Improving firefighter tenability during entrapment and burnover: An analysis of vehicle protection systems. (December 2020) - Penney, Greg
Abstract: When attempting to suppress severe wildfire the possibility for firefighting crews to be overrun by wildfire, known as entrapment and burnover, remains a catastrophic and all too common occurrence. While improvements have been made to vehicle protection systems to increase the safety of firefighters caught in burnover, the potential effectiveness of these systems remains limited. This study involved systematic analysis of 62 historical entrapment and burnover reports from the USA, Australian and New Zealand from 1978 to 2020 (Phase 1), and 135 simulated wildfires encompassing the 99th percentile of Australian fire weather conditions, fuel structures and terrain (Phase 2). Analysis of historical entrapments identified existing vehicle protection systems have failure points well below the reported Fire Danger Index associated with the majority of house loss during wildfire events in Australia. Increasing the performance threshold of vehicle protection systems to the historical mean fire line intensity identified at the point of entrapment increased efficacy, and, prevented vehicle protection systems being overwhelmed in simulations regardless of Fire Danger Index and up to windspeeds of 55 kmh −1 . In order to further improve firefighter protection during entrapment and burnover it is recommended the radiant heat flux performance threshold of vehicle protection systems are increased.