Role Overview
Lead the design and engineering of tunnel ventilation and smoke control systems for road and/or rail tunnels, covering normal ventilation (comfort/air quality), emergency ventilation (fire/smoke control), jet fan and ducted systems, and full integration with Fire & Life Safety (FLS) requirements and authority expectations. The role requires strong capability in 1D network modelling, 3D simulation and CFD to support design decisions, performance verification, and safety case documentation.
Key Responsibilities
Develop and manage the Tunnel Ventilation Basis of Design, design criteria, and performance requirements for normal and emergency ventilation systems across concept to IFC and construction support.
Design and size tunnel ventilation systems, including as applicable:
Longitudinal / semi-transverse / transverse ventilation configurations
Jet fans, axial fans, supply/exhaust fans, smoke extraction systems, dampers, ducts, shafts, portals and ventilation buildings
Ventilation control philosophy (modes, scenarios, sequences), redundancy and maintainability requirements
Perform and lead comfort and air quality analyses for normal operations:
Contaminant dispersion and compliance with exposure limits (CO/NOx/visibility as applicable)
Thermal comfort, airflow velocity limits, and user comfort criteria for road/rail tunnels and underground interfaces
Support operational strategies for congestion, maintenance modes, and seasonal conditions
Lead fire and smoke control engineering in coordination with FLS/Fire teams:
Define design fire scenarios, critical velocity, backlayering control, smoke stratification considerations, tenability criteria
Coordinate interfaces with egress routes, cross-passages, emergency exits, pressurization systems, and fire service access requirements
Develop ventilation response strategies for different incident locations and ventilation zones
Prepare and/or supervise simulation and modelling to validate tunnel ventilation performance:
1D ventilation network modelling for airflow distribution, pressure losses, fan duty points, portal effects, and scenario testing
3D simulations and CFD analysis for smoke movement, critical velocity validation, stratification, temperature/visibility, and localized effects near portals, ramps, and shafts
Manage inputs/outputs, calibration assumptions, sensitivity studies, and reporting for design assurance and authority submissions
Coordinate with multidisciplinary teams and systems interfaces:
Mechanical/Electrical (power demand, MCC/VFD, UPS needs if applicable, cable routing, earthing)
Civil/Structural (shafts, ventilation buildings, fan room layouts, penetrations, supports, acoustic treatment provisions)
Fire Protection / FLS (fire scenarios, cause & effect, integration with detection, emergency controls)
ICT/SCADA/BMS for monitoring, control logic, instrumentation, alarms, and operational HMI requirements
Produce and review design deliverables: design reports, calculations, ventilation schematics, equipment schedules, datasheets, drawings, MTO/BOQ inputs, specifications, and interface matrices.
Support procurement and delivery: technical bid evaluations, vendor clarifications, shop drawing reviews, RFIs, and value engineering with performance protection.
Prepare and support testing & commissioning and operational readiness:
FAT/SAT requirements, commissioning procedures, airflow measurement strategy, functional testing of modes, and integrated testing with FLS cause & effect
Support trial operations, O&M documentation review, and training requirements
Ensure compliance with relevant standards and guidance, including NFPA and tunnel FLS requirements, and support authority/independent checker responses as required.
Qualifications & Experience
Bachelor’s or Master’s degree in Mechanical Engineering (or equivalent); specialization in ventilation/fire engineering is an advantage.
12–16 years’ experience in tunnel ventilation design and smoke control for road and/or rail tunnels, including delivery through concept to detailed/IFC and construction support.
Demonstrated expertise in:
Ventilation sizing and system selection, pressure loss calculations, fan selection and duty point verification
1D network modelling and scenario-based operational analysis
3D modelling / CFD for smoke and airflow performance verification, including interpretation of tenability results (visibility, temperature, CO exposure where applicable)
Comfort/air quality assessments and operational ventilation strategies
Integration with FLS and strong working knowledge of NFPA requirements relevant to tunnel ventilation and life safety (project-dependent), with ability to translate requirements into design criteria and operational modes
Experience coordinating with fire engineers, systems (SCADA), electrical power, and civil/structural interfaces is essential.
Exposure to authority submissions, safety case documentation, and independent checker/peer review processes is preferred.
Software
1D Tunnel Ventilation / Network Modelling:
SES (Subway Environment Simulation) and/or IDM / TUNVEN / Ventsim (as applicable to project type)
Equivalent network modelling tools acceptable with proven tunnel applications
CFD / 3D Simulation & Fire/Smoke Modelling:
ANSYS Fluent / CFX and/or OpenFOAM (CFD airflow/smoke)
FDS (Fire Dynamics Simulator) + Smokeview; PyroSim (preferred) for fire/smoke simulations
Thermal/comfort and airflow analysis tools: project-specific tools and validated calculation methods; strong Excel-based modelling capability
Design & Coordination: AutoCAD, Revit, Navisworks, ACC/Autodesk Construction Cloud
Reporting and data handling: MS Excel, Word, PowerPoint (clear technical reporting is essential).
