Although the history of bridge building dates back to the stone age, bridges have lost nothing of their fascination over time. It’s simply breathtaking to look down from a height of one hundred metres onto a miniature landscape or imagine that, since June 2011, you can drive over a 42.5 km bridge in China. Here, too, the limits of technological feasibility are continuously being extended in a very impressive manner. Ever higher, ever further, ever more imposing.
ALPINE is also currently involved in the construction of a staggering structure: the Unstrut Valley Bridge is being built between Erfurt and Leipzig (see also INSIDE 2.2010). On completion, it will be the second longest railway bridge in Germany with a total length of 2.67 km. Work is taking place at heights of up to 45 m. With the help of a formwork carriage, 46 sections of track are gradually taking shape.
Première for an innovative device
Where the carriageway has already been completed, the cap is currently being mounted. This is the name for the parapet that forms the closure to the track on either side. Alongside acting as a footpath and a mounting point for the guard rails and noise barrier, it also performs several other tasks. For example, it serves as protection for the sealing layer. The sections are concreted directly onto the bridge. All the material is moved by a revolving tower crane. This particular type of crane is being employed for the first time ever on the Unstrut Valley Bridge. It was introduced as recently as 2010 at the BAUMA (International Trade Fair for Construction Machinery, Building Material Machines, Mining Machines, Construction Vehicles and Construction Equipment).
The special feature of this crane, representing a major technical innovation, is the crawler undercarriage. It makes the crane mobile. Until now, only so-called bottom-slewing cranes (crane tower and boom revolve on the carriage) could be moved easily and quickly. Special rails would have to be laid first for top-slewing cranes (boom revolves around the crane tower). The new system makes the job easier and reduces costs. “Our whole team is delighted and privileged to be the first users of this innovative device,” reports Richard Steinbauer, the employee in the Technical Equipment Division at ALPINE Bau Deutschland responsible for giant equipment. “No rail tracks get in the way of our work and we are making excellent progress. The feedback to the hire company is entirely positive.”
Unstrut Valley Bridge photo gallery – crane with crawler undercarriage
All-rounders for hire
ALPINE also has its own state-of-the-art machinery. One example of a genuine all-rounder is the under-bridge inspection unit ABC 170 LS/190 LS. It facilitates the performance of inspection, maintenance and renovation work on edge beams and bridge undersides. Not only on traffic bridges, but also on narrow footbridges. During deployment, first the HGV with the unit is placed on the bridge and part of the equipment – similar to the mast element of a crane – is guided out over the bridge perimeter. Then the working platform can be extended underneath the bridge. It has an impressive reach of 19 metres. Operation is possible up to a wind speed of 45 km/h. This versatile piece of equipment is not only of use to ALPINE employees – the under-bridge inspection unit can also be hired simply and cost-effectively by third parties (see information sheet).