Three Doosan excavators have helped demolish and replace a road bridge over a busy railway line in Germany within a tight timescale.
The contractor, Beller, had exactly 72 hours to complete the work – but it won the race against time with Doosan DX255LC-5, DX340LC-5 and DX380LC-5 excavators.
Beller had bought the excavators from Doosan dealer, Ummenhofer, which is based in Pfullendorf in Baden-Wurttemberg, during the previous two years.
Demolition of the bridge was necessary because strong vibrations caused by the rail traffic had made it so unstable it could no longer be used by heavy vehicles. A future-proof solution could only be created by demolition and new construction.
Apart from the time constraints, Beller had to be particularly careful about a main data line that connects a large part of the region to the internet and runs through the construction site area.
At exactly midnight, rail operations were stopped and approval given to start work. From then on, around the clock, the operation was carried out in shifts. After the railway line was covered, the excavators created a gravel bed protect it and demolition started. Particular attention was also paid to protecting the overhead lines.
With the help of several pulverisers, chisels and grabs, the DX340LC-5 and DX255LC-5 tackled the old foundations and the DX380LC-5 the superstructure. The actual demolition was completed in a short time, and around 800 t of concrete was removed and reused in Beller’s own reprocessing plants.
The spaces left by the foundations being demolished were filled in and compacted. This was extremely important as the foundations go down to a depth of 2 m (6 ft 6 in) below the rail tracks and without this work, the stability of the rails would have been put in question when driving over them with heavy rail vehicles.
The route was opened to traffic again on time after 72 hours. The Doosan excavators also took care of the subsequent earthworks and the loading of the trucks.