Kent designed TP-less foundation secondary structures successfully installed at the Hollandse Kust Zuid Wind Farm

A proud milestone for Kent as the TP-less foundation installations are now completed, including the offshore installation of all Kent-designed secondary structures at the Hollandse Kust Zuid Wind Farm (HKZ). HKZ is the first unsubsidised offshore wind farm in Europe. The project is also the world's largest so far to adopt TP-less monopiles.

Kent's scope of work was centred around concept development and detailed design of Secondary Steel structures, including the design of an airtight platform (ATP), the boat landing structure (BLS) and the external working platform (EWP).

The project has been running for over three years and will culminate in 140 individual 11MW WTGs with a combined power output of 1.5GW. The wind farm is already generating power. However, the complete wind farm is scheduled for operation in 2023.

Highlights from the project included:

• Successful installation of the TP-less WTG foundations, including offshore installation of all secondary structures.

• Design and installation challenges have been overcome through effective collaboration between Kent and Vattenfall, together with the installation and fabrication contractors.

• Technology advances: Connection design details were developed specifically for the requirements of the TP-less installations and the high wave run-up pressures. This included a BLS uplift restraint, which Kent identify as the BLS ‘5th support’.

• Efficient and optimised design solutions were developed using Kent's in-house optimisation software.

This was a major project for Kent after being appointed to the Vattenfall Framework. Following this project’s success, Kent is looking forward to future collaboration with Vattenfall.

Cerianne Cummings, Kent's Director of Offshore Wind, said, "We are proud to have been involved in the detailed design of these structures and celebrate the successful installation of the foundations. We look forward to continuing our professional relationship with Vattenfall into the future."