Short Fire Run — NSW RFS Methodology

Assess the reduced bush fire risk from a short fire run — a parcel of vegetation too small or too narrow to support a fully developed fire — using the NSW Rural Fire Service methodology, and compare the radiant heat against a fully developed fire.

A short fire run is a performance based solution under Planning for Bush Fire Protection and must be supported by a Bush Fire Design Brief recording the site particulars, the methodology and these inputs and outputs. The vegetation must have no connectivity to a larger parcel capable of a fully developed fire, and the Bushfire Attack Levels shown are indicative context rather than a compliance result.

Site
Appendix A fuel loads, shown as surface and elevated / overall including bark and canopy. Classify by structure and formation per Keith (2004).
From Table A2.3 of Planning for Bush Fire Protection for the local government area. Used by the forest formations only.
°
Capped at 15° for upslope. Downslope beyond 30° is outside the model and needs an alternate calculation in the design brief.
°
Slope between the asset and the vegetation. Limited to 20° for fuel management reasons.
m
Asset to the classified vegetation — drip line to gutter line in the fact sheet worked example.
m
Measured perpendicular to the contours, from the furthest point of vegetation to the closest. Limited to 150 m measured on the effective slope.
m
Forest formations: average elevated fuel height for Project Vesta, maximum 2 m — see the Appendix B height key. Heath formations: the vegetation height measured on site.
Sets the flame temperature per the fact sheet footnote 7.
Advanced options
m
Height of the assessed element above its own ground level.
km/h
Nominally 30 km/h. The fully developed fire is always computed at the NSW RFS worst case of 45 km/h.
kJ/kg
°C
%

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