The development will feature three offshore wind farms, which will generate enough energy for about 800,000 homes in the UK.
Located 120km off the Yorkshire coast, the project is expected to feature between 150 and 332 offshore wind turbines based on the size of the units selected.
Fugro used its M/V Greatship Manisha and M/V Bucentaur geotechnical vessels to carry out the site investigation work.
The vessels performed nearly 2800m of seabed cone penetration testing and over 5000m of boreholes on wind turbine and offshore substation positions.
Fugro GeoConsulting senior project manager Daniel Deen said: "The performance on this project has been exemplary of how the various parties should come together and deliver a large-scale project during the winter months, which historically have not been kind."
Dong Energy team leader for site investigation project management Søren Egede Johannesen said: "This is the biggest geotechnical campaign we’ve undertaken and among the largest seabed investigation campaigns the offshore wind industry has seen."
Hornsea Project One, which is expected to start services around 2020, is part of the Hornsea Offshore Wind Farm zone that has a maximum capacity of 4GW.
The zone is one of the Crown Estate’s Round 3 offshore wind programme.
Image: Fugro used its M/V Greatship Manisha and M/V Bucentaur geotechnical vessels to carry out the work. Photo: courtesy of DONG Energy A/S.
