Single Blast - Top Stemming Length

This dashboard aims to provide an overview of the difference between top stemming design and actual top stemming length. The top stemming length of a hole is a key environmental and safety factor. Using this dashboard can help identify both isolated events and systemic implementation issues. 


Calculation Logic

Hole Compliance 

Each hole is evaluated based on the following:


The Stemming Deck Length Deviation is calculated for each hole, hence marking the hole as one of the following: 

  • Within Tolerance – if the Length Deviation does not exceed any of the drilling length tolerances (over or under). 
  • Overloaded– if the Length Deviation is positive and exceeds the site’s Top Stemming tolerance. 
  • Underloaded– if the Length Deviation is negative and its absolute value exceeds the site’s Top Stemming tolerance. 
  • or, No Data – There is not sufficient data to run the analysis. E.g. the hole has an actual length but no design length (these holes might have been added in the field). 

Note: The stemming deck being evaluated is the stemming deck closest to the collar, i.e. the Top Stemming. 


Blast % Compliance 

The Blast’s Drilling Length % Compliance is calculated with this formula: 



This dashboard uses the site level Deck Horizon (Top Stemming Length) Reporting Tolerances defined in the Admin Portal. 

Any changes to these tolerances in the Admin Portal will apply to all single blast dashboards across the site. To learn more about Reporting Tolerances, click here. 


Dashboard Components


  1. Select a Blast – Choose a blast from the drop-down list. Users can type in to search for the desired blast. 
  2. Take a Snapshot – Generate a summary blast report. The report includes all dashboards with the latest available data.
  3. System of Measurement – Choose to display the values in Metric or Imperial units. 
  4. Blast Plan View displays an area per hole coloured according to the hole compliance. In the case of over and under stemmed holes, the greater the length difference, the darker shade the colour will be (see the colour legend). To learn more, click here
  5. Summary Statistics - displays the Blast’s % Compliance and other helpful statistics. 
  6. Hole Cross Section Bar Chart - displaying each hole's actual cross-section, using the latest actual information available, compared to the design collar, grade, and toe elevations marked by lines and an X respectively.
    • Click and drag horizontally to scroll through all the holes in the blast.
  7. Histogram – displays the count of holes for each deviation range. Click and drag horizontally to zoom in on a section. Double click to reset zoom.
  8. Box Plot– displays the deviation distribution of the blast. Click here to learn more about this type of chart.
    • Click and drag horizontally to zoom in on a section. Double click to reset zoom.
  9. Hole Tablelocated below the other dashboard components, displays one hole on each row and columns relevant to the top stemming dashboard


Was this article helpful?
0 out of 0 found this helpful
Have more questions? Submit a request