IBEW Underground Tunnel Safety
Core Safety Principles for Operating Underground
A detailed Job Hazard Analysis (JHA) should be performed at the start of every work day.
Never enter an unsafe space.
Never bypass a safety system for any reason, under any circumstances.
Never ignore air monitoring readings.
Never let schedule pressure rush you past a safety step.
Always look out for your fellow worker.
Never hesitate to report an incident or ask a question. Contact IBEW 11 Safety — that's what they're there for.
Personal protective equipment (PPE)
Hard hat
High-visibility clothing
Safety glasses
Steel/composite toe boots
Cut-resistant gloves
Hearing protection
Respiratory protection
Arc-rated clothing
Fall protection
Waterproof gear
Underground hazards & controls
Collapse & Ground stability
Tunnel collapses and cave-ins remain one of the most serious risks due to:
Loose or fractured rock
Water intrusion
Vibration from blasting or equipment
Improper or failed ground support
OSHA requires:
Inspection of tunnel walls, face, and roof every shift
Scaling or supporting loose material
Competent person oversight at all times
Early warning signs:
Cracking or popping sounds
Falling dust or small debris
Bulging walls or shifting supports
Water seepage increasing suddenly
If something looks wrong, STOP WORK. Notify your IBEW 11 designated safety officer.
No production target outweighs a life.
Air Quality & Atmospheric Hazards
A respiratory injury can end your career and affect you the rest of your life. It is important that the environment you are working in has continuous air monitoring, along with regular testing and ventilation systems delivering fresh air at all times.
Atmospheric Risks:
Oxygen levels below 19.5%
Exposure to toxic gases such as Carbon monoxide (CO), Hydrogen sulfide (H₂S), and Nitrogen dioxide (NO₂)
Diesel exhaust exposure from heavy machinery
Silica dust (drilling, cutting)
Early warning signs:
Headache, dizziness, confusion
Burning eyes or throat
Sudden fatigue or nausea
Workers “not acting right”
Access, Egress & Emergency
Underground work limits escape routes and visibility. You should always be thinking of an escape route. If you don’t know your way out, you are already behind.
Atmospheric Risks:
Fire or explosion
Flooding
Equipment failure
Gas release
Required Controls:
Clearly marked escape routes
Secondary egress where possible
Check-in/check-out system for accountability
Emergency communication systems
OSHA mandates tracking all workers underground and maintaining evacuation procedures .
Electrical hazards unique to tunnel work
Electricians face compounded risk underground. These environments can amplify electrical hazards due to wet conditions, tight quarters, and reduced escape time.
Underground Tunnel Hazards:
Energized cables in confined spaces
Moisture increasing conductivity
Limited clearance around live systems
Poor lighting conditions
Required Practices:
Lockout/Tagout (LOTO)- Visit this IBEW 11 story on LOTO
Proper grounding and bonding
Arc flash protection
Insulated tools and PPE
Heavy Equipment & Struck-By Hazards
Heavy equipment doesn’t stop fast—and tunnels don’t leave room. These hazards are only intensified by the confined space you are working in and limited visibility.
Equipment Hazards:
Haul trucks and loaders
Tunnel boring machinery
Hoisting systems
Moving materials in tight shafts
Risk of Injuries:
Struck-by incidents
Caught-between hazards
Crushing injuries
Human Factors & fatigue
Real conditions underground have a serious effect on your health. It is physically demanding. You must stay aware of your surroundings and remain hydrated.
Potential issues include:
No natural light
Loss of time awareness
High physical demand
Heat and humidity
Key Practices:
Maintain situational awareness
Stay hydrated
Work at a steady, sustainable pace
Speak up when something isn’t right