ABSTRACT
Gemco HP7/ 6 t XW Sandstone/Phyllite XW Sandstone/DW Jacro 200 N* = 40-100 Phyllite: N* = 50-200 Jacro 500 12 t DW Phyllite N* = 70-300 DW Metasiltstone
N* = 50-200 Is (50) ∼ 2MPa N* = 100-500
◦ Drilling bits:
– V – bit is hardened steel. – TC bit is a tungsten carbide. – RR – rock roller.
