Following a series of coordinated offshore operations, the spotlight now turns to the subsea rock installation vessel Rockpiper as it begins solid ballast work at the DolWin epsilon platform within the Borkum Riffgrund 3 offshore wind farm.
After the recent tow-out and deck transport of the DolWin epsilon platform by the semi-submersible Mighty Servant 1, and the oceangoing tugs BOKA Sweeper, BOKA Keeper, BOKA Striker, and Princess, Boskalis continues its offshore campaign with a new phase. This time, the focus is on stabilizing the structure for long-term seabed positioning.
The Rockpiper has been specially outfitted with a solid ballast spread on its aft deck. This modification enables it to pump eclogite—a high-density rock—directly into the four hollow legs of DolWin epsilon. This form of ballast provides critical weight and structural stability, designed to anchor the platform securely against the harsh North Sea environment for decades. Prior to this phase, water ballasting had been completed by SMIT Salvage, a Boskalis subsidiary.
Unlike typical ballast stones, eclogite’s density offers higher resistance to displacement. The pumping process is not only about weight—it’s about precision. Any imbalance could shift the platform off-center, affecting both operational safety and power transmission.
Beyond ballasting, Rockpiper is set to deploy its inclined fallpipe to install armour rock around the platform’s base. This additional layer of rock provides scour protection, helping prevent erosion of the seabed around the legs. In essence, it’s like putting gravel around the foundation of a house to keep the rain from washing away the soil.
These offshore phases are critical milestones in the wider wind power transmission project managed by TenneT, with DolWin epsilon serving as a crucial grid connection hub. Each vessel in the fleet plays a specific role—some tow, others transport, and Rockpiper now locks it all in place.
