Cleaning of Bismarck Monument in Hamburg, Germany

In the middle of the Elbe metropolis of Hamburg, between Landungsbrücken, St. Pauli and Michel stands the world's largest Bismarck statue. Kärcher cleaned the 113 feet high and over 100 year old monument over a period of almost two months.

In the middle of Hamburg, between Landungsbrücken, St. Pauli and Michel stands the world's largest Bismarck statue, which is currently being cleaned by Kärcher. The granite surface of the 113 feet high and over 100 year old monument is heavily soiled by biological growth such as algae, lichens and moss and by graffiti. The work will take a total of two months, during which Kärcher's experts will clean the enclosure wall, the pedestal and the statue itself of any contamination.

In order to determine the optimum process, Kärcher experts carried out various tests and created sample areas in advance. "The chosen procedure without chemicals removes the impurities in a gentle way," explains Nick Heyden, who as project manager of Alfred Kärcher SE & Co. KG, is responsible for the on-site implementation. "We are proud to be able to make a contribution to the preservation of the monument with our material-conserving cleaning technology."

The Kärcher experts use three different cleaning techniques. First, larger plants on the surface are removed by hand before dust, bird droppings and other biogenic vegetation are removed with the help of a hot water pressure washer. The 176 to 194 degree hot water hits the surface at a pressure of 1 to 2 bar - a particularly gentle method for granite stone. The five cleaning experts then use a low-pressure particle blasting process with the blasting agent aluminium silicate (grain size 40-180 μm) to remove graffiti and lime deposits. Finally, the entire monument is vacuumed with commercial wet/dry vacuum cleaners, and at the end the last remaining dirt is rinsed off again.