kirra-docs

Pattern Preparation

Pattern Preparation is an optional scheduling phase that appears before drilling in the Gantt chart. It represents the floor preparation work that must happen before drill rigs can safely access a blast pattern.

Screenshot coming soon


Why Pattern Prep?

In open-cut mining, the bench floor is rarely ready for drilling immediately after the previous blast fires. Common preparatory tasks include:

Neglecting to schedule this work is a common source of drilling delays. By giving Pattern Preparation its own Gantt phase, planners can see the full timeline and avoid scheduling conflicts with ancillary equipment.


Typical Prep Sequence

The machines involved in floor preparation typically work in this order:

Step Equipment Task
1 Excavator Pull the walls and remove overhanging material
2 Loader Load out batter trims and debris
3 Dozer Rough-prep the floor for drilling access
4 Grader Grade the floor to a smooth surface
5 Roller Compact the floor for final preparation

Not every blast needs all five steps. You can assign any combination of ancillary equipment (or none at all) depending on site conditions.


Setting Up Pattern Prep

Via the Blast Form

  1. Open the blast form (click + Add Blast or the pencil icon on an existing blast)
  2. Scroll to the Pattern Preparation section
  3. Set:
    • Prep Start – The date floor prep begins
    • Prep Days – How many calendar days the prep work will take
    • Assigned Ancillary – Select ancillary equipment to assign from the multi-select list
  4. Click Save

Screenshot coming soon


Gantt Chart Display

Section

The PATTERN PREP section appears at the top of the Gantt chart, above DRILLING. It only shows rows for blasts that have a prep start date set.

Bar Appearance

Info Column

The Info column for PATTERN PREP rows displays:

Interactions


Dependency Behaviour

Pattern Preparation is currently not linked to the automated dependency engine. The prep start and duration are set manually by the planner. The prep phase is intended as a visual planning aid – it does not automatically cascade into drilling start dates.

Tip: When planning your schedule, ensure that drilling does not start until prep is complete. You can visually verify this on the Gantt chart by checking that the teal prep bar ends before the blue drill bar begins.