While 10 MW offshore wind turbines are only now starting to be marketed, the Ulstein Group has developed a design for a “future proof” heavy lift jack-up installation vessel able to carry and install four 15 MW wind turbines on each round trip.
Developed by Rotterdam-based Ulstein Design & Solutions BV, the new Ulstein J102 design is part of the company’s X-Jack series.
Ko Stroo, product manager at Ulstein Design & Solutions BV, believes the J102 is “the closest one can get to an optimal yet cost effective jack-up design. Using a high capacity crane of up to 2,500 t and 160m hook height above deck, the J102 design will allow contractors to efficiently carry and install four 15 MW wind turbines per round trip.”
Key to the X-Jack design is its patented lay-out with a simple cruciform primary structure to achieve weight savings of 10 to 15% and create the most direct load path during preload operations.
Positioning the legs widely apart in a square pattern results in efficient use of available deck space, at the same time effectively counteracting the crane overturning moments. This set-up also creates more body around the legs, enabling the use of large spud cans to reduce loads on the seabed.
“The Ulstein X-Jack series is part of our strategy to complement our offshore wind design portfolio and strengthen our position as a long-term partner for supporting the offshore wind industry with sustainable and cost-efficient assets,” says Edwin van Leeuwen, managing director at Ulstein Design & Solutions BV. “Being innovative in our designs and focused on market needs, we achieved market leadership in offshore wind service vessels and heavy lift construction vessels. For wind turbine installation jack-ups, we like to become the industry’s preferred choice as well.”
The following key features characterize the Ulstein X-Jack series:
- Kite-shaped hull allowing for large leg spacings
- Main crane around stern leg on centerline
- Cruciform primary structural arrangement superior to torsion box solution
- No ballast water needed for lifting as the vessel is naturally balanced
- Large spud cans, reducing bearing pressures on seabed
- Vessel beam enables floating lift operations
- Increased propulsion efficiency as wake of spud cans does not interfere with thruster inflow
Main dimensions of Ulstein’s new J102 heavy lift jack-up vessel design are:
- Length 145.0 m
- Width 88.4 m
- Depth 11.0 m
- Complement 120 POB
- Water depth 65 m
- Free deck area 6,500 m2
- VDL 10,500 t
- Wind turbine capacity 8 x 8 M or 4 x 15 MW
- Main crane 2,500 t @ 39 m
- 1,250 t @ 65 m
- Main hook height 160 m above deck