3D printed propeller is milestone is spare parts

Last week the world’s first Class approved 3D printed ship’s propeller was unveiled at the Damen shipyard in Rotterdam. The propeller dubbed WAAMpeller owes its name to the process by which it was produced (Wire Arc Additive Manufacturing) and was made possible by close collaboration between The Port of Rotterdam’s RAMLAB, Promarin, Autodesk, Bureau Veritas and Damen.

The propeller has been rigorously tested on a Damen tug proving that 3D printing is viable for components that are subject to harsh operating conditions. Previous use of 3D printing for ships spares was limited to simple components such as palm-sized plastic fans for motors produced in a project by Maersk.

The propeller tested recently was the second produced by the partners in the Dutch project with the first prototype having been constructed in the summer.

“Production of the second WAAMpeller was greatly improved because we had learned a lot from producing the prototype,” says Vincent Wegener, Managing Director RAMLAB. “This 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.”

With the second WAAMpeller complete, the project then progressed to the testing stage, the first phase of which saw the WAAMpeller installed on a Damen Stan Tug 1606. Damen’s testing engineers performed operational testing of the WAAMpeller on 20 November, with representatives from all of the consortium partners present. The testing programme included bollard pull and crash stop testing in addition to speed trials and was overseen by Bureau Veritas surveyors throughout.

Martijn Nieuwenhuijs, Chief Executive of Bureau Veritas Marine & Offshore Netherlands comments: “Bureaus Veritas has witnessed every step of the making and testing of the WAAMpeller. Some challenges needed to be tackled along the way, but the final product is technically sound and ready for commercial application.”

“Of course, we were all a bit nervous beforehand – after all, innovation always comes with a certain amount of unknowns – but the testing was a success,” says Kees Custers, Damen Project Engineer R&D enthusiastically.

“We are pleased to report that the WAAMpeller displayed the same behaviour as a conventional casted propeller in all of the tests. This includes the same level of performance in the crash stop scenario, which – going from full throttle ahead to full throttle reverse – is the heaviest loading that a propeller can experience.

Talking before the WAAMpeller unveiling event, which took place on 30 November, Allard Castelein, CEO Port of Rotterdam took the time to highlight the efforts of the collaborating partners: “The WAAMpeller project is special for many reasons. Not only has it produced the world’s first class approved 3D printed ship’s propeller, but this has been accomplished within a very impressive seven-month timeframe and only one year after the official opening of RAMLAB.”

“Everyone involved has worked extremely hard to make this happen. Damen, Autodesk and Bureau Veritas have supported the project all the way. Promarin have really shown their expertise with the finishing of this WAAMpeller. And last, but not least, the production process at RAMLAB continued 24/7, with their experts permanently on hand.”

Looking at the bigger picture, Mr Castelein went on to identify the implications of the WAAMpeller project on the maritime industry. “This project has shown the shipbuilding industry the potential of 3D printing techniques for the production of vessel components. We continue our intensive research into this very exciting area.”

The WAAMpeller project is a major step forward in many ways beyond the final object being class approved. Most 3D manufacturing is done using powder as the raw material and the feed bed machines that are used means that the final size of objects is limited.

With Wire Arc Additive Manufacturing the system employs robotic arms and mobile gantries that allow large objects to such as the 1.35m propeller to be produced. The second propeller was made of nickel aluminium bronze which unlike the metal powders is the same material commonly used for large cast components. WAAM results in a somewhat rougher finish than metal powders but with post processing a similar result to cast components is achievable.

WAAM makes use of standard welding torches and wire feed systems making it a cheaper and quicker process than with metal powders. Furthermore, with standard welding wire a fraction of the price of metal powders, the finished articles can eb produced ata fraction of the price.