As wind turbines become bigger, so do balance of plant components. Transporting and installing these huge components has presented significant engineering challenges the Dutch industry has successfully overcome. The modern needs of the offshore wind industry dictate a need for large construction barges and heavy lift vessels. New crane designs and lifting technology that can cope safely and efficiently in challenging conditions are also needed.
Thanks to strong in-house engineering teams, Dutch companies have invested in a new fleet of purpose built heavy-lift vessels, floating sheerlegs (essentially large floating cranes used in ports, shipyards, and offshore construction facilities), and other specialist equipment for the transport and installation of today's XXL-sized foundations, turbines, substructures, and cables.
The Dutch now offer floating sheerlegs with a lifting capacity up to 5,000 tonnes. The latest vessels have large deck spaces and load capability for component transport, new large heavy lift cranes (lifting capacity up to 8,000 tonnes in one case), helidecks, and space to accommodate all the equipment and crew required for efficient installations. This reduces the need for additional work barges significantly.
A new breed of integrated crane vessels are also used to install large wind turbine foundations efficiently. Dynamic Positioning systems and revolving cranes are used to ensure swift installation even under the toughest conditions.
Other innovations include modifications such as spreader beams to add the ability to hoist 2,000 tonnes each, and new skidding grippers, suitable for monopiles with a length up to 90 metres and diameters between 7 and 11 meters (bottom part). Grippers can also be equipped with a Noise Mitigation System and be complemented with a skidding hammer platform for hammers up to 1,200 tonnes.
The Dutch Approach
The Netherlands is home to some of the world's most experienced and innovative marine engineering and offshore wind vessel contractors and manufacturers. With an extremely strong supply chain in this sector, Dutch companies have the design experience, are continuously innovating, and have invested heavily in expanding production capacity to meet future demand. They can provide the right solutions for offshore wind projects in different site conditions around the world. Furthermore, Dutch research institutes, universities, and government agencies are also at the forefront of innovation in foundation design and installation techniques.