NSW Safety Watchdog WorCover has issued a safety alert regarding the use of mobile plant and machinery around overhead powerlines following numerous incidents being reported daily.
This post by SafetyCulture.com.au has more:
WorkCover and NSW Electricity supply authorities continue to receive notifications of incidents where mobile plant have come into contact with energised overhead power lines.
Since July 2011, there have been a total of 55 incidents reported where cranes, machinery and other mobile plant have come into contact with power lines.
Such incidents include:
- A mobile crane operator struck a 11kV power line when unloading a truck.
- A truck driver raised a tipper and struck a 11kV power line.
- An excavator boom struck a 11kV power line.
- A low loader struck low voltage overhead power lines.
- An operator raised a drill rig into high voltage transmission lines.
- A wheat harvester struck power lines, which resulted in a fire that engulfed the machine.
- A cement truck reversed into an overhead service line at a residential property.
The state safety administrator points out that each of these incidents is the result of a failure to identify the hazard of overhead power lines and a failure to implement a safe system of work, including the maintenance of safe approach distances from the energised power lines
When working with power lines overhead, authorities suggest you treat all electric power lines as live and either have them de-energised or create an exclusion zone around them and keep workers out. De-energising power lines should only be done once arrangements have been made with electricity authorities during the planning stages.
Once the risks have been identified, the employer should conduct a written assessment of the risk and it’s potential for harm.
In assessing the risk the employer or self-employed person should consider the following:
- The minimum clearance distance between the crane/machinery and the power line
- The characteristics of the load being transported in the case of cranes, including dimensions of the load and whether the load is conductive. Similarly to electric lines, loads should also be assumed to be conductive until proof that it is not has been provided by a person qualified to do so.
- Also consider whether the load is above the electric line. If it is there is a possibility of it falling onto the lines.
- Also consider unexpected movement of the terrain, ground or surface upon which the crane or plant is located, possibly resulting in a corresponding surge or sudden movement towards live electric lines.
- Consider the weather, prevailing or unexpected wind strength and direction.
- What are the chances of swaying or sagging of over lines. This can be caused by weather or varying temperatures.
- Whether the functional behaviour of the crane, load or plant may result in contact with electric lines overhead.
- What is the likelihood of crane or plant or machinery becoming live through contact with energized line.
- How the load being carried by a crane is secured and if a part of the load may come into contact with the electric line.
The next step in the process would be to develop strategies to either eliminate the hazard or minimise its risk. With all workplace risks, elimination is always the preferred method of dealing with risks.
There are a variety of methods that can be undertaken to eliminate the risk, such as de-energising lines, rerouting electric lines or replacing existing overhead lines with underground lines.
Often, elimination is not possible, so replacing the risk with one less risky would be the next alternative.
The next step in the process would be the isolation of the hazard. Some examples of this may be to erect a physical barrier to prevent any part of the machine or the load being moved from entering the exclusion zone and injuring someone outside of the zone. A non-conductive physical barrier should be erected and be capable of withstanding an impact from falling objects, loose materials or other plant or machinery.
Alternatively re-designing equipment or the work process should be undertaken. This may involve using limiting devices to limit the movement of the machinery so that it does not accidentally injure a worker nearby. Where the limiting device prevents movement, sudden stopping or the momentum of the load should be considered.
The introduction of administrative measures is the next measure that should be considered and can include using a safety observer to watch and warn workers and machinery operators of dangers while the machinery is in movement.
It does not need to be said again because all workers should be wearing the appropriate personal protective equipment (PPE). Using insulated gloves may be one such method, as it will prevent electrocution when the worker comes into contact with a conducting part of the crane, plant or
When implementing risk treatment measures need to be developed when elimination is not possible. Monitoring and reviewing the risk treatment measures developed should be conducted regularly and whenever the work site changes. Modification of the measure or its implementation should then be carried out.
Posted by Steven Asnicar