World first: a hollow propeller blade produced by 3D printing!

Additive manufacturing in stainless steel

The design work for 3D printing of this container ship propeller blade was carried out at the Joint Laboratory of Marine Technology, founded in 2016 by Naval Group, Centrale Nantes and the University of Nantes (France).

This one-third scale prototype paves the way for producing a propeller with a diameter of 6 metres (2 x 3-metre blades), which was previously unfeasible using traditional foundry methods. The method used – additive manufacturing – which involves depositing layer-upon-layer of wire, has several advantages over conventional manufacturing by moulding.

Lightweight, high-performance propellers

First and foremost, 3D printing can lead to savings of up to 40% of propeller mass, thus reducing manufacturing costs. In use, the propeller obtained has better propulsive performance along with reduced fuel consumption. The icing on the cake is that the new geometrical characteristics of the part appear to reduce radiated noise (i.e. noise produced by the blade in the water), as well as the vibrations felt on board.

It should be noted that this work was carried out as part of European project H2020 Ramsses, which aims to reduce the environmental impact of ships. According to Patrice Vinot, Naval Group’s Propeller Package Manager for the Ramsses project “printing hollow parts opens up very interesting possibilities for designers to improve propeller performance.”