How fast can a fire spread?

How quickly can a person run?

The Boonoke Fire in 1987 burnt out 120,000 hectares in the Riverina, New South Wales and is one of the fastest recorded grassland fires. The midday temperature was 40.6°C, relative humidity of 7%, wind speed of 44.5 km/hr and had a head fire rate of spread of 23 km/hr.

Donovan Bailey, the current world record holder, completed a 100 metre sprint in 9.84 seconds (average 36.6 km/hr). Provided that the smoke did not fill their lungs or sting their eyes so badly to temporarily blind them, someone running at this speed would be able to outrun the fastest fire over a distance of 100 metres.

However, lacking the benefit of years of training for 10 explosive seconds on the track, and weighed done by our bushfire attire (heavy boots and overalls), many of us would be lucky to run at half the speed of Bailey, let alone as fast as the Boonoke fire!

Courtesy of : Liam Fogarty
New Zealand Forest Research Institute

Extract from Fire Technology Transfer Note Number14 December 1997 - New Zealand Forest Research Institute.