A prototype of the WAAMpeller – the first 3D printed class approved ship’s propeller – has been produced by a consortium of companies including Damen Shipyards Group, RAMLAB, Promarin, Autodesk and Bureau Veritas. The prototype WAAMpeller will be used for display purposes, and plans for a second example with class approval are underway ahead of an installation on one of Damen’s tugs later in the year.
Fabricated from a nickel aluminium bronze (NAB) alloy, the 1,350mm diameter and 400kg propeller was created at the Rotterdam Additive Manufacturing LAB (RAMLAB) in the Port of Rotterdam with the wire arc additive manufacturing (WAAM) method using a Valk welding system and Autodesk software.
"For large scale 3D metal deposition, the WAAMpeller is really ground-breaking for the maritime industry," says Wei Ya, postdoctoral researcher from the University of Twente at RAMLAB. "This technology is a fundamental change in the concept of how we make things. With additive manufacturing, you can print most metallic components that are needed in principle. There is so much potential for the future – these techniques will have a big impact on the supply chain.”
The propeller is also a milestone in 3D printing techniques, being a triple-bladed structure which uses the Promarin design used on Damen’s Stan Tug 1606. “The challenge has been to translate a 3D CAD file on a computer into a physical product. This is made more complex because this propeller is a double-curved, geometric shape with some tricky overhanging sections,” explains Kees Custers, project engineer in Damen’s R&D department.
Extensive testing of the printed material for tensile and static strengths was required to ensure compliance with Bureau Veritas standards. Three-dimensional materials display different physical properties in different directions, while steel or casted materials have the same properties in all directions. Material characterisation and mechanical testing have ensured that material properties can meet the needs of the application, while also optimising production strategy for 3D metal deposition.
The WAAMpeller will be CNC milled at Autodesk’s Advanced Manufacturing Facility in Birmingham, UK.