuan. The SRSEC showcases visuals and artefacts from past incidents as reminders of the need for vigilance and continuous improvement for SMRT staff.<ref name="lianhe zaobao y530">{{cite web | title=SMRT铁路安全体验中心启动 强化员工安全意识 | website=联合早报 | date=25 June 2024 | url=https://www.zaobao.com.sg/news/singapore/story20240625-3977614 | language=zh | access-date=19 May 2026}}</ref><ref name="MOT j203">{{cite web | title=Speech by Dr Amy Khor, Senior Minister of State, Ministry of Sustainability and the Environment & Ministry of Transport, at the Launch of the SMRT Rail Safety Experiential Centre (SRSEC) | publisher=Ministry of Transport | date=25 June 2024 | url=https://www.mot.gov.sg/news-resources/newsroom/speech-by-dr-amy-khor--senior-minister-of-state--ministry-of-sustainability-and-the-environment---ministry-of-transport--at-the-launch-of-the-smrt-rail-safety-experiential-centre--srsec-/ | access-date=19 May 2026}}</ref>
The depot is being expanded by {{cvt|16|ha}}, doubling its underground capacity to support a larger fleet of 133 trains.<ref>{{Cite web|url=https://www.straitstimes.com/singapore/transport/biggest-underground-train-depot-set-to-become-even-bigger|archive-url=https://web.archive.org/web/20200305133742/https://www.straitstimes.com/singapore/transport/biggest-underground-train-depot-set-to-become-even-bigger|url-status=dead|archive-date=5 March 2020|title=Biggest underground train depot set to become even bigger |website= The Straits Times|date=5 March 2020|access-date=5 March 2020}}</ref> The expansion project, expected to be completed with the CCL6 stations, would include a bus depot above the facility.<ref name="LTA 2015 CCL full circle"/><ref name="g201">{{cite web | last=Sketchley | first=Elisha | title=Singapore Land Transport Authority expand Kim Chuan Depot | website=Digital Construction Today | date=29 August 2019 | url=https://www.pbctoday.co.uk/news/digital-construction-news/bim-news/kim-chuan-depot-expansion-project/62295/ | access-date=19 May 2026}}</ref> The contract for the depot's expansion was awarded to Woh Hup for S$1.21 billion (US${{ToUSD|1.21|Singapore|y=2017|r=1}} billion).<ref name="channelnewsasia.com">{{Cite web|url=https://www.channelnewsasia.com/news/singapore/first-circle-line-6-contracts-worth-s-1-75b-awarded-by-lta-9198368|archive-url=https://web.archive.org/web/20200305133756/https://www.channelnewsasia.com/news/singapore/first-circle-line-6-contracts-worth-s-1-75b-awarded-by-lta-9198368|url-status=dead|archive-date=5 March 2020|title=First Circle Line 6 contracts worth S$1.75b awarded by LTA |website=Channel NewsAsia |date=5 March 2020|access-date=5 March 2020}}</ref>
=== Signalling === The Circle Line is equipped with Alstom Urbalis 300 Communications-based train control (CBTC) moving block signalling system on the MASTRIA system with Automatic train control (ATC) under Automatic train operation (ATO) GoA 4 (UTO).<ref>{{Cite web|title=Singapore Northeast Line: will soon be the largest, fully automatic metro system in the world|url=http://tsdtemp.turnlav.net/cbtc/projects/SIG_Singapore_AutomaticMetro_en.pdf|url-status=live|archive-url=https://web.archive.org/web/20200615162321/http://tsdtemp.turnlav.net/cbtc/projects/SIG_Singapore_AutomaticMetro_en.pdf|archive-date=15 June 2020|access-date=16 June 2020|pages=4 to 8}}</ref><ref>{{Cite web|title=URBALIS Evolution: Controlling the Performance|url=http://www.sanprotechwriting.com/translation/URBALIS_May14_rev.pdf|url-status=live|archive-url=https://web.archive.org/web/20200615162738/http://www.sanprotechwriting.com/translation/URBALIS_May14_rev.pdf|archive-date=15 June 2020|access-date=16 June 2020|page=4}}</ref> The subsystems consist of Automatic train protection (ATP) to govern train speed, Iconis Automatic Train Supervision (ATS) to track and schedule trains and Smartlock Computer-based interlocking (CBI) system that prevents incorrect signal and track points to be set.<!--Note:Please do not delete any hidden content in the train control section-->
Train Data Management System (TDMS) which concentrate and dispatch the rolling stock information with fixed equipment. The IAGO Waveguide communications network has the capability to transmit video and is almost maintenance-free. Base stations are located within the signalling equipment room.
