Use of explosives is a high hazard occupation. Over many years systems of work have been devised to ensure that all operations may be safely undertaken. How the shot firing is undertaken is set out in the blasting specification and the shot firing rules. The specification drawings must be examined to ensure that all information has been collected and the borehole, face and geological information compared.
Ensure that the system for profiling the face is suitable for your conditions and that the actual position of the holes is identified The risks do not come just from explosives, any work on top of a face may be dangerous if the proper procedures are not taken.
Fly rock being projected from a face blast. Correct blasting specification will avoid this.
Here a drill rig and other equipment has been moved along the edge of an unstable and unprotected edge
Drill rigs need to be properly maintained, including their brakes.
Do not forget the compressor! This New drill rig was placed with the old compressor during travelling the drill rig stopped but the compressor did not.
This drill rig has no guard to protect the operator or emergency stop button or pull wire.
One false move and this driller will fall from the face. Appropriate edge protection or harnesses must be worn.
The driller is wearing a full body harness to stop him falling from the face edge. Precautions must be taken to ensure that the lanyard does not become entangled with the rotating drill rod.
Portable fences have been developed which protect face workers from falling. In this case holes are drilled before the face is blasted to enable the fence to be re-erected with the minimum of effort.
Noise is a serious problem on drill rigs and rigs with cabs are preferred. Where this is not possible suitable hearing protection must be worn. There must be suitable arrangements on the drill rig to enable the drill hole to be drilled according to the blasting specification both in direction, azimuth and dip.
Explosives must be transported in vehicles and containers that are clean, secure and free from grit.
Detonators should be carried in a locked box and taken out one detonator at a time.
Vehicle movements must be strictly controlled. Only vehicles that are intended to work near the site should be allowed in the blasting area. There is a danger of running over explosives, and damaging detonator lines etc.
Detonators should be carried in a locked box and taken out one detonator at a time. The use of mobile phones and radios must be carefully controlled to prevent premature detonation.
Anfo must be mixed in accordance with the licence and where hand mixing is carried out it must be in a tray and shovel.
Anfo mixed in sacks is not acceptable * Explosives should be used as they are unpacked.
Mixing trucks must be cleaned out when charging is complete to remove all mixed explosive. Here mixed explosive has spilled onto the ground. They should also be equipped with an earthing chain.
Where cast primers are used the correct primer must be used for the number of detonators used. Here this primer is designed for using two detonators
Two detonators being inserted into the primer. You must ensure that they are properly inserted to prevent damage to the detonators and possible premature ignition
Shotfirers have to use a suitable shelter when blasting
The tip and excavation rules, face inspection, drill log and the geotechnical assessment will need to be looked at before designing a blast. Incorrectly designed blasts can damage surrounding houses, schools, farmland and passing vehicles and kill and injure. This vehicle was carrying LPG tanks when it was struck by flying rock
Nets can be used to prevent fly rock in difficult blasting situations. Lightweight nets should not be held down but allowed to float up with any debris.
Heavy wire netting (submarine nets) may also be used where it is not possible to reduce the danger zone by other means.
Primary blast initiation, note the path of shrapnel from the detonators which could cause a misfire. Good practice is to place 200 mm of cover over surface initiation systems.
Large clay band in primary blast, manager decided to reduce charge weights around clay band and use a net to arrest the clay during blasting operation.
The net has performed its duty.
Blast completed and all clear given.