Saipem 7000, Seaway Strashnov to Begin Dogger Bank B Offshore Construction Work

April 9, 2024, by Adrijana Buljan

The installation of the offshore substation topside and monopile foundations is about to commence at Dogger Bank B offshore wind farm, the second of the three 1.2 GW phases of the 3.6 GW Dogger Bank Wind Farm in the UK.

Installation vessels Saipem 7000 and Seaway Strashnov are expected to arrive at the project site in the coming days and start construction work, as are HEA Leviathan and Edda Boreas which will be deployed for the commissioning of the offshore substation (OSS) and underwater noise monitoring, respectively.

According to AIS data available online, Saipem 7000 is en route from Norway to the Dogger Bank B site, where the vessel will install the OSS topside on the jacket foundation that was installed last year. The topside is being transported to the site onboard the cargo barge Castoro XI which is being towed by the anchor-handling tug (AHT) Pacific Discovery.

The installation of the topside is expected to take until 18 April, when the commissioning will begin from the jack-up vessel HEA Leviathan (formerly Seajacks Leviathan), which will be providing accommodation during the work that will be taking place until mid-August.

The jack-up vessel Seaway Strashnov is scheduled to arrive around the time the OSS topside is in place and commence monopile installation, with the company Subacoustech Environmental set to perform underwater noise (UWN) monitoring during the installation of the first five monopiles using the service operations vessel (SOV) Edda Boreas.

As reported in January, monopile installation on the 1.2 GW Dogger Bank B was scheduled to start in September 2023, but the campaign was delayed.

According to a filing by the Dogger Bank Wind Farm consortium with the UK’s Marine Management Organisation (MMO) in November 2023, “unavoidable piling delays were incurred after a mechanical fault in the monopile lifting tool was discovered following the Dogger Bank A (DBA) foundation installation campaign” and, at the time, the installation vessel Seaway Strashnov demobilised for planned maintenance, after which it was contracted for a separate job in Angola over the winter period.

In a Notice to Mariners dated 6 April, the Dogger Bank Wind Farm project team says the monopile installation will run until approximately the third quarter of this year.

AIS data for Seaway Strashnov is currently showing the vessel in Maasvlakte in the port of Rotterdam.

For Dogger Bank B, the foundations are being delivered by the consortium of Sif Netherlands and Smulders Projects Belgium, under a contract the companies signed in 2020 for the first two phases of the Dogger Bank Wind Farm.

The first two 1.2 GW phases of the Dogger Bank Wind Farm, Dogger Bank A and Dogger Bank B, will comprise 95 Haliade-X 13 MW turbines each. The third phase, Dogger Bank C, will feature 87 Haliade-X 14 MW turbines.

Dogger Bank A is currently in the wind turbine installation stage and has already produced the first power last year.

Jan De Nul’s vessel Voltaire installed the first of the 95 Haliade-X 13 MW turbines at the Dogger Bank A site in September 2023 and has since installed eleven more, before leaving for scheduled maintenance in Vlissingen. The vessel is expected to resume work in May.