Cable strikes during excavation are one of the most common causes of electrical injury on UK construction sites. Underground cables may carry voltages from 230V to 132kV and can be at shallower depths than expected. Preventing cable strikes requires a systematic approach combining utility records, cable detection, safe digging practices, and trained operatives. This talk explains the cable strike prevention process from start to finish.
Key Hazards
Fatal electrocution from striking a high voltage underground cable
Severe arc flash burns from short circuit caused by cable damage
Explosion and fire from fault energy released at the strike point
Cables at unexpected positions or depths not matching utility drawings
Control Measures
Obtain up-to-date utility plans from the asset owners before any ground disturbance begins.
Carry out a CAT and Genny survey of the full dig area and mark all detected services on the ground.
Hand dig trial holes to confirm cable positions before using any mechanical excavation equipment.
Maintain a 500mm hand-dig exclusion zone around all identified or suspected cable routes.
Use insulated hand tools when digging within the hand-dig zone around detected cables.
Brief all operatives and machine drivers on cable locations and safe digging procedures each day.
Ensure CAT operators hold a current competency card and have completed refresher training.
Stop work immediately if any cable is exposed and verify its status with the asset owner.
Report all cable strikes and near misses through the site incident reporting system without delay.
Emergency / Rescue
If a cable is struck, do not touch the cable or the machine. Evacuate all persons at least 15 metres from the strike point. Call 999 and the asset owner's emergency number. If a person is in contact, do not touch them until the supply is confirmed isolated.
Remember
Obtain utility plans and carry out a CAT and Genny survey before any ground disturbance
Hand dig trial holes to confirm cable positions before using mechanical excavation methods
Maintain a 500mm hand-dig zone around all identified or suspected cable routes at all times
If a cable is struck, evacuate everyone at least 15 metres and call 999 immediately
Report all cable strikes and near misses through the site incident reporting system
Applicable Legislation: Electricity at Work Regulations 1989 · HSG47 (Avoiding Danger from Underground Services) · Health and Safety at Work etc. Act 1974 · CDM Regulations 2015