kirra-docs

Timing Sequences

Timing controls the order and delay between hole detonations in a blast. Correct timing is essential for fragmentation, vibration management, and flyrock control. Kirra provides tools to design, visualise, and validate timing sequences across your entire blast pattern.

Key Concepts

Term	Meaning
Delay	Milliseconds from the initiation signal to a hole’s detonation
Inter-hole delay	Time between consecutive holes in the same row
Inter-row delay	Time between consecutive rows
From Hole	The hole that triggers the current hole (the timing connection source)
Connector	A line drawn on the canvas showing the timing link between two holes
Firing time	The absolute calculated time a hole fires, accounting for all upstream delays

The Connect Tool

The primary way to build a timing sequence is the Connect tool. It links holes together to define the firing order.

How to Connect Holes

Activate the Connect tool from the toolbar or the Timing panel
Click the source hole (the hole that fires first)
Click the target hole (the hole that fires after the source, with a specified delay)
A connector line appears between the two holes on the canvas
Enter the delay in milliseconds when prompted
Repeat for additional connections

Each connection sets two properties on the target hole:

Property	What It Stores
From Hole	The ID of the source hole (the hole it is connected from)
Delay	The time delay in milliseconds between the source and target

Viewing Connections

Enable View > Show Connectors (or press Ctrl+C) to display connector lines on the canvas. Lines are colour-coded to help you trace the firing sequence visually.

Deleting a Connection

Select the connector line on the canvas and press Delete, or right-click a hole and choose Remove Connection.

Screenshot coming soon

Automatic Timing Sequences

Instead of connecting holes one at a time, you can apply automatic timing patterns to an entire selection.

Row-by-Row (Along Row)

Holes fire in sequence along each row, then advance to the next row.

Select the holes to time (or select the entire entity)
In the Timing panel, choose Along Row
Enter the Inter-hole delay (e.g. 42 ms) and Inter-row delay (e.g. 25 ms)
Choose the row direction: Left to Right, Right to Left, Bottom to Top, or Top to Bottom
Click Apply Timing

Echelon (Diagonal)

Holes fire in a diagonal wave across the pattern, producing smooth face movement. This is ideal for production bench blasting.

Select the holes
Choose Echelon
Enter inter-hole and inter-row delays
Set the echelon angle
Click Apply Timing

V-Cut (Chevron)

Holes fire from the centre outward in a V-shape, creating relief for the burden. This is well suited to confined blasts or tunnel rounds.

Select the holes
Choose V-Cut
Enter delays
Click Apply Timing

Manual Timing

Assign delays hole-by-hole for full control:

Select Manual mode
Click each hole on the canvas and enter its delay in the right panel or the Timing panel input field
Set the From Hole connection for each hole

Timing Flow Across a Pattern

Timing sequences build up from the first hole in the chain. Each hole’s absolute firing time is calculated by summing the delays along the connection chain from the initiation point:

Hole A (0 ms)  -->  Hole B (42 ms)  -->  Hole C (84 ms)
                         |
                         v
                    Hole D (67 ms)  -->  Hole E (109 ms)

In this example:

Hole A fires at 0 ms
Hole B fires 42 ms after Hole A (absolute time: 42 ms)
Hole C fires 42 ms after Hole B (absolute time: 84 ms)
Hole D fires 25 ms after Hole B (inter-row delay; absolute time: 67 ms)
Hole E fires 42 ms after Hole D (absolute time: 109 ms)

Colour Coding by Delay

Activate View > Colour by Timing to shade holes on the canvas according to their firing delay:

Earlier-firing holes appear in cooler colours (blue, green)
Later-firing holes appear in warmer colours (orange, red)
A colour legend is shown in the bottom-left of the viewport

This gives you an instant visual check of the firing sequence across the entire pattern.

Connector Display Options

Setting	Description
Show Connectors	Toggle connector lines on or off (`Ctrl+C`)
Show Timing Values	Display the delay value on each connector line (`Ctrl+T`)
Connector Curve	Adjust the curve amount on connector lines (0 = straight)
Connector Colour	Each hole’s connector colour is stored individually and can be set per-hole

Validating Timing

Kirra automatically checks for common timing problems:

Warning	What It Means
Unassigned hole	One or more holes have no timing connection (orphaned)
Circular reference	A hole’s timing chain loops back to itself
Duplicate delay	Two or more holes fire at exactly the same time
Negative delay	A calculation produces a negative firing time

Warnings appear as indicators on the affected holes and in the log panel.

Manual Checks

Look for crossed connector lines — they often indicate incorrect firing order
Verify that the timing sequence flows logically from the free face inward
Check total blast duration (very long blasts may cause vibration concerns)

Editing Timing After Assignment

Change a Single Connection

Right-click the target hole
Choose Edit Timing (or double-click the connector line)
Modify the delay in milliseconds
Optionally change the From Hole reference
Kirra recalculates all downstream firing times

Clear All Timing

Go to Timing > Clear All Timing to remove all timing connections and delays from the selected holes or the entire pattern.

Exporting Timing Data

Timing information is included in all standard export formats:

Format	Timing Data Included
Kirra CSV	From Hole, Delay (ms), and total Firing Time columns
Epiroc XML	Maps to the IREDES timing fields
PDF Report	Timing summary table and connector diagram
DXF	Connector lines exported as LINE entities

Pattern Generation — generate your pattern before assigning timing
Editing Holes — select and modify holes
Adding Holes — place individual holes manually