The vessels currently available fall into two categories, large floating craft and jack-up construction vessels. Jack-up vessels have legs, which extend to rest on the seabed and push the body of the vessel clear of the water to provide a stable platform. None of the ships used by the offshore oil and gas sector have proved to be ideal for wind plant installation. For this reason the UK's Mayflower Energy is building a special-purpose vessel for the wind industry.
The vessel, costing EUR 45 million, will be used for the construction of National Wind Power's North Hoyle wind farm off the coast of North Wales. It can accommodate up to ten 3.5 MW turbines, or a maximum load of 7200 tonnes. It is 131 metres long, 38 metres wide and includes a crane for lifting 300 tonnes over a 25 metre radius. It is equipped to stay at sea for between 25 and 60 days, depending on the number of crew. Mayflower has an option on a second vessel, with a 700 tonne crane, and hopes to build more as needed by the industry.