On many vacuum excavation projects, it can be difficult to manoeuvre the vacuum excavator as close to the work site as one would like: the valve chamber is off-highway; access on the industrial site is hampered by pipes, silos and walkways; enabling works on the housing development have yet to be completed.
Vacuum excavators are very adaptable and, using simple extension pieces, can typically remove materials at a distance of up to 80m – 150m away from the vehicle. However, as the suction hose gets longer and heavier, it becomes far more difficult for the operator to control the nozzle. Suction power also diminishes as the length of the hose increases.
LMD has developed a ‘parent and child’ approach which gives the operator full control of the nozzle and maintains vacuum power. In the ‘parent and child’ approach, a hose and extension pieces is run from the parent vacuum excavator to the child unit. The child unit is located at the site where the materials need to be excavated or removed. The child unit is small and light, and is equipped with rubber caterpillar tracks that enable it to cross uneven ground.
The child unit has an onboard compressor to generate the air required to operate the air lance regardless of distance from the parent unit, and its own hydraulic system for the nozzle which gives the operator the ability to remove material accurately and quickly. There is no intermediate storage, the excavated material going straight into the skip on the parent vacuum excavator.