A Liebherr tower crane was erected on top of Baden-Württemberg's tallest building – the elevator test tower in Rottweil, Germany – with the aid of another Liebherr tower crane, type 280 EC-H 12 Litronic.
The 280 EC-H 12 Litronic, with a hook height of 265 metres, will now be supported by an 85 EC-B 5 FR.tronic flat top crane erected on the top of the building.
The two cranes are working on the interior fittings, the facade and on the surrounding construction work for the test tower in Rottweil.
Using Micromove fine positioning mode, the 280 EC-H 12 was able to position the crane components for the 85 EC-B 5 with precision even at an altitude of 225 m, Liebherr said. The 85 EC-B 5 FR.tronic was bolted to a steel structure specially manufactured for this purpose.
Michael Weissschädel, Liebherr Tower Crane Solutions project manager, said, “This steel structure had to be permanently connected to the building, assembled with millimetre precision and must not bend even when loaded, to ensure the stability of the crane at this altitude when it is both operating and shut down.
“The base tower section is directly secured to the steel structure. That means economical installation using standard Liebherr tower sections.”
The 85 EC-B 5 was erected with a special short jib with a radius of just 12.5 m so that the two cranes can work together in a small space without hindering each other. As a result of its special configuration, the 85 EC-B 5 FR.tronic can reach the required 260 m hoist height and can hoist 4.2 tonnes.
The crane has an additional resistor cabinet to provide high-speed, long-term lowering.
The 280 EC-H 12 Litronic was fitted with a 110 kilowatt high-performance hoist gear to enable it to handle loads at high speed and great altitude. In combination with the second tower crane, this saves time for general contractor, Züblin.
Liebherr-Werk Biberach, the Nagel Group of Companies and Züblin worked closely on planning the job. Together they prepared the perfect plan for the site and ensured the high-speed erection of the crane, liebherr said.