ABSTRACT
The raise boring technology was developed to meet the demands of the underground mining industry, but has also found numerous applications in tunneling or infrastructural projects for ventilation purposes even in very hard rock formations or in opening deep shafts like in the Gothard Tunnel in Switzerland. Raise boring provides a safe means of excavating a shaft between two levels of a mine without the use of explosives. Raise boring machines operate on the principle of first drilling a small pilot hole and then reaming the hole, in one or more stages to the desired size.
