Fire Safety Science Digital Archive

A fault tree analysis (FTA) of the sprinkler systems for large high-rise office buildings is being carried out to determine the reliability of systems in Australia. This analysis is particularly intended to provide information on the sensitivity of the reliability to various factors in the building operations such as, rate at which tenancy changes occur, monitoring of valves and back up batteries, maintenance procedure etc.. To determine probabilities of the occurrence of various sprinkler system components failure, a comprehensive survey is being conducted involving a number of Australian high-rise office buildings (in this paper data from nine buildings are presented). In addition, data from overseas surveys has also been considered based on their relevance to the office buildings being considered. In this paper the analyses are confined only to wet-pipe systems, as these constitute the vast majority of automatic sprinkler systems in Australia and New Zealand. To develop the fault trees, the designs found in usual practice are considered, rather than the designs just complying the Australian codes with the minimum requirements. Analysis shows that sprinkler systems for high-rise office buildings in Australia are likely to be more reliable than that indicated by recent US store and office fires statistics. The difference may be attributable to the wet-pipe only system and stringent maintenance requirements by Australian regulations. Sprinkler zone shut off during tenancy changes appears to be the main factor that may lead to a sprinkler system failure.