RESEARCH SUMMARY 



Maximum load-loss rate within the combustioa zone of a vertically 

 (downward) spreading fire was obtained for excelsior (0.07 cm in cross- 

 section) at bulk densities from 0.0016 to 0.026 g/crn^. Fuel was contained 

 within a continuously weighed circular wire mesh basket 1 f t ^ (929 cm ) in 

 circular area and 0.5 ft (15.2 cm) deep, surrounded by a separate annular 

 basket of fuel, to minimize edge effects. Load-loss rates were similar to 

 those obtained by Rothermel (1972) for horizontally spreading fires in the 

 same fuel at the same bulk densities. 



The peak rate of load loss per unit, area exhibits a strong dependence 

 upon bulk density for both vertically and horizontally spreading fires. The 

 maximum of this peak rate occurs at the same bulk density in the two cases. 

 Because of these similarities, this method offers an alternative for investi- 

 gating the combustion dynamics of fire; moreover, the vertical array is 

 much easier to use than the horizontal array. 



