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| CRL1 tunnel chart as of end-2025, to the team's best knowledge. |
Tunneling works along the Cross Island Line (CRL)'s phase 1 have been progressing well, thanks to the favourable soil conditions in the eastern side of the island. Soil here is typically composed of old alluvium, great for tunneling as seen through the quick work made of tunnels under several contracts of late.
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| August 2023 - A view of the displays within the CRL1 Project Information Centre. The display on the left shows the Soil Profile along the CRL1. |
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| A screenshot of the Soil Profile along CRL1. Source: CRL1 Virtual PIC |
Old Alluvium is a dense and strong material, capable of supporting the surroundings while tunneling work is being carried out. While strong, it is also easier to tunnel through than Bukit Timah Granite, an extremely hard rock that dominates the soil profile of Western Singapore. The transition from Old Alluvium to Bukit Timah Granite takes place in the vicinity of Ang Mo Kio and Teck Ghee.
With the favourable Old Alluvium in Eastern Singapore, here are some updates on tunneling work across CRL1.
- Contract CR106 - The second tunnel boring machine (TBM) has passed under housing blocks and is in the vicinity of Loyang Avenue.
- Contract CR109 - The westbound TBM has completed its second & final drive. Eastbound TBM was boring underneath Tampines Road in the vicinity of Tampines Dormitory.
- Contract CR111 - Both TBMs have completed their drives towards Hougang station.
- Contract CR112 - According to the Land Transport Authority (LTA), both TBMs have completed their drives toward Serangoon North station.
- Contract CR116 - As of end-November, the TBM's second drive was 63% completed.
