What is Raise Boring?
Raise boring is the process of boring a raise. A pilot hole is drilled from the drill rig to an underground cubby or tunnel. A reamer head with cutters is then attached to the drill string. The drilling rig at the surface or upper level then pulls tension onto the drill string while rotating, causing the large diameter cutting bit to cut a large hole from the underground tunnel or level to the surface or upper level.
The cuttings are removed as this fall to the ground due to gravity feed. The process sounds simple but requires skilled operators, good quality down hole equipment and powerful drill rigs.
What is Raise Bore Drilling used for?
Raise boring is used to create a circular vertical or horizontal excavation between two existing levels or tunnels in an underground mine. It is mostly used for ventilation shafts from the surface to underground.
