Night shift in Luxembourg: Liebherr crane duo lifts 92-tonne motorway bridge

Motorway bridges have a finite life, either due to the loads they endure or planned road expansion measures. This is also the case in Luxembourg. The new bridge was necessary due to the widening of the A3 to six lanes, including a hard shoulder and an exit lane leading to the Aire de Berchem Quest service area. The bridge spans a remarkable 85 metres without supporting pillars. A difficult task for Frederic Kleinhans, Operations Manager at ATS Cranes in Frisange, Luxembourg. "Using our cranes, we had to turn the five girders weighing 87 and 92 tonnes by 90° before installation and then set them down on the abutments. For this purpose, the positions of the two mobile cranes were planned to the centimetre, because the 90° slewing and placement on the abutments had to be done in one operation."

The LTM 1650-8.1, which is only around 15 months old, was the star of the night-time work on the construction site. With a boom length of 45.3 metres, a 17.5-metre radius and 180 tonnes of ballast, it carried the main load. The LTM 1300-6.3 was ballasted with 94 tonnes and its boom was extended to 29.4 metres with a radius of 15.3 metres. Both telescopic cranes were operated by experienced professionals who know "their" equipment inside out. The slewing process in particular, during which the 87 and 92-tonne steel girders were "swung through" only centimetres from the cranes' luffing cylinders, demanded concentration and precision work. The crane driver teams – Nuno de Almeida, Michael Monzel and Rui Lopez (LTM 1300-6.3) and Johanes Schmit, Christopher Steil and Rene Perlich (LTM 1650-8.1) – unanimously praised the extremely sensitive hydraulics on the heavy Liebherr telescopic cranes. With good weather and almost no wind, the girders were lifted in an operation lasting several hours over a weekend.

Tandem lifts are not only spectacular, but also complex to plan. For this job, ATS/Steil used its own CAD software, which takes into account the footprint, overhangs, payloads, start and end radius and the ground pressure. Based on this data, options for different set-up configurations and boom combinations were calculated and visualised. The 3D drawings thus provided a basis for decision-making to ensure exactly the right set-up on the construction site. "We can't afford to do any measurement work on site at night due to the narrow time windows," explains Frederic Kleinhans. "It has to run smoothly, because our client Eiffage Perrard may only close the A3 completely for as short a time as possible, so everything has to run meticulously." The LTM 1300-6.3 was positioned on the construction site a few days before the lift. The experienced and well-coordinated team had to erect and ballast the LTM 1650-8.1 on site on the evening of the first lift. A Herculean task that was completed in two hours.

Frederic Kleinhans praised the enormous commitment of his highly motivated and well-trained team, which lifted the last girder into position at 3 am on Sunday morning.