Fire Safety Science Digital Archive

The times for which sticks in a wooden crib continue to flame have been measured in experiments on spreading fires. No direct measurements of either the intensity of radiation or the surface temperature of the fuel are available, but for these experiments the velocity of burning, i.e. the original thickness of a stick divided by the time of flaming, is inversely proportional to the density of the original wood and decreases with stick thickness and nominal moisture content of the fuel bed. The velocity of burning also appears to increase with increasing permeability of the wood along the grain. Because the effect of this permeability is a function of the length of the stick along the grain, the width of the crib itself might affect the rate of spread in wood of high permeability, but further experiments are required to test this.