249 - PBD of a large car park with EVs (Case study) with Jonathan Hodges, Mark McKinnon and Christian Rippe

From the SFPE Performance Based Design Conference in Singapore, we sit down with Jonathan Hodges and Mark McKinnon (UL Research Institutes) and Christian Rippe (Jensen Hughes) moments after their case study presentation to break down a modern parking garage fire engineering workflow with a huge does of performance based and probabilistic approaches.We talk about what changes when today’s vehicle fleet makes multi-vehicle fire spread more plausible, and why picking a single car fire curve can quietly bake bias into an entire performance-based design. The team shares how they use real incident data, vehicle size distributions, ignition location categories, and percentile-based heat release rate curves to build design fires that are transparent and defensible. We also dig into EV charging as an initiating mode, what the data can and cannot support, and how a “gap analysis” mindset helps practitioners avoid false precision.Then we get into the risk machinery: scenario binning, frequencies, sprinkler reliability assumptions, and how CFD (FDS) fits when you cannot simulate 100,000 possibilities. Finally, we go structural with concrete spalling, thermal finite element modeling in Abaqus, and a scripted workflow that iteratively removes damaged concrete to understand how exposure evolves during long-duration multi-vehicle fires.For this episode, there is a ton of resources. From Jonathan:Reference for first design fire paper: https://doi.org/10.1016/j.firesaf.2024.104145Reference for second design fire paper: https://doi.org/10.1016/j.firesaf.2026.104721Reference for database paper: https://doi.org/10.1007/s10694-025-01701-5Reference for number of parking garages: https://doi.org/10.1016/j.firesaf.2022.103565Reference for ULRI vehicle fire data: https://doi.org/10.1016/j.dib.2026.112471Reference for ULRI material database: https://materials.fsri.org/Reference for NERIS: http://neris.fsri.org/Reference for NFPA Vehicles data: https://www.nfpa.org/education-and-research/research/nfpa-research/fire-statistical-reports/vehicle-firesAnd two from myself:Outcomes of the massive fire with spalling in Warsaw https://doi.org/10.1016/j.firesaf.2025.104352Open sided car park report by OFR https://www.gov.uk/government/publications/fire-safety-open-sided-car-parks/real-fires-open-sided-car-park-fire-resistance-introduction-and-conclusion  ----The Fire Science Show is produced by the Fire Science Media in collaboration with OFR Consultants. Thank you to the podcast sponsor for their continuous support towards our mission.