Example 4: 



The Wandilo Fire of April 5, 1958, in South Australia near Mt. 

 Gambier was documented by McArthur and others (1966). A 

 "fire storm" developed and caused the death of eight 

 firefighters. The fire started in tea tree {Leptospermum spp.) 

 scrub as a surface fire with no crowning, but entered an un- 

 thinned, unpruned cluster pine {Pinus pinaster) plantation about 

 1230 and started crowning and spotting. The wind reduction 

 was from about 20 mi/h (32.0 i<m/h) at 33 ft (10 m) to 

 7.6 mi/h (12.2 km/h). This reduction suggests the fire was pre- 

 dominantly a scrub fire, which is indicated in the narrative. The 

 fire moved into a Monterey pine (Pinus radiata) stand and pro- 

 ceeded at a somewhat slower rate with occasional crowning. The 

 fire area and perimeter at this time suggest a slower growth rate 



with winds on the fire of 6 to 7 mi/h (9.6 to 11.2 km/h). The 

 wind at 33 ft (10 m) was averaging 22 mi/h (35.2 km/h) so the 

 reduction factor was 0.31. The general area of the fire storm 

 contained stands of die-back timber and heavier fuel accumula- 

 tion that facilitated crowning. This allowed crown fires to 

 develop, and dovwiwind spotting caused almost an area ignition. 

 It is difficult to say whether the fire advanced by spotting or 

 crowning, but the fire shape by the double ellipse model fits 

 reasonably well with a wind on the fire of about 12.5 mi/h 

 (20.0 km/h). The reduction factor for 23 mi/h (36.8 km/h) to 

 12.5 mi/h (20.0 km/h) is 0.54, which agrees with what would be 

 expected just above a vegetation layer as compared to the wind 

 33 ft (10 m) above the layer. The elliptical fire shapes for 1330, 

 1500, and 1530 hours are presented in figure 12. 



Example 4. The Wandilo Fire of April 5, 1958, in South Australia started in tea 

 tree scrub as a surface fire, but after entering unthinned, unpruned pine plan- 

 tations it became a crown fire. 



Variable 



Documented 



Simple ellipse 



Double ellipse 



Double ellipse 





values 



values 



values 



adj. values 



Time 



1140 hours 









Area 



8.0 acres 



8 



13.5 



8 



Perimeter 



.3 miles 



.3 



.5 



.5 



Distance 



.2 miles 



.1 



.1 



.2 



Windspeed 



NNW 17.0 mi/h 





1.0 



7.75 



llw 



2.6:1 



1.3:1 



1.5:1 



2.6:1 



Time 



1230 









Area 



114 



114 



144 



114 



Perimeter 



2.2 



2.2 



2.3 



1.« 



Distance 



1.0 



1.0 



1.0 



.7 





NWN 20 







J o.o 



i/w 



2.8:1 



5:1 



4:1 



2.8:1 



Tims 



1330 









Ar63 



381. 



381 



381 





Pprimptpr 



■ CI 1 1 1 IdCI 



0.\7 









Distance 



1.5 



1.8 



1.8 



1.2 



Windspeed 



NW 17-22 





13.8 



7.6 



i/w 



2.5:1 



4.4:1 



4.7:1 



2.5:1 



Time 



1500 









Area 



900 



900 



986 



900 



Perimeter 



5.9 



5.9 



6.2 



4.8 



Distance 



2.0 



2.8 



2.8 



1.8 



Windspeed 



NW 21-23 





12.8 



6.8 



//w 



2.3:1 



4.2:1 



4.2:1 



2.3:1 



Time 



1530 









Area 



1,547 



1,547 



3,016 



1,547 



Perimeter 



8.4 



8.4 



9.7 



7.6 



Distance 



3.4 



4.0 



4.0 



3.4 



Windspeed 



NW 23 





10 



12.4 



flw 



4.1:1 



5.3:1 



3.2:1 



4.1:1 



Time 



2230.0 









Area 



3,383.0 



3,383 



3,383 





Perimeter 



14.5 



14.5 



9.5 





Distance 



4.6 



7.1 



3.7 





Windspeed 



14.0 





7.7 





//w 



2.5:1 



7.5:1 



2.5:1 





15 



