French defence contractor
Naval Group has successfully 3-D printed a next-generation propeller using its own DED-based process called metal wire fusion. Mounted on the propellor shaft of the Andromède, a Tripartite minehunter, it is now in service with the French Navy.
The propeller, which has a 2.5m span and is supported by five 200kg blades, left Naval Group’s Nantes-Indret facility in October 2020 to be mounted on the propellor shaft of the Andromède in Brest. Sea trials were then performed successfully at the end of December.
Emmanuel Chol, director of the Nantes-Indret facility, said: “Obtaining the necessary military naval quality requires rigorous development. Nearly three years of R&D — carried out by the technical and innovation department in cooperation with the Ecole Centrale de Nantes within the framework of the LabCom Joint Laboratory of Maritime Technology — went into the development of the deposition process of metal wire fusion.
“It is the largest metal 3D-printed thruster ever to have been manufactured and the first-ever propeller produced using this technology, and manufactured for use beyond just sea trials.”
The harsh conditions in which ships are used warrant the need to meet strict requirements (corrosion, fatigue and shock resistance). Naval Group worked together with Bureau Véritas throughout the process to present its technical justification file in order to allow the Fleet Support Services and the French Defence Procurement Agency to authorise the trial of the blades produced for a military ship in normal operating conditions. The blades received certification from Bureau Véritas.
Eric Balufin, director of the Naval Group site in Brest, said: “The assembly of this 3-D printed propeller shows great promise for the future. This new technology will enable us to considerably reduce technical constraints, and therefore allow for new manufacturing solutions for complex geometrical shapes which cannot be produced through conventional manufacturing processes. It will also enable us to greatly reduce production time and in-service support as a result.”
This propeller is a first step. A new development phase will now begin, aimed at revamping the detailed design of other parts so that they benefit from 3-D printing in areas that include acoustic discretion, weight reduction and increased productivity of parts.