VIDEO: Boskalis Scour Protection at West of Duddon Sands

Boskalis Offshore was responsible for the post-lay installation of scour protection around 108 monopiles at the offshore wind farm West of Duddon Sands. 92,000 TE of 9 – 18” armour rock was installed through the side dump unit of DP fallpipe vessel Seahorse.

With 108 wind turbines producing almost 400 megawatts, West of Duddon Sands is one of the larger European wind farms. It is a joint venture of Dong Energy and Scottish Power Renewables. Boskalis Offshore and Volker Stevin Offshore – in an Offshore WindForce joint venture – were responsible for the transport and installation of the 108 foundations for the wind farm.

The wind farm is located in the Irish Sea, South of Walney and West of Blackpool. The water depth is 18-24 meters with a large tide difference of just over 8 meters.

After the award of the contract in the second quarter of 2012 a large team of experts worked on all the different aspects of the project. Once the work kicked off in the first quarter of 2013, about 200 people have been working on the project.

Before the monopiles were installed, the Boskalis Rockpiper, the largest fallpipe vessel in the Boskalis fleet, installed 108 perfectly round scour protection filter layers on the seabed. In total 165,005 Te filter rock and an additional 11 cable crossings were installed.

Offshore Windforce was responsible for the timely delivery of the monopiles and transition pieces from Aalborg in Denmark to Belfast, a journey of 1,500 kilometers. In total the chartered EIT Palmina undertook 22 voyages to deliver the 108 mp’s and tp’s.

After handover to the client infield cables were installed and wind turbine generators were placed. The energy is transferred to land through a substation using an export cable. VSMC, another joint venture between Boskalis and Volker Wessels was responsible for laying the export cable. After the installation of the cables, a Boskalis fallpipe vessel placed the final scour protection layer around the piles using 95,000 tons of rock. The project was completed mid-2014.