0.5s detonators ranges from 0 to 10 and sometime 15s for bigger cross section. The electric detonators are successively being replaced by nonelectric method, NoNel.
The blasting patterns are based on the following diameter of the blast holes 41,45,64 mm and wedge or parallel hole cuts of two types
- central, large diameter empty hole with parallel charged holes
- Parallel, holes close to each other,alternately empty and charged hole of the same diameter as the rest of the drilling
The heading rounds achieved with such cuts are usually 4 to 5m and in single cases 6 to 7m deep that the blasted drilling broke.
Sine 1997,the blasting vehicle jumbo SWSS-5 from Nitro-NOble, for pneumatic jet or pressure charging was introdced.