December 16 - Liebherr's PowerBoom has been used for the first time on its 1,000-tonne capacity LR 11000 crawler crane during the installation of a 220-tonne machine room on a wind turbine tower in northern Germany.

The Liebherr LR 11000 crawler, which is owned by Austrian heavy load contractor Felbermayr, was shipped to Bremerhaven from the Romanian port of Constanta for use by crane contractor Nolte at an offshore wind turbine test field 20 km south of Cuxhaven.

The crawler crane was fitted with the parallel boom ready to hoist the load with a hook height of 147 m. Parts from the luffing jib were used for the set-up version with the double lattice main mast boom, while the standard main boom sections were then used as the luffing jib.

Liebherr explained that this exchange provided the crane with up to 50 percent more load capacity in the configuration with the luffing jib. The PowerBoom increases the crane's load capacity by its enhanced lateral rigidity and increase in torsional moment.

With a radius of 30 m the LR 11000, together with the load cross beam and hook block, hoisted the 220-tonne load to a height of 130 m.

Klaus Ruhland, project planner and heavy hoisting professional at Felbermayr, explained that "normally an LR 11350 or a CC 8800 would have been required" for the hoist of the large machine room. Without the PowerBoom, the crane only have been able to hoist around 160 tonnes with the same hook height.

The crane also lifted the star of rotor blades, which were pre-assembled on the ground and had the huge diameter of 152 m.