With a completely new cruciform structure [ds_preview]for a jack-up vessel design, Ulstein and SeaOwls want to expand their share in the offshore market.
The partners emphasize, this structure makes the patent-pending solution »Soul« more than 10% lighter than conventional jack-up vessel designs. In combination with a high capacity crane, the concept aims to install the next generation wind turbines (10-12 MW) in the same time frame as currently used for installing 6-8 MW units.
According to the partner, scaling-up conventional heavy lift jack-up vessel designs proves challenging due to the disproportional weight increase compared to gain in Variable Deck Load (VDL). »We noticed this created uncertainty with turbine manufacturers, wind farm operators and installation contractors on how to install the future generation wind turbines, as floating vessels are not a viable alternative«, comments Erik Snijders, founder and managing director at Rotterdam based SeaOwls, and continues: »So we went back to the optimal jack-up design, a square platform with the legs spaced out as much as possible. Rotating the platform by 45o provided a natural bow shape with two legs and the crane on vessel centre line.«
»This seemingly simple twist in the design allowed to make a huge improvement in operational aspects as well,« adds Bram Lambregts, deputy managing director at Ulstein Design & Solutions BV. »With the main crane around the stern leg, optimal main deck reach and over-the-side lifting capabilities is created. And as the hull now houses much larger leg footings, bearing pressures on the seabed are reduced, while the wake of the spud cans does not interfere with the inflow to the propulsion thrusters.«
