Stage 3 breakthroughs

Over the past month or so, several breakthroughs have been taking place along the Downtown Line stage 3, with the latest being at Geylang Bahru station. Under Contract 933, contractor Penta-Ocean Construction is building 4 tunnels out of the Bendemeer station. TBM3, named Bendemeer, which is manufactured by Herrenknecht as machine S-740 bore the Bukit Panjang-bound tunnel towards Geylang Bahru station. The tunnel enters a stacked configuration shortly after leaving the Bendemeer station with an escape shaft being constructed near the Whampoa River. Launched in February 2013, the machine finally docked at Geylang Bahru station.

DTL3 Tunnel Chart for June 2014

S602 Breakthroughs, BP Bound Completes

Completion of all bored tunnels within DTL2

At last, the final TBM (S602) has docked into Sixth Avenue Station, concluding 36 months of tunnelling works for the entire Downtown Line 2 when S548 was first launched at Beauty World on 8 June 2011. McConnell Dowell, which coordinated this final TBM docking at Sixth Avenue, is the same contractor which facilitated the inaugural TBM launching at Beauty World 3 years ago. CP1&2 has been excavated and supported, while the last cross passage 3 is currently being mined.

We'd like to acknowledge Herrenknecht, Kawasaki and Hitachi Zosen, the manufacturers for the 19 TBMs along Stage 2. Herrenknecht AG has a renowned history in producing the quality S-number TBMs of various sizes and uses since 1975. The local demand for their machines have steadily grown over the years since the successful implementation of S134 and S135 between Farrer Park and Boon Keng stations along the North East Line. A further 9 machines were procured to construct the southern half of the bored tunnels for the Circle Line. 22 machines had been ordered throughout DTL2 and DTL3, and more will come with the increasing demand of upcoming metro lines.

Kawasaki from Japan delivered 5 machines that were ordered under GS and SK for Contract 913 and 915. Most of their machines used in Singapore are of the slurry type, with a few currently involved in the SP cable tunnel project. Hitachi Zosen supplied STEC 4 Earth Pressure Balance Machines under C920.

These sophisticated machinery would not have been able to operate without the hundreds of men working beneath the surface under immense pressure and poor ventilation. A very big thank you to the tunnelling team from all nationality.

Below is a flashback of the earlier few TBM launches along the stage.

Inaugural launch at Beauty World

S605 Breakthroughs, Expo Bound Completes

The last frontier of the 16.6km long Expo Bound tunnel for the entire Downtown Line 2 has just been successfully broken through at Botanic Gardens station at 9am this morning. S605 has come a long and arduous journey from the moment of launch, facing many challenges posed by the alternating layers of mix ground and aggregates, as well as tunnelling below existing bridge, canal and tunnel infrastructures without compromising their structural integrity.

The finale breakthrough of S602 would take place at Sixth Avenue station later this month.

Breakthrough of S605 at Botanic Gardens (Photo credits - Alix Thierart)

DTL2 Tunnel Chart, Early June

Frequent updates throughout 605's tunnelling phase made possible by Masud & Bidhan, (Dongah-ACL group)