The initial stage of the redevelopment work is being undertaken by Finnish contractor Takanen using Liebherr equipment. "Large areas of land are being reclaimed here," explained Johanna Takanen, "therefore the ground is very soft and must be well compacted."

In order to compact the ground, Takanen made use of a Liebherr duty cycle crawler crane HS 8130 HD with a 14t drop weight. The weight was dropped from a height of 10m in free fall onto the building area to be compacted. This achieved an impact between 50 and 70kN/m2 and compacted the ground down to a depth of 7m. The weight hit the ground 110 times per hour, about 50,000 times during the whole project phase.

The duty cycle crawler crane is fitted with an optional piling control, which controls the lift and the free fall fully automatically and avoids unwanted unwinding of the rope. Takanen filled the funnel-shaped craters created through the impaction with new soil using the Liebherr crawler tractor PR 736 Litronic. Subsequently, the dynamic soil compaction started all over again. This process was repeated four times on the 25,000m² building site.

The HS 8130 HD is a new addition to the Takanen fleet, which comprises about 50 machines. In addition to dynamic soil compaction, Takanen deploys the duty cycle crawler crane for grab or dragline operation, as well as for lifting work. Since the crawler side frame does not have to be removed for transportation, the machine can be quickly and easily moved between job sites.