SeaOwls and Ulstein unveil innovative jack-upVessel & ROV News // February 8, 2017
SeaOwls and Ulstein launched a new heavy lift jack-up vessel design, the 'SOUL', at the Offshore Wind Journal conference on 7 February.
The companies say the cruciform structural layout of the jack-up makes the patent-pending solution more than 10 per cent lighter than conventional jack-up vessel designs. "In combination with a high capacity crane, SOUL enables operators to take the next step in developing offshore windfarms," they said.
The concept was developed with installation of next-generation wind turbines in the 10-12MW class in mind, but is also suitable for installing 6-8MW.
“The development of this novel jack-up vessel is the logical next step in our strategy to widen our portfolio and become a leading company in supporting the offshore wind industry with more efficient assets”, said Tore Ulstein, deputy CEO at Ulstein Group. “Combining the track record in heavy lift vessel designs from Ulstein in The Netherlands and SeaOwls’ experience in jack-up technology has resulted in an innovative jack-up vessel concept based on proven technologies.”
The companies notes that scaling-up conventional heavy lift jack-up vessel designs is challenging due to the disproportional weight increase compared to gain in Variable Deck Load (VDL).
“We noticed this created uncertainty with turbine manufacturers, windfarm operators and installation contractors about how to install future generation wind turbines," said Erik Snijders, founder and managing director at Rotterdam based SeaOwls.
“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 45 degrees 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,” said 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.”
The SOUL series will come in various sizes, allowing the transport of between three and six 10-12MW wind turbines. All loading and installation operations can be performed without the need for ballast water.