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.

CR109 - Launch of TBMs!

 

15 June 2024 - A photo of the dignitaries in front of the eastbound tunnel boring machine.
Source: LinkedIn

Talk about being at the right place at the right time - yesterday the Land Transport Authority (LTA) together with contractor China Communications Construction Co (CCCC) held a launch ceremony to kick off tunneling works for the contract. The name of at least one tunnel boring machine (TBM) was unveiled - Hua Mulan. TBM Hua Mulan will begin boring the westbound (Tuas-bound) tunnel for the line from Tampines North station towards Pasir Ris station from the northern launch shaft. A second TBM has also been lowered in months prior but will commence tunneling work at a later date after Hua Mulan advances a distance away. But yes, we stopped by the Tampines North station site yesterday and could see the banners hanging at the northern launch shaft saying "Congratulations" but due to the angle, could not make out any further words.

CR109 - Tampines North update February 2024

 

25 February 2024 - An aerial view of the contract CR109 work site.

Unfortunately for contract CR109, we were only able to get an update in February for the first quarter of the year. But nonetheless, the visit to the work site has shown some noticeable differences. Excavation work has progressed with soil stabilising work taking place at the sides. You might notice that the work site is rather long and elongated - this is due to the station having an accompanying section of cut & cover tunnel to the south which will allow for a crossover.

CR109 - Tampines North Q1 2023 update

 

30 March 2023

We begin swinging to the eastern end of the Cross Island Line (CRL) phase 1, starting at Tampines North. The site has since been cleared and diaphragm wall works have commenced at the northern end of the station. Meanwhile other preparatory works are still going on further south in the station box.

30 March 2023 - A view of the station site from the south.

30 March 2023 - A close up view of the heavy machinery towards the middle of the station box.

30 March 2023 - On the left is an auger machine and to the right is a soil mixer to improve the
conditions of the soil.

30 March 2023 - Diaphragm wall machines at the northern end of the station.

Currently there is 1 hydrofraise machine and 1 clam shell grabber machine as well. Both are located at the northern end of the station, likely to begin constructing the diaphragm walls for the northern launch shaft. From here, tunnel boring machines will be launched to build the running tunnels towards Pasir Ris station.

30 March 2023 - Slurry betonite silos.

30 March 2023 - A view of the southern end of the work site which includes a crossover box
towards the southern end of the site. Bishan can be seen in the background.

30 March 2023 - A view of the station site from the eastern end, Tampines North bus interchange
can be seen in the foreground.

30 March 2023

30 March 2023

30 March 2023

30 March 2023 - A view of the hydrofraise machine at work. The clam shell grabber was not in use.

30 March 2023

30 March 2023 - A desander machine separates the soil from the betonite slurry and allows the
slurry to be recycled for use again.

30 March 2023 - Contract CR109 site office.

It is great to see that diaphragm wall works have commenced at another station site besides Hougang station. Do stay tuned as we continue to provide updates on the different sites along CRL1.

This post is available on Instagram & Facebook.

CRL1 Video directory

 

Yesterday, the Land Transport Authority (LTA) released a video showing a flythrough of the upcoming Tampines North station along the Cross Island Line (CRL) phase 1. LTA has been noticeably more active in uploading videos of & marketing the CRL across its social media channels. In addition to the new video on Tampines North, they also uploaded another video on the Rectangular Tunnel Boring Machine (RTBM) being used at the Teck Ghee station under contract N109A to construct subways to two exits located within Bishan-Ang Mo Kio park.

CR109 - Tampines North 2022 year-end update

16 December 2022 - An overview of the station site.

 Compared to the last time we were at Tampines North, work has advanced some. During the last visit the works were centred on soil investigation & some site preparation. These have since progressed to site set up with machinery on site & load testing. Heavy machinery is now on site to perform various work activities such as lifting, piling & moving of soil.

CR109 - Tampines North pre-site preparation

A render of the station exit.
Source: LTA & CCCC

19 August 2022 - An aerial view of the station site.

Things have changed slightly since our last visit to the Tampines North station site. The presence of soil investigation rigs indicate that construction works are almost ready to commence. Drainage has been laid on site as well along the rough outline of the future Tampines Avenue 11 which will be extended northwards. The station will lie beneath this roadway.

CRL1 - Detailed station location maps

During the ministerial visit and announcement at Bright Hill station for Cross Island Line stage 1 (CRL1) this morning, there were no exhibits showing the detailed station location maps for each of the 12 stations along the announced section. Additionally, the Land Transport Authority does not appear to have released such maps either. Instead, we have noted various Members of Parliament have been posting these on their social media platforms. Do have a look at some of the more detailed station location plans we've found and we will continually update on any new maps as we come across them.

Edit @ 1634pm - Defu, Serangoon North & Tavistock station location maps added.

Edit @ 0953am on 26 Jan 19 - Aviation Park, Hougang, Ang Mo Kio, Teck Ghee & Bright Hill station location maps added.

Aviation Park station location map.
Source: LTA

CRL1 announced

The Land Transport Authority announced the station locations for Cross Island Line stage 1 (CRL1) this morning at a site visit by Transport Minister Khaw Boon Wan to Bright Hill station. This will be the location of stage 1's western terminus.

Do stay tuned as the official press release becomes available later this afternoon.

Speculated station locations

After collating all the sightings of soil investigation works, we can finally compile a list of probable station locations for the Cross Island Line eastern (CRLe) section. Knowing that the line stretches from Changi to Bright Hill, here's our list of the speculated stations.

Speculated alignment of CRLe

Credit: y2koh

Soil Investigation: Tampines North

Spread of soil investigation boreholes around Tampines North as of 07 August 2018.

As far back as 2016, boreholes have been spotted in the vicinity of Tampines North area. Additional boreholes have also been noted around Tampines Industrial Avenue 2 with some as recently as May 2018. It is expected that the line will cut through the existing Paya Lebar Air Base to connect to the Defu area which was covered in our previous post.