Nordkraft Vind in Norway was contracted to use the Eileen yoke with a CC NT 2800 to assemble 11 wind turbines during the autumn. The turbines were at the Nygårdsfjellet Wind Farm outside Narvik, Norway.
Rental firm Vest Kran, also based in Norway, supplied the equipment and operator in charge of using the Eileen yoke.
Vest Kran’s operator explains how the yoke was used. "The Eileen is mounted on two beams, one in the bottom section of the crane boom and one on the top section of the crane boom. Between the beams there is a wire going along each side of the crane boom.
"When we attach the yoke, Eileen as it is called, they attach two wires that go over to the wires that run along the side of the crane boom, it is these wires that control the blades’ sideways movement.
"When the blade is mounted, they have a remote trigger or release to remove the straps on one side of the yoke, then it is just to swing out and go down to retrieve the next blade. It takes about two or three hours to mount the three blades."
The installation began after the turbines were transported up to the installation site, where 40-50 people worked to assist installation.
Siemens hired the lifters for a demanding operation. "Each turbine weighed a total 300USt and the largest single lift is about 85USt. The machine housing, with great precision, is to be placed 90m above the ground. The rotors’ length of 45m also demonstrates the challenges that Vest Kran crews faced," said Vest Kran’s operator.
The firms managed to complete the heavy lifts before the deadline despite receiving the equipment two weeks late, due to shipping damage on a central crane component.
Siemens said: "The delay was two weeks; Vest Kran managed to catch up. They made good progress and activity and showed good project management. We would like to cooperate more with Vest Kran and their subcontractor, FairWind."
The new wind turbines, after entering Phase II of construction, will provide 82GWh of added electricity to households in the Narvik area.
Vest Kran has previously worked with Siemens in Norway on the installation of 27 turbines in the Høg-Jæren wind park last spring.
Elsewhere in Europe and Norway, Vest Kran has since been commissioned by Enercon to install turbines internationally, in both Norway and elsewhere in Europe.
Morten Martinessen, managing director of Vest Kran, says: "Many years of experience and the flexibility we offer when we combine our large crane, the CC NT 2800, with other cranes enables us to deliver good and smart solutions to customers. It makes us attractive also for new projects. But we will not stand still with this. We are going to develop us to be even better."