A new wind turbine blade installation concept that promises “significantly faster” rotor assembly at an offshore project site has been launched by GustoMSC and NOV Lifting & Handling.
The Sjøhest – Norwegian for ‘seahorse’ – is designed to reduce downtime linked to high winds at sea, which make it difficult to perform bolt-on of blades with a conventional crane vessel, often at heights of 175-200 metres.
Devised around converted jack-up vessel equipped with a small handling crane, the system picks up blades from an onboard rack and feeds a trolley with a telescopic leader boom that “connects and aligns” the Sjøhest with the turbine tower. Each blade is then horizontally transported up, rotated into a vertical position, and attached to the rotor using a Liftra gripping tool.
“Blades are highly susceptible to wind loads, so they currently take the most time to install,” said GustoMSC commercial director Marc Doorduin.
“Like the seahorse’s unique and strong grasping tail enables it to resist ocean currents, the Sjøhest connects to the tower, creating an aligned movement for safe and efficient blade installation.
Other advantages of the system, which can be fixed onto “any” jack-up, according to GustoMSC, include avoiding the need for bigger higher-price crane vessels, and that components can be loaded on the jack-up from different ports for assembly at an offshore project site.
“Large installation jack-up vessels have relatively high day rates; therefore, increased installation time or downtime is costly and needs to be avoided as much as possible,” said Doordin.
“Sjøhest offers an alternative installation methodology whereby the larger installation jack-up equipped with heavy lift cranes install the towers and nacelles, while the dedicated vessel fitted with integrated equipment installs the blades.
“The installation methodology with Sjøhest ensures major time savings as all three blades per turbine can be installed in one day.”
Doordin added that the Sjøhest installation technique makes it possible “to split tower, nacelle and blade mobilisation into separate onshore hubs… [affording] much more flexibility in the mobilisation location and benefits the entire logistics process.”
