Magic Glasses: Power Lines
- Mar 18
- 5 min read
Updated: Mar 23
At first glance, a Hiab working near a power line can look like a normal unload. The truck is set up, the load is not unusual, and the line feels close but not too close. When you put on the Magic Glasses, you stop relying on what looks fine and start seeing the one detail that can turn an ordinary job into a fatal one.
Quick Scene-Setter
A Hiab is unloading materials into a tight area beside a boundary. The truck is parked in a workable position. The load can be reached. There is an overhead power line running along the edge of the job.
From the ground, it looks manageable.
The line is visible. The operator knows it is there. The unload only needs a small lift and place.
In the image for this post, the Hiab will be shown making contact with the line.
What Most People See
Most people see a routine job.
They see:
a normal Hiab unload
a line that seems clear enough
a competent operator who will be careful
a short job that will only take a few minutes
The thinking is usually simple.
“The line is there, but we can stay away from it.”
“It is only one lift.”
“We can watch it.”
That is where people get caught.
What the Magic Glasses Show You
The trained view is different.
In New Zealand, the baseline rule for mobile plant is clear: keep at least 4 metres between any live overhead electric line and any part of the machine or load, unless the line owner provides written consent for a reduced distance.
WorkSafe’s low-voltage guide also states that without written consent, workers must maintain a minimum approach distance of at least 4 metres, and that cranes are one of the types of plant to which this guidance applies.
That sounds simple until the job starts moving.
The Magic Glasses pick up the parts that change the risk:
The clearance is not just about the boom tip. It is about any part of the Hiab or the load.
Operators can find it hard to judge line clearance accurately, especially when buildings, trees, fences, or awkward sightlines are involved.
The danger does not start only when metal hits the wire. Electricity can arc. WorkSafe says touching a live low-voltage overhead line with a body part, tool, or equipment can cause death or serious injury, and the line can still be dangerous even if it appears insulated.
A setup that looks clear while the crane is still may not stay clear once the load swings, the boom settles, or the operator adjusts position. Guidance for cranes working near power lines specifically warns that minimum clearance may need to be greater to account for load swing after the crane stops.
A spotter is not just a nice extra. When working near power lines, a spotter should be designated to monitor line clearance and provide timely warnings. A spotter should not be doing other jobs at the same time.
That is the shift in thinking.
The hazard is not just the wire.
The hazard is the false sense that because the line is visible, the risk is under control.
The Controls That Matter
Identify overhead lines during site assessment, before the truck is positioned.
Treat every overhead line as live unless the power authority or owner has confirmed otherwise in writing and on site.
Work to the New Zealand 4 metre minimum from the live line to any part of the Hiab or the load, unless written consent allows a reduced distance.
First, ask whether the supply can be isolated before work starts. WorkSafe states this is the safest option.
Set the truck up so the lift can be done without tracking the boom or the load toward the line.
Allow for load swing, boom movement, and repositioning. Do not judge risk solely from the start position.
Use a dedicated spotter whose only job is line clearance.
Mark and protect the no-go area so the control is visible to everyone on site.
Brief the team before the lift so everyone understands the line hazard and the stop points.
Stop the job if the margin is not clear. A “careful” lift is not a control if the setup is wrong.
Inattentional Blindness“I knew that power line was there. I just did not see it.” That is often inattentional blindness - when a person is focused on the load, the landing point, the truck position, or the next move, and misses a fully visible hazard. A powerline can be right there and still not register when it matters. That is why overhead lines must be treated as a planning hazard, not just a hazard people are expected to notice on site. Do not rely on seeing it in the moment. Identify it early, plan for it, and control it before the boom moves. |
Magic Glasses Checklist - Power Lines
Is there any overhead line within the Hiab working area?
Has the line been treated as live?
Has the 4 metre New Zealand minimum been checked?
Have you measured for the machine and the load?
Can the power be isolated before the lift?
Has the truck been positioned to avoid reaching toward the line?
Has the load swing been allowed for?
Is there a dedicated spotter?
Does the crew know the no-go area?
Is there a clear stop-work point if the margin starts disappearing?
Consider tools like power line warning markers.
Power line incidents do not always start with a reckless job. Many start with a job that looks ordinary.
That is why this is a good Magic Glasses lesson. Once you learn to see the real clearance, the load path, the swing, and the false comfort of “it looks fine from here,” you start making better decisions before the lift begins.
Seeing it early is the skill. Acting on it is the standard.
If You Hit the Line
This is handy knowledge that might save your life.
If you are in the cab
Stay in the cab if it is safe to do so.
Do not touch metal parts if you can avoid it.
Warn everyone else to stay well clear.
Call 111 and wait until the power authority confirms it is safe.
If you are outside the cab
Stay away from the truck, crane, load, and outriggers.
Do not approach to help.
The ground around the outriggers may be energised.
If you must move away
Keep both feet close together.
Shuffle away. Do not walk or run.
Do not take long steps.
Keep shuffling until you are well clear.
Electricity can travel through the crane and spread into the ground. That is why the danger is not only at the line. It can radiate out from the outriggers as well.
Magic Glasses: The magic glasses come from the reality of - when I look at my books, I don't see a problem. But when my accountant looks at the books, it's a whole different story. He must have a special set of glasses.
As PCBU's, Officers and Workers, we have an obligation to learn what we are up to and the risks. Our actions and the standards we accept also affect those around us. This magic glasses post is made to help others see what we see.
