Understand the four basic surface firing patterns

The firing pattern is a tool to break and fragment a mass of rock in the most effective way for further handling and treatment in the mining or quarrying process. Although there are a lot of different patterns used in the industry, most of them are derived from the following four basic designs:

1. Row by Row - This firing pattern can be applied in a pure row-by-row initiation sequence with delay times only between rows or in a pattern with short delay times between holes and long delay times between rows so there is no interaction between the rows. This design requires at least one free face.

2. Chevron - In a Chevron firing pattern the delays between holes and rows are chosen so that the firing sequence results in a V-formation. By using different delays, the angle of the V-formation can be modified. The Chevron design requires at least one free face.

3. Echelon - The Echelon firing pattern is simply one half of a Chevron pattern. Echelon pattern requires at least two free faces.

4. Diamond - Diamond firing pattern is used for box cuts, sump blasts and other applications where there are no free faces parallel to the blast holes. The broken rock will be displaced upwards, with an increased risk of fly-rock.