Ventilation strategies for road tunnels in different countries and consequences using Fixed Fire Fighting System (FFFS)

Sammanfattning: A study is carried out on the ventilation strategies for road tunnels in different countries and consequences using fixed fire fighting systems (FFFS). The type of ventilation strategy for road tunnels can ensure the safety of people during the evacuation stages and protection of the rescue services during their intervention of the fire. Ventilation strategies vary from country to country and therefore it is important to get a suitable strategy which can be applied in these countries [1]. FFFS in road tunnels are defined as fire fighting equipment, which is permanently installed in the tunnel with a pipe system that water or other extinguishing agents. Usually FFFS are water spray systems and can be either high pressure or low pressure systems. Such systems will be able to fight fires that are relatively large and thereby potentially prevent a major disaster. In a tunnel without a fire suppression system, a slightly lower ventilation velocity is preferred to slow down the fire growth at the initial stage of evacuation. At the fire fighting stage the ventilation velocity can be adjusted up to critical velocity. In order to explore the effects of FFFS during different ventilation conditions, an analysis will be conducted on a large scale Runehamar and model scale tunnel fire experiments conducted at SP. The analysis show that the longitudinal ventilation system and FFFS will provide a tenable environment for safe evacuation.