Construction ship “Seabreeze”, Germany

As to avoid supply bottlenecks for their own projects concerning the construction of wind farms, a german renewable energy company has commissioned construction of two offshore specialist ships of the same type with the Korean shipbuilder Daewoo Shipbuilding & Marine Engineering.

After their completion the construction ships, 109 m long and 40 m wide, will be able to not only transport up to four offshore wind turbines of megawatt class 5 and 6 complete with foundations and even under rough sea conditions, but will also be able to erect them. This gives the company significant time and cost advantages.

The ships can be fixed into position to the exact centimetre in the sea via satellite. They are capable of operating in water depth of over 40 m and are thus ideally suited for constructing the offshore wind farms planned by RWE Innogy.

Montanhydraulik and Muns Techniek jointly supply the complete hydraulic lifting system for the ships, consisting of cylinders, bolting units and guide frames, and the corresponding hydraulic power unit and electrical control system. The particularity in the construction of the ships lies in two, per supporting leg synchronously movable lifting frames, whose movement is controlled by a synchronous control system especially developed for this project. Because of this it is possible to implement the lifting and lowering of the four supporting legs via the required stroke in synch, without the need for stopping the platform for the bolting procedure.

Hydraulics: Hydraulic cylinders:
  • hydraulic performance: 3,990 kW
  • max. oil flow: 9,600 l/min
  • max. operational pressure: 325 bar
  • 48 traction cylinders: 630/280 x 3,000 mm
  • max. cylinder speed, leg up/down, floating: 1.0 m/min
  • max. effective speed, leg up/down, floating: 0.84 m/min
  • max. effective speed, barge up/down: 0.70 m/min
  • piston rod coating: ceramic with integrated displacement measurement system