The vacuum excavator (also called vacuum bagger or suction excavator) operates on the vacuum cleaner principle: a powerful blower generates negative pressure that suctions soil, gravel, sand and water through a suction hose into a collection tank. Compressed air models additionally use air jets to loosen compacted soil.
The major advantage: non-destructive exposure of buried utilities (gas, electricity, water, fiber optic) without risk of damage from excavator buckets. Utility companies increasingly mandate vacuum excavator use near pipelines. Flow capacity ranges from 100–1,000 m³/h air with suction performance up to 350 mbar negative pressure.
Manufacturers such as RSP (vacuum excavator pioneer from Germany), MTS, Dino and Vacuworx offer truck-mounted and trailer-mounted vacuum excavators. The collection tank (3–15 m³) is hydraulically tilted or emptied via removable containers. Applications: utility construction, archaeology, explosive ordnance disposal and cleaning of sewers and shafts.