First 3D printed screw propeller ready for use

Following the example set by the automotive, medical and aviation and aerospace industry, the shipbuilding industry is now discovering the advantages of 3D printing. After several tests and prototypes the first fully 3D printed screw propeller, developed and finished by a team of engineers in the Netherlands, is now ready for use at sea.

The WAAMpeller - 1.35 m long and 200 kg in weight - was officially presented at Damen Shipyards in Gorinchem, Zuid-Holland.

The screw was manufactured by means of WAAM technology (wire arc additive manufacturing) and is the result of a close cooperation between the Damen Group, screw manufacturer Promarin, Bureau Veritas and RAMLAB (Rotterdam Additive Manufacturing LAB) of the Port of Rotterdam, who joined their knowledge and resources for this project. The WAAMpeller was extensively tested afterwards to verify that it was suitable for the intended purpose.

Baptism of fire 

In August the first prototype was ready, a second, greatly improved prototype followed in the autumn. Improvements mainly concerned the hardware/software interaction because, when laying down 298 layers of Nickel Aluminium Bronze alloy, it is important to have a tight control on all process parameters. 

The second prototype was installed on a Stan Tug 1606 (towboat) to check how it would behave in real operational situations at sea. These tests are expensive, because the components have to meet the strict environmental rules and regulations applicable in all ports around the globe. Also scenarios involving speed and crash stops were extensively tested because these exert a lot of pressure on the screw. The 3D printed screw displayed the same behaviour as a conventional cast propeller in all of the tests. 

After the last challenge was overcome, the final product became technically reliable and ready for commercial use. The project, which was accomplished in only seven months, therefore succeeded in demonstrating the potential of 3D printing techniques for the ship building industry in the production of vessel parts.

Importance of AM for ship building industry

When a ship enters a port for the replacement of a specific part, it may take weeks or even months before it is available. Result: millions are lost by companies and they are required to store spare parts in a warehouse. Thanks to additive manufacturing (AM) these parts can be made in just a few days time. In case of the WAAMpeller, the WAAM technology was used, a process which involves welding steel with a flame arc. The parts were finished by means of traditional CNC milling. Such an approach stands for time and money saving, precision and premium performance.

(Images: Damen Shipyards)