The landscape of Singapore’s northwest is poised for a massive underground transformation following the Land Transport Authority’s (LTA) final contract awards for the Downtown Line Stage 2 Extension (DTL2e). This ambitious infrastructure project, totalling a massive S$1.26 billion investment in civil works will see the existing Downtown Line (DTL) push past its current terminus to forge a critical link with the busy North-South Line (NSL) built in the 1980s to improve connectivity, cut travel times, and strengthen network resilience in the north‑west of Singapore.
Deep Boring and Strategic Tunnelling
The project’s backbone consists of two tunnelling packages. The first, worth S$326 million, was secured by a joint venture between Woh Hup Engineering Pte. Ltd. and Underground Technology Engineering Construction Pte. Ltd. The project involves constructing three bored tunnels – approximately one kilometre each, at a depth of 21 metres to connect the new stations and provide a reception track for the Gali Batu Depot. The project also requires additions and alterations works within the depot.
The second tunnel contract, at S$199 million, was awarded to China Railway Tunnel Group. This involves boring 1.8km of twin tunnels from the existing Bukit Panjang station toward the new DE1 station.
Engineering the Interchange Hubs
In addition to the tunnels, two major station contracts totalling S$735 million have been awarded. Woh Hup Engineering will lead the S$285 million DE1 station project at Sungei Kadut Avenue. Meanwhile, a joint venture between Samwoh Corporation Pte. Ltd. and China Communications Construction Company (Singapore Branch) is awarded the S$450 million contract for the NS6/DE2 interchange, a complex multi-level facility linking underground DTL platform with new aboveground NSL tracks.
Navigating challenges from the Ground and Live Rails
Each segment of the DTL2e presents technical challenges from complex ground conditions, particularly the presence of hard granite, ground water and the need to maintain ground stability beneath the existing waterways. The projects are also presented with constrained workspaces in the proximity to the live metro line. With the construction slated to begin in mid-2026, the DTL2e is on track to enhance regional transit by 2035, saving travel time by up to 20 minutes.
Source:
https://landtransportguru.net/downtown-line-stage-2-extension-civil-contracts-awarded/
https://www.straitstimes.com/singapore/transport/final-contract-for-construction-of-tunnels-in-dtl-extension-awarded-work-to-start-in-q3?ref=latest-headlines
https://www.lta.gov.sg/content/ltagov/en/newsroom/2026/1/news-releases/lta-awards-first-civil-contract-for-the-downtown-line-2-extensio.html
https://www.lta.gov.sg/content/ltagov/en/newsroom/2026/2/news-releases/lta-awards-two-civil-contracts-for-dtl2e.html
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