Water mist fire protection systems : The development of testing procedures for marine and heritage applications

Sammanfattning: Modern, commercial water mist fire protection system technology evolved at the beginning of the 1990s due a need to replace halon fire-extinguishing systems and improve fire safety on passenger ships. This thesis documents the unknown water mist system development work by two Swedish companies during the 1970s and 1980s. It also documents the development of the first international installation recommendations and fire test procedures for marine applications.Several of these fire test procedures needed revisions. A research project in the thesis showed that those for machinery space protection can be significantly improved by using simple and inexpensive measurements and performance measurement parameters. In another research project, tests simulating fire on a ro-ro cargo space of a ship was conducted. The results indicate that large water droplets are required for fire suppression, but smaller water droplets cool the fire gases well. For the protection of heritage buildings, a field study suggests that functional testing is essential to maintain the function of a system. Testing using commercial nozzles indicate that exposure of sensitive wall paintings to water spray could cause significant damage under real-life conditions, even if the flow rate is low.Future research should focus on improving fire test procedures based on experience as well on a theoretical understanding of the mechanisms of water mist. Long-term field experience is also desired for continual improvements of the performance and reliability of systems. In order to convince authorities, insurers, fire protection consultants and end-users on using water mist, these issues need to be dealt with in a systematic manner.