Hazard Tree - No Work Zones


Knowing the exact time a given hazard tree (or compromised section) will fail is extremely difficult, and is, in many cases, an unpredictable task. Given this fact, we need to manage firefighters’ exposure to these hazards by creating a safe work area or No Work Zone (NWZ). The size and extent of the NWZ must be determined by onsite conditions, such as terrain, stand structure, and fire impacts on the tree and adjoining trees.
When an identified hazardous tree or trees cannot be felled, then perform an assessment of which areas have too high a risk, and post a lookout to warn the personnel to stay clear of these areas while working in adjacent areas. If hazard still exists before leaving the area, flag the NWZ so that personnel entering the area will be able to recognize the hazard. Use the following failure zone illustrations as examples to help manage firefighter exposure to these identified hazards. Also, remember to include the possibility of the Domino Effect to surrounding trees.
Figure 1 - 1 1/2 X Height of snag | Figure 2 - 1 1/2 X Trunk-to-branch-tip distance | Figure 3 - 1 1/2 X Length of dead top |
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- 10 & 18 Poster, PMS 110-18
- 10 Standard Firefighting Orders, PMS 110
- 18 Watch Out Situations, PMS 118
- Interagency Standards for Fire and Fire Aviation Operations (Red Book)
- NWCG Incident Response Pocket Guide (IRPG), PMS 461
- NWCG Standards for Helicopter Operations, PMS 510
- RT-130, Wildland Fire Safety Training Annual Refresher (WFSTAR)
- Wildland Fire Lessons Learned Center
Have an idea or feedback?
Share it with the NWCG 6MFS Subcommittee.