Keep an Eye on the Blast Crew
Is your blasting crew operating safely? Or, is an outside blasting crew you hire following proper safety methods?
Here are few safety techniques that all “blasters” should follow. Are yours?
- Ensure visitors and suppliers know that blasting is scheduled—and are aware of what the warning signals mean.
- Before loading explosives in a borehole, the blaster should examine the drilling logs to identify potential problem areas such as presence of mud seams, voids, or geological anomalies. This is followed by a visual inspection of the highwall face and bench top.
- The blaster should look for the presence of overhangs, back breaks, softer stratum, and other irregularities. Laser profiling data, if required, is examined at this time.
- Blast sites should be secured and warning signs posted before loading boreholes.
- The detonation device should be securely kept by the blaster during the entire process of loading and hook-up to prevent any unintentional detonation.
- Federal regulations prohibit driving vehicles and equipment over explosive material or the initiating system.
- The rise of an explosive column in a borehole should be checked during the loading process.
- The blaster or a designated employee should connect the individual holes to the firing line. (It is a good practice to walk along the firing line to re-examine the connections.) If any instrumentation for recording ground vibration and air blast has been deployed, it should be checked and set at this time.
As the time nears …
- The blaster should clear all employees from the area, post guards at all entrances, and communicate to the quarry foreman about the impending blast.
- The blaster (and helpers, if any) should go outside the area or stay inside a shelter. Upon receiving clear and unambiguous feedback from the guards and mine foreman, blast signals should be sounded and the shot fired.
- Before sounding an all-clear signal, the blaster should conduct a visual inspection of the site and check for undetonated explosives, misfires, and other problems.
- The blasting log should be finalized at this time, and all unused explosives returned to the magazine.