Wolff cranes in Dusseldorf

The flat-top duo comprises a Wolff 7534.16 and a Wolff 6015.8 with respective jib lengths of 50m and 37.5m.

“Since the cranes cannot be tied to the building due to the situation on site, they have to work freestanding despite substantial heights under hook of 93.3m and 82.5m respectively,” said Carsten Druske, head of rental Germany and branch manager of Wolffkran Dortmund. In order to provide the required stability for lifting formwork and concrete components as well as the extravagant facade elements, both cranes were mounted on a foundation anchor embedded in concrete.

The higher assembled Wolff 7534.16 additionally features a BT 29 Wolff tower section with external dimensions measuring 3x3m at the base of the tower.

A 250t mobile crane assembled the Wolff 7534.16 to a height under hook of 48.3m. Next, the already operational tower crane assembled the smaller Wolff 6015.8 to a 37.5m under hook height. When structural work on the high-rise reached a height of around 40m, the Wolff 7534.16 was climbed to 93.3m height under hook and in turn used to bring the Wolff 6015.8 up to its final height. “Thanks to the custom-made assembly concept of one crane erecting the other, the use of mobile cranes was kept to a minimum,” Wolffkran said.

Once the building was structurally complete, the Wolff 6015.8 was dismantled while the Wolff 7534.16 remains on the project to help finish the building work.