GENERAL INFORMATION

 

Scaldis is an important player in the growing sectors of renewable energy and environmental care. Previous activities include:

• Placing of GBS structures, jackets, monopole foundations and transformer for wind turbines.
• Placing of wind turbines and associated works.
• Oil recovery and associated inspection operations.

 

 

Installation of jacket and 5mw wind turbine generator at the Beatrice Offshore Windfarm, Scotland

 

 

Installation of Rødsand transformer module at Lolland, Denmark

 

 

Lifting and installation of the SeaGen Tidal Current Generator in Strangford Lough, Ireland

 

 

THORNTON OFFSHORE WIND FARM

 

Since 2003 Scaldis has been heavily involved in the preparations of a unique project in Belgium waters. This project is the installation of in total 60 wind turbines of each 5MW, sufficient to supply yearly 600.000 citizens with electricity, on an offshore location.
On the Thornton bank, approximately 20nm offshore 'Zeebrugge' a wind farm is realized. In several phases the 60 wind turbines will be installed. Scaldis installed the first 6 Gravity Based Foundations (GBF) for the turbines in the spring of 2008.

 

The 6 concrete GBF's were built on a specially reinforced quay in the port of Oostende. By multiwheel trailers from Sarens the GBF's were transported to the quayside. Scaldis lifted off the 3000T weighing GBF's from the quay, lowered them partly in the water, sailed to the Thornton bank and lowered the GBF's on a prepared gravel bed.
The lifts were executed with a special designed lifting frame and four 1250T hydraulic plate shackles.

 

 

During the 6 hour voyage from Oostende to the Thornton bank the Rambiz was towed aft-wards because the load was partially submerged and suspended in the hooks of the Rambiz. The structure was prevented from getting too much movement during the sea passage by two sets of wires from the stern of the Rambiz to the GBF.

 

The lowering of the GBF's was achieved by ballasting the structure with water and keeping a constant hook load of 1200T. Two sets of high capacity pumps for the ballasting of the structure were installed onboard the Rambiz. All GBF's were installed within centimeters from the target location.

 

BEATRICE WIND FARM (part 1)

 

Installation of the two wind turbines of the Beatrice Wind Farm Demonstrator project is complete. Scaldis, under the authority of the combination Talisman Energy/ Scottish and Southern Energy, lifted two 5MW wind turbines in position offshore Scotland. The first turbine was lifted in Aug 2006 and it started generating energy some months after. The second turbine was placed in the summer on 2007 onto its previously installed jacket foundation.

 

The Beatrice Windfarm Demonstrator project included the placement of two turbines, 145m above water with blades of 63m each, that we are connected to the infrastructure of the existing Beatrice Oil Platform. The turbines were placed in a nature reserve, habitat to a large number of exceptional species. Universities and research centres still carry out extensive studies on flora and fauna, before, during and after the installation using. The information gained on the effect of the wind turbines at this location.

 

Prior to the offshore installation, a number of years were used to design and prepare the method of installation. Scaldis was part of the project team, which included Client, Wind Turbine Fabricator engineering companies and other specialists.

 

In July 2006 Scaldis' heavy lift vessel Rambiz mobilised to place the two wind turbine foundations and one turbine. The Beatrice Wind Farm is not only the first wind farm in which the turbine is lifted completely onto a jacket foundation in open sea. The structures are located in deeper waters then ever realised before.

 

The two jacket foundations, almost 70m in height, were fabricated at a Scottish yard and transported horizontally on a barge one by one to the Beatrice installation field. In the field the pre-installed rigging was connected to the crane blocks of the Rambiz. The jacket was lifted off the barge and the empty barge sailed back to the yard for the load out of the second jacket.

 

In the meantime the Rambiz upended the jacket and placed it onto the 43,5m deep seabed. Four foundation piles were hammered trough sleeves on the jacket legs into the seabed. The piles were connected to the jacket by the so-called swaging technique, an alternative to grout connections. The foundation pile inside the jacket sleeve is deformed by means of high pressure. This creates a connection created inside the sleeve, that fixes the jacket into the seabed.

 

 

 

After the first jacked was installed and fixed, swaged the second jacket arrived in the field and was placed. Additional installation appendages were to be installed. These appendages were used for the installation of the wind turbine, to operate the turbine and/or to provide access to the turbine by boat.

 

 

 

 

BEATRICE WIND FARM (part 2)

 

So far, offshore wind turbines were built in parts and the assembly of the parts was executed offshore. In this project the complete wind turbine was constructed onshore and lifted completely by the Rambiz cranes. The rigging was pre-installed on shore. The turbine was lifted by using a frame at the foot of the tower, and a spreader bar between the two cranes. The construction was lifted in the cranes, just above the Rambiz deck. At the Rambiz deck shear stoppers were welded to prevent horizontal movements of the turbine during the sea transport. After a test lift and a test of the specially designed soft-landing system, the Rambiz sailed out to the Beatrice Field. The complete transport and installation period required wind and good weather conditions for a minimum of 3 days.

 

Prior to the offshore and installation phase, extensive dynamic analyses were carried out, to determine the maximum acceptable weather conditions, to minimise movements of the turbine in the Rambiz cranes. In addition the Rambiz carried out a reality check in the Cromarty Bay before sail out, to experience the real movements. The Rambiz rotated a few times around her axis, and it was clear that the turbine was stable.

 

The transit from the Cromarty Firth to the Beatrice Field went well, and lifting of the turbine started upon arrival, as soon as the four point mooring system of the Rambiz was installed. The turbine was lifted by its lifting frame and set onto the jacket, 17m above water line. The landing of the turbine onto the jacket was muted by the soft-landing system. The hydraulic cylinders were activated to absorb possible shock loads during placing. The cylinders were designed to gradually take over the load from the crane blocks and pass it on to the jacket. The system was removed together with the temporary aids. The turbine was commissioned in the months following the lifting, and is currently operational.

 

Lifting of the second turbine took place in 2007. The preferred lifting period was summer time, because of the required weather conditions. In June 2007 the Rambiz returned to the Cromarty Firth for remobilisation and loading of the second wind turbine. An extensive test was again carried out at the yard before sail out to the field. The aim was to place the second tower remote controlled completely. After Client, Marine Warranty Surveyor and the Scaldis Project team agreed that all conditions were within limits, the Rambiz sailed out once again with the huge wind turbine in her cranes.

 

The installation frames had been installed on the jacket in 2006, and everything was confirmed ready for receiving the turbine prior to Rambiz sail away. Upon arrival in field, the Rambiz set her anchors and positioned for the lift. The lift was carried out using a survey positioning system, and a camera system installed on both the turbine structure and the Rambiz for positioning. After landing the orientation could de adjusted by jacks in the system. The turbine was bolted to the jacket before the frames and lifting aids were removed from the structure. Rambiz returned to the yard for demobilisation.

 

Client and third parties are now commissioning the second turbine before the Beatrice Wind Farm Demonstrator Project is completed. Now all of us are looking forward to seeing the results of the demonstrator, and participating in the plans for further developing the wind farm activities.