Ground Check operates track mounted Commachio MC-305 Hollow Stem Auger drilling rigs, which combine the benefits of shell & auger/window sampling and rotary drilling into one unit for maximum flexibility. The rig is suited to sites with restricted access and low headroom conditions. The drilling method is also ideal for combined geotechnical and environmental investigations required for brownfield redevelopment projects.

These powerful and versatile rotary rigs are capable of drilling in soils to depths of +30m. Holes are advanced using hollow stem flight auger casing, inside which window sampling barrels or testing equipment is inserted on drill rods. This method can be used to recover continuous undisturbed samples of soil in PVC core-liners up-to 1.5m length, which are suitable for geotechnical testing.

Downhole hammer bits can also be attached to prove rock or penetrate layers of concrete, rubble, or boulders that would normally impede shell & auger drilling.