Tunnel Boring Machine (TBM) Operations Safety Inspection Checklist

Are all gas monitoring devices (CH4, H2S, CO, O2) calibrated within the last 30 days, with records available?

Are gas monitors positioned within 10 feet of the tunnel face and at regular intervals along the tunnel bore?

Is the ventilation system delivering the required airflow (CFM) to maintain gas concentrations below permissible exposure limits (PELs)? Verify with anemometer readings.

Inspect ventilation ducts for damage (tears, punctures, collapses) and ensure proper sealing at joints. Repair or replace as needed.

Verify the emergency ventilation system is functional and can be activated within 60 seconds. Conduct a drill.

Are potential ignition sources (e.g., non-intrinsically safe electrical equipment) prohibited within 50 feet of areas where methane concentrations exceed 1%?

Is the air velocity at the tunnel face maintained at a minimum of 30 feet per minute to dilute and remove contaminants?

Confirm that the gas alarm system is audible and visible throughout the tunnel and that all personnel are trained on alarm response procedures.

Verify continuous monitoring of oxygen levels to ensure adequate breathable air (19.5% - 23.5%).

Are gas monitoring records maintained and readily available for review, documenting gas levels and ventilation system performance?

Are appropriate fire extinguishers (Class A, B, C) readily accessible within 25 feet of potential fire hazards (e.g., welding areas, electrical panels, TBM cutter head)?

Are fire extinguishers inspected monthly, with inspection tags indicating the last inspection date and condition?

Are hot work permits required for all welding, cutting, and grinding activities, and are they properly completed and authorized?

Are flammable liquids stored in approved containers and in designated, well-ventilated areas, away from ignition sources?

Is the TBM equipped with a functional fire suppression system (e.g., automatic sprinkler system) that is regularly inspected and maintained?

Are emergency egress routes clearly marked and unobstructed, with emergency lighting functional and tested weekly?

Verify the fire alarm system is functional and audible throughout the tunnel. Conduct a monthly test.

Are designated fire brigade members trained in fire suppression techniques and emergency response procedures?

Is the tunnel free of combustible materials (e.g., wood scraps, oily rags) that could contribute to a fire?

Are welding blankets or screens used to contain sparks and prevent fires during welding operations?

Are all moving parts of conveyors (e.g., rollers, belts, pulleys) adequately guarded to prevent contact?

Are emergency stop devices (e-stops) readily accessible along the entire length of the conveyor system and tested weekly?

Are lockout/tagout procedures in place and followed for all maintenance and repair work on conveyors and rotating equipment?

Inspect conveyor belts for proper alignment and tracking. Adjust as needed to prevent material spillage and belt damage.

Are all rotating parts of machinery (e.g., pumps, motors, gearboxes) properly guarded to prevent contact?

Are nip points on rotating equipment (e.g., belt and pulley interfaces) adequately guarded?

Are maintenance records available for all conveyors and rotating equipment, documenting inspections, repairs, and lubrication schedules?

Are warning signs posted near conveyors and rotating equipment, alerting personnel to potential hazards?

Does the conveyor system have overload protection to prevent material jams and potential equipment damage?

Are belt cleaners installed and functioning properly to prevent material buildup on conveyor belts?

Are segment rings handled using appropriate lifting equipment (e.g., vacuum lifters, cranes) with certified lifting capacity?

Is lifting equipment inspected daily before use, with records maintained of inspections and maintenance?

Are slings inspected before each use for damage (e.g., cuts, abrasions, kinks) and removed from service if necessary?

Are segment rings stored on stable, level surfaces to prevent tipping or collapse?

Is a personnel exclusion zone established during segment ring lifting and installation operations?

Is a clear communication system in place between the crane operator, signal person, and installation crew?

Are workers installing segment rings using appropriate fall protection equipment (e.g., harnesses, lanyards, lifelines) when working at heights above 6 feet?

Are workers trained to recognize and avoid pinch points during segment ring installation?

Are workers using the correct tools for segment ring installation (e.g., alignment pins, hydraulic jacks)?

Is a written segment ring installation procedure available and followed by the installation crew?

Is adequate lighting provided in the segment ring installation area to ensure safe working conditions?

Is the hyperbaric chamber inspected daily for leaks, proper functioning of pressure controls, and communication systems?

Are approved decompression tables readily available and followed during decompression procedures?

Are all personnel involved in hyperbaric operations trained and certified in hyperbaric procedures and emergency response?

Is a standby diver available and equipped to respond to emergencies during hyperbaric interventions?

Is a reliable communication system in place between the hyperbaric chamber and the surface?

Is medical support readily available for personnel undergoing hyperbaric interventions?

Are emergency procedures in place and practiced for hyperbaric incidents (e.g., rapid ascent, chamber fire)?

Is the oxygen level within the hyperbaric chamber continuously monitored to prevent oxygen toxicity?