Borssele V slip joint connection: design, certification and installation of the world's first full‐size submerged slip joint

Abstract

In April 2020 the world's first full‐size submerged slip joint connection was installed at the Borssele Site V offshore wind farm. This event marked the launch of a new, alternative transition piece/monopile (TP/MP) connection for the offshore wind market. An extensive qualification programme in terms of numerical modelling and testing was set up prior to installing the slip joint. This process was witnessed, reviewed and accepted by DNVGL. It led to a certified slip joint design for Borssele V, with a 9.5 MW wind turbine generator (WTG) on top of the foundation as well as an A‐level component certificate for the slip joint in general. The installation of the slip joint for Borssele V was the first use of this connection in a commercial full‐size wind turbine.