The burn, or parallel hole, cut relies on larger diameter uncharged holes to provide the initial void to fire into.

These ‘reamer’ holes have limited volume so the burn cut starts with firing holes on very small burdens to ‘nibble’ the rock out until sufficient void and a second free face is created.

The initial holes pulverise the small amount of rock in the cut and then use the high pressure gases to clear the void. Unlike bench or stripping blasting the broken rock must undergo a change of direction and be squirted out the narrow cut area. This process takes some time and is the reason for the use of ‘Long Period’ (LP) delays.

As a second free face and void is developed blasting transitions to stripping geometries with maximum burdens and sufficient relief.

The burn cut requires a high degree of drilling accuracy to be reliable and there is a trend toward machine guidance systems on drilling machines to optimise drill accuracy.

Whilst these have been shown to be very effective in maximising blast effectiveness, and have been widely adopted into construction tunnelling, they have had limited acceptance in mine development due to operator resistance and maintenance issues.