BESSAC teams continue to make significant progress on the construction of the Ang Mo Kio station and its ancillary structures (CR116 project) in Singapore, as well as on Lot 4 of the Toulouse metro. Both projects involve demanding tunnel boring operations, marked by technical challenges successfully overcome and steady advancement.
CR116 – Singapore: a Controlled First Drive and Major Technical Innovations
The CR116 project involves the construction of the Ang Mo Kio metro station in Singapore and several associated structures. The first 200-meter tunnel drive, successfully completed in July 2025, confirmed the reliability of the methods implemented and the client’s satisfaction.
The passage beneath ongoing civil works was completed without incident: no surface settlement was detected, despite a minimal cover equivalent to one tunnel diameter.
Following this achievement, a complex operation to dismantle and reassemble the tunnel boring machine (TBM) was launched in the adjacent shaft. This phase introduced two major technical innovations designed to enhance safety and productivity:
The first innovation concerned the disassembly of the front and intermediate shields, carried out in several sections using integrated hinges and keys similar to those used for segment rings.
The second focused on dismantling the cutterhead, for which a secure hydraulic tilting system was developed with our subcontractor, allowing the cutterhead to be safely rotated. Used for the first time in Singapore, this system is now the subject of a patent application.
Toward an Optimized Second Drive
The TBM reassembly phase was completed in mid-October, enabling the start of the second drive. This new cycle fully benefits from the lessons learned during the first launch: several technical adjustments have already proven advantageous in terms of efficiency and reliability.
With four drives planned in total, the CR116 project offers an ideal platform for experimentation and continuous improvement. Each stage provides an opportunity to optimize methods, ensuring progressive skill development and enhanced technical mastery of the project.
Toulouse Metro Line 3 – Lot 4: Successful Tunneling and Preparation for Dismantling
On October 14, 2025, the tunnel boring machine Marguerite de Catellan completed its journey on Lot 4 of the Toulouse metro, after excavating 4.2 km of tunnel and 150 meters of station sections.
Having resumed operations at the end of August from Jean Rieux – Côte Pavée station, the TBM successfully crossed the most sensitive section of the route, both geologically and environmentally.
To pass beneath the SNCF railway lines, the Port Saint-Sauveur district, and the Canal du Midi, teams maintained an intensive pace of excavation—seven days a week.
Dismantling of the TBM began immediately after breakthrough, with a 750-ton crane positioned at the foot of the Canal for the lifting of the cutterhead.
Civil works are progressing according to the initial schedule, allowing teams to complete the stations under construction within the planned deadlines.
Congratulations to all BESSAC teams!
