Linden Comansa and BKL install a modular building on a Berlin rooftop

German rental and crane specialist BKL supplies a tower crane model 21LC750 for the Construction of a modular hotel on top of a shopping centre.

One of Germany's most powerful hire cranes, a Linden Comansa 21LC750 from BKL Baukran Logistik's crane fleet, now stands on the parking deck of Berlin's mall Ring-Center.

Until the summer, this 750 tonne metre giant, with maximum load capacity of 48 tonnes, will be installing 151 wood modules of almost 8 tonnes in weight each, building an exceptional hotel with a modular design concept.

"A special feature of the SKYPARK hotel concept by MQ Real Estate is that it exploits the inner-city potential of adding another storey", says Reiner Dinse from the Hannover office of BKL Baukran Logistik GmbH. He goes on: "The hotel's modular design requires large wood modules, each 20 square metres and weighing some 7.5 tonnes, to be lifted over a distance of up to 75 metres. Not many cranes can handle such a Herculean task".

A special steel construction

Given the challenging requirements of load capacity and radius, the team picked from BKL's fleet a 21LC750 flat-top, one of Germany's most powerful hire cranes. Thanks to its 80-metre-long jib and the PowerLift system, this model is perfect to lift the approximately 7.5 tonne modules from the street, around 20 metres below the site of the crane, to their destination on the aboveground park deck, almost 80 metres away.

As the bearing capacity of the car park roof is insufficient for such an exceptional load, the building contractor MQ Real Estate teamed up with the crane specialists at BKL Hannover and a steel constructor to design a special 16.5 by 16.5 metre steel substructure to transfer the load, assembling the crane on its 10 metre folding cross base.

Time-efficient assembly

The BKL specialists settled on a 500 tonne machine from their fleet of mobile cranes to assemble the Comansa tower crane and lift its approximately 24 tonne cross base. The Ring-Center's central location on Frankfurter Avenue, one of Berlin’s main arterial roads, called for a tight schedule, not just to assemble the 21LC750 crane, but also to set up and dismantle the mobile crane. The BKL project team planned a synchronized plan of transport and delivery of the crane parts to the site to install the steel substructure and the construction crane in just five days.

The 21 LC 750 is to lift the 151 room modules, which are fully equipped apart from the moveable furniture, by August 2018. With 151 rooms in all, the SKYPARK Berlin hotel overlooks the Berlin-Mitte district, which holds the city’s Historic centre.