Posted on: 30 December 2016
When carrying out blasting work on a construction site, it's essential for the safety of all concerned that the correct clearing and guarding procedures are in place.
Here's an overview of a well-thought out-clearing and guarding approach that should form part of the Blaster-in-Charge's risk management plan for every blast job.
Clearing and Guarding
An area around the shot area should be determined and cleared. All entry points to the shot area should be guarded to prevent unauthorised entry. During the operation, the Blaster-in-Charge must be in continual radio communication with everyone involved.
Five minutes before the blast time -- and only once the area has been confirmed by the guards as secure -- the Blaster-in-Charge should connect the initiation device. The five-minute warning signal can then be sounded. One minute after this, the final blast warning signal should be sounded. The Blaster-in-Charge will give the instruction to fire the blast precisely at blast time.
When the post-blast fumes have receded to safe levels, the Blaster-in-Charge will inspect the area for:
- dangerous rock conditions
- undetonated explosives
- any other hazards
When the Blaster-in-Charge has confirmed that the area is clear, the entry way guards may be relieved and the all-clear signal can be given to re-open the site to contractors, the public and nearby roadways.
A misfires plan must be in place, just in case of confirmed or suspected blasting misfires. The Blaster-in-Charge is responsible for determining the affected area in the event that a misfire occurs.
The area must be secured and no entry permitted for at least 30 minutes following the blast and suspected misfire. Once the half hour period has elapsed, only the minimum required operatives should enter the area. The Blaster-in-Charge must then supervise the recovery of un-shot explosives before overseeing the washing out of the area.
When the area is confirmed to be clear, the blast may be reset and reattempted. It should be noted that the blast security area must be expanded if the Blaster-in-Charge thinks that the fly-rock potential will be increased when the misfires are detonated.
The Blaster-in-Charge must record the location of any suspected undetonated explosives on the site blast report.
The Blast Emergency Plan
A blast emergency plan should be drawn up for all operations where shot blasting will take place. At a bare minimum, the plan should include the following elements:
- All emergency contact telephone numbers: medical response, fire department, police, home numbers of all site staff and management.
- Clear instructions on how the plan is to be clearly communicated to all personnel.
- Definition of notification procedures and timings.
- Clear instructions as to the location of first aid kits and identification of all qualified first aiders.
The above provides an overview of a correct approach to blast management clearing and blast procedures. For more information and guidance, have a chat with a blasting specialist firm like Rock On Ground.Share