Ground Check operates Dando 150 and 2000 shell & auger rigs, which are manned by teams of skilled drillers and assistant drillers. These heavy duty rigs represent a tried and tested drilling method, and have been the mainstay of the site investigation industry for many years. The soil investigation rigs are capable of drilling to depths of +50m, where holes are sunk using cable percussive (drop tool) drilling methods.

This technique involves driving lengths of steel casing into the ground to stabilize the sides of the borehole as soil is removed using shell and clay cutter tools. Boreholes are usually advanced using 150mm or 200mm casing, although hole sizes can be increased to 300mm diameter if required.

The drilling method is ideally suited to geotechnical and environmental investigations; where testing and sampling requirements can be combined to increase value and cost effectiveness of the operation.