Contract 991 - The first DTL2e civil contract awarded

An overview of the DTL2e worksites near the 2 stations under the extension.
Source: LTA

Today, the Land Transport Authority (LTA) awarded the first of 4 civil contracts for the Downtown Line 2 extension (DTL2e) project - contract 991 for the construction of tunnels between the 2 stations and Gali Batu depot. The contract was awarded to a joint venture between Woh Hup & Urban Technology Engineering Construction, according to the LTA.

List of DTL2e contracts, tender float, close & award dates with delivery dates.

Under the contract, a total of 3 tunnels will be constructed. Two of these will be for the extension's main line, while the third will be for a single reception track connecting to the existing Gali Batu depot.

An aerial view of the Gali Batu depot where the new reception track will likely connect.
Source: GoogleMaps (Satellite view)

A close up view of the likely connection point at Gali Batu depot.
Source: GoogleMaps (Satellite view)

The new reception track will likely connect to an area within Gali Batu depot bounded by a service road and the fenced off area between the rolling stock workshop/administration building at the northern end and the stabling shed further south. An existing set of tracks extends beyond the railway area boundary fence towards the road and was most likely used for transfer of new rolling stock from low bed trailers onto the rail tracks.

Geological map of Singapore, showing the various geologies spread across the island.
Source: NUS Faculty of Science

Geological profile of DTL1 - 3.
Source: International Journal of Geoengineering Case Histories, Vol 3. Issue 3

Works for the contract are due to commence in Q2 2026, for completion by March 2035. One may ask, why is such a long period required for the construction of such a short section of line? The geological profile of the area plays a part, among other factors, in contributing to the lengthy time required. From the above diagrams, we can see that the geological profile in the vicinity of the project consists of Bukit Timah Granite. This is a hard and abrasive rock type, meaning that this contributes to higher wear & tear rates for tunnel boring machines, and more effort to remove the same amount of material compared to other soil types. Additionally, this and neighbouring contracts take place in close proximity to existing rail infrastructure, requiring close observation to prevent disruption to existing rail services.

Proximity of project sites to residential developments also entails enhanced mitigation measures against noise and dust pollution. All these factors unfortunately contribute to a longer project development time.

Details of bidding companies for contract 991 and bid prices.
Source: Gebiz

Interestingly, the winning bid was not the cheapest bid put in by the bidding companies. That said, the evaluation criteria typically employs a mixed weightage between construction methodology and pricing. This means that pricing is not the sole factor that goes in to determine a winning bid and is merely a percentage of the overall bid quality, depending on the established criteria.

As the year progresses, one can expect there to be more contract awards. We'll do our best to keep you updated as these take place. You'll be able to keep update on contracts and station details (DT36, DE1, DE2) on the dedicated pages, in addition to our usual blog posts.

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