The company's machinery was to be extended in 2021 by a new screening plant. The requirements: The plant had to be flexible, above all, and perform in the gravel quarry just as well as on the recycling site – which is not an easy task. After all, whereas sand and fine-grained material are processed in the gravel quarry, in the recycling of rubble and railway ballast Krebs processes almost everything. Also including, for example, topsoil which is often particularly cohesive. The screening plant therefore has to deal with stone material ranging from very fine to very coarse as well as with all degrees of contamination.