Australian Trials

In 1961 the designer of the Australian tent, Alan King, personally tested the prototype protective shelter in experimental fires in jarrah forest in Western Australia. The tent was placed in a 4 x 5 m area raked clear of fuel; fuel loads were reported to be 20 t ha-1 in a 12 year old fuel type; the rate of spread of the fire was 4 m per minute; and, the intensity was up to 2400 kW m-1 with flames to 3 m high and flashes to 10 m. King reported conditions inside the tent were "quite comfortable" (King 1962).

For a demonstration test near Canberra in 1967, a tent was placed in a 2 x 1 m cleared area in a dry forest carrying 10 to 15 t ha-1 of fuel. The fire intensity was not recorded but estimated at less than 1500 kW m-1. The internal bonding of the tent caught fire during the test inflicting severe burns on the occupant.

In 1985, Knight (1988), carried out thermal measurements on an unoccupied prototype crew tent and modelled the maximum fire intensity that could safely impinge on this type of shelter. Knight calculated that a tent in a 10 x 10 m clearing could withstand a maximum forest fire intensity of 5600 kW m-1 and keep the mean body temperature rise less than 2 to 3 C. American experts considered that the threshold internal temperature of 100 C used in Knight's model might be on the low-side (Monesmith and Jukkala, 1987). Knight established in his model that while the tent was highly effective in reflecting radiation loads (to the point that these could be excluded from the theoretical calculation) the tent provided relatively poor protection against hot air currents which largely determine the internal temperature of the tent.