The more than 35-year-old Kocher viaduct near Geislingen on Kocher near Heilbronn is being renovated from 2013 to 2015 – work is taking place simultaneously here at several construction sites. At 185 meters, the Kocher viaduct is the highest bridge in Germany. 50,000 vehicles cross it daily. The Kocher viaduct was designed as a prestressed concrete box girder bridge. Demolition will be performed inside of the box girder of the 1,128 meter-long bridge during the course of the rehabilitation. The LEONHARD WEISS Group, the construction company performing the work, is using the 1-ton excavator with dual power from Wacker Neuson here, which was purchased specifically for this application. "Our excavator 803 dual power is the ideal machine for such an application, because it was designed and developed specifically for this purpose," says Thomas Knapp, sales manager for the region of Stuttgart at Wacker Neuson.
With the dual power option, the 803 mini-excavator from Wacker Neuson can – in addition to the standard diesel engine – be connected to the external electro-hydraulic power unit HPU8. With the generator, the excavator is operated electrically and completely emission-free. The excavator with the dual power option meets all requirements for conventional compact diesel excavators, but in a few minutes can be converted to a unit for emission-free work if necessary – without losing any machine performance or application flexibility. "A powerful machine with compact dimensions was needed for the demolition application on the Kocher viaduct. We needed a machine that could also work in confined spaces and in particular be operated without exhaust gas emissions," says Hartmut Bagg, project manager at LEONHARD WEISS as he explains the requirements. "The dual power option was convincing in application."
The simple handling of dual power is particularly important for end users. If, for example, the excavator is required for demolition / renovation work, the operator drives it in conventional mode to the site of operation. Two openings are incorporated in the excavator's dozer blade in which the HPU8 generator can be secured for transport. The dimensions of the excavator and the generator are matched to each other so that the operator can easily drive through narrow door openings with the set. Once arrived on site, the operator connects the unit to the excavator's undercarriage and can then continue to work completely free of emissions. The hydraulic supply for the excavator takes place via the travel gear so that the pivot radius remains unrestricted over 360 degrees. The operating weight, stability and dimensions of the excavator have not changed with this option. For the operator, the sequence of operations thus remain completely unchanged after the connection of the generator.