Bridge demolition: Swiss giant creates “clear conditions” in Hanau

An extremely complicated demolition process, which the company Max Wild from Berkheim is carrying out in two stages with its crane partner, Emil Egger. Railway tracks had to be closed and overhead lines dismantled. A temporary bridge was installed, diversions set up and hundreds of other trades, institutions and specialists prepared for the major demolition job.

At the start of December 2024, the time had come. Visible proof of the efforts was the assembly of the LR 1700-1.0 from Liebherr with a weight of 900 tonnes and a 60-metre-long main boom as well as a 36-metre-long derrick boom It arrived on 38 trucks and was erected and calibrated by three experienced Egger crane professionals and a 120-tonne telescopic crane in just three days. Proof of the carefully thought-out modular concept. 50 tonnes of central ballast, 150 tonnes of revolving platform ballast and the large suspended ballast ensure stability.

The first dismantling phase was to be completed by 31 December 2024 and consisted of 15 lifts totalling 4,000 tonnes of material. Demolition by means blasting or hydraulic hammers was ruled out due to the surroundings and the sensitive railway structure. Max Wild decided to saw out the individual segments, each weighing between 70 and 280 tonnes. After the installation of the LR 1700-1.0, the work really began: the team laboured around the clock. During sawing, the bridge section to be cut out was attached to the LR 1700-1.0 with lifting straps and chains. The lifting gear was under tension, as the load was only released and suspended from the crane's hook when the last saw cut had been completed.

Stefan Beeler has been with Emil Egger AG for three years and switched to the crane hire company specifically because of the LR 1700-1.0. He drives this crane for around 600 hours a year and is particularly satisfied with its extreme sensitivity. He confirms that, although assembly and dismantling are no child's play, they can be completed in just a few days with a 130-tonne auxiliary crane thanks to the excellent accuracy of fit, the simple plug-in connections and the clear erection guidelines.

There were and still are plenty of unpredictable aspects to the job, as the 38 trucks carrying the components of the Liebherr LR 1700-1.0 crawler crane had to travel backwards under the bridge structure to the assembly site. The crane has been there since mid-December and will remain there until the end of February, as the second part of the assembly with a further 16 lifts will begin in the second half of February. Equipped with 60 metres of main boom and 36 metres of derrick boom with 2 x 8-fold reeved rope (winch 1 and 2), the LR 1700 is the perfect tool for this sensitive bridge demolition.

In the first dismantled section, the heaviest part weighed 280 tonnes. To handle this, an additional 375 tonnes of suspended ballast had to be added on. The challenge with this was that the boom had to be luffed as soon as the component was released and hung on the hook. The crane then had to move back a few metres and then slew through about 180 degrees to gently place the bridge component on the dismantling site. Many people can do this, but the Swiss are particularly good at it, which is why Simon Walcher, site manager at Max Wild, is convinced that, with Egger, he has the right partner by his side for this complicated construction project.

The LR 1700-1.0 from Liebherr is the second-largest crane in Switzerland and also the second-largest in the Egger fleet after the LR 11000. "There isn't much wind power in Switzerland," confirms Stefan Beeler, crane operator at Egger. This is why construction work, assembly work, especially on bridges, buildings and industrial structures, as well as loading in harbours, are the bread and butter business for the LR 1700, which after three years of use and 1,800 operating hours looks as if it has just left the one-million-square-metre Liebherr plant in Ehingen.