by Rachael Bower-Yekpe | Mar 2, 2026 | Water
After 17 days of meticulous tunnelling — passing just 66 cm beneath two major wastewater pipes — a 1,730 mm (external) / 1,400 mm (internal) diameter microtunnel in Port-Jérôme-sur-Seine (near Le Havre) is now complete. The 159‑metre-long microtunnel will double...
by Rachael Bower-Yekpe | Dec 11, 2025 | Oil & Gas
OPTIMUM is proud to have accompanied NaTran throughout the trenchless works — a combined 1300m across two microtunnel crossings — successfully completed yesterday near Aix-en-Provence in southern France.Installed at more than 25m deep, this crossing will ensure the...
by Rachael Bower-Yekpe | Mar 20, 2025 | Water
The CanaMarne project is entering its final phase, the last of the AVN 1800 tunnels having been completed this week. This latest gravity flow tunnel runs 500 metres underneath agricultural land and a major canal to the east of Paris. Works spanned 5 weeks, with teams...
by admin-optimum-549 | Dec 21, 2024 | Electricity
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. After the successful...
by admin-optimum-549 | Dec 5, 2024 | Water
Having powered 835m through marl and gravel, AVN 1800 microtunnel « Magali » successfully finished tunnelling this week. This curved section is the longest and largest microtunnel in the 9km long CanaMarne project (3km microtunnel, 6km open trenches) which will...
