This article was written in collaboration with WSP Technical Specialist, Fire & Risk Andrew Purchase; Tunnel Ventilation Engineer Lily Liu; Tunnel Ventilation Engineer Nicole Nishimura; Director, Tunnel Systems Silas Li; and Tunnel Ventilation Engineer Bo Rim Seo. It was first presented as a part of the 8th edition of the International Symposium on Tunnel Safety and Security (ISTSS) in Borås, Sweden.

Ventilation systems form an integral part of the fire-life safety systems for underground rail or metro systems. For older systems there is a need to assess the condition of equipment and assess options for rehabilitating or upgrading performance to try and meet modern present day standards. This paper outlines a comprehensive approach to rail system ventilation rehabilitation considering fire potential, ventilation performance, and overall fire-life safety risk.