Heritage wall restoration

The island of Mainau, known as Lake Constance’s “flowering isle” is home to Germany’s second-largest butterfly house and a famous rose garden. It is here that a 20m-long section of a historic wall suffered damage.

In order for the restoration to begin, all damaged pieces of wall have to be lifted separately and removed. Stone masonry and sculpture company Eduard Schnell chose a Liebherr L1-24 fast-erecting crane to carry out this work. The crane is supplied by Liebherr’s rental fleet.

As the crane was to be positioned directly on top of the backfill of a historic rampart wall, the ground was assessed by BfB-Büro für Baukonstruktionen.

The site can only be reached via a bridge, the weight limit of which is insufficient for a tractor vehicle towing ballast and the crane. On the day of assembly, the fast-erecting crane was transported over the bridge using one of Mainau’s own tractors, towed past the castle and then assembled by service technicians at the Liebherr site in Stockach.

As the condition of the substrate couldn’t be specified with absolute certainty, the best possible precautionary measures were taken. Large-format steel plates were placed under the supports to keep the corner pressure points as minimal as possible. The crane was also positioned as far as possible from the collapsed section of wall.

As the island of Mainau is now open to the public again, additional safety measures were put in place regarding visitors. Liebherr’s sales and rental partner had an ABB operating range limiting system installed in the crane specifically for this purpose. This system prevents the crane from overshooting defined areas with its load.