Châtelier lock: Dredging workshop in “4 ballast drive” mode!

The NESSIE robot carried out an impressive dredging operation at the Châtelier lock (lock no. 48) located in the commune of Saint-Samson-sur-Rance in Brittany. The job, humorously described as a “4 ballast drive” in allusion to off-road 4x4s, is further proof of NESSIE’s versatility and power in complex environments.

Site history

The Châtelier lock, commissioned in 1832, is part of the Canal d’Ille-et-Rance, a strategic waterway built during the Napoleonic era to link Rennes to Saint-Malo and provide a connection between the English Channel and the Atlantic Ocean. The lock, located at the canal’s outlet into the Rance river, has been modified several times over the decades to improve its functionality, notably with the addition of a floodgate to better manage the tides.

Dredging operation

As part of this intervention, the NESSIE robot was deployed for deep dredging. Dredging is a key operation to ensure the smooth operation of the lock, by removing naturally accumulating sediments that can interfere with water level regulation and the efficiency of the sluice systems.

Thanks to its advanced technical capabilities and maneuverability, NESSIE was able to intervene with precision despite the difficult conditions, both for the lock structure and due to the influence of the tides. Its four ballasts give it the stability and flexibility needed to work safely in this type of environment, while limiting the environmental impact of the operation.