=== Station facilities === All CCL stations are wheelchair accessible. A tactile system, consisting of tiles with rounded or elongated raised studs, guides visually impaired commuters through the station,<ref name="LTA Tactile">{{Cite web |date=30 July 2021|title=Tactile Guiding System: Studs and Strips to Guide Your Way|url=https://www.lta.gov.sg/content/ltagov/en/who_we_are/statistics_and_publications/Connect/tactile-guiding-system.html|access-date=11 September 2021 <!-- |website=lta.gov.sg -->|publisher=Land Transport Authority|archive-date=11 September 2021|archive-url=https://web.archive.org/web/20210911021750/https://www.lta.gov.sg/content/ltagov/en/who_we_are/statistics_and_publications/Connect/tactile-guiding-system.html|url-status=live}}</ref> with dedicated tactile routes that connect the station entrances to the platforms.{{sfn|Cheong|2012|p=149}} Wider fare gates allow easier access for wheelchair users into the station.{{sfn|Cheong|2012|p=149}} Platform screen doors (PSDs) along the line were installed by Singapore Technologies Electronics Ltd and supplied by Westinghouse.<ref name=":0" /><ref name="Allison 2007">{{cite web |date=15 July 2007 |title=Platform Screen Doors: Circle Line (Phases 1 + 2) |url=http://www.platformscreendoors.com/psd/projects/circleline_1.php |url-status=dead |archive-url=https://web.archive.org/web/20070715201528/http://www.platformscreendoors.com/psd/projects/circleline_1.php |archive-date=15 July 2007 |access-date=27 August 2021 |website=Westinghouse Platform Screen Doors |publisher=Westinghouse Rail Systems}}</ref><ref>{{cite web |title=Global Project Portfolio |url=http://westinghouse-brakes.com/en/archive/globalprojectportfolio/globalprojectportfolio.jsp |website=Westinghouse Brakes |archive-url=https://web.archive.org/web/20160827050844/http://westinghouse-brakes.com/en/archive/globalprojectportfolio/globalprojectportfolio.jsp |archive-date=27 August 2016|publisher=Knorr-Bremese}}</ref>{{efn|The PSDs of the CCL6 stations are also supplied by ST Engineering Electronics.<ref>{{cite web |title=Annual Report 2018/19 |url=https://www.lta.gov.sg/content/dam/ltagov/who_we_are/statistics_and_publications/report/pdf/Annual%20Report%201819.pdf |website=Land Transport Authority |page=61 |access-date=3 September 2021 |archive-date=20 December 2020 |archive-url=https://web.archive.org/web/20201220010202/https://www.lta.gov.sg/content/dam/ltagov/who_we_are/statistics_and_publications/report/pdf/Annual%20Report%201819.pdf |url-status=live }}</ref>}}
Eleven stations on the CCL are designated as Civil Defence (CD) shelters, which will be activated in times of national emergency. Apart from reinforced construction, the stations are designed and equipped with facilities to ensure the shelter environment is tolerable for all during shelter occupation. These facilities include protective blast doors, decontamination facilities, ventilation systems, power, water supply systems and a dry toilet system.{{sfn| Cheong| 2012| p=176}} ==Notes and references== ===Notes=== {{notelist}} {{reflist|group=note}}
===References=== {{reflist|30em}}
==Sources== * {{cite conference |last=Champaud |first=Xavier |date=October 2005 |title=CCL – The Longest Automatic Metro Line in the World |conference=Institution of Railway Signal Engineers Technical Convention |location=Singapore |publisher=Institution of Railway Signal Engineers}} * {{Cite book |last=Cheong |first=Colin |url=https://www.lta.gov.sg/content/dam/ltagov/who_we_are/statistics_and_publications/books/pdf/Circle_Line_Book.pdf |title=The Circle Line, Linking All Lines |date=2012 |publisher=Land Transport Authority |isbn=978-981-4342-02-5 |location=Singapore |language=en}} * {{Cite book |last=Feng |first=Zengkun |title=Downtown Line: Soaring to new heights |publisher=Straits Times Press |year=2017 |isbn=978-981-4747-66-0 |publication-place=Singapore |oclc=1003852882|url=https://www.lta.gov.sg/content/dam/ltagov/who_we_are/statistics_and_publications/books/pdf/The_Downtown_Line_book.pdf}} * {{cite journal |last=Kumarasamy |date=2017 |title=Geology and Its Impact on the Construction of Singapore MRT Circle Line |url=http://doi.nrct.go.th/?page=resolve_doi&resolve_doi=10.14456/seagj.2017.20 |journal=The Geotechnical Engineering Journal of the SEAGS & AGSSEA |volume=48 |page=2431 |doi=10.14456/SEAGJ.2017.20 |access-date=16 May 2026 |first=Jeyatharan}}
==External links== * {{Commons category-inline}} * [https://www.lta.gov.sg/content/ltagov/en/getting_around/public_transport/rail_network/circle_line.html Circle Line] * [https://www.lta.gov.sg/content/dam/ltagov/who_we_are/statistics_and_publications/books/pdf/Circle_Line_Book.pdf LTA's commemorative book detailing the construction of the Circle Line]
{{Singapore MRT stations|circle=yes}} {{Rail transport in Singapore}} {{Urban Rail Transit in ASEAN}}
{{DEFAULTSORT:Circle Line}} Category:Mass Rapid Transit (Singapore) lines Category:Railway lines opened in 2009 Category:Railway loop lines Category:2009 establishments in Singapore