Stevens - Excavation Completes

Excavation works for the station box are largely completed down to the paid linkway level, with the dismantling of the temporary earth retaining structural system commencing concurrently. Architectural works for certain portions of the concourse level have started ahead of the overall station BSC due to the delay in the project timeline.

The opening of TEL3 is currently being dragged by the progress of the station, which at present estimate is likely to be delayed by up to 6 months.

TEL3 Tunnel Progress, March 2019. The final TBM 4 is projected to breakthrough at Napier by the middle of Q2.

Stevens Station

Stevens - TBM 2 Completes

Excavation works for the Woodlands bound tunnel from Mount Pleasant to Stevens completed today with the docking of TBM 2 outside the d-wall of the station. The NFM slurry machine was launched in September 2016, having spent the last 2 years completing the 1.44km tunnel drive. The final month of tunnelling works proceeded cautiously between the stacked DTL tunnels, as well as beneath the Wayang Satu Flyover and Bukit Timah Canal.

Its sister machine is approximately 100m behind and is similarly scheduled to dock at the station next month.

TEL3 Tunnel Chart - September 2018

Docking of TBM 2 (left) at the D-wall of Stevens Station (Photo: Oop Pocca)

Outram Park - Tunnelling Completes

Tunnelling works for the T222 project have completed following the breakthrough of the third drive (TBM 1 refurbished) along the Woodlands Bound tunnel on Apr 27 and the fourth drive (TBM 2 refurbished) along the Changi Bound tunnel on Jun 21 between Outram Park and Havelock Station (800m).

This is the final tunnel to be completed under the C4 team, and the second final project along the overall line to complete bored tunnel excavation works.

Breakthrough of the NFM EPBM at Havelock Station, Woodlands Bound (April 27, Photo: Ram)

Shenton Way - Tunnelling Completes

Bored tunnel works for the T225 project completed in the early hours of today with the docking of TBM 2 at Maxwell station. Tunnelling works were unique in this project due to the stacked configuration of the 2 launch shafts, one of which is within the permanent structure of the station. Geological constraints were also experienced beneath McCallum St resulting in prolonged delays and the eventual re-sequencing of the TBM drives.

T225 is the 3rd last team to complete tunnelling works for the line, ahead of T222 later this month and subsequently T216 in Q4.

Upper/Changi Bound tunnel towards Maxwell completed by TBM 2

Final TBM Assembly

Assembly works for the final TBM for the Thomson Line (C1-C4) are in progress at the Dalvey Launch Shaft for the 300m Woodlands bound tunnel towards Stevens Station. The said TBM is a refurbished STEC Earth Pressure Balance machine previously used on the line which had been additionally procured by the project team in an effort to achieve the crucial basic structural completion for TEL3 by the end of the year. The 5th machine supersedes the intended second drive of the NFM TBM 3, which is currently still excavating the Woodlands Bound tunnel towards Napier.

The choice of using an EPBM as opposed to the existing Slurry TBMs is likely due to the constraints for the Slurry Treatment Plant, which was designed to only accommodate concurrent tunnelling works for TBM 3 and 4. Favorable geological data obtained from the previous excavation of the parallel Changi bound tunnel likely bolstered the decision of using an EPB shield.

The TBM was lowered down in the second week of May and is scheduled to commence mining next month.

Internal assembly of TBM 5 being executed at Dalvey LS

TEL3 Tunnel Progress, June 2018

TEL2 Tunnelling Completes

Bored tunnel works for Stage 2 of the line completed with the breakthrough of TBM 2 last Thursday, completing the Changi Bound tunnel between ULS and Caldecott Station. The TBM is the last of 23 TBMs along the northern half of the original Thomson Line to dock. 

Dismantling of the TBM, cross passage, FSC and bracket installation works will proceed within the next quarter prior to reinstatement of the ULS site by year end.

Completion of bored tunnel excavation works for TEL1 and TEL2

Breakthrough of the T212 JTSC TBM 2 at Caldecott Station on April 12 (Changi Bound)

Marina South - Tunnelling Completes

Tunnelling works for the T227 project have completed, with the breakthrough of the Changi bound tunnel between Marina South and Marina Bay achieved today following the relaunch of the TBM in January. The average advancement rate for the second drive was significantly high at around 7 rings/day.

Breakthrough of CREG TBM at Marina Bay Station on April 14, completing the EPBM's second and final 750m Changi bound tunnel drive between both stations

Great World - Tunnelling Completes

RC works are in progress at the station and entrances, with pipe jacking works for the subway beneath Kim Seng Road underway. Both Changi-bound tunnels to Havelock and Orchard have completed, wrapping up tunnelling works for the project.

Breakthrough of Herrenknecht S-946 at Havelock Station on March 27, completing the Mixshield's second and final 500m Changi bound tunnel drive between both stations (Photo: Padraig Higgins, HK)

Mount Pleasant - Basic Structure Completion

The station achieved the basic structure completion at the beginning of the year, with backfilling works done up. RC works for the entrance and ventilation structures are progressing at ground level. 

A completed portion of the staging ground has been hoarded up in preparation for partial handover to T250. The remaining uncompleted portion around launch shaft 9 will be handed over following the complete dismantling of the TBM, backfilling and casting of the trackwork access opening.

