A review of regulations of tunnel smoke control systems

With the rapid development of traffic systems for dense urban areas, many tunnels were constructed. There are deep concerns on fire safety in such vehicular and railway tunnels. Smoke control systems are identified to be an essential fire service installation for providing life safety. However, regulations and associated codes implemented are not yet demonstrated by in-depth research studies. To understand better on designing smoke control systems for tunnels, the current regulations and codes of practices have to be reviewed. A review study on fire codes and design guides for tunnels were carried out and will be reported in this paper. Practices in USA, France, Germany, Switzerland, Norway, UK, Netherlands and Hong Kong were surveyed. As recommended in the international road tunnel design guidelines, the provision of smoke control systems for road tunnels should be based on the traffic condition (bidirectional or unidirectional traffic), traffic intensities, tunnel length and the site location (urban or non-urban area). Natural ventilation is generally accepted to be adopted in road tunnels with length approximately less than 250 m for urban areas with unidirectional traffic. For longitudinal ventilation, it is recommended that the maximum tunnel length can be up to 900 m. However, for tunnels in urban areas with congested conditions, longitudinal ventilation should be allowed only if risk analysis is acceptable and the maximum tunnel length should be within the range of 500 to 600 m. When the tunnel is over 1000 m, smoke extraction over a specified distance must be achieved. A distance of 400 m in an urban tunnel and 600 m in a non-urban tunnel are recommended.