Four out of five upper steel shafts have been lifted onto the gravity based foundations built for the Blyth Offshore Demonstrator Project at the Neptune dry dock on the Tyne in Newcastle, EDF Energy Renewables said.
Welders are now preparing to join the upper and lower sections. Each gravity based foundation weighs 15,000 tonnes.
In June 2016, Royal BAM Group won a contract to design, fabricate and install five full-size gravity base foundations on the offshore wind farm located 5.7km off the coast of Blyth, Northumberland.
The foundation design utilises ‘self-installing’ technology, developed by two BAM companies, BAM Nuttall and BAM Infra. The design has been carried out by BAM Infraconsult, which assigned COWI to assist with geotechnical interpretation and load definition.
The foundations combine a steel reinforced concrete foundation, with a steel monopile, allowing the installation in water depth of up to 45 metres while eliminating noise from pile hammering during installation.
The 41.5MW Blyth Offshore Demonstrator Project is the first to utilise the hybrid gravity based foundations, as well as 66kV electrical infrastructure.
It will feature five MHI Vestas 8MW turbines optimised to deliver a maximum output of 8.3MW.
The installation works are expected to commence during summer.