The two substations for the 487MW Seamade offshore wind farm were successfully installed in the Belgian North Sea in “record time”, according to Scaldis.
The installation deployed a new transportation method conceived by the company to reduce time to pick up, transport and install the 1200 tonne topsides on their monopiles.
Each structure was picked up by Scaldis’ crane vessel in a sheltered port and sea-fastened on deck, using a modular sea-fastening.
The sea-fastening has been designed and built to transport the topside partially suspended in the main cranes to the offshore project site.
The load was maintained into the cranes during transport to optimise the lean and cost-effective sea-fastening configuration, according to Scaldis, eliminating the need for mooring, offshore barges and auxiliary tugs.
Otary, Electrabel and Eneco are developing the offshore wind farms Mermaid and Seastar, collectively known as the Seamade project.
The Mermaid and Seastar fields are respectively in the northernmost and central concessions of the Belgian offshore energy zone.
Both offshore wind farms combined have a total capacity of 487MW, deploying 58 Siemens Gamesa wind turbines.
On behalf of DEME Offshore, Scaldis was responsible for the transport and installation of the Mermaid and Seastar offshore substations.
Mermaid’s offshore substation arrived in Vlissingen where it was picked up by HLV Gulliver and transported to site first.
The substation was lifted from deck with HLV Gulliver approaching the last 100 metres towards the monopile in DP2 mode.
On the instructions of the heavy lift supervisor, the substation was lowered over its stabbing guides.
Mermaid was installed in a record time. Seastar’s substation took even less time, according to Scaldis.