Seafastening Equipment – Veja Mate OWF

Smart seafastening structures for the installation of 67 monopile foundations

The Boskalis/Volker Wessels joint venture needed to transport and install 67 monopile foundations on the Veja Mate offshore wind farm using Seajacks’ jack-up vessel Scylla. TWD designed seafastening cradles as well as a custom lifting beam and rigging arrangement to safely lift the monopiles.

Since the monopiles had a diameter of 7,8 meters and weighed up to 1300 tonnes, we had to tackle the challenge of fitting all the monopiles on the deck. Therefore, our teams designed the seafastening cradles in a way that maximized the deck space and distributed the transit loads effectively. In addition, TWD managed the fabrication process, which included the follow-up of technical queries, checking the fabrication and test procedures, performing site inspections as well as providing consultancy during the dimensional control, FAT and SAT tests.

Veja Mate (402 MW) has been successfully installed bringing green energy to 400.000 homes annually.

Project highlights

• A stacked cradle with a hydraulic hinge system enabled two piles to be stacked on top of each other while maintaining easy access to the bottom pile
• The upending line featured a rotating cradle to clear the way for self-propelled modular trailers (SPMT), which were used to upend the monopiles