Cross River Rail – Innovations in Metro Tunnel Ventilation and Fire Life Safety

Cross River Rail (CRR) is a new metro rail line in Brisbane, Australia. Currently under construction, and nearing completion, the project includes 5.9 kilometres of twin tunnels and four new underground stations.
Tunnel ventilation is one of the key systems that will keep users of this city-shaping infrastructure comfortable and safe. The design of the CRR tunnel ventilation system incorporates numerous industry innovations in form and function. The CRR tunnel ventilation system (TVS) is discussed with respect to design philosophy and challenges, particular 1-D and 3-D numerical simulations undertaken, and the practical implementation of hardware and controls. A discussion is presented of interesting ventilation features, and importantly, how they interact with other life safety controls in the tunnels, on the rollingstock, and in the stations. To help minimise excavated station volumes, fan plant is centralised, tunnel ventilation ducts are integrated into station structural elements, draught relief paths are rationalised, and over-platform exhaust ducts are designed to also service air-conditioning supply. To minimise the number of fans, tunnel ventilation fans are used for both tunnel and station exhaust functions. Design challenges included working with structural constraints for trackway exhaust points and alignment of train operations and a new signalling design.
Underground fire life safety (FLS) is largely about smoke management. To provide a robust emergency response in tunnels, CRR utilises Saccardo nozzles at all station ends. For station trackway fires, CRR employs tunnel ventilation exhaust fans to bias smoke extraction over the platform, instead of over the train, and makes use of fire-hardened platform screen elements to reduce risk. To facilitate station evacuation, escalators automatically stop and reverse in certain fire emergencies, and front-of-house (FoH) lifts remain operational during a fire. These approaches are not common for modern metro systems.
This paper presents CRR as a case study in modern FLS and TVS thinking. Rather than dwell on design features, modelling, and design approaches considered to be “business-as-usual” for a modern greenfield metro system, the discussion focuses on a number of innovations and novel aspects of the CRR design which help to reduce asset and life safety risks, particularly during fire emergencies.
KEYWORDS: Rail, Metro, Fire Life Safety, Tunnel Ventilation, Cross River Rail