Hole Parameters & Properties
Every drill hole in BlastCAD carries a comprehensive set of engineering parameters. This page explains each field, its units, and how BlastCAD calculates or uses it.
Table of contents
- Geometry Parameters
- Ring & Pattern Parameters
- Charge & Explosive Parameters
- Initiation Parameters
- Drilling Status
- Calculated Fields
- Editing Hole Properties
Geometry Parameters
| Parameter | Unit | Description |
|---|---|---|
| Collar X / Y / Z | m | World-space coordinates of the hole start point (top of hole). In local coordinates after origin offset. |
| Toe X / Y / Z | m | World-space coordinates of the hole end point (bottom of hole). |
| Length | m | Total drilled length: length = |collar − toe|. |
| Diameter | mm | Borehole diameter. Determines the charge cross-sectional area. |
| Dip | ° | Inclination from horizontal. 90° = vertical; 0° = horizontal. |
| Azimuth | ° | True bearing of the hole projected onto the horizontal plane. Measured clockwise from North. |
| Dump Angle | ° | Rotational angle of the hole within the ring plane. 0° = perpendicular to baseline. |
| True Dip | ° | Dip angle recomputed in the ring plane’s local coordinate system. |
| True Azimuth | ° | Azimuth recomputed accounting for the ring dump angle. |
| Uphole | bool | True if the hole is drilled upward (toe above collar). Changes charge calculation logic. |
| Subdrill | m | Extra length drilled below the design toe to ensure full stope floor breakage. |
Ring & Pattern Parameters
| Parameter | Unit | Description |
|---|---|---|
| Ring | — | Ring name/ID the hole belongs to. Holes are grouped by ring. |
| Hole | — | Hole number within the ring (typically 1, 2, 3… from left). |
| Layer ID | — | The project layer this hole is assigned to. Determines display color. |
| Offset | m | Lateral offset of the collar from the ring pivot point (within ring plane). |
| Collar Offset | m | Horizontal offset of the collar from the drive centerline. |
| Collar Offset Vertical | m | Vertical offset of the collar from the pivot height. |
| Pivot U / V | m | 2D coordinates of the hole collar in the ring plane’s local U/V coordinate system. |
| Collar Distance | m | 3D distance from the ring pivot to the hole collar. |
Charge & Explosive Parameters
| Parameter | Unit | Description |
|---|---|---|
| Explosive | — | Primary explosive product name (from the Explosives Database). |
| Explosive Amount | kg | Mass of the primary explosive column: mass = π (d/2)² × L × ρ where d = hole diameter, L = charge length, ρ = explosive density. |
| Total Explosive Amount | kg | Sum of all explosive segments in the hole (excluding stemming and air decks). |
| Charge Length Total | m | Total length of all explosive and stemming segments combined. |
| Charge Collar Length | m | Length of the collar stemming (top of hole to top of explosive). |
| Charge Toe | m | Distance from the toe of the hole to the bottom of the lowest explosive segment. |
| Ungassed Charge Length | m | Explosive column length before gassing expansion (for bulk emulsion). |
| Ungassed Collar Length | m | Collar stemming length before gassing. |
Initiation Parameters
| Parameter | Unit | Description |
|---|---|---|
| Delay | ms | Nominal firing delay from time zero. Used for timing analysis and vibration prediction. |
| Detonator | — | Detonator type assigned to this hole (from the Detonators Database). |
| Primers | — | List of primer placements — each with a distance from the collar or toe (m). |
| Leads Length | m | Length of detonator lead wire or shock tube from the collar. |
Drilling Status
| Parameter | Unit | Description |
|---|---|---|
| Actual Drilled | m | Recorded as-drilled length (from survey or MWD data). Compared against design length. |
| Comments | — | Free-text field for surveyor or engineer notes. |
Calculated Fields
These fields are computed automatically by BlastCAD and cannot be directly edited:
Explosive Mass Calculation
For each charge segment of type explosive:
Where:
- $m$ = explosive mass (kg)
- $d$ = hole diameter (mm)
- $L$ = segment length (m)
- $\rho$ = explosive density (kg/m³, from the Explosives Database)
Dip and Azimuth from Collar/Toe
\[\text{Dip} = \arcsin\left(\frac{Z_{toe} - Z_{collar}}{L}\right) \times \frac{180}{\pi}\] \[\text{Azimuth} = \text{atan2}(X_{toe} - X_{collar},\ Y_{toe} - Y_{collar}) \times \frac{180}{\pi}\]Note: BlastCAD uses the right-hand coordinate system internally, where:
- Local X = Easting
- Local Y = Elevation
- Local Z = −Northing (negated to match OpenGL convention)
Editing Hole Properties
Via Properties Panel:
- Click a hole in the viewport or in the Explorer’s drill tree.
- The Properties Panel populates with all editable fields.
- Modify any field and press Enter — the 3D viewport updates instantly.
Via Hole Table:
- Open Hole Table from the top bar.
- A spreadsheet-style table displays all holes with sortable, filterable columns.
- In-cell editing is supported for most fields.
- Export the table to CSV for handover to drill operators.
Via Bulk Edit:
- Select multiple holes using Shift + click in the Explorer tree.
- Right-click → Bulk Edit to apply the same delay, explosive type, diameter, or comments to all selected holes simultaneously.