(Photo: SweetCrisis / FreeDigitalPhotos.net)
NSW authorities are consistently receiving notification of incidents involving mobile plant coming into contact with overhead power lines. In fact authorities cite an astonishing number of incidents where cranes, machinery and other mobile plant come into contact with power lines every year. Since 2011 a total of 55 incidents have occurred.
Such incidents include the following as reported on WorkCover’s website:
- 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.
The incidents above could have been avoided if the operators had identified the hazard in time and were able to implement a safe system of work and maintain a safe distance from the energised power lines.
The serious risk of contact with overhead power lines is that electrocution can result. The worker may suffer electric shock or burns. There is also the possibility of fires and explosions that may immobilise mobile plant involved in work and cause injury or death of the operator.
According to WorkCover an employer or person conducting a business or undertaking near energised overhead power lines and associated electrical apparatus should adhere to the following before commencing work:
Clearly identify the height and voltage of high and low voltage power lines, including overhead service lines to buildings.
Conduct a risk assessment of the proposed work.
If necessary, consult with the relevant electricity supply authority about the work and comply with any special conditions imposed by them.
A cement truck reversed into an overhead service line at a residential property.
Eliminate the risk by arranging for the electricity supply authority to isolate the electricity supply for the duration of the work.
If the risk cannot be eliminated, separate the electrical hazard from the mobile plant and the workers by ensuring the following approach distances are maintained:
Up to 132,000 volts – 3 metres
Between 132,000 volts and 330,000 volts – 6 metres
Above 330,000 volts – 8 metres.
Note: when applying the above approach distances, it is important to take into account the ‘sag and swing’ of the powerlines, the movement of the mobile plant and the strength of the wind, as well as possible operator error or equipment malfunction.
Ensure a safety observer is used whenever a mobile plant is in motion and is likely to come closer than the above approach distances.
Ensure an effective communication system is in place for the workers performing the work.
Remember the safe work procedure when working near overhead power lines – LOOK UP AND LIVE.
Emergency response to a power line incident
Should contact be made with a live overhead power line and a vehicle, the following actions must be taken.
Try not to panic. Remain calm and stay in the vehicle. Don’t risk being electrocuted by attempting to leave the vehicle.
Advise anyone near the incident site to stay at least eight metres away from the vehicle or any fallen power lines.
Source: Source: http://www.workcover.nsw.gov.au/Pages/default.aspx
Operators should also remember that in the event of an emergency they should contact the local electricity supply authority to have the electricity turned off. Emergency services should be immediately contacted by dialling 000 especially in a life threatening situation.
Operators involved in an incident should attempt to break the vehicles contact with the live power line if it is safe to do so. But if it will create another hazard then it should not be done.
Operators who are involved in an incident involving a fire or life threatening situation that requires them jumping out of the vehicle, should avoid contact with the vehicle and ground at the same time. Also the operator should ensure that they land with their feet together and then continue to jump or shuffle with their feet together until at least eight metres clear of the vehicle or power lines.
It is also important that untrained or unequipped persons should not attempt to rescue a person who has received an electric shock as this has been the cause of secondary deaths of people just trying to help who are electrocuted themselves.
If you are a bystander, before you attempt to help in such a situation, ensure that the vehicle is immobilised, the power supply switched off and it is safe to do so.