Windpower development is gaining momentum across Europe - both on land and at sea. Determined to establish a strong market position, a British company, Marine Projects International, has built a special ship for installing wind turbines at sea.
The Resolution has been designed primarily for use in the hostile environment of the North Sea around the coast of the UK. The ship will also be used for similar projects under consideration in other areas of Europe, the USA and other regions where wind energy can be utilised. Marine Projects International (MPI) has great faith in this ship, which is optimising and enhancing the efficiency of the installation process.
Six legs
The six-leg vessel, which uses a hydraulic jacking system and is equipped with a 300t crane, has the DNV class notation @1A1, Self-Elevating Unit, Crane, Dynpos AUT, E0. This has been prepared and approved by the DNV design team in London with support from Norway and the DNV Nauticus Modelling Centre in Poland. A full and complementary team of engineers and surveyors from MPI and DNV China were present in the shipyard throughout the building and commissioning period.
The vessel is a unique combination of known technologies applied in innovative ways. For DNV, it has been a challenge to apply the DNV Rules to a vessel that has the mixed characteristics of a ship, a floating crane, a dynamic positioning system (DP) and self-elevating unit.
Seizing opportunities
If wind energy is to be profitable, the offshore installation of wind turbines has to be cost-effective. In order for offshore windpower to succeed, the industry has to have access to purpose-designed equipment.
Based on their own experience, MPI used a total of nine different vessels to install 30 turbines at North Hoyle near Rhyle in North Wales. The Resolution would do the same job with no support vessels and far more efficiently.
10 wind turbines
The ship is able to carry 10 full sets of turbines and foundations and whatever else is needed to install the 10 turbines during each 14-day trip. At the same time, a ROV will install the cables that go between the various turbines and connect the wind-energy field to the power grid onshore. The Resolution is able to maintain a speed of 12.5 knots in the water.
As soon as it arrives at the installation site, the ship is manoeuvred into place using dynamic positioning. It is then jacked clear of the water (one metre a minute) and turns from a ship into a completely stable working platform. The Resolution has a regular crew of 34. With the addition of the erection team, the vessel will hold 60-70 people during the installation process.
From dream to reality
MPI management are clearly proud of what they have achieved. The vessel has been designed from scratch and is the only one of its kind.
Prior to awarding the contract, MPI spent a lot of time with various turbine manufacturers and wind-farm developers to find out what was needed - and what difficulties they would encounter. They also checked the market. The information gathered was reduced to what is required to install one windmill a day, creating a production line approach that was totally self-sufficient with regard to both installation and sea transport.
Built in China
The vessel has been constructed in China's Shanhaiguan shipyard in Qinhuangdao, located 300km east of Beijing. The flag of registry is the Isle of Man, and the marine crew will be of European origin and hold the superior class of competency certification necessary for all marine operations associated with passage, DP, control and jacking operations.
High growth potential
The vessel has completed installation of three turbines in North Hoyle, and it is now working on the foundations of Kentish Flats wind farm.
The British government wants to have renewable energy and is giving developers large subsidies. GBP 260 million has been granted for the coming three-year period in order to achieve 10 percent of the total energy consumption by 2010 from renewable energy. A second vessel is currently under consideration by MPI.