Dajin Expands from Foundations into Offshore Installation with Ulstein’s HX122 Design

Vessel concept and notable features

Ulstein in 2022 to address a shortage of specialised installation vessels for next‑generation foundations. Key technical elements in the HX122 concept include:

• U‑STERN hull solution: allows monopiles to be stored and upended longitudinally along the vessel's centreline at the stern, a configuration intended to streamline handling of very large monopiles.
• X‑BOW hull design: combined with the U‑STERN, Ulstein says this improves vessel motions and operability in demanding offshore conditions, increasing the available weather window for installation campaigns.
• Capacity for 4XL monopiles: the design is said to be capable of installing future, very large monopiles.
• Large working deck, advanced lifting equipment and dynamic positioning to support precise installation operations.

Operational flexibility and secondary markets

Ulstein's design can also be applied beyond offshore wind. The HX122 configuration is adaptable for offshore oil and gas construction and decommissioning activities, giving the platform commercial flexibility if demand shifts between sectors or regionally.

Over the previous year Dajin added two heavy cargo newbuilds capable of transporting extra‑large monopile foundations, and a third vessel in that series was due for delivery by the end of September. The installation vessel will complement these transport assets, allowing Dajin to offer a combined manufacturing, transport and installation package for foundation delivery.

Implications for project delivery and supply chains

If Dajin executes the integrated model, project developers could face fewer interfaces between foundation manufacture, transport and installation contractors. That could simplify contract management and logistics, and potentially reduce project scheduling risks tied to vessel availability. The HX122's focus on enlarging the weather window and handling very large monopiles also matches industry trends toward larger foundations that require specialised installation platforms.

Dajin's adoption of Ulstein's HX122 design represents a deliberate move to add installation capability to its foundation supply chain services. The design targets the specific handling and seakeeping challenges of very large monopiles and aims to reduce execution risk for large‑scale offshore wind projects by offering a more integrated delivery model.