The research in both grass and forest indicates that rate of spread increases with fire head width up to a limit which varies with wind speed. Under calm conditions, all fires move at the same slow speed regardless of width. However, with strong winds, fire speed will keep rising up to a width of perhaps 200 metres. Because they show there is no simple relationship between wind speed and fire spread during the early stages of fire growth, the findings pose problems for fire investigators trying to work out when a blaze started. But if the wind is not very variable, like a sea breeze, then the fire might spread for an hour before it reaches its maximum speed.
Fires can take even longer to build up to their potential rate of spread in forests.
The research has also confirmed the value of efficient attacks on the flanks of fires. Eventually it will run into a natural barrier or something that might allow you to catch up with it. However, the findings highlight the need for care in lighting lines of fire along a break or fire trail when burning out in an attempt to secure a perimeter. This could be very much faster than the behaviour that has been observed in a fire developing from a single point, and could cause problems for firefighters elsewhere along the fire trail. It could not have been conducted without the collaboration and support of the Bush Fires Council of the Northern Territory and the Department of Conservation and Land Management, Western Australia.