The Storm-Damaged Roof and the Live Line
A severe storm has passed. You are on a crew tasked to a two-storey brick home where a large tree has fallen, bringing down a powerline that now lies across the driveway and against the metal gutter of the house. The homeowner says the power "went out an hour ago" but a neighbour's lights are on. A child is standing at an upstairs window, and the homeowner wants to move the branch off the line with a rope. Rain is still falling and the ground is wet. Your crew has a chainsaw and hand tools but no line crew.
1. What is the priority hazard and what do you instruct the homeowner?
Read the worked answer
Priority hazard is the fallen powerline, which may still be live - a neighbour's lights being on means the supply is not necessarily isolated, and a line can be re-energised remotely. Wet ground and a metal gutter make the whole house and driveway a potential conductor.
Instructions:
- Tell the homeowner to stop immediately and not to touch the line, the branch, the rope, or the gutter. Do not approach within at least 8-10 m of the line and anything it is touching.
- Move people indoors and away from windows and the metal gutter, or better, evacuate the house if the line is against the structure, using a route away from the line.
- Keep the child away from the upstairs window and from any metal frame.
- Call the electricity distributor/emergency services to isolate and make safe; do not attempt to move the line or the tree yourself.
- Establish a cordon and warn neighbours.
2. How do you manage the tree and the crew's tasks while waiting for the line crew?
Read the worked answer
- No chainsaw work on or near a tree in contact with a line - the tree can conduct, and cutting can cause the line to spring or the tree to move unpredictably.
- Treat the task as a scene control and welfare job: cordon, keep bystanders back, check for other hazards (gas, damaged roof, water entry), and gather information for the line crew (which pole, which span, whether the line is arcing or sparking).
- Do not enter the roof space or use ladders near the line.
- Document and hand over to the line crew; only resume tree work once the distributor confirms isolation in writing/verbally to your officer.
3. What would you do if the line begins to arc or a person is electrocuted?
Read the worked answer
- Arcing/sparking: withdraw all personnel and bystanders further back, call the distributor urgently, and consider evacuating adjacent homes if the line is against a structure or vegetation is burning.
- Person in contact with the line: do not touch them. The rescuer becomes the second casualty.
- Isolate the supply via the distributor or the main switch only if it is safe and you know it controls that line; otherwise wait for isolation.
- Use a dry, non-conductive item to move the person only if you are certain the supply is isolated and you are trained and protected.
- Begin CPR/first aid once the person is clear of the conductor, and call an ambulance.