Plant & Powerlines – A Dangerous Cocktail
Across Australia and the rest of the world, there are way too many stories of fatalities and near fatalities resulting from interaction between plant & powerlines.
At Plant Assessor, we see the issue of ensuring safe systems of work for plant around powerlines as a real challenge.
There is a wealth of information available today regarding working around powerlines.
In Australia, the best sources of this information include safety regulators and energy industry participants such as regional energy distributors.
APPLICATION OF THE HIERARCHY OF CONTROLS
The application of the hierarchy of controls is crucial in dealing with any safety hazard.
Review of regulator and distributor guidance highlights a consistent approach by these authorities to the application of the hierarchy of controls in relation to safety when working around powerlines.
The guidance contains the following key themes:
Quantify the hazard
1. Determine power line voltage
2. Question/challenge the need to work in the vicinity
3. Identify the owner of the power lines (often a regional energy distributor) and consult their guidance information. (In some instances this guidance information requires contact with the distributor)
Assess the risk
1. Conduct a comprehensive risk assessment of site, conditions, task, machinery to be used and loads to be shifted
2. The results of this assessment must then be used to eliminate or minimise risks posed by suitability or otherwise of machinery, conductive loads, site or other environmental conditions – using a combination of control types as listed below
Eliminate and/or Isolate the hazard
1. Arrange for the energy network operator to isolate the power supply and de-energise the lines
Utilise Engineering Controls
1. Use a machine that cannot encroach upon the minimum approach distances for the type of power lines involved
2. Utilise interlocks or other forms of machine control adjustment and limitation so that the machine cannot be operated in a way that will encroach minimum approach distances
Administrative Controls & PPE
Often the most heavily relied upon control set:
1. Develop and utilise a comprehensive safe work methods statement for the task, which will often or always include:
a. Highlighting presence of powerlines with signage, tiger tails, bunting etc
b. Using trained staff and observers, and implementing warning signals to ensure plant does not encroach on minimum distance requirements
c. Implementing and enforcing strict exclusion zones
d. Ensure staff are trained in emergency procedures in the event of a machine becoming energised at any point during commissioning, decommissioning or during the task
2. Utilise (as set out in SWMS, and depending upon voltage, conditions and SWMS contents) PPE such as insulated gloves, mats and so on
Unfortunately, in many circumstances, practicality and commerciality see a heavy reliance upon ADMINISTRATIVE CONTROLS such as those set out above to manage this hazard.
As a consequence of this, safe systems of work are heavily reliant upon following procedures, and the competency and vigilance of people involved. As most of us know from grim experience, maintaining the relevant competency and vigilance can be difficult due to human and other factors.
In essence, this slide down the hierarchy of controls is the reason that it is common for fatal or near fatal incidents to occur when working around powerlines. This is the reason it is critical to follow a diligent and comprehensive process when approaching the task of operating plant around powerlines.