Offshore Windfarm Construction Vessels

The offshore wind industry in Europe is booming with 39 windfarms in nine European countries currently in operation contributing over 2,000MW to the grid, as of October 2010. Over 100GW of offshore wind projects are in various stages of planning including the UK's Round 3 wind farm sites which will contribute over 32GW.

DSB Offshore has been involved in over a dozen offshore windfarms starting with Middlegrunden in Copenhagen in 1999. We have provided equipment for site surveys, foundations, construction, top side installation, maintenance, cabling work and bird surveys. In the last 12 months we have had the following vessels on charter to windfarm sites - 95tbp AHT used to support cable lay barge, shoalbuster, 2 x flat top barges, 4 x crew transfer vessels, bird survey vessel, multicats.

Constructing an offshore windfarm involves three main stages with a great variety of marine equipment / vessels required. Typically the process is as follows -

1. Planning and Permitting

This includes finding a site with adequate wind and in an area that can be connected to the onshore grid, environmental impact assessment, application for permits, yield predictions and financing. A MET mast is installed at the proposed site to monitor weather and tidal conditions. After the contracts have been awarded bird surveys and MMO (marine mammal) surveys are undertaken for up to 2 years to investigate potential impact on local wildlife.

2. Procurement and Construction

The construction of a windfarm is split into several key components typically executed by one or two subcontractors -

  • Turbine Installation & Construction (foundation monopile, transition piece and turbine)
  • Export Cabling
  • Array (infield Cabling)
A spread of different offshore windfarm construction vessels is required to successfully undertake these operations including barges, jackups, multicats, anchor handling tugs and crew transfer vessels.

3. Operations and Maintenance (O & M)

The operations and maintenance phase commences once the wind farm is commissioned and operational. The requirement for remote monitoring and visual inspection is vital to avoid downtime and to keep the windfarm operational. Occasionally it will be necessary to perform turbine and gearbox repairs which in turn may require the use of specialised vessels such as jackups, crewboats and barges etc.


Offshore Windfarm Construction Vessels Offshore Windfarm Construction Vessels Offshore Windfarm Construction Vessels