The capacities involved made this a unique lift for this application, the turbine manufacturer said.

Weldex bought the crawler used in the lift from Ehingen and had it delivered to the North Sea East offshore windpark, off the island of Heligoland, where it was installing turbines for clients Mammoet.

Weldex used the boom and crane combination to lift 378t gross weight machine housing, 18m long and seven metres high, to a 110m height.

Normally the machine housing lift is divided into separate lifts, lifting the drive train and other large components only after the housing has been lifted.

The component belonged to the 6 Megawatt class turbine from manufacturer Repower.

The crawler was configured with the boom at a steep angle and a mast length of 144m.

Crane drivers Brian Doherty and Mark Hall carried out the one-hour lift and the movement of the heavy-duty crane by about 10m, with the load at a height under hook of 120m.

The wind gauge on the boom tip of the crane showed increased wind speeds as Just as the machine housing was secured, and fitters had to wait to place the rotor hub and the blades.

Leibherr launched the PowerBoom attachment, an attachment that enhances capacities, along with the a 3,000t LR 13000 crawler crane last June.

The power boom increased lifting values over a traditional lattice boom by more than 70%.

Liebherr originally developed the PowerBoom, introduced last year, for the LR 13000 crawler.

The company is now making the PowerBoom option available on the smaller capacity LR 11350 crawler.

Liebherr said that avoiding difficult assembly of the individual components at a great height, saved time for the wind turbine fitters.

Increased resistance to high wind conditions means that wait times are also decreased.

Simon Langefeld, Repower’s team leader on the site, said, "We could of course also have carried out the assembly of this machine housing with an LG 1750, but then we would have needed several lifts, and several more days to do it."

The works call for 48 6M Repower wind to be installed from 2013 onwards.