Flying towers

Teams from Liebherr-Baumaschinen AG and Rotex Helicopter AG worked together to complete the complex airlift at the summit of the 44-year old Corvatsch railway in Switzerland.

“When it comes to helicopter assemblies, the demands on the entire team are very heavy. Experienced staff and optimal preparation of the crane and site are crucial to safe and efficient crane assembly,”said Hans-Martin Frech at Liebherr.

At the summit station the Liebherr 30 LC, with 12 m tower base section, was assembled on a mobile undercarriage with 3 m track guage. Under-hook height was 11.2 m and working radius was 24.7 m. To ensure that the crane was structurally stable while out of service it was guyed to withstand wind speeds up to 200 km/h.

The K-Max heavy-duty helicopter, used for the assembly, can lift up to 2,700 kg. Individual components of the 30 LC weighed a maximum of 1,700 kg and were ideally suited for the worksite conditions, Frech explained.

Multilifts

“Thanks to both teams'precise logistics planning and the pilot's perfect flying, the 30 LC tower crane was fully assembled in around four hours. A total of 28 helicopter trips were required to collect all of the individual parts, including ballast and counterweights. The helicopter had to make five trips from the valley station because the large parts were too big to take to the intermediate station by rail,”Frech added.

The restoration and reconstruction work at the summit station was carried out by construction firm Hartmann Nicol & Cie AG. At a later stage the two cable car supports will be replaced. The first will be shifted a few metres further up the mountain, while the second will remain in its existing position. The station's mountain restaurant will also be retained.

An enhanced aerial lift at the summit base, incorporationg cabins to accomodated up to 100 passengers, is due to go into service in December 2008.