German crane and transport contractor Schmidbauer co-ordinated a 600 tonne lift at the ABC-Halbinsel offshore terminal in Bremerhaven using two 750 tonne capacity Liebherr LR 1750 crawler cranes.
The lift was to carry the upper section of a jacket structure for the Borkum West II offshore windpark and keep it held in place while it was welded to its 900 tonne base.
According to Schmidbauer, this was the first time two identical LR 1750s executed a tandem lift of a single object.
The two cranes were configured with 42 metre main booms, 28 m luffing jibs and 31 m derrick booms with 260 tonnes of suspended ballast.
Moving in parallel, at a distance of 70 m, the two Liebherrs carried the jacket from its assembly platform and placed it onto the lower section on the first attempt.
The cranes then held the structure in place for two days while welding work was completed.
The shackles and ropes were then removed at a height of 50 m using a 450 tonne telescopic crane with luffing jib.
The ABC-Halbinsel offshore terminal in Bremerhaven is used for the temporary storage of offshore wind parks and to load this equipment onto construction vessels for offshore installation.