Tunnel ventilation

We have a diverse global team of tunnel ventilation experts. They combine deep experience with powerful simulation tools to harness natural airflows and/or optimise the mechanical plant, reducing the size and cost of excavation, as well as the project’s whole life carbon footprint.

Our ventilation experts are a key part of our Total Tunnel Design ethos. Their experience and insight from projects such as the Second Avenue Subway help reduce the impact and cost of a tunnel’s ventilation systems without compromising the comfort and safety of its users.

Nature first

Our start point is, wherever possible, to harness natural ventilation. A tunnel’s length and function obviously affect the viability of this, but by minimising mechanical plant, we save both excavation and operating costs, creating less energy-intensive, more sustainable alternatives.

Informing smarter design

Tunnel vent design is rightly driven by safety standards that take account of both normal operations and rare eventualities such as fire. Simply following codes can impose the inclusion of huge systems, fans and vents that will rarely – if ever – be used.

As co-authors on many of the global committees that publish tunnel ventilation standards, we understand the intent of these codes, and create lower-impact answers that deliver the required performance.

Digital tools

Our team works with advanced Computational Fluid Dynamics tools and our own agent-based modelling tool – Arup Mass Motion – to better understand human responses and the physics of ventilation in tunnel environments in emergencies. Those insights allow us to accurately plan for evacuation scenarios from a tunnel affected by fire smoke and identifying – for example - where people will be able to exit underneath smoke caused by fire. 

Applying this data-driven, quantitative analysis of risk early on helps us establish a realistic, performance-based view of ventilation requirements even at concept design stage.