Offshore Wind Force (OWF) is awarded with the construction of the Wikinger Offshore Wind Farm in the German section of the Baltic Sea. The work comprises the transport and installation of 70 wind turbine foundations. A Menck Hydro Sound Damper (HSD) will be utilized for the installation of the monopiles. To bring the HSD system outboard, TWD provided OWF a custom designed HSD deployment frame, starting on short notice and finished within an extremely short lead time of 3 weeks.
After designing previous HSD deployment frames, this was the first frame where we applied a rotational movement to bring the HSD system outboard. Together with OWF, we considered several options for the frame’s deployment: fixed, skidding, sliding and upending, telescopic and rotating. The rotating concept was chosen for its simplicity and operational advantages.
A number of operational advantages reduce costly downtime offshore. The simple design is easy and fast to deploy without the need of the main board crane. The HSD deployment frame is moved in- and outboard with a step by step push-pull system. This system is hydraulically operated, without any manual labor. The frame is accessible in both inboard and outboard position. The strong design of the main structure allows the frame to stay overboard during infield transits.
Because of the rotating deployment motion, the design has only a limited height from the deck, allowing the main crane to slew over it during any point in the operation. When rotated inboard, the frame occupies little deck space due to its compact design.
TWD was also requested to design a seafastening for the HSD system when lowered on the deck below the HSD deployment frame. The seafastening design allows the HSD to be simply lowered on a seafastening ring, utilizing guides underneath the HSD to ensure proper alignment. The seafastening ring fits optimally in the HSD donut shape constraining the HSD in the horizontal direction.
A close cooperation with Menck (HSD and winch platform supplier), VSF (fabricator) and Elcee (bearing supplier) was key to insuring proper interfacing between different project parts. The interface of the HSD deployment frame with the Menck winch platform is rather simple. By making strategic anticipating design choices, our design was able to adapt to the progressing design by Menck.
Due to the limited time, VSF required on-the-spot assistance with numerous engineering requests. We assisted in discussing possibilities regarding material certificates adjusting weld details to VSF’s preferences, setting up transport and handling plans, checking their shop drawings and other fabrication issues. Our assistance ensured the quality of the HSD deployment frame, a smooth fabrication process, avoiding delays and reducing the fabrication costs.