Hazards and control measures
Overhead power line hazards and control measures
The hazards of working near overhead power lines: cranes, tippers, MEWPs, ladders and scaffold tubes touching or arcing to live wires. Who gets hurt, and what HSE GS6 and the law expect, from diverting or switching off the line to barriers, goal posts and exclusion zones.
What are the hazards of working near overhead power lines?
The hazard is a crane, tipper body, MEWP boom, ladder, scaffold tube or even a jet of water touching or coming too close to a live wire, so that electricity flows to earth through the machine and anyone touching it, causing electric shock, burns, fire or explosion. The wire does not need to be touched, because electricity can arc across small gaps. HSE guidance GS6 expects you to treat every line as live, plan any work within 10 m of it, ask the owner to divert or switch it off, and otherwise keep people and plant away with barriers, goal posts and exclusion zones.
Last updated . Facts checked by the SiteSurvey team on 24 October 2026 against HSE: Avoiding danger from overhead power lines (GS6), Electricity at Work Regulations 1989, regulation 14 and Construction (Design and Management) Regulations 2015, regulation 25.
Where overhead line hazards show up
HSE says people at work are killed or seriously injured every year when they come into contact with live overhead power lines. The incidents often involve machinery such as cranes, lorry-loader cranes, combine harvesters and tipping trailers, equipment such as scaffold tubes and ladders, and everyday activities like loading, unloading, lifting, spraying and stacking. Builders, roofers, scaffolders, tree surgeons, grounds teams, farmers and event crews putting up marquees and flagpoles all work near them.
The lines themselves are easy to miss. GS6 says people simply do not notice them when they are tired, rushing or cutting corners, and that they are hard to see in fog or dull light, at the edge of woodland, or where several lines run together. Most high voltage lines, meaning over 1000 volts, have bare wires, and HSE says all high voltage lines should be treated as uninsulated. The covering on some low voltage wires may be old or not insulate at all.
Who is harmed, and how
When a machine, scaffold tube, ladder or jet of water touches or gets too close to a wire, electricity is conducted to earth. GS6 says this can cause fire, explosion, and electric shock and burn injuries to anyone touching the machine or equipment. A wire does not need to be touched, because electricity can jump, or arc, across small gaps. The person most at risk is often not the operator in the cab but the slinger holding a load, the labourer steadying a tube, or the driver who climbs down onto the ground.
A line that trips and goes quiet is not safe. HSE warns that a dead line may be switched back on automatically after a few seconds, or remotely later if the owner does not know it has been damaged. For the wider rules on live conductors, see electrical hazards.
What the law expects
The Electricity at Work Regulations 1989 allow work near a live conductor only where it is unreasonable for it to be dead, reasonable to work near it live, and suitable precautions are taken. On construction work, CDM 2015 requires lines that put the work at risk to be directed away or isolated, and only if neither is reasonably practicable, warning notices with barriers or suspended protection where vehicles pass beneath. GS6 follows the same order. Plan any work within 10 m, measured along the ground from below the nearest wire, and assume the line is live until its owner confirms it is dead. First avoid the work near the line. Then ask the owner to divert it, put it underground or switch it off for the work.
If the line stays live, keep people and plant away. Ground level barriers set 6 m from the nearest wire create a safety zone, with bunting 3 to 6 m up where cranes work. Where plant must pass beneath, a fenced passage with non-conducting goal posts and notices giving the crossbar height. For short work under the line, exclusion zones of 1 m for low voltage, 3 m for 11 kV and 33 kV, 6 m for 132 kV and 7 m for 275 kV and 400 kV, with physical limits on plant reach and direct supervision. In SiteSurvey, the RAMS template asks whether the line owner has been consulted whenever overhead power lines are listed, and the Suggested controls list puts planning the work away from the lines first.
Suggested controls
Overhead power lines: control measures, most effective first
These are the 5 controls the SiteSurvey RAMS and risk assessment forms offer for this hazard as a tick list, grouped by their level in the hierarchy of controls. They are a starting point from HSE guidance, not an assessment of your job: tick what applies and say how it works on your site. If only personal protective equipment is ticked, the form says so. How suggested controls work and the hierarchy of controls explained.
Take the hazard away altogether, usually by doing the job a different way or from a different place.
- Work and plant routes planned away from the lines
Keep people away from the hazard with a physical measure: a guardrail, a barrier, extraction, isolation.
- Barriers and goal posts where plant or vehicles pass beneath
Change the way the work is done: a permit, a check, training, supervision, timing.
- Line owner consulted and the lines made dead or shrouded where agreed
- Plant height and reach restricted and the limit briefed to drivers
- No work beneath the lines unless the owner has advised it is safe
Offered to: Construction and building work, Roofing, scaffolding and work at height, Events, exhibitions and staging, Grounds, landscaping and tree work.