Backfilled compacted hardcores over the completed station structure

Upper Thomson Cast (III)

Excavation works by TBM 3 concluded earlier this week, completing the 960-ring Woodlands Bound tunnel between the Upper Thomson Launch Shaft and Caldecott Station. TBM 2 will similarly arrive in a month's time, thereafter concluding tunnelling works for the first 2 stages of the line.

Casting of the station, entrances and ventilation structures are progressing, with basic structure of the station targeted to be achieved after the next quarter.

Completion of the 1.35km Woodlands bound tunnel bored by TBM 3 between ULS and Caldecott Station

Breakthrough of the Japanese TBM at Caldecott Station on March 12, 2018, concluding 16 months of tunnelling works

February Tunnel Progress

The T215 and T217 projects have successfully completed all tunnelling works this week with the docking of the 2 Herrenknecht Mixshield TBMs at the Caldecott cripple siding tunnel and Napier station respectively. 14 bored tunnel drives remain - bulk of which would be completed in the second quarter of the year.

The next breakthrough will take place at Caldecott by TBM 3 under the T212 project around end Feb/early March. Its sister TBM 2 will subsequently arrive approximately 6 weeks later, concluding the tunnelling works for Stage 2 and TELC2 in April.

TEL1/2 Tunnel Chart (January 2018)

Gardens By The Bay - Tunnelling Completes

Tunnelling works for the T228 project have completed ahead of schedule, with the Hitachi Zosen EPBM breaking through the station d-wall from the return Changi bound tunnel drive earlier this month. RC works for the station's internal structure continues, with excavation works starting at entrance A. Preparations for the reinstatement of Marina Gardens Drive over the completed subway are in progress with implementation scheduled next quarter.

Gardens By The Bay station

Marina South Cast (IV)

RC works for the internal structure of the station continues up to the roof slab. The TBM has completed the Woodlands bound drive to Marina Bay and reassembly works for the Changi bound drive have begun with the dismantling of the backup gantries & assembly of the heavy lift crawler crane on site. The relaunch of the TBM is scheduled next quarter - the 2nd last to be facilitated along the TEL1-3.

Marina South station

Shenton Way Cast (IV)

Casting of the internal structure within the station is ongoing concurrent with the excavation and RC works at the unpaid linkway. Excavation works for TBM 1 has resumed with a further 100 rings advanced this quarter. In view of the lost time caused by the challenges at McCallum St, the project team is re-using TBM 2 to complete the Changi bound tunnel towards Maxwell. The TBM commenced mining works today, making it the 3rd last TBM relaunch along TEL1-3.

Shenton Way Station

Great World Cast (IV)

Reassembly of the 2 Herrenknecht machines took place this quarter, nearly a year after the initial 2 launches were carried out. EPBM S-945 commenced on its initial drive back to Orchard, while the mixshield has almost completed assembly works and would begin excavation works next month. RC works are in progress at the station and entrances, with pipe jacking works at the subway beneath Kim Seng Road set to commence next month.

Entrance B & subway link roof slab cast

Stevens Diverts (IV)

The final and semi-permanent traffic diversion stage 5 has been implemented, which sees the worksite for the basement excavation and casting works situated in the center of both carriageway following the completion of the entire station roof slab. This layout is rarely preferred as it severely limits the working space and site movement of the construction activities, however necessary as the most optimal solution so as to not disrupt access from the residential apartments and side roads along both sides of the road.

Excavation works at the station to the concourse slab is in progress with the first section of the concourse slab cast. D-walling works are in progress at entrance B. The RTBM drive is almost completed and will reach the escalator shaft wall within the next few days.

Stevens station with TD5 implemented

Lentor - Tunnelling Completes

Bored tunnelling works for TBM 1 completed earlier this week, concluding the 18 months long Changi bound tunnel drive from Lentor to Mayflower station through the 5XO site. Its sister TBM 2 is 91% out of the 970-ring drive and targeted to complete by the end of the month. The tunnel roof structure of the 5XO is completed and backfilling works have commenced. Structural works for the station entrances are progressing on the surface level.

Lentor Station

November Tunnel Progress

Bored tunnelling works progresses across the line, with multiple TBM breakthroughs due around the new year of 2018. The Changi bound tunnel was completed at Orchard last month, completing all bored tunnel works under the T219 project - the first project to do so along TEL3.

TBMs with envisaged completion between Dec 2017 and Jan 2018:

T209 TBM 1&2

T212 TBM 1

T215 TBM S-936

T227 TBM 1

T228 TBM 1

TEL1/2 November Tunnel Progress (No change since Sep)

Shenton Way Excavation (III)

Bored tunnelling works between Marina Bay and Shenton Way stations have completed with the second and final drive of TBM 2 docking at the upper platform of the station. FSC works have commenced for the lower tunnel. The porous geological conditions around the former shoreline beneath Shenton Way has created an ongoing challenge for TBM 1 since its launch in April, which has progressed little since its main drive conversion.

Bulk of the station's structure has reached the under-lower platform level, with a final zone of excavation works due for completion within a month. Excavation and shoring works have commenced at entrance C.

Completion of 144-bored pile linkway between the station, entrance C and Asia Square

Great World Cast (III)

Excavation works have reached the formation level and the first zone of the station's underplatform level is being prepared for casting. Casting of the internal structure and external walls will proceed from here.

The first drives of both TBM S-945 & S-946 have completed and the replacement TBM shields have arrived at the site of both launch shafts in preparations for the relaunch.

T220 Great World station