August Tunnel Progress

Tunnelling for DTL3 is on track of wrapping up with the further confirmation of 3 more completed tunnels between the Stadium shaft and Tampines West station, and Mattar and Macpherson station in the last quarter. These 2 TBMs will relaunch at the stadium shaft eastwards to Tampines Central station. The expo bound machine has just launched last night (Aug 30), while the new shields of the Bukit Panjang bound machine can be seeing at the top of the shaft.

Over at the prison shaft, there was a slowdown in tunnel progress due to management issues within CMC the past year. With the issued resolved, tunnelling progress has hasten with an average of 4-5 rings per day. The expo machine is now at ring 586 out of 818 rings (~72% completed). The BP machine is at 433 out of 836 rings (52% completed). Both machines will breakthrough in 3 to 4 months, before re launching back at prison shaft for the drives to Tampines West station. The final TBM launch for the entire Downtown Line will be undertaken by these 2 machines, estimated in January 2015.

Over at Tampines East, GS is doing up its final preparations for the re launch of its TBM that will bore the Bukit Panjang bound tunnel from Tampines East to Tampines Central. The tunnel works will pose a slight challenge this time round as the TBM tunnels right beneath the foundation of the existing Tampines Regional Library. The machine will launch in 2 weeks and breakthrough at TPC in January 2015.

DTL3 Tunnel Chart - August 2014

Overview of Stadium Shaft

Tan Kah Kee

The roof slab of the station has been completed at Tan Kah Kee and the excavation pits have been covered. The entrance can be seen in the pictures and the superstructure will be coming up from the 4th quarter onwards.

Backfilled C&C tunnels

Drawn by Seloloving, Skyscrapercity

Photo of TKK in Q4 2012. The excavation pits can be seen by the STP

Existing photo of the site which has been backfilled

Bukit Panjang bound tunnel from TKK C&C to Sixth Avenue

Botanic Gardens

Alongside Stevens, the superstructures at Botanic Gardens have risen quickly within the past 4 months. The cooling tower and lift shaft is completed. The entrance structure is being worked on.

Drawn by Seloloving, Skyscrapercity

Aerial view of the entire station

A render of how the Botanic Gardens station exit will appear when the station is completed.

Stevens

The magnificent structure at Stevens has started taking shape since our last update in May. The exit structure will be integrated with the cooling tower, vent shafts, taxi stand and bus stop. This will be the first stacked station to not feature any escalators or stairs within the paid area. 

Under the DTL project, Stevens will initially open with its main entrance E along Bukit Timah Road. The remaining entrances will be completed under the TSL project in 2021. Drawn by Seloloving, Skyscrapercity

A render of what the Stevens station exit will look like once completed.

The entire station layout is extremely complicated as the architecture maximizes the amount of end to end connections between the various exits, concourse and platform levels. Below is a simplified layout.

B1 - TSL Concourse

B2 - DTL Expo Bound Platform/ Future TSL mezz & canal linkage to Entrance C and D

B3 - DTL mezzanine/ Future TSL platforms

B4 - DTL BP Bound Platform

A rough guide of the Stevens station cross section, done by y2koh, Skyscrapercity.
*B2: canal linkage to Entrance C and D is not directly linked to DTL platform/concourse
*B3: DTL mezzanine & Future TSL platforms will not be directly linked

There will be 2 lift shafts. The south shaft will connect the surface to both unpaid levels. The north shaft will connect the surface to an initial unpaid areas at the north end of both platforms. These unpaid areas will eventually be converted to paid areas for the linkage between the TSL transfer levels, and the faregates will be relocated to the street level.

Additions to the DTL structure under the Thomson Line project:

• A further 2 lifts will be constructed at the roof of the DTL station in the future to link the TSL concourse to the surface of entrance E. (Ground level to B1) 
• A third lift will be constructed directly below the Wayang Satu Flyover to link the TSL Concourse, canal subway and DTL mezzanine. (B1, B2 and B3)

Vent Shaft 2 taking shape at the corner of the station. A future taxi bay will be located here when Robin Walk reopens

Newton

Following the partial reinstatement of Bukit Timah Road in June, the remaining structure of the entrance and vent shaft have begun to form. The launch shaft have almost been completely backfilled and a future pavement can be seen forming. The full road reinstatement should take place by year end. The escape shaft at City Towers also has the POB landing reconstructed.

Newton station - Drawn by Seloloving, Skyscrapercity

A render of what the Newton station exit will look like, done by SAA Architects.

The structure of Entrance C taking shape 

Little India

M&E and Architectural works are in full swing within the Little India station.

Entrance E and F are new additions to the interchange under the DTL project. Also included are A&A works to Entrance A and C for the construction of lift shafts. Piling and Excavation works are currently underway respectively. Drawn by Seloloving, SkyscraperCity

Architecture works above the platform level

Entrance F and E over the new backfilled Rochor canal

Rochor

We kick start our Q3 updates for Stage 2 with Rochor. Works on the super structures have progressed throughout the past 4 months and is nearing completion. Casting and waterproofing works for the future North South Expressway tunnels are on-going. Backfilling works should commence and complete by year end. Jointly updated with C921 SSY FB.

Schematic map of Rochor station - Drawn by Seloloving, SkyscraperCity. This shows the location of the station's
entrances, which are both barrier-free accessible. Also shown is the covered walkway network which will extend 400m
from the station entrances.

Platform of Rochor Station

3 Superstructures - Entrance A&B in the background, cooling tower in the foreground

Downtown Line 3 Extension

This morning together with the announcement of the eastern stretch of the Thomson-East Coast Line (TEL), the locations of the Downtown Line 3 Extension (DTL3e) were announced. The extension stretches 2.6km and will see two new stations being added to the existing and upcoming Downtown Line.

Realignment of Upper Bukit Timah Road

The 9th Traffic Diversion (TD9) for C916 has been successfully implemented at the Beauty World site yesterday, realigning Upper Bukit Timah Road over the backfilled-crossover tunnels. This traffic diversion saw a 3-day closure of Chun Tin road over the National Day weekend as the project team rushed the necessary road resurfacing works. Works may now proceed for the entrance that is to be located in front of Beauty World Plaza.

Southbound road now operates as a 2 lane carriageway

Miscellaneous works to reinstate the walkways around the shophouses

Looking towards the station side where the entrances' structure is beginning to surface

Downtown Line 3 shafts

Some readers were wondering what are Prison, Stadium and PIE shafts. So thought it would be a good idea to explain in a post what these are and where they are located that more people may understand.

In essence, the three shafts are cylindrical-shaped shafts that are constructed from ground level down. Once excavation has completed, these are used to launch 2 TBMs twice, once for each bound in each direction. For instance, TBM A will bore the Expo bound track from the shaft to station 1. TBM A will then be brought back once that drive has been completed and relaunched for the Expo bound track towards station 2. Once the drives are completed, a cross-passage (emergency walkway that connects both tunnels) will be built within the shaft prior to it being back filled.

An exhibit explaining about the shafts on 11 July 2013 - DTL3 tunnel works commencement ceremony

Construction sequence