The replacement of wind turbine assemblies on a wind farm is typically an easy job for a crawler crane. But when there is only one assembly to be replaced, it doesn’t make financial sense to erect a large crawler crane on the job site. Such was the case for German-based crane rental company, Sommer, during a project at a wind farm near Bremen, Germany.
The project needed a mobile crane with enough reach and capacity to get to the job site quickly and perform the lift. Sommer found a cost-effective fit with a 400 t Grove GMK6400. While many mobile cranes would not have the 131 m reach to replace the wind turbine assembly, the crane was fitted with both a MegaWingLift and luffing jib attachment to complete the job.
“Crawler cranes conventionally have been used to erect wind turbines due to the fact that they are some of the only mobile cranes capable of reaching these heights. But using a crawler crane to replace a generator that weighs only 1 t would have been far too expensive for this project,” explained Andreas Meyer, crane operator at Sommer. “After visiting the site, however, we knew immediately that our Grove GMK6400 had the capacity and reach needed to perform this challenging lift.”
The GMK6400 has a 60 m boom. When rigged with the luffing jib that extends from 25 m – 79 m, the maximum tip height reaches 134 m. With this setup, the crane can perform lifts no other six-axle or even seven-axle crane can currently achieve.
The GMK6400 has a 60 m boom. When rigged with the luffing jib that extends from 25 m – 79 m, the maximum tip height reaches 134 m. With this setup, the crane can perform lifts no other six-axle or even seven-axle crane can currently achieve. A single-engine drive system on the GMK6400 drives both the carrier and superstructure. This reduces its overall weight and improves fuel economy.
The crane was fitted with a MegaWingLift system and a luffing jib bringing its reach to 133 m. Its capacity was also enhanced to 8,9 t which easily handled the 1 t wind turbine assembly. In all, the job only took two hours to complete, which was much more efficient than bringing in a crawler crane for the job.
“We are very satisfied with the superior strength and mobility of the GMK6400 and we look forward to using it again to help provide more efficient and flexible solutions for our customers,” said Meyer.
Sommer Kranverleih GmbH was founded 1959 and is based in Delmenhorst, Germany. It offers crane rental and lifting services mainly across North Germany.