Fire Safety Science Digital Archive

The paper describes some recent work on the growth and spread of fire in the open. The importance of heat transfer from the flames has led to a study of the factors determining flame size as a result of which the lengths of flames from laboratory fires burning wood have been related to the size and rate of burning of the fuel bed by formulae derived from a simplified dimensional analysis. The effects on the length and orientation of flames of a wind blowing across a long fuel bed are also described. Comparisons made with data from some experimental fires with flames up to an order of magnitude larger are reasonably satisfactory. The results of preliminary experiments to assess the distance at which separate flames merge together and other published data are shown to be in approximate agreement with a simple theory. Some studies of fire spread in continuous beds of fuel are being made using long cribs of wood sticks, so far mainly in still air. The results of these experiments covering a range of fuel bed conditions can largely be accounted for by the radiant heat transfer from the burning zone through the fuel bed.