Germany-based wind energy company Enercon used a Liebherr 1000 EC-B 125 Litronic tower crane to erect a wind turbine with a hub height of 149 metres - the largest turbine erection ever for this crane, the company said.
The turbine - with a rotor diameter of 115 m - was erected at an altitude of around 800 m in the Prechtaler Schanze Wind Farm in the Black Forest, Germany, on the hills between the towns of Gutach and Mühlenbach. The 1000 EC-B, with its small footprint, had never before been assembled to such a height for Enercon.
With its 31.5 m jib and a hook height of 164 m, the crane was still able to hoist 100 tonnes reeved with four falls of rope. The capacity of this crane is 125 tonnes on six falls of rope and 100 tonnes on four.
The area required for erecting a complete flat top tower crane is approximately half of the normal standing area of other crane systems, Enercon said. The jib used in this case was very short, which is why no additional site clearance work was required for its assembly.
In addition, the logistics required to transport the 1000 EC-B 125 is much less than for comparable crane systems since the various components of the tower crane are supplied in small packages. The jib components of the large crane can be inserted into the tower elements, transported on a truck and assembled on site.
A 200 tonne capacity Liebherr LR 1200 crawler crane was used to assemble the tower crane to its initial hook height of 39 m. From there the tower crane erected the wind turbine and climbed the turbine tower as it rose using its own climbing equipment.
It was climbed to a hook height of 110 m and guyed to the wind turbine at a height of 100 m. Using this single guying, the crane climbed to a final hook height of 164 m. Both free standing and also fully climbed and guyed, these represented hook heights that Enercon had never achieved before.