Loading of boreholes with explosives

Claim 1

Method of loading explosive cartridges into a borehole comprising: a. providing a cartridge-guiding assembly comprising a length of flexible tubing; b. feeding said assembly into a substantially vertical borehole until the leading end of said assembly is positioned at a location, short of the bottom of the borehole, where explosive cartridges are to be discharged, thereby leaving a cartridge-discharge space in the borehole, said assembly extending through substantially the remainder of the borehole, and being sufficiently heavy, at least at its leading end, so as to be dragged downward against the frictional forces produced at the borehole wall and through any water which may be present in the borehole; c. directing a stream of water through said assembly; d. feeding explosive cartridges into said length of tubing whereby said cartridges travel through said tubing together with said stream of water and are discharged from the leading end of said assembly into the cartridge-discharge space adjacent thereto; e. sensing the passage of said explosive cartridges through, or their discharge from, said assembly; f. retracting said assembly when the space adjacent thereto is filled, as evidenced by the cessation of cartridge discharge, whereby additional cartridge-discharge space is created; g. creating a cartridge-feeding opening in said retracted length of tubing in the vicinity of the borehole collar; and h. repeating Steps (c), (d), (e), (f), and (g) as required until the desired number of cartridges have been discharged into the borehole.