An extremely lightweight crane for the maintenance of offshore wind turbines has been developed by Dutch lifting and drilling specialist Huisman. The Foldable Offshore Crane combines 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. Its use for the maintenance of offshore wind turbines will therefore require a smaller, and thus more cost-effective, jack-up vessel than currently required.A foldable boom makes this crane lighter than conventional hardware. Image credit: HuismanA foldable boom makes this crane lighter than conventional hardware. Image credit: Huisman

The crane is capable of exchanging wind turbine components to around 160 m (525 ft) above deck level from jack-ups with a length of about 70 m (230 m). The folding boom results in a very small footprint when in storage position and leads to a much lighter crane compared to conventional options.

Extra boom clearance is created by slightly tilting the knuckle, a feature that simplifies lifting of large loads and reduces the required boom length to reach above the middle of a nacelle. The crane can also be retrofitted on existing jack-ups, which is especially useful for operators in need of more hook height in answer to the growing demands of the offshore wind industry.