Lifting a roof structure

Lifting and rigging of 30 m long, 14 t heavy roof elements at 8 anchor points and a 30° inclination using two 80-ton cranes.

In Überlingen on Lake Constance, the new five-part gymnasium on the school campus will open in 2020. After a seven-year break, the students can finally use their own gymnasium again. In this context, Schmidbauer was commissioned to install the roof elements. Originally, according to the structural engineer, the elements were to be evenly lifted from 8 anchor points using a 400-ton mobile crane with a 20 m long spreader beam. However, obtaining a 20 m spreader beam with 14 t load capacity was problematic. Spreaders were unsuitable for this application. Therefore, a new proposal was engineered.

Finally, a LTM 1200 and a GMK 5130 came into operation. The four long sling chains per crane and the corresponding chain hoists simply attached the 14 t roof elements and threaded them in a tandem lift.
The newly engineered proposal which was submitted to the customer also saved the client considerable costs. The omission of the 20 m long spreder beam and more favorable arrival and departure costs of the much smaller mobile cranes were the reason for the savings. The 400-ton crane originally ordered would not have been able to assemble the elements. In the end, the "special solution" turned out to be much easier and faster than planned.

Thanks to the experience of the company and the finesse of its employees, Schmidbauer was able to meet this challenge. The result was a thoroughly satisfied customer who has an optimally seated roof structure over the school campus in Überlingen.



  • Liebherr LTM 1200
  • Grove GMK 5130


Location: Überlingen a. Bodensee, Germany
Period: July 2019