Maritime Propeller Repairs BV (MPR), an associate company of S-T Diesel and Marine group based in The Netherlands, has obtained the DNV-GL certification to perform in situ welding for propeller repairs – a service previously unavailable across the industry.
In recent years, MPR has invested in special welding equipment and carried out analysis and tests in order to obtain results that comply with the requirements set by DNV-GL, the world’s leading ship and offshore classification society. The successful results were followed by class approval and certification, thus making MPR the only company certified for welding in vertical portions on propellers.
“We carried out several tests before the results were in accordance with the rules of DNV-GL,” writes Gert Hendriksen, managing director of MPR. “We have invested in special welding equipment to get the required result. From now on it isn’t necessary to dismount the propeller to repair cavitation damages or repair damaged edges. This will save a lot of time and is much more cost effective for the customers.”
In order for these repairs to be carried out, DNV-GL regulations require a special ultrasonic investigation of the propeller material. MPR, together with a specialised partner, has developed a specific technique for the microstructural characterisation of nickel-aluminium bronze (NAB) alloys, widely used in the manufacturing of propeller blades.
On the steps that lead to this pioneering technique, Gert Hendriken writes:
“Two years ago we were asked by the classification society to investigate the possibility of in situ welding in the vertical uphill (PF) position. After personally discussing the details in a meeting, our company decided to undertake this challenging task. We invested a lot of time and resources in this study, because we believed in the ultimate objective: lifting the burden off our customers when they have damaged propellers or blades. By developing this innovative method and acquiring the certified approval, we can now offer the complete service package when ultrasonic investigation is required by class.”
MPR conducts repair services on propellers and propeller blades in their workshop in Drunen, The Netherlands, and also on location worldwide. ([email protected])