Petrofac has installed the jacket foundation in preparation for the offshore substation topside for the 1100MW Seagreen offshore wind farm off Scotland.
The subcontractor engineered and built the six-legged jacket, weighing 5100 tonnes, which is fixed to the seabed at a water depth of around 55 metres.
The jacket was secured on the seabed using the Saipem 7000 heavy lift vessel.
Topside installation will take place in early 2022.
The jacket has a seabed footprint of 43 metres squared and has built-in tubing designed to guide the incoming 15 array cables bringing the electricity generated by the turbines to the substation.
In addition, the jacket also has tubing to guide the outgoing three export cables from the offshore substation to the seabed.
When completed in late 2022/early 2023, Seagreen will consist of 114 Vestas V164-10.0MW turbines, the first of which was installed last week.
Situated around 27 km off the Angus coast, the £3bn wind farm is a joint venture between SSE Renewables (49%) and TotalEnergies (51%).
SSE Renewables is leading the development and construction of Seagreen and will operate the wind farm on completion for its expected 25-year lifetime
Seagreen project directorJohn Hill said: “Hot on the heels of the installation of the first wind turbines comes another significant construction achievement with the offshore platform jacket being placed and secured safely on the seabed.
“Everyone involved can be justifiably proud of achievements like these which set the foundations for the project’s delivery over the next 12 or so months.”
The installation of the offshore platform will be undertaken alongside the ongoing Seagreen turbine installation programme and the foundation installation campaign.
First power is expected by early next year with the offshore wind farm expected to enter commercial operation in 2023.
Petrofac project director Vipul Sawe said: “We are proud to be part of this important project for Scotland’s energy transition, as engineering, procurement, construction and installation contractor.
“The installation of the Seagreen jacket was completed safely amidst Storm Arwen and Storm Barra, using several measures to minimise environmental impacts, such as low hammer energy and acoustic deterrent devices.
“We will continue to work closely with our partners to prepare for the safe and successful installation of the 4800 tonne topside in early 2022.”