The final turbines have been installed on the latest offshore wind farm, Global Tech I, in the German North Sea.
Fred. Olsen Windcarrier’s two high performance vessels transported and installed 75 towers and nacelles and 22 rotor stars of the total of 80 AREVA 5MW turbines, bringing the project to completion on schedule.
The installation vessels, Bold Tern and Brave Tern, completed construction of the turbines in eight months, largely due of their experience, capability and reliability and flexible deck layout.
The vessels were able to transport and install four complete towers and nacelles or two towers and nacelles together with two rotor stars on each deployment without the need to change the deck layout.
By separating the installation work schedule to suit the weather-sensitivity of the turbine components, Bold Tern and Brave Tern achieved good progress throughout the winter, spring and summer. Fred. Olsen Windcarrier also obtained multiple gold awards among its suppliers in the project for its excellence in HSE culture and a low number of incidents.
The flexibility of the Bold Tern and Brave Tern was the key to achieving its operational target – their record performance was the transportation and installation of eight turbines in one week, including 10 hours transfer time each way to the wind farm.
The loading of the towers and nacelles took place at the offshore terminal ABC Peninsula of the logistics provider BLG in Bremerhaven. The processes ran smoothly, with the loading of four towers and nacelles in just over one day.
Pre-assembly and loading of the AREVA rotor stars was performed at JadeWeserPort in Wilhelmshaven. Trips with two rotor stars, each weighing 100-tonnes with a diameter of 116 metres took four days, including loading and installation, without any weather delays.
As well as the vessels, Fred. Olsen Windcarrier also provided engineering services, project management and technical manpower to the wind farm’s development – one of the first to feature the AREVA 5MW turbines.
Global Wind Service, a Fred. Olsen-related company, brought invaluable knowledge and experience to the project, supplying a total of 65 offshore workers, including offshore construction managers, lifting supervisors, deck foremen, technicians and QA personnel.
Felix Fliege, Package Manager Transport and Installation, of Global Tech I Offshore Wind GmbH, the project company building and operators of the wind farm, said: “The key to success in the offshore wind farm’s construction was, thanks to the flexible decks layout, the deployment of the jack-up crane vessels either for the tower or nacelle or the rotor star installation. This flexibility enabled us to amend installation plan when ever needed.”
Even Larsen, project manager for Fred. Olsen Windcarrier, said Brave Tern had begun installation at the turn of the year, loading from Bremerhaven and installing the first tower and nacelle at the end of January, with Bold Tern joining her sister in March.
Global Tech I was Fred. Olsen Windcarrier’s third installation project in the German waters since the Brave Tern and her sister vessel Bold Tern were launched in 2012/13.
Global Tech I was a really fast track project for Fred. Olsen Windcarrier, where complete project planning including full engineering scope in addition to grillage design, manufacturing and installation was completed in 2 months.
“Global Tech I was an excellent example of how the Fred. Olsen related companies can work together to deliver a market-leading performance under a single contract interface. We hope that this teamwork will be repeated in many projects to come,” said Lars Petersen Global Wind Service CEO.
Fred. Olsen Windcarrier has its own in-house engineering team making such fast track projects possible. All project-specific lift plans, transit procedures, jacking procedures and HSEQ plans were completed and approved in time for the project.
Carl McGrath, lifting supervisor, said time had been saved on the project by leaving the AREVA designed lifting frame on the components avoiding the need to reattach and disassemble the frames.
“We are delighted to have contributed to the timely completion of such a high-profile project. Weather in the German bight may sometimes be quite rough, and all jacking locations were at a water depth of approximately 40 meters. This project has perfectly demonstrated the flexibility and efficiency of our vessels.”
The lifting sequence was the 180-tonne S3 tower followed by the S2 and S1 tower sections tower weighing 90 tonnes each finishing with the nacelle, which weight 235 tonnes.
The Bold Tern is currently mobilising for installation on Butendiek Offshore Wind Farm, also in the German Bight, whilst the Brave Tern will shortly transit to Fredrikshavn to begin mobilsation for the Carbon Trust Trial Installation project for Universal Foundation.