The construction’s huge dimensions – the finished Marine Donut weighs 540 tons – presented Bluegreen’s engineers with massive challenges. This included meticulous and watertight welding of the ring-shaped main construction made up of individual 1-ton plastic HDPE (High Density Polyethylene) components. For this undertaking, Bluegreen CEO Nils-Johan Tufte and his team turned to the plastic welding experts at Inter-Supply AS. Eirik Tveitdal from Inter-Supply AS, official representative of Leister products in Norway, quickly and expertly responded to the unusual request.
Welding a combined distance of 20,000 m with WELDPLAST S2 and WELDPLAST 600
Between 8 and 10 tons of welding rod were needed for joining the HDPE components for welding a combined distance of 20,000 m. In order to ensure perfect seam quality, agile Leister WELDPLAST S2 and powerful WELDPLAST 600 extruders were used. The smaller and lighter WELDPLAST S2 with its arrow-shaped body is perfect for working in corners and hard to access places. The powerful WELDPLAST 600 and its large output volume of 6 kg/h is particularly suited to the construction of large polyethylene objects. Elg Ragnar Thunes, Bluegreen partner, confirms: “Leister devices are focused on quality and practical application. Both these factors help our welders achieve high quality welds. We use reliable Leister extruders for all manual welding work and we have virtually no downtime.”
Estimated water baptism: early summer 2023
If everything goes to plan, the world’s first Marine Donut should have its water baptism in early summer 2023. With its Donut, Bluegreen is looking forward to making an important contribution to sustainable fish farming to supply the world’s population.
- Material: Polyethylene (HDPE)
- Total height: 14.64 m internal and 17.51 m external
- Diameter: 55 m plus walkway
- Width (shell cross section): 16.2 m
- Volume: 22,000 m3
- Water flow speed: <0.8 m/s
- Water inflow depth: 15 to 40 m
- Inflow water UV cleaning
- Construction work started: April 2022
- Completion and fish introduction: < June 2023
Bluegreen is a Norwegian company with leading expertise in thermoplastic constructions. Bluegreen’s vision is to provide the most environmentally friendly solutions worldwide for and in water – hence the name Bluegreen: “Green solutions for blue water and blue air”. Source Bluegreen website: https://bluegreengroup.no/en