With a span of 70 metres, it is the largest column-free heavy-duty bridge that the German civil protection and disaster relief organisation has ever erected: the temporary bridge over the Danube near Tuttlingen. The key tools for the THW’s challenging task were four Liebherr compact cranes. The LTC 1050-3.1 cranes assembled the four segments of the building-height truss structure from hundreds of individual parts.
A particular challenge of the project was the limited space on the pre-assembly site. The cranes had to share the confined space with stored materials, lorries, forklift trucks, telescopic handlers and lifting platforms. To maximise manoeuvrability, the front box – which serves as a storage compartment – was removed from some of the cranes. This reduced the vehicle length to 10.35 metres – making the LTC 1050-3.1 even more space-efficient and manoeuvrable.
“Unbeatable lifting cab”
The four compact cranes with raised operator’s cabs were frequently in action. The THW had opted for this optional feature on all the units it had ordered. “Especially when building bridges, the height-adjustable cab is simply unbeatable for me,” says Niklas Stein, who operated one of the LTC 1050-3.1s for a week during the operation. “Particularly when assembling the upper steel sections, having a direct view of my colleagues from a height of seven metres is, of course, a major safety benefit.”
Stein is part of one of 16 groups of volunteer experts specialising in bridge construction that the THW maintains across the country. At regular intervals, they erect temporary bridges to maintain their operational readiness and keep their skills sharp. Niklas Stein has been responsible, alongside others, for the crane belonging to the THW’s Müllheim local group in south-west Germany for just under two years. “Here on the construction site, the machine’s advantages are particularly evident,” says Stein. “And despite its compact dimensions, the LTC simply has a huge lifting capacity.”
New cranes, shorter construction times
Two years ago, the THW collected the first of a total of 18 of these compact cranes from the Liebherr plant in Ehingen. “In the past, we mainly used our own loading cranes for operations like this,” explains Patrick Weisser. The engineer coordinated the operation on the Danube together with Fiona Mager, head of the bridge construction specialist group at THW Müllheim. “With the new Liebherr LTC 1050-3.1s, we are now in a much stronger position and can complete projects such as this temporary bridge in less time. Here in Tuttlingen, we were even five days ahead of schedule.”
After the four bridge segments, each weighing around 100 tonnes, had been pre-assembled, they were transported over a distance of several hundred metres to the river. There, the emergency services used the compact cranes to join the truss segments together to form a continuous structure. Using a pushing technique, the structure was moved approximately halfway across the Danube. For the final lift, two Liebherr LTM 1650-8.1 mobile cranes were on standby on both banks. Working in tandem, the cranes from MSG Krandienst GmbH and Scholpp Kran & Transport GmbH lifted the structure onto the abutments and positioned it in its final location.
