NEWSROOM

Construction of the onshore link from the coast to RTE’s converter station is in full swing. The 84-metre-long AVN 1200 microtunnel section under the River Élorn and the Paris – Brest railway is now complete and the cable ducts installed.

Completion this week of an important phase of RTE’s Envision project with the successful installation of a 130-metre-long microtunnel near Arras in northern France. Within the framework of the project owner’s network extension, the DN1200 microtunnel now passes under both the Paris – Lille highspeed railway tracks as well as the 6-lane A1 motorway, two of the country’s busiest transport links.

Proud to have accompanied project owner RTE for the successful completion of a new microtunnel under the River Neste at the foot of the Pyrenees in southern France. The project falls within the framework of RTE’s ongoing network renewal and extension in the region. Despite the relatively short tunnel length, the 65-metre-long, 12-metre-deep, AVN1800 microtunnel merited close monitoring, given the complex and varied geology of the area. The hard and abrasive nature of the successive alluvium, limestone, marble and granite blocks, made for challenging conditions and called for supervision by trenchless specialists.

Proud to announce the successful first phase of RTE’s Chevalet project, which was completed this week in northern France. The 130-metre-long, 1.5 metre wide microtunnel, carried out by EIFFAGE GENIE CIVIL RESEAUX, crosses under the A1 motorway as well as the high-speed Paris - Lille railway link. The Chevalet project, part of France’s renewable energy development programme, called for in-depth geotechnical analysis and engineering design, which was carried out by OPTIMUM from 2020 to 2022 in collaboration with RTE’s project team. OPTIMUM also accompanied RTE during the contractor selection phase and monitored the construction work, which took place between January and April 2024, ensuring all environmental, technical and regulatory constraints were respected.