Monday, September 27, 2010

Transport Of Explosives

5.1. GENERAL VEHICLE REQUIREMENTS
For the safe and secure transport of explosives all vehicles should adhere to the following general requirements:
- be in sound mechanical condition and repair.
- provide adequate segregation of detonators from other explosives.
- all explosives to be transported in a safe and secure manner either in securely attached containers or other fit for purpose means.
- where packaged explosives may be in contact with interior surfaces, the surfaces should be kept in a clean condition and free from any projections that are likely to cause damage.
- before vehicles are serviced they needs to be thoroughly cleaned, and inspected by a person who has the necessary competence and then certified in writing by that person to be free of explosive residues.

5.2. HIGHER RISK TRANSPORT OF EXPLOSIVES
The degree of risk and subsequent requirements for vehicles carrying explosives on a mine site should be managed based on the types and quantities of explosives carried and the suitability and condition of the vehicle. Where large quantities of explosives are transported together there exists the possibility of sympathetic detonation. For the safe and secure transport of explosives, the vehicles used can reduce the risk
associated with the function by implementing the following controls:
Hazard – Fuel fire
- Use a diesel engine vehicle in preference to petrol since petrol has a very low flash point.
Hazard – Electrical fault
- Have electrical wiring protected with conduit and also have a battery isolation switch located in an accessible position.
Hazard – Exhaust flames/sparks
- The vehicle should be fitted with a spark arrestor in accordance with AS 1019.
Hazard – Stray radio current
- Electrical detonators should not be transported in a vehicle with a radio transmitter unless the radio is capable of being isolated, locked out or the radio wattage is sufficiently below the required initiation power. This is to prevent blasting circuit being energized by the electric field produced by radio transmitters.
Hazard – Vehicle fire
- The vehicle should be fitted with a dry-powder fire extinguisher with a rating not less than 40 B(E), as specified in AS 1850. Alternatively, or in addition, an automatically operated AFFF (Aqueous Film Forming Foam) system can be utilised for a fire under the bonnet. Fire extinguishers are to fight a fire on the vehicle. However in the event of the explosive on fire do not attempt to extinguish the fire, retreat a safe distance from the vehicle.


Figure 12: Explosives vehicle at a mine site with separate explosives 
receptacles and fire extinguishers.

5.3. SECURITY AND SAFETY WHILE IN TRANSPORT
The following general precautions should be taken to ensure the security and safety of explosives during transport:
- Before leaving the magazine, the vehicle operator needs to ensure that all explosives are securely stowed and the quantity and type of explosives recorded.
- Explosives should be kept in their original boxes where possible to facilitate ready identification and containment.
- The transport route between the magazine and shot area should be pre-planned and all relevant mine personnel notified.
- No smoking or naked flames allowed within the vicinity of the vehicle. If any ignition sources are required they should be carried in a sealed container in an appropriate section of the vehicle.
- If the vehicle is unavoidably left unattended (e.g. emergency), it should be parked in an appropriate area with all receptacles and the vehicle locked.
- Where a vehicle is parked on a slope it should be suitably located to avoid the possibility of unplanned movement.

5.4. VEHICLE MARKINGS
Vehicles, that are used to carry explosives, need to be identifiable. This is to be achieved by being fitted with appropriate signs. Additionally, vehicles carrying explosives at mine sites are to be easily identified other than by signs, for example a flashing light of a distinctive colour is required, and this enables, in the underground environment, to show that explosives are being transported on the vehicle.

5.5. COMPETENCY OF PERSONS
Every person required to transport or handle explosives should be authorised. The Mining and Quarrying Safety and Health Regulation 2001 requires that such persons be authorised in writing by the site senior executive.

5.6. VEHICLE ACCESS TO EXPLOSIVE STORAGE SECTION
Where vehicles have access to the explosives storage section of the magazine (e.g. forklifts), they need to have the necessary modifications for operation within the vicinity of an explosive area. The following requirements are specified in AS 2187.1 and are applicable to all powered vehicles:
- The vehicle shall not be started inside the explosive storage section of the magazine.
- The vehicle shall not be stored in the explosive storage section of the magazine.
- The vehicle shall not be refuelled, maintained or left running unattended within the vicinity of the magazine.

5.6.1. Internal Combustion Engines
Every internal combustion engine that powers a vehicle that accesses the explosive storage section is required to be equipped with suitable safety modifications for operation within an explosive area (AS 2187.1). The vehicle should be designed to protect the explosives against accidental ignition from heat, friction, pressure, incompatible materials, sparks and extraneous electricity. These hazards can be controlled as outlined in Section 5.1 and 5.2 of this Guidance Note.

5.6.2. Electric Motors
Every electric engine that powers a vehicle that accesses the explosive storage section is required by AS 1915, to be designed to the specifications for electrical equipment used in explosive atmospheres (AS 1915). This requirement is to protect the explosives against accidental ignition from heat, friction, pressure, incompatible materials, sparks and extraneous electricity. These hazards can be controlled as outlined in Section 5.1 and 5.2 of this Guidance Note.

5.7. MATERIALS HANDLING EQUIPMENT
5.7.1. Pumps
Where pumps are used for the transfer of bulk explosives there is a potential risk of an explosion initiated from heat, friction, sparks or electricity. The pump being fabricated from non-ferrous and non-combustible materials and electrical wiring being protected by conduit can largely control these hazards. Further guidance for the requirements of pumps in explosive areas can be attained from AS 2187.1.

5.7.2. Miscellaneous Equipment
Where miscellaneous equipment such as pallet trucks, trolleys or lifting appliances is used in the magazine there is a potential risk of an explosion initiated from heat or sparks. The equipment should be fabricated from non-ferrous and non-combustible materials and suitable for use within an explosive environment. Further guidance for miscellaneous equipment in explosive areas can be attained from AS 2187.1.