A Review on Fire Safety

Abstract

Ventilation in tunnels is required for normal and emergency operation. During normal operation, its purpose is to provide a clean air environment and to maintain reasonable temperatures during congested conditions. During emergency operation, ventilation is needed to influence the flow of smoke and combustion products so as to create a safer environment for tunnel users to escape and for emergency services to intervene. This document presents a guide to tunnel ventilation systems and their operation during emergency conditions. The emergency ventilation system design requires the identification of the potential fire and smoke threat in terms of visibility, temperature and toxicity effects. The proper operation of a ventilation system plays a key role in tunnel safety. Foremost, the ventilation system needs to provide acceptable air quality for the safe passage of tunnel users. Further, it needs to provide tenable environment and to facilitate rescue conditions during a smoke or fire event. While accomplishing the first task (normal operation), i.e. providing sufficient fresh air, is relatively straightforward, dealing with the second issue is the subject of considerable debate since defining the best means to ventilate a tunnel during a fire emergency is not always clear.