CR117 - Completion of westbound tunnel

Graphical representation of tunneling progress for contract CR117. Based on compilation of
available information and may not be the most accurate nor up to date.

Contract CR117 has been one of the more elusive contracts to track progress of, mainly due to the different geology at the location which necessitated different construction methods. For instance, the earth retaining & stabilising structure (ERSS) employed at the site uses bore piles instead of diaphragm walls. Similarly, it has been a little difficult to track the progress of tunneling works. Nonetheless, we've managed to probe a bit more and finally have some idea of the progress when it comes to tunneling.

Undated image - A photo of the slurry tunnel boring machine used for the contract.
Source: Skymard / Hnjtx / China Construction Machinery Association

CR106 - Completion of eastbound tunnel

 

Another tunnel that has recently been completed along the Cross Island Line's (CRL) phase 1 section is the eastbound tunnel under contract CR106. This contract will be responsible for the construction of Loyang station and tunnels connecting to neighbouring Pasir Ris East station. Two tunnel boring machines (TBMs) are being used for the construction of the tunnels, with the launch shaft constructed under contract CR107, next to the Pasir Ris East station before being handed over to contract CR106.

CR109 - Completion of tunneling works

 

A collage of images from the recent eastbound tunnel breakthrough.
Source: CR109 Telegram group

It has been a rather quite time at SGMC since the end of the year due to the multitude of things going on in this author's personal life - lots of assignments for school while still holding down a full time job. Thankfully assignment season is over and we can celebrate a few milestones that we'd like to catch you up on. The first, and most recent one, being the completion of tunneling works for contract CR109.

Tunnel updates - CR106, CR109, CR111, CR112 & CR116

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. 

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.

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.

CRL - A snapshot in October 2025

Overview of CRL1 stations CR4 - CR12 as at October 2025.
Top (L - R): CR4 – Pasir Ris East, CR5/CP1 – Pasir Ris, CR6 – Tampines North
Middle (L - R): CR7 – Defu, CR8 – Hougang, CR9 – Serangoon North
Bottom (L - R): CR10 – Tavistock, CR11 – Ang Mo Kio, CR12 – Teck Ghee

Overview of CPE stations CP2 - CP4 & CRL2 stations CR16 - CR19 as at October 2025.
Top (L - R): CP2 – Elias, CP3 – Riviera, CP4 – Punggol
Middle (L - R): CR16 – Maju, CR207 – Twin bored tunnels, CR17 – Clementi
Bottom (L - R): CR18 – West Coast, CR210 – Twin bored tunnels, CR19 – Jurong Lake District

It's been a while since we've done such an extensive coverage of the Cross Island Line (CRL) across its three current phases that have been announced thus far, hence we thought we'd let October be our month of diversity. Updates for this month stretch from Pasir Ris East all the way to Punggol & Jurong Lake District. If you've been curious on how things were progressing, this post is for you. Do be ready, this update's kind of MEGA.

CRL3 - Speculated station locations

 

Note from SGMC: The station locations have yet to be officially announced. This article puts together facts to create an educated guess as to the team's speculated locations of stations under phase 3 of the Cross Island Line (CRL). These locations should not be taken as official until confirmed by the Land Transport Authority (LTA).

Since the announcement of the Changi Terminal 5 station on the eastern end of the Cross Island Line (CRL), the next anticipated announcement will be that of the locations of the stations along phase 3 of the line. The imminent announcement of the line was heralded by the publication of the pre-qualification exercise commencement on 9 September 2025, which aims to short-list eligible contractors for the 8 civil construction contracts that make up the phase. We'll jump into where we speculate the stations under phase 3 of the line will be after we review some of the facts first.

CRL3 - Gul Circle

 

Image of the proposed mixed development concept, located next to the existing EWL Gul Circle
station. Also indicated in the image is the proposed location of Gul Circle station.
Source: URA

We have for some time known that the Cross Island Line (CRL)'s western terminus will be located at Gul Circle station. Previously, the Urban Redevelopment Authority (URA) had released some images on its websites during the period when engagement was ongoing for the Long Term Plan Review, the lead up to the development of the URA Draft Masterplan 2025. In particular, the above image was released which gave details on the likely location of the CRL3 Gul Circle station. We saved the image, a fortunate move, as the image was since replaced with the CRL indicative location and mention since removed.