Offshore turbine maintenance with Huisman

International lifting and offshore services specialist Huisman has developed a new crane series for maintenance work on offshore wind turbines.

Features of the Foldable Offshore Crane include “unparalleled lifting heights and more than sufficient lifting capacity with a foldable boom resulting in less required deck space and a low own weight of the crane,” according to the Dutch company. It will need a smaller and, therefore, cheaper jack up vessel than is required with existing cranes for this application.

The new crane can be used to change turbine components to a height of 160 metres above deck from a small (70 m long) jack-up vessel. Its folding boom means a small footprint when in storage position. Models designed so far in the series range in capacity from 200 to 500 tonnes, with maximum load moment ratings from 12,000 to 30,000 tonne-metres. Larger models will be possible as the turbines get larger, the company said.

David Roodenburg, Huisman director of strategy and business development, said, “In addition to our innovative solutions for the installation of increasingly large wind turbines, we see many opportunities to improve efficiency, and thus lowering costs, for maintenance. With this new crane type we believe to have designed a cost-effective means to perform maintenance on existing and future wind turbines.”

Storing the lifting hooks inboard simplifies inspection and maintenance. Extra boom clearance is gained by tilting the knuckle. It simplifies lifting large loads and reduces the required boom length to reach above the middle of a nacelle, Huisman said.