Core tube displacer for long reach drilling machines

The long-reach drilling machine is for exploration drilling and core sample collecting and comprises a drill string comprising a variable number of hollow drill rods, a drill bit installed at a first end of the drill string, a ground-resting drill base for installation outside a borehole, a mast attached to the drill base, a drill head installed on and movable along the mast and to which a second end of the drill string is connected, the drill head rotating the drill string, a core tube movable within the drill string between a first position at the drill string first end for receiving a core sample and a second position at the drill string second end, an borehole core tube displacer capable of displacing the core tube between its first and second positions, and an external core tube displacer, distinct from the borehole core tube displacer, comprising a frame that is fixed relative to the drill string, a tube prehension device mounted to the frame and capable of traction on the core tube, and an actuator mounted to the frame and selectively actionable to activate the tube prehension device for allowing the core tube to be displaced relative to the frame beyond its second position.