Dead man zone

The dead man zone is defined as the area directly around a bushfire that is likely to burn within five minutes given the current wind conditions or an anticipated change in wind direction. The distance this zone extends from the firefront is highly dependent on terrain, windspeed, fuel type and composition, relative humidity and ambient temperature, and can range from under 100 m to well over 1 km.

Project Vesta

The term dead man zone was coined by members of the CSIRO research team in Australia who were investigating the spread of bushfires (Project Vesta). Project Vesta, headed by scientist Phil Cheney, found that when the wind changes direction, the line of fire will move out at its maximum rate of spread almost immediately, and that that speed was nearly three times what was previously thought. Project Vesta's research into bushfire behaviour makes up the majority of what is known about bushfires today.

Outcomes

Outcomes from Project Vesta have been integrated into firefighter training in Australia, and are beginning to appear in the United States.

Firefighters try to stay out of the dead man zone at all times, working from safe points such as burnt ground or a large area of non-burnable ground, i.e. a cricket or Australian rules football oval, or a large car park. This is achieved by attacking the fire from the flanks, or the rear, so that burnt ground is always nearby, and the fire is always in front of the firefighters. (Were they to attack fires at the head of the fire, they risk having spot fires start behind them. They would also risk changes in wind behaviour accelerating the spread of the fire.)

The result of several inquiries into firefighter death in Australian bushfires found that firefighters should stay out of the dead man zone, and that they should always keep 250 litres of water in their truck for personal safety. This is now a standard operating procedure in the NSW Rural Fire Service, Country Fire Service and Country Fire Authority in Australia.

See also

External links

This article is issued from Wikipedia - version of the Sunday, November 02, 2014. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.