Fire Safety Science Digital Archive

Data are presented for the variation of the probability of a fire spreading beyond the room of origin and control time with the delay in arrival of the fire brigade. This information is required in order to isolate the effects of factors connected with the building, its contents and use, etc. It is found that in most cases delay in the arrival of the brigade causes significant increases. The probability of fires becoming large, for which data are also given, increases with the time from discovery to call of the fire brigade, but decreases with the time from call to arrival, presumably because delay time tends to be correlated with risk. About 50 per cent of fires are fought before the brigade arrives. For these fires the mean delay before the commencement of fire fighting is of the order of two minutes. About one quarter of fires fought before the arrival of the brigade are out on arrival. For the remaining fires the likelihood of spread appears to be little altered by the earlier fire fighting. Fires are more likely to be fought before the arrival of the brigade if they are small on discovery.