The Obernkirchen sandstone quarries are located at the point where the powerful mountain ranges rise from the North German plain, four kilometres east of Obernkirchen and six kilometres south of Stadthagen. Here, on the plateau of the Bückeberg elevation, sandstone has been taken from one of the oldest active quarries in the world for 1,000 years, and is supplied to customers all over Europe.
While at first, the extraction and treatment of the raw blocks was completed primarily with muscle power and very basic tools, in the course of industrialization the first machines were used in the quarry. Using hand drill or wedge-hole hammers, numerous drill or wedge holes are driven into the rock so that the outline of the block is predefined. These rows of holes weaken the rock, so that it can be separated by hammering wedges, working with crowbars or by using gunpowder explosions. After having released the raw blocks out of the main body of the mountain, they are wrapped in chains and lifted by a derrick crane up against the rock face.
Since the 1980s, specially designed wheel loaders have been used for the extraction of sandstone. They drive a stripping mandrel between the layers of natural storage and hydraulically release the sandstone from the mountain in the form of large blocks. The resulting pieces are prepared for further processing with a block saw in the quarry itself.
In contrast to other building products, no energy is required for the manufacture of the building material. Just as it was formed by nature, we take the stone from the ground with minimal noise and air pollution. Of course, energy is used for machining - but the amount of energy used here and the resulting emissions is negligible in comparison.