- Title:
-
Assessment of the Application of Compressed Air Foam Technology for Grassfire Fighting
- Date:
- February 2006
- Organisations
- BCRC
- Authors:
- Guy Barrett and Paul Killey
- Location:
- Australia, ACT, Australia
Overview
This research project was established to determine the most appropriate use of compressed air foam (CAF) for suppressing grassland fires. Experiments compared various applications of CAF, water and aspirated foam to determine their durability, effectiveness as a wet line for stopping fire spread and effectiveness for direct attack. These experiments were conducted in a Philaris sp. grassland (6.2 t/ha) in Monash ACT, under high fire danger conditions. The durability of a range of CAF solutions applied in wet lines were investigated by monitoring fuel moisture content and ground level humidity. Elevated fuel moisture content and ground level humidity was found to persist for up to two hours after application, with moisture persisting at the base of the grass longer than in the tops. The dry on wet CAF mix application maintained the highest moisture contents and persisted longer than other applications tested. The dry mix provides some insulation to the wet mix. This application requires more water to generate than others tested, as it requires two passes. Wet CAF solutions were found to persist for longer periods than dry solutions.
The effectiveness of wet lines of different CAF solutions, normal aspirated foam and water were tested against two moderately intense (4000 kW/m) grassfires. All solutions tested were ineffective at stopping a fire lit 45 minutes after application, but were found to stop a fire lit 15 minutes after application. This second wet line was breached by spotting. Wet CAF applications applied 2.5 hours prior to ignition were found to prevent spot ignitions from ember attack, while dry mix applications allowed spot fires to start.
This testing occurred under milder conditions than the durability tests and the expected periods effectiveness under extreme fire weather would be significantly less.
