Tetrahedron today launches a novel crane for the installation of the next-generation of offshore wind turbines

Tetrahedron today launches a novel crane for the installation of the next-generation of offshore wind turbines, designed to fit on both existing and new jackup wind turbine installation vessels.

This novel crane is developed specifically for the offshore wind industry. A new motion principle exchanges unused extensive reach for useful height. The crane design incorporates: a jackup-leg-encircling position, ample lifting height, lifting capacity, lifting radius and lifting jib-clearance. The crane allows existing jackup vessels to be refit to install today’s 12-14MW wind turbines.

Jackup installation vessels owners face a multitude of risks with installing the latest 10-14 MW class turbines, but if owners are unable to increase the lifting height sufficiently on existing installation jackups, their ships are at risk of becoming unusable within the offshore wind industry by 2023. Netherlands-based Tetrahedron has developed an innovative crane that can make existing jackup vessels suitable for installing the next generation of wind turbines at sea, with a design that is future-proof even for future turbine developments up to the 20MW class. The innovative crane can be retrofitted onto existing jackup vessels easily, delivering a competitive upgrade in lifting height and allowing existing vessels to compete well into the next decade. Founder and Director Wilco Stavenuiter says: “Due to its unique design and patented technology, the Tetrahedron crane simply lifts 50m higher than existing cranes, without adding any weight or complexity”.
Stavenuiter continues: “In practice, jackups that are originally designed to install 5MW turbines can be upgraded without hull re-enforcement (due to the low moment a Tetrahedron crane exerts on the jackup) and will be able to install future wind turbines such as the SG 14-222 DD or the GE Haliade-X.” This drop-in solution on existing jackups unlocks additional earning power for jackup vessel owners. As an example, the Tetrahedron 45 can lift a Haliade-X nacelle at 40m radius, 180m above the waterline with sufficient clearances to install the blades, while still fitting on smaller jackups with minimal modification.
Offshore installation contractor Van Oord, Delft University of Technology and various industry suppliers have contributed to the development of the crane in collaborative projects co-funded by the Netherlands Enterprise Agency (RVO). The concept design of the crane is completed and verified by DNV GL and today Tetrahedron company focusses on crane delivery in Rotterdam by 2022. The strong engineering team is led by Engineering Lead Alexander Ronse, who mentions “interested parties should follow us on LinkedIn, where we will post regular developments on both our cranes and realisation of the first unit”.