Try it
Build the controls for overhead power lines
Tick the controls you would put in place, see which levels of the hierarchy they reach, and score the risk before and after. Or fill in the example from a completed RAMS to see how one crew did it.
Interactive
Try it: overhead power lines
Works the same way as the RAMS form. Nothing you tick is saved or sent anywhere.
Your controls, by level
- Eliminatenot ticked
- Substituteno control at this level for this hazard
- Engineeringnot ticked
- Adminnot ticked
- PPEno control at this level for this hazard
Nothing ticked yet.
3. Score the risk with these controls
What the law says
- Electricity at Work Regulations 1989, regulation 14
- No work on or near a live conductor unless it is unreasonable for it to be dead, reasonable to work near it live, and suitable precautions are taken to prevent injury.
- Electricity at Work Regulations 1989, regulation 4(3)
- Every work activity, including work near an electrical system, is carried out so as not to give rise to danger, so far as is reasonably practicable.
- Construction (Design and Management) Regulations 2015, regulation 25
- Overhead cables that put construction work at risk are directed away or isolated; failing that, warning notices with barriers, suspended protection where vehicles pass beneath, or equivalent measures.
- GS6: Avoiding danger from overhead power lines
- HSE guidance on planning work near lines, consulting the owner, barriers, goal posts, exclusion zones and what to do after a contact.
Worked example
Overhead power lines in a completed RAMS
The hazard entry exactly as it was recorded in one of our completed example RAMS: the controls ticked from the list, how they apply on that job, and the score before and after the further action.
Grounds, landscaping and tree work
Kingsmere Primary School: storm-damaged ash dismantle
- Hazard
- Overhead power lines: 11 kV line crossing the south-east corner of the field, about 12 m from the tree
- What could happen, and to whom
- Electrocution or flashover from the MEWP boom, the chipper discharge chute, rigging lines or a swinging section coming too close to the live 11 kV conductors. The line is within the reach of the 18 m MEWP boom. The crew.
- Controls ticked
- Work and plant routes planned away from the lines
- Line owner consulted and the lines made dead or shrouded where agreed
- Barriers and goal posts where plant or vehicles pass beneath
- Plant height and reach restricted and the limit briefed to drivers
- No work beneath the lines unless the owner has advised it is safe
- How they apply on this job
- The DNO (line owner) was consulted on 4 November and has agreed to shroud the span across the field for the day. Nothing goes up until the DNO engineer confirms the shroud is on, which is the first hold point. The MEWP is set up on the north side of the tree so the boom works away from the line, and the slew is limited to the field side. The chipper route and the timber stack are on the north side, under goal posts set at 4 m where the pickup passes the line. No sections are rigged on the south side of the tree, and nobody works beneath the line at any point.
- Risk with these controls (likelihood x severity)
- 4 x 5 = 20 (High)
- Further action
- Written confirmation from the DNO that the span is shrouded, received by H. Prosser on the morning and photographed. Goal posts and the exclusion line under the span set out before the MEWP leaves the track mats. Boom limit briefed to C. Beddoes and marked on the field with a cone line 9 m from the conductors. Owner: H. Prosser.
- Residual risk
- 1 x 5 = 5 (Medium)
A fictional job, filled in as a worked example. The form and the report are real.
Overhead power lines: common questions
How far from an overhead line do we need to plan for it?
GS6 says you should manage the risks if you intend to work within 10 m of an overhead line, measured horizontally at ground level from below the nearest wire. Inside that distance, the line belongs in the RAMS with named controls. The owner, usually the local distribution network operator, can tell you the voltage and advise on safe clearances. Heights should only be measured by a suitably trained person using a non-contact device.
Is a proximity alarm on the crane or excavator enough?
No. GS6 says insulating guards or proximity warning devices fitted to plant are not adequate protection on their own without other precautions. Machines working near a line should have physical restraints that stop them reaching into the exclusion zone, and the work should be directly supervised by someone familiar with the risks. Barriers and goal posts on the ground stay in place as well.
What should a driver do if their machine touches a line?
Either stay in the cab or, if they must get out, jump as far clear as they can and do not touch the vehicle while standing on the ground. Nobody returns to the machine until it is confirmed safe. Call the emergency services, say electricity wires are involved and ask them to contact the line owner. Keep everyone back, because the ground around a wire that is down may be live.
Can the line owner make the line safe for a day's work?
Often, if you ask early. GS6 says the owner may be able to divert the line, put it underground, switch it off for the work, or fit temporary insulating shrouds to low voltage wires near buildings, and may charge for it. They need time to consider the request. In the worked example, the owner agreed to shroud the 11 kV span for the day and nothing was lifted until their engineer confirmed it was on.
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