The overall site management and site supervision is currently being organised. The main positions have been filled and we are now doing our utmost to fill the last positions, both from Elsam's and Tech-wise's current staff and from external sources.

The site management and supervision will have their offices in Esbjergværket's premises at Vestkraftgade 1, 6700 Esbjerg. From early March the offices will be ready and at about the same time the actual supervision has to start at the construction site at Port of Esbjerg.

Traffic control
A Traffic Control Unit will be established. Their job will be to control safety at sea and to coordinate the many different vessels that will call at the Horns Rev offshore construction site. The Traffic Control Unit will supervise the positions of all vessels and will log all persons, who are physically present between the Port of Esbjerg and between or at the temporary construction site area at Horns Rev during the entire construction period.

Diving control
All diving activities in connection with the construction of the Horns Rev wind farm will be coordinated and monitored by Elsam. Diving operations may be of a high risk and consequently, much focus will be put on planning, monitoring and reporting this type of work. Diving operations will primarily be carried out in connection with the pulling of the sea cables but other installation activities also require the assistance of professional divers in the North Sea which are difficult waters with strong currents and frequently changing sea conditions. The diving control unit is being established at present.

Marking of the construction area has been reported to the Royal Danish Administration of Navigation and Hydrography (Farvandsvæsenet). Further information may be found at their homepage under Notices to Mariners in the menu Publications:

www.fomfrv.dk

Foundation parts are being shipped out of Antwerp. On February 13, 2000, the first shipment arrived of piles and transition pieces for MTH's storage area at the Port of Esbjerg. The coaster hired for the purpose can only transport two piles and two transitions pieces on deck and in the coaster's cargo room, a total of four complete foundations.

[Coaster with two transition pieces on deck. The piles have been unloaded]

Piles and transition pieces are unloaded by means of two large crawler cranes that bring the parts to the storage area next to the berths. Here, sand and gravel heaps have been arranged in 2´ 2 rows on which the piles are placed.

Unloading of pile

Unloading of transition piece

The production of towers, nacelles and rotors is well under way at Vestas' factories.

The towers are produced at the facilities in Varde and are then transported to the painter's, Gardit, in Esbjerg for abrasive blasting, painting and treatment of internal surfaces including fitting of ladders, platforms, electrical installations and lighting. Each tower section is subsequently placed at temporary storage facilities at Gardit's before being transported to Vestas' pre-assembly area at the Port of Esbjerg (Traffic).

Five towers are ready at the temporary storage facilities at Gardit's.

As mentioned in our January Newsletter, A2SEA, a sub-supplier of Vestas' that are supplying and operating the two crane vessels for sea transport and lifting of the wind turbines, are currently testing the first crane vessel, Ocean Hanne at the Horns Rev site.

From the Port of Esbjerg the vessel has conducted a number of testing sessions for positioning of the vessel, jacking-up the legs and simulating on-site lifting jobs of turbine components under various weather conditions.

The tests will continue for some time but there is a break in early March during which the vessel will be fitted with hotel containers etc. This will be done in Esbjerg.

The second crane vessel, Ocean Addy, has left the yard at Frederikshavn to have the same fitting jobs done as Ocean Hanne.

A beautiful day at Horns Rev

Foundations for Horns Rev - Manufacturing of piles

MT Højgaard work with two Dutch sub-suppliers, who produce and process the steel parts for the Horns Rev turbine foundations. One of these contractor, SIF Group, produce the base material for the piles and transition pieces whereas the other contractor, Rheden Steel, fits the piles and transition pieces with steel equipment such as boat landing arrangement, J-tube sleeves, platforms, etc. Rheden Steel is also responsible for the surface treatment of the pieces.

For this job Rheden Steel has rented some facilities at a former shipyard in Antwerp where there is ample space and cranes for storing and handling large and heavy components. The access to the river Shelde from the shipyard is a great advantage. The foundations are easily shipped to Esbjerg from here.

Transition piece ready for crane handling

Components after paint treatment

Elsam has signed a contract with Uni-Fly A/S for helicopter transportation to the offshore wind farm at Horns Rev. Throughout the year, Uni-Fly A/S places a helicopter at Elsam's disposal to fly maintenance staff to wind turbines with operating failures.

The wind conditions at Horns Rev are good, which however means that sailing may be difficult due to wave conditions, especially during winter. That is why it has been decided to fly maintenance staff to the wind farm, hoist the staff down on to the turbines and pick them up again in the same way as in rescue operations after they have done the job. The method is widely used abroad, for instance in the Channel where the hoisting method is used for transporting pilots from ship to ship.

Elsam has signed a contract with Uni-Fly A/S for helicopter transportation

Since spring 1999 a number of measurement systems have been installed at Horns Rev measuring wind, wave and current conditions as well as water depths.

The systems are full automatic and are currently sending results ashore both via GSM communication and via a special-purpose radio transmitter. The systems are primarily operated by solar power. An exposed device measuring the currents is however operated by a built-in battery that is changed at intervals of a few months.

Despite the harsh climate at the reef, the systems have been highly reliable and since 1999 we have gathered quite a lot of data on the conditions in which the wind farm will operate.

Knowledge of the wind conditions is of course crucial when it comes to calculating the actual production of the turbines and the turbine design will also be have to be adapted to, for instance, how strong the wind gusts are and to the character of the wind (turbulence).

The wave conditions also depend on the wind, both the strength and direction of the wind and also on currents and water depths.

All these data are used in the planning of how and when maintenance is to be carried out. Different means of transportation are suitable for different wind and wave conditions and special effort will be put into optimising the choice of the right means of transportation. The choice will be based on the probability of being able to operate under the given conditions against an estimated loss of production due to non-operation of the turbine and on the amount of money to be paid for the waiting time of the maintenance staff.

All these considerations have resulted in the choice of a helicopter as the main means of transportation to the turbines and boat/zodiac has been chosen as number one alternative. Since this is the first time such a big offshore wind farm is built we have no previous experience to draw upon when it comes to transportation. That is why we also work with the alternative of a larger boat calling the turbines directly.

Based on the wind and wave measurements it has been calculated which types of boats would be best suited and how power it would take to keep them in position at the turbines. The turbine foundations are consequently prepared for installation of boat landing arrangements if it should prove necessary to change to boat as primary means of transportation.

Since spring 1999 a number of measurement systems have been installed at Horns Rev measuring wind, wave and current conditions as well as water depths.