Fixed fire fighting systems in road tunnels: an overview of
current research, standards and attitudes

Abstract: The way of looking at the use of Fixed Fire Fighting Systems (FFFS) in road
tunnels in Europe has changed during recent years due to several
catastrophic tunnel fires (CTF). Tests have been conducted which have
proven some statements from the past to be wrong but this is still a field
that has to be studied further to gain a more accepted status in Europe.
When installing a water based FFFS in a road tunnel it is important to
understand that the system’s objective is to suppress or control the fire
and not necessarily to extinguish it. Furthermore, the engineer must have
an understanding on how the FFFS will do this. Smaller droplets will attack
the flame and larger droplets will attack the fuel. This knowledge is
important for example concerning hazardous goods. The FFFS should be
designed so that it operates together with the ventilation system to get
maximum effect on suppress or control abilities and the possibilities for
self evacuation.
Standards and guidelines to be used regarding FFFS in road tunnels are the
national standards combined with NFPA 502 and the guidance published by
UPTUN.
Japan and Australia are two countries with experience of using FFFS in road
tunnels. Especially Japan has a long experience with FFFS using it for
about four decades. Europe has a lot to learn from these countries not only
when it comes to the use of FFFS in road tunnels but also on how to regard
its role in general.