Crane operators drew on experience, as well as calculations, as they lifted 157m, 70t steel plates for installation on the underside of a 65m high extradosed bridge.
Twin cranes at work on the Horb High Bridge site. Credit: Liebherr
The new bridge over the Neckar valley, the Hochbrücke Horb (Horb High Bridge) in southwest Germany will carry a federal highway. It is being built to an extradosed design, as a cable-stayed pre-stressed concrete structure. The slender decks are further stiffened with continuous steel plates, fastened with thousands of anchor bolts.
Rather than welding these plates piece by piece, contractor Wiesbauer elected to assemble the plates on the ground and lift them using a twin Liebherr crane assembly.
Although Wiesbauer used planning software to simulate the lift in preparation, crane operator Tim Moll leant heavily on his own craft. “In this type of operation, experience makes all the difference. Calculations are not enough: you need to have the right 'feel' for the load and the position of the counterweight."
PORR Spezialtiefbau is responsible for the bridge’s structural and shoring foundations, and the client is Karlsruhe Regional Council.
