Fire propagation through arrays of vertically mounted fuel elements is considered. Simple experiments and the work of Vogel and Williams [1] suggests a geometrical model for fire propagation from one element of the array to another. The advantages of a geometrical model are that an inclined base can easily be accommodated, and that a physical model for simulation of fire propagation naturally appears. From the former, a critical slope can be found beyond which heat transfer is no longer rate limiting.

[This publication is referenced in the "Synthesis of knowledge of extreme fire behavior: volume I for fire managers" (Werth et al 2011).]