A method of loading a borehole for directional blasting comprises placing two or more cartridges containing a primary explosive into the borehole, the cartridges being spaced evenly apart and abutting 10% to 50% of the borehole perimeter on a desired direction of blasting; securing wiring to a detonator in each cartridge, the wiring connectable to a controller that can activate all of the detonators simultaneously; and filling a remainder of the borehole with an emulsion or ANFO having a lower velocity of detonation (VOD) than the primary explosive. A system of interlocking cartridges for use in the method and a method of loading a borehole for main field blasting are also disclosed.
