The Land Transport Authority (LTA) marked the start of the Cross Island Line (CRL) Phase 1 construction with a groundbreaking ceremony today (18 Jan).
The CRL will be Singapore’s eighth and longest fully-underground MRT line at more than 50 km long when fully completed. It will serve the existing and future developments in the eastern, western and northeastern corridors, linking major hubs such as the Jurong Lake District, Punggol Digital District and Changi.
The projected daily ridership of the entire CRL is more than 600,000 commuters in the initial years from 2030, increasing to over 1 million in the longer term. It will be constructed and opened in three phases.
The first phase – CRL Phase 1 – spans 29 km and comprises 12 stations from Aviation Park to Bright Hill. This will serve residential and industrial areas such as Loyang, Hougang and Ang Mo Kio.
Construction of the CRL Phase 1 is expected to be completed by 2030. It will be linked to East-West Line at Pasir Ris station, North-East Line at Hougang station, North-South Line at Ang Mo Kio station and Thomson-East Coast Line at Bright Hill station.
LTA is progressively calling tenders for CRL Phase 2, which comprises six stations from Turf City to Jurong Lake District, while engineering studies are ongoing for the third phase.
The CRL Bright Hill station will also be connected to a new Transit Priority Corridor (TPC) along Sin Ming Avenue to allow multi-modal transfer to the bus and active mobility networks. The 2-km stretch of TPC, which is scheduled for completion in 2029, will consist of a dedicated bus lane, new cycling paths and wider footpaths.
Construction challenges and methods
LTA revealed that various technologies have been adopted for the CRL project to improve construction efficiency and safety. These include the use of virtual reality and augmented reality tools to enhance capabilities and facilitate coordination. Productivity is further increased through platforms such as computer simulations of different operating scenarios at the Changi East Depot.
Large-diameter tunnel boring machines (TBMs) will be used to construct various stretches of tunnels between the CRL stations, including between Aviation Park and Loyang stations. According to LTA, the 12.6 m-diameter TBMs will only have to bore through the ground once for the construction of the tunnel with two tracks eventually housed in it. This will be the largest TBM to be deployed on an LTA rail project and it is expected to increase work productivity and reduce manpower requirements.
Construction works for the paid transfer link to the existing East-West Line (EWL) Pasir Ris station are also ongoing, added LTA. Due to site constraints at the track viaduct, specialised equipment – like a low-headroom mobile crane – has been deployed for works such as the construction of the diaphragm wall.
LTA said that at the CRL Teck Ghee station, a rectangular TBM will be used for the construction of the underground linkways. To enhance overall construction productivity and safety, LTA will be adopting the trenchless method, where operational parameters during tunnelling are controlled to minimise surface settlement. LTA will also be exploring other innovative construction methods on the CRL project to improve overall construction productivity and safety.
All images: LTA