Heerema Marine Contractors’ semi-submersible crane vessel (SSVC), Thialf , has installed the first three monopile foundations and transition pieces at EnBW’s He Dreiht offshore wind farm in Germany.
The He Dreiht offshore wind farm is located approximately 85 kilometres northwest of Borkum and about 110 kilometres west of Helgoland.
EnBW, the developer of the project, selected Steelwind Nordenham to deliver 64 monopiles for the offshore wind farm in May 2022. The units have a diameter of 9.2 metres, a length of approximately 70 metres, and a weight of up to 1,350 tonnes.
The transition pieces are manufactured by the joint venture Sif-Smulders.
The Netherlands-headquartered Heerema is tasked to drive the monopiles into the seabed using a hydraulic impact hammer. The firm is also responsible for the installation of the transition pieces under a contract signed with EnBW in April 2022.
In order to achieve the highest level of noise reduction to protect life below water, Heerema uses the double-walled noise mitigation template specifically designed for this project – the T-NMS-10000, the company said.
“ We are well on our way and are confident that we will complete this project successfully and safely. What’s more, the double-walled T-NMS-10000 enables us to stay below the German decibel limit. This is a great development in protecting life below water when pile driving,” said Erik Bögels , Project Manager.
With the first three monopiles and transition pieces now installed, an additional 61 units are scheduled to be installed over the summer, according to Heerema.
The monopile foundations will support Vestas’ flagship V236-15.0 MW wind turbines .
When completed, the He Dreiht offshore wind farm is expected to have a capacity of over 960 MW, providing renewable energy for approximately 1.1 million households.
EnBW is the majority owner (50.1 per cent) and the developer of He Dreiht. The consortium consisting of Allianz Capital Partners on behalf of Allianz insurance companies, AIP and Norges Bank, holds the remaining 49.9 per cent in the wind farm.