How are cables laid under roads, forests or bodies of water?

In sensitive areas such as roads, forests or bodies of water, the horizontal directional drilling method is used - a trenchless and particularly environmentally friendly method.First, two excavation pits are created: a starting pit and a target pit. From the start pit, a steerable drilling head works its way in a gentle arc under the respective obstacle. Its position is continuously monitored. A bentonite drilling suspension - a special mixture of clay and water - is pumped into the drill channel via the drill rods. It flushes the loosened soil through the channel back to the starting pit and stabilizes the borehole at the same time.After the so-called pilot bore, the drill head is removed and a widening bulb is attached, which gradually enlarges the channel. Only when the bore channel is sufficiently dimensioned are the empty pipes pulled in. These are later used to pull in the medium-voltage cables and fiber optic cables.The drilling slurry forms a stable casing around the pipes. Finally, it is disposed of professionally and the excavation pits are backfilled.