TUN/General/TBT-TUN-006
Emergency Evacuation From Tunnels
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Emergency Evacuation From Tunnels
Toolbox Talk Record
Ref: TBT-TUN-006 | Issue: 1 | Date: March 2026
| Presenter | Project | ||
| Location | Date |
What?
- Tunnel evacuation is uniquely challenging — there are limited exits, poor visibility, and long escape routes.
- Fire in a tunnel fills the bore with smoke in seconds, reducing visibility to zero.
- Gas ingress from the ground can create toxic or explosive atmospheres requiring immediate evacuation.
- All tunnel workers must know the evacuation route, assembly points, and alarm signals before entry.
- Refuge chambers or safe havens may be provided in long tunnels as intermediate points of safety.
- Self-rescuer breathing apparatus provides 10-20 minutes of air for escape from a smoke-filled tunnel.
- Communication systems — PA, radio, or hard-wired — must reach all parts of the tunnel for alarm purposes.
- The Confined Spaces Regulations 1997 and CDM 2015 require documented evacuation procedures for tunnels.
- Evacuation drills must be carried out regularly to test the procedure and train the workforce.
- Emergency lighting powered by battery backup must illuminate escape routes throughout the tunnel.
Why?
| Smoke fills quickly | Tunnel fires generate smoke that fills the bore in seconds, cutting off escape routes. |
| Limited exits | Tunnels typically have only two exits — if one is blocked, the other must be reachable. |
| Toxic atmosphere | Gas ingress or fire creates conditions incompatible with life within minutes. |
| Legal requirement | Confined Spaces Regulations and CDM mandate emergency evacuation plans for all tunnels. |
| Do | Don't |
|
See also: Tunnelling Safety Awareness | Tunnel Ventilation Requirements |
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