Oceanteam’s subsidiary KCI the Engineers has been awarded with a subsidy from Dutch consortium Knowledge and Innovation, Wind at Sea (TKI - WoZ) for the further research & development of its promising Double Slip Joint (DSJ) concept. The DSJ is a smart alternative to grouted or bolted connections between the transitional piece and monopile for offshore wind turbines.
In the Double Slip Joint concept, two sets of steel rings with matching conical surfaces are integrated into the standard cylindrical tubes of the Monopile (MP) and the Transition Piece (TP). The TP is installed by lifting it over the MP. Contact is made concentrated at two sets of rings, which have a small taper angle of about 2⁰ and an exact fit. Thus providing a well-defined self-locking steel on steel connection after installation of the TP.
The tower, nacelle, blades can be installed immediately. In the DSJ concept, the TP will automatically settle under the gravity loads and operational turbine loads within a short period of time, to reach a final stable locked condition, rigidly connected to the pile, as if “welded” together. With the DSJ, there are two options for the connection with the MP: above the water and below the splash zone, with the so-called “inverted” DSJ.
One of the most appealing benefits to the industry will probably be the short installation time, resulting in a sharp decrease of installation costs.
Scale steel prototype
KCI will use the subsidy for designing, testing and the validation of a medium scale steel prototype by comparing the self settling behaviour to previous smaller plastic prototypes. Besides, the company will test effects of larger scale, the use of steel and the prototype fabrication method. KCI has teamed up with Van Oord Offshore Wind Projects and SIF for the further development of the innovative concept.
Read more about DSJ’s impressive advantages here