June 9, 2026
CNN MCO on the scene in Brest for the BCR Somme’s final technical stop
In Brest, our CNN MCO teams are currently working on a major project: the final major technical overhaul of the BCR Somme, an iconic French Navy vessel that has been in service for over 30 years.
Here’s our report.
A strategic ship nearing the end of its service life
The BCR Somme is a Command and Supply Ship that entered service in 1990. At 157 meters long, it is one of the largest vessels in the French Navy still in active service. It resupplies other ships at sea with fuel, provisions, and equipment.
Originally scheduled for 2027, its decommissioning has been postponed to 2028 to ensure a smooth transition to the new resupply ships. This final technical overhaul is therefore intended to ensure its operational capability until the end of its service.
A large-scale project involving multiple tasks
This maintenance shutdown, which began in early 2026 in Brest, involves a wide range of expertise over several months. On average, 60 workers are on site each day, and more than 30 companies (suppliers and subcontractors) are involved.
The work, which will last 22 weeks, covers the entire ship. A significant portion of the equipment is being dismantled for inspection, repair, or replacement in the workshop before being reinstalled on board.
At the same time, work is being carried out directly on systems that cannot be dismantled.
The project also includes specific operations to degas the tanks, carried out over a period of 4 weeks, followed by a tank-filling phase lasting 1 week prior to the vessel’s return to service.
Among the projects currently underway are:
- Maintenance of the main engines and propulsion systems;
- Technical work on shaft lines, propellers, and gearboxes;
- Inspection of fuel tanks, including cleaning and inspection of internal structures;
- Work on the hull (cleaning, treatment, and repainting) ;
- Inspection of refueling equipment.
Certain specific operations include on-site machining to ensure the vessel’s watertight integrity, and the replacement of damaged components with parts sourced from older ships.
All of this work requires the ship to be in dry dock for 14 weeks and undergo dock trials for 3 weeks.
The need for rigorous organization and a high level of technical expertise
A technical shutdown of this magnitude required several months of advance preparation, in line with the needs identified by the French Navy.
On-site, 10 CNN MCO employees are coordinating the numerous contractors involved. Depending on the phase of the project, up to a hundred different trades may be involved, making project management a major coordination challenge. Activity thus varies between very intense periods (disassembly, reassembly) and workshop phases, where the equipment is processed. It is also necessary to coordinate with the crew, consisting of approximately 150 sailors, who participate in certain maintenance operations alongside the technical teams.
Safety remains a key priority, with strict procedures and constant monitoring of personnel on board.
CNN MCO, Pilot Program for Maintaining Operational Readiness
CNN MCO is overseeing the overall operations. It’s a complex project, but one we’re used to: since 2016, our teams—made up of former sailors—have been responsible for maintaining the French Navy’s BCRs in operational condition. And CNN MCO had already been involved in the technical overhaul of the BCR Somme in 2019.
Our role is extensive:
- coordinating the work,
- facilitate communication between our team members and the crew,
- monitor the progress of the project,
- ensuring compliance with deadlines, budgets, and technical requirements.
CNN MCO also stands out for its expertise in managing end-of-life vessels. This in-depth understanding of issues related to aging equipment allows us to tailor our interventions and optimize technical choices to extend the service life of the vessels.
This project is part of a broader effort to maintain amphibious helicopter carriers in operational condition, including the Tonnerre’s ATI currently underway in Toulon and the Dixmude’s ATM, for which operations are being prepared for the start of the new school year, illustrating CNN MCO’s ongoing commitment to serving the fleet.
An imminent return to normal operations before missions resume
After several months of work, the BCR Somme is set to be relaunched soon. Two days of sea trials are scheduled to verify that the systems are functioning properly. Then, until it is decommissioned in 2028, CNN MCO will continue to support the French Navy in the technical monitoring of this iconic vessel.
To learn more, read the article published in Mer et Marine in May 2026: https://www.meretmarine.com/fr/defense/a-brest-cnn-mco-acheve-l-ultime-arret-technique-du-bcr-somme
