Japanese contractor Penta-Ocean Construction has commissioned Ulstein Design and Solutions to design its new heavy lift vessel for offshore wind foundation installation.
The customised Ulstein HX118 design will feature a 5,000t Huisman main crane and the Ulstein U-Stern, which enables installation of increasingly larger monopile foundations. Following feasibility and concept studies in 2023, Penta-Ocean Construction selected Ulstein for the project. Ulstein proposed the HX118 with the U-Stern, a design that builds on Ulstein’s successful track record of crane vessels. The selected design offers a balanced combination of a flush work deck, lifting capacity, accommodation and DP capability and will be the largest X-Bow vessel to date.
The U-Stern, developed by Ulstein, features longitudinal storage and upending of monopiles along the ship’s centreline. This innovation enables the installation of longer monopiles without overhanging the ship’s sides and allows the vessel to face into the waves during the installation, minimising ship motions, fuel consumption and emissions.
Since summer 2024, Ulstein has been collaborating with Penta-Ocean Construction on the Basic Design of the heavy lift vessel, including an extensive model test programme. The design is being developed at Ulstein’s Rotterdam office, with significant support from Ulstein Poland during the Basic Design phase.
Ko Stroo, lead designer, Ulstein Design & Solutions, said: “We are honoured that Penta-Ocean Construction chose us to design their new heavy lift vessel. This project represents a powerful collaboration between Penta-Ocean Construction, Ulstein and Huisman to design this most capable monopile installation vessel. As the project moves forward with its construction at the Seatrium shipyard, Singapore, we remain committed to supporting the parties throughout the construction phase.”
Image: Rendering of Ulstein U-Stern heavy lift vessel (credit: Ulstein Design & Solutions)
