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.

CRL - A snapshot in August 2025

Overview of CRL1 stations CR3 - CR10 as at August 2025.
Top (L - R): CR3 - Loyang, CR4 - Pasir Ris East
Middle (L - R): CR5/CP1 - Pasir Ris, CR8 - Hougang
Bottom (L - R): CR9 - Serangoon North, CR10 – Tavistock

Overview of CRL1 station CR11 & CRL2 stations CR17 - CR19 as at August 2025.
Top (L - R): CR11 – Ang Mo Kio, CR207 - Launch shaft
Middle (L - R): CR17 - Clementi, CR18 - West Coast
Bottom (L - R): CR210 - Launch shaft, CR19 - Jurong Lake District

Roughly about three-quarters into the year, how has progress been along the Cross Island Line? We take a closer look at some of the key sites along the line in both phases 1 and 2 in this August look-back.

CR110 - Sneak peek at the action

 

A view of the launch shaft.
Image from LinkedIn.
Thanks to Yekai for the heads up.

Have you ever wondered what the tunneling site for a large diameter bored tunnel looks like? Are there any appreciable differences from the tunneling of a regular twin bored tunnel? We've come across a few images online of the launch shaft for contract CR110 that allow us to see what these look like.

CRL3 - Around the corner

Today, the Land Transport Authority (LTA) unveiled what is most likely to be some welcome news - pre-qualifications for Cross Island Line (CRL)'s phase 3 have opened. In total, there are 8 contracts up for pre-qualification, one likely being for the construction of a depot facility as indicated in the Qualification Criteria. This is likely to be contract CR301, going by past precedent of contract X01s being assigned for depot facilities - CR101 for Changi East depot, J101 for Tengah depot, T301 for the East Coast depot and T201 for Mandai depot.