Offshore Construction Start

Offshore construction at the Hornsea Three offshore wind farm effectively began with the start of scour protection installation at wind turbine generator (WTG) foundation locations on 25 December 2025. Ørsted’s Notice to Mariners (Weekly Construction Update) explains that contractor DEME is undertaking this scope using the rock-laying vessel Flintstone, which mobilised from Jelsa Quarry in Norway on 23 December 2025 and then commenced offshore installation work two days later. The campaign is scheduled to continue through to approximately 31 March 2026, placing permanent scour protection on the seabed at multiple WTG foundation positions within the Hornsea Three site in the UK sector of the North Sea.[1] This milestone is part of a wider transition from preparatory activities into full offshore construction. The same Notice to Mariners details ongoing export cable pre-lay operations along the Eastern Export Cable Route by Jan De Nul’s trailing suction hopper dredger Pedro Alvares Cabral and pre-lay grapnel run activities by the vessel TSM Ouessant, as well as boulder and debris relocation along the inter-array cable routes and foundation areas by Normand Subsea and Grand Canyon III.[1] In parallel, Trinity House’s vessel THV Galatea has been deploying 23 construction demarcation buoys around the Hornsea Three site from 17 December 2025 to 15 January 2026, delineating the working area for the broader offshore campaign.[1] Collectively, these activities confirm that Hornsea Three is in its main offshore construction phase.