Förfarande och apparatur för borrning av vattenhål

摘要

Method and apparatus for drilling water drainage holes into a hollow-core slab, the hollow-core slab cast or cut by sawing into the final length being lifted and transferred in said method from the casting bed to a separate drilling station (1,2,3) by means of lifting elements. In the method, the hollow-core slab is grabbed by lifting elements at the ends of the slab substantially at the places, where the drainage holes will be drilled at the ends of the slab, the mutual distance of the lifting elements grabbed to the slab is determined, the mutual distance of the drilling units (6) for drilling the drainage holes to the opposite ends of the slab is determined based on the mutual distance of the lifting elements, and the drilling units (6) for drilling the drainage holes to the opposite ends of the slab are moved to the determined distance from each other.