Drilling of grout holes in an inspection tunnel under the Ohra dam in Oberhof, Germany . The inspection tunnel which extends under the dam has a length of 100 meter and an inclination of 25 degrees. The purpose of the grout holes which has a length varying from 50-90 meter was to create a grout curtain against the dam. Stump Spezialtiefbau GmbH was the drilling contractor.
The benefit with using Wassara in this project was the improved working conditions in the tunnel with reduced dust and no oil mist in the air.