West of Duddon Sands, meteorological mast


Offshore operations in the tempestuous waters of the Irish Sea is a challenge in its own right. But then, erecting a 90 m high meteorological mast is of a different caliber altogether. Yet, meteorological information is a crucial parameter for wind force forecasts and for efficient and safe operation of an offshore wind farm. Just as crucial is the transport, manipulation in heavy seas, and the installation of a high towering mast.

The client, RES Offshore, was awarded an ‘Engineering, Procurement and Construction’ (EPC) contract for design and installation of a met mast at the West of Duddon Sands (WoDS) offshore wind farm, a joint venture between ScottishPower Renewables and Dong Energy. The wind farm is located 14 km south west of Walney Island off the coast of Barrow-in-Furness in the Irish Sea. WoDS consists of 108 turbines with a total installed power of 389 MW, one substation and one meteorological mast. DEME company GeoSea were contracted by RES Offshore.  

Our solution

GeoSea made use of its DP2 heavy-lift jack-up vessel ‘Innovation’, which came available directly after completion of the Westermost Rough foundation installation works.

This allowed the re-use of equipment already installed on board. The foundation pieces were fabricated in Arnish. The mast was fabricated in Denmark and shipped to Arnish for load-out.

The foundation of the meteorological mast consists of a driven monopile and grouted transition piece with a working platform. GeoSea collected the foundation and mast from the Port of Arnish and transported the same to the WoDS site in the Irish Sea.

Due to limited geotechnical data at the load-out berth, the load-out in Arnish was performed floating, implying tidal restictions. The scope further included the installation of a single monopile, the installation and grouting of a single transition piece, and the installation of the meteorological mast in two pieces. GeoSea executed the contract in the 2014 summer season, at a time when also the last turbine was installed.

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