SINGAPORE - Construction on six new MRT stations that make up

phase two of the upcoming Cross Island Line (CRL)

has officially begun, with tunnelling work that will go underneath Singapore’s largest nature reserve having started in May.

The works also include building Singapore’s deepest underground station in King Albert Park at 50m – or 16 storeys – below ground, surpassing Bencoolen station on the Downtown Line (DTL), which is 43m underground.

Acting Transport Minister Jeffrey Siow said on July 7 that engineering studies for the third phase of the CRL are nearing completion, with more details about

future stations serving the Jurong Industrial Estate

expected at the end of 2025.

The CRL, Singapore’s eighth MRT line, will significantly improve the resilience of the rail network, Mr Siow said during a groundbreaking ceremony for CRL Phase 2 in Clementi.

It will be connected to all existing lines except the Circle Line, with eight of its 21 announced stations serving as interchanges.

Mr Siow described the CRL as Singapore’s “next outer ring”, providing passengers with more alternative routes during rail disruptions and potentially opening up new windows for maintenance, a task now restricted to night hours.

“As our rail network expands and ages, more maintenance and renewal works will be needed,” he added.

Time savings

Spanning 50km, the CRL will be Singapore’s longest underground MRT line.

Its first phase, covering 29km with 12 stations from Aviation Park to Bright Hill, is slated to open in 2030, serving residential and industrial areas, such as Loyang, Tampines, Pasir Ris, Defu and Serangoon North.

A four-station extension from Pasir Ris to Punggol will open in 2032.

Acting Transport Minister Jeffrey Siow speaking during a groundbreaking ceremony for CRL Phase 2 in Clementi on July 7.

ST PHOTO: KELVIN CHNG

Phase two of the CRL, a 15km stretch from Turf City to Jurong Lake District, is also expected to be completed by 2032.

This phase includes interchanges with the DTL at King Albert Park and the East-West Line (EWL) at Clementi station. The remaining two stations are located in Maju and West Coast.

The Land Transport Authority (LTA) said on July 7 that transfer links to the CRL will be built at the existing Clementi and King Albert Park stations. This will be done in stages to minimise disruptions to existing train services.

While LTA has not given cost estimates for the rail line, the authority has awarded contracts worth more than $16.6 billion for the CRL so far, including tenders for the depot in Changi East, the trains and rail systems.

The design and construction of the stations and tunnels for phase two alone will cost upwards of $4 billion.

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When completed, this phase of the CRL is expected to

benefit 40,000 households

, including those living in Sunset Way and West Coast Road, which are not served by the MRT today.

LTA said it expects a significant reduction in travel time for passengers, with journeys from West Coast to Ang Mo Kio Industrial Park cut by up to 40 minutes via public transport.

As for the third phase of the line, past tenders have indicated that it will comprise at least four stations, with possible interchanges at Jurong Pier station on the upcoming Jurong Region Line and Gul Circle station on the EWL.

The CRL is expected to have a daily ridership of at least 600,000 in its initial years, growing to one million in the long term.

Mr Siow said this will likely be the last MRT line that cuts across the island from east to west, as there is no space left for another rail line like this. But there are provisions in place to move the CRL up from six-car trains to eight-car trains, if needed.

CRL Phase 2, from Turf City to Jurong Lake District, includes interchanges at King Albert Park and Clementi. The remaining two stops are in Maju and West Coast.

PHOTO: LTA

Environmental impact

During the early planning stages of the CRL, a major concern was whether a stretch of the line between Bright Hill and Turf City would run directly under the Central Catchment Nature Reserve (CCNR) or skirt around it.

After a two-phase assessment, the Ministry of Transport decided in late 2019 that the CRL will run directly underneath the CCNR at a depth of 70m – the deepest any MRT tunnel will go here. At its deepest, the tunnel along this stretch will run 80m underground.

LTA said on July 7 that this 5km section of tunnel will be built using

a large-diameter tunnel-boring machine

12.8m wide, which is capable of creating a two-track tunnel at one go , boosting efficiency and productivity.

To improve environmental sustainability, the stations in CRL phase two will be built using steel and concrete produced with methods that emit less carbon, LTA added.

The use of electric machinery, such as battery-powered excavators, tipper trucks and cranes, will also be explored to reduce construction-related emissions and noise.

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While CRL phase two will span biodiverse areas such as Eng Neo Avenue Forest, Maju Forest and Clementi Forest, LTA noted that comprehensive environmental impact assessments were done before construction began, and a “robust” environmental monitoring and management plan has been rolled out.

Mitigati ng measures include the creation of a new freshwater marsh at the King Albert Park site and the establishment of a biodiversity training centre in Fairways Drive , off Eng Neo Avenue, to provide mandatory wildlife awareness training for site workers.

LTA said it has been working with nature groups since 2013, noting significant improvements that have resulted from this partnership . These include more than halving a worksite area in Windsor near the CCNR, and installing aerial rope bridges to allow the safe movement of animals across roads.

It was previously reported that even with the various measures to mitigate the environmental impact, phase two of the CRL could still deal a

major blow to nearby forests due to irreversible habitat loss

.

LTA said it will continue to engage with nature groups throughout the construction and operation of the rail line.