This paper compares two 2XL monopile installation methods: at the leeward side of the heavy lift crane vessel and in the recess at the stern of the vessel. The multi-body system of the vessel, monopile, crane, and mission equipment induces interaction and resonance behaviour. Operational limits are assessed at the crane tip and pile gripper during upending and lowering of the monopile. Stern installation provides a larger operability window during upending compared to side installation. During the lowering stage, the operability depends on the monopile submergence: side and stern installation provide a comparable operability. Considering both stages, stern installation shows promising results.

This paper addresses the growing offshore wind market's demand for larger turbines in deeper waters by highlighting limitations in existing installation solutions and proposing a new concept with a floating monohull, named Moonshot, which will thus be different than traditional jack-up or semi-submersible crane installation vessel options. This paper discusses the design process, which combines Ulstein Rotterdam’s Controlled Innovation and Blended Design to develop the concept. This process is used to explore various market scenarios to determine optimal vessel parameters. Results demonstrate how optimizing for financial performance or seakeeping behavior impacts the design. Moonshot's initial parameters are established, and its performance is compared to existing installation solutions.