Offshore staff
ROTTERDAM, the Netherlands – Van Oord’s vessel Aeolus has installed the slip joint foundation at the Borssele wind farm site V in the Dutch North Sea.
This is the first time a submerged slip joint was used on a full-sized offshore wind turbine on a fully commercial basis, the company said.
The slip joint is an alternative connection between foundation elements, a monopile and a transition piece. It consists of two conical sections placed on top of each other. It is based on friction, with the weight ensuring firmness and stability. Installation takes place by sliding the wind turbine’s foundation elements over the monopile, without having to use grout or bolts.
The slip joint makes a submerged connection possible, allowing for a more balanced weight distribution between monopile and transition piece, the company said. It therefore opens the possibility of manufacturing larger foundations for the next generation of wind turbines with existing manufacturing facilities and installing them at deep-sea locations using existing vessels.
Located about 20 km (12 mi) off the Dutch coast, the Borssele Site V is designated as an innovation site within the Borssele wind farm zone.
Two Towers BV, consisting of Van Oord, Investri Offshore and Green Giraffe, has been awarded the project and given the opportunity to introduce technologies for commercial application in future offshore wind farms with larger turbines and in deeper waters and to demonstrate the practical value.
The other technologies demonstrated at the Borssele Site V are thermally sprayed aluminium, impressed current cathodic protection optimization, oval cable entry holes, and eco-friendly scour protection.
Once operational in 2021, the 19 MW offshore wind farm is expected to power 25,000 households.
04/28/2020
