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Challenging but familiar waters

  • 60 foundations and transition pieces
  • 385 megawatts of renewable generating capacity
  • 400,000 households will be supplied with renewable electricity
  • More than 35 kilometres north of Rügen Island, Germany

The 385-megawatt offshore wind farm Arkona is located more than 35 kilometres north of Rügen Island, Germany. Arkona will be fully operational in 2019, when it starts supplying sustainable energy to 400,000 households. Van Oord was responsible for the transport and installation of the 60 monopiles and transition pieces. Heavy lift installation vessel Svanen was deployed to install heavy monopiles in the inhomogeneous Baltic seabed while limiting the impact on the surrounding area. Due to our previous experience in the Baltic and innovative noise mitigating measures the project was successfully and safely executed. 

Back in the Baltic

The Baltic seabed consists of many different soil types, making it hard to predict what to encounter during pile-driving activities. The Svanen is familiar with these soil condition, since it has played a leading role in several Baltic projects. New for the Svanen were the long and heavy monopiles for the Arkona offshore wind project. They weigh up to 1,200 tonnes and have a maximum length of 81 metres. The installation strategy was based on the special feeder concept, with the foundation components being floated to the Svanen at the installation site.  In accordance with the highest quality and safety standards, all sixty monopiles were successfully installed. 

Noise mitigation

The noise that goes along with pile-driving can negatively impact marine mammals. Avoiding disruption to marine life was a crucial factor in the tender award and execution of the project. Smart techniques were used to minimise the impact of the installation works. During pile-driving operations a Hydro Sound Damper (HSD) was used. It was attached to the piling frame on the Svanen. This net, containing air-filled elastic balloons and special PE foam elements, formed a curtain around the monopile and reduced underwater noise. To further dampen the sound underwater, two temporary bubble curtains were laid on the seabed around the pile-driving location. The curtains released bubbles of air that rose to the surface to form a barrier around the Svanen, breaking acoustic waves and further reducing noise levels.  

An excellent performing Svanen and a reference landmark in noise mitigation: A real achievement by the Van Oord team in close cooperation with our client.

Moritz Horn, Managing Director Van Oord Offshore Wind Germany
Moritz Horn, Managing Director Van Oord Offshore Wind Germany

FaunaGuard

To keep porpoises outside the piling zone, Van Oord deployed its innovative FaunaGuard system, which it developed in-house. This acoustic device safely and temporarily deters various marine fauna species and uses special underwater acoustics to prevent potential harm to porpoises. FaunaGuard has proven itself during use on several other offshore wind projects, like Gemini and Luchterduinen. Thanks to the various sound-damping systems and the FaunaGuard the impact on porpoises in the vicinity of the project site was minimised. 

Additional information
  • Start date
    April 2016
  • End date
    February 2018
  • Location
    German Baltic Sea
  • Business Unit
    Offshore Wind
  • Client
    E.ON and Statoil