Recently, the Land Transport Authority (LTA) announced that the tunnelling works are now completed for the Circle Line 6 (CCL6). The CCL6 line consists of three new stations – Keppel, Cantonment and Prince Edward Road. The construction of this line started in August 2019. The first stretch of tunnelling works was done from Keppel station towards HarbourFront station. The second tunnelling work was carried out between Keppel and Cantonment stations. The final stretch of works from Prince Edward Road station to Cantonment station has been completed in January 2022. Now, let’s check out what the Circle Line 6 will look like moving forward.

• The structural connections will be carried out in the bored tunnels and stations in tandem with the rest of the works for the three new stations for CCL6.

• Then the contractors of CCL6will install track-related equipment as well as electrical and mechanical services and systems.

• All systems will be tested and commissioned before the tracks open in 2026.

Minister for Transport S Iswaran said that the completion of this final stretch of tunnelling works is an "important milestone", noting that there were "a series of challenges”. Apart from the pandemic, there were also engineering challenges, such as constructing tunnels beneath the foundations of commercial buildings and other MRT stations. LTA said they used 600 monitoring instruments to detect any movements of the building during the tunnelling works.

About the Circle Line

The Circle Line connects HarbourFront to Marina Bay with 33 stations and 12 interchange stations. The CCL6 is on track to open in 2026. When the CCL becomes fully operational, commuters from Telok Blangah will get a direct, faster and more convenient route to the Marina Bay area. If you’re travelling from Paya Lebar and Mountbatten, you can get faster access to the retail and office centres in the HarbourFront area. You can also have a direct route to the Central Business District. The CCL line is operated and marinated by multi-modal transport operator - SMRT Corporation.

For two consecutive years, SMRT Trains has achieved 1 million mean kilometres between failure (MKBF) for the North-South and East-West Lines and Circle Line. This achievement will give commuters confidence in the reliability of our rail systems, and we are proud of our team for this accomplishment. Apart from rail reliability, we are also sparing no effort to ensure our MRT and LRT systems are safe, clean, and hygienic during and beyond the pandemic,” said Mr. Lam Sheau Kai President of SMRT Trains.

Commenting on how SMRT is fostering a vibrant rail ecosystem, SMRT Chairman, Seah Moon Ming, said: “We’ve established the Singapore Rail Standards (SRS) together with LTA, the Institute of Engineers Singapore, and SBS Transit. The SRS sets a common baseline standard for operations and maintenance, and staff competency. It also serves as a useful reference for the design of systems and solutions.


Building the Circle Line (CCL) requires innovations in design, engineering and construction as it comes with engineering challenges. Once it becomes fully operational in 2026, it will provide better connectivity and greater time savings for commuters. LTA and SMRT need to work together to ensure the Circle Line stays safe, reliable, and convenient for commuters as it is now.

About the Author

Arthur Wilson

Arthur has a post-graduate degree in construction engineering and management. He has worked as a tunnel engineer on numerous projects in the past 25 years. Currently, he is leading and educating tunnel engineers in various countries.