SINGAPORE: A series of upgrading works has begun on the Circle Line (CCL) to prepare for the opening of Circle Line Stage 6 (CCL6), the Land Transport Authority (LTA) and SMRT said in a joint news release on Thursday (Jul 25).

The enhancements will allow the decade-old CCL to support a larger CCL network and train fleet when three new CCL6 stations start operating in 2025.

The stations will also close the loop for the CCL by connecting HarbourFront Station to Marina Bay Station. 

Construction of the three new CCL6 stations – Keppel, Cantonment and Prince Edward Road stations – commenced in 2017. Works are progressing smoothly and are expected to be completed on schedule, said LTA and SMRT.

Tunnelling for the new stations also began on Thursday. 

“With the network reaching the 10-year mark, it is essential that we start the renewal process early and apply the lessons learnt from the renewal of the North-South and East-West Lines network to improve rail reliability,” said SMRT Corporation Group Chief Executive Officer Neo Kian Hong.

Artist's impression of the concourse of the upcoming Cantonment MRT station on the Circle Line.

Artist’s impression of the concourse of the upcoming Cantonment MRT station. (Image: LTA)

LTA Chief Executive Ngien Hoon Ping added that “daily operations will not be impacted” as they carry out the upgrading works on the 30-station network. 

“With the completion of the upgrading works, we can look forward to the smooth integration of the existing CCL system with the three new CCL6 stations when they are ready.”

The ongoing enhancements to the existing Circle Line network include upgrading the signalling system to monitor and support the larger number of CCL trains. 

The power supply system will also be upgraded to improve system availability and resiliency. The installation of an additional hardware component called the load break switch at substations will help to maintain continuity of power supply in the event of a power outage.

circle line map

The three new stations that will close the loop on the Circle Line. (Image: LTA)

TUNNELLING WORKS BEGIN

Tunnelling works for CCL6 began on Thursday with the launch of the tunnel boring machine (TBM) at Keppel Station. 

This tunnelling machine will tunnel from Keppel Station to CCL HarbourFront Station. Two other TBMs are expected to be launched in September and October this year.

Foundation and excavation works are also in progress for the expansion of Kim Chuan Depot.

The expanded integrated Kim Chuan Depot will provide additional stabling facilities to support the larger CCL network and train fleet of 133 trains, and the above-ground bus depot will house 550 buses.

Map of Circle Line 6

Map of Circle Line 6. (Image: LTA)

LTA is also purchasing 12 new trains from Alstom to cater for the expected increase in passengers when the CCL is fully operational. These trains will be delivered progressively from 2024.

In addition to the 11 trains that were bought in April 2018 for CCL6, these 23 trains will increase the total CCL fleet size by 36 per cent to 87.

When CCL6 opens in 2025, CCL will have a total of 33 stations with 12 interchanges to connect to all existing MRT lines and the future Thomson-East Coast Line.