New safety zone research: MAKE THEM BIGGER!

This is some critical preliminary research!  New safety zone research is out (Published March 2014).  Here’s the paper in the Journal of International Wildland Fire. JFSP posted a summary here. In short, safety zones need to be much bigger than what the previous calculations called for.  Calculations are based on vegetation height, not flame height as in the past.

Calculate a safe separation distance (SSD):
SSD = 8 * Slope wind Factor * Height of the surrounding vegetation SLOPE-WIND FACTOR Wind Speed Flat 0%

Additional notes:
1. For a 20-person crew, add 10 feet of radius and for a vehicle add another 5 feet of radius.
2. The area in red requires large natural openings or construction by mechanized equipment.
3. The proposed rule is to be used for flat ground rather than the existing flame height rule.
4. Also consider additional lookouts on the ground and in the air to monitor fire activity with early egress to escape routes and safety zones.
5. At 30% or greater slopes, hot gases tend to stay close to the ground.

View research overview PDF >

Access full research paper online >