Of Wolves and Bears – Three WOLFF Cranes at the BäreTower in Berne

Its name is reminiscent of the his toric Bären (Bear’s) Inn, which has been an institution in the  Swiss municipality of Ostermundigen for over 100 years. The  new BäreTower will now rise in the same location. The 100-me ter-high building will provide 152 rental apartments, a hotel and  a medical center offering grand views of the Swiss Alps. It will  also be home to a new panoramic restaurant serving more re fined versions of the dishes to be had at the original inn. Con tractor Estermann AG rented three flattop WOLFF Clear Cranes  for the project. The complex construction site required inten sive teamwork early in the planning phase. 

Advertisement

In particular the location of the construction site near the Bern-Belp  Airport had a significant impact on the crane concept. The planning  team opted for WOLFF Clear Cranes, due to their lower assembly  heights and easily discernible maximum overall heights. Both the  crane assembly and operation had to be reported to the Federal Office of Civil Aviation and the two highest cranes equipped with ob struction lights and warning sleeves on the slewing part. Due to the  immediate proximity of the construction site to a rail line, all three  cranes were also fitted with a working range limitation to comply with  the safety requirements of the railroad.

Special facade solutions for tie-ins

The highest crane, a WOLFF 6031.8 Clear, was initially assembled  to a hook height of 81 meters, then climbed and tied to the building  twice during the construction process to its final height of 126.5 me ters. “Due to the design of the facade elements, the tie-ins could not  be attached to the floor slabs as is usual but had to pass through  window and door openings to be fixed inside the building,” explains  Johannes Eckert, Head of Sales at WOLFFKRAN Schweiz AG. The  attachment points of the tie-ins on the building and crane tower had  to be precisely determined prior to the crane assembly and the foun dation of the WOLFF 6031.8 Clear calculated accordingly. The fa cades are installed in one go as soon a floor is completed, which is  typically every seven days. “The order in which the facade compo nents are installed is thus fixed and a later installation almost impos sible,” explains the certified Crane Expert Beni Buchs. “Door and  window frames of the affected facade elements have therefore been  modified to allow for an installation around the tie-ins.

Contractor Estermann and WOLFFKRAN Switzerland have been  working together since many years and are currently also collabo rating on the Claraturm mixed-use high-rise and the Baloise Park  commercial redevelopment in Basel. “The WOLFFKRAN team  brings its vast experience to every construction site and building  phase,” says Buchs. “Their detailed planning and reliable advice  help us ensure a smooth building process every time.” 

Two of the three WOLFF cranes have since been dismantled. The  126.5-meter WOLFF 6031.8 Clear will remain on site until June, re lentlessly lifting concrete and facade elements into place in lofty  heights. While the last of the 32 floors are still being built, interior  work on the lower apartments has already been completed and two thirds of the 152 units have already been leased.