Fire Science Show

Performance-based engineering or the use of probabilistic methods in building design are not inventions of Fire Safety Engineering. But we sometimes tend to act like we need to 'discover' and work out everything on our own. I strongly believe this is not the best way forward. And certainly not the cheapest one...

Where I see a lot of potential is the adaptation of methods and models that work in other parts of civil engineering, that could act as solutions to issues related to fire. Such a case is with The Pacific Earthquake Engineering Research (PEER) Center’s Performance-Based Earthquake Engineering (PBEE) - brought to the fire safety engineering community by David Lange (a previous guest on the show) and Asif Usmani in 2014, and now is championed by my today's guest Dr Negar Elhami Khorasani. Negar gives us a very in-depth view of the status of Structural Fire Safety Engineering and shows an inspiring framework in which probabilistic inputs at different stages of the analysis can be used to build up a model of safety in a building, that is much more informative than whatever we assume through design with prescriptive rules. A step up from the structural fire safety engineering framework, but one that feels very smart and natural. 

The best part of this episode is reading this framework between the lines. Yes, it is adopted for structural design. But it does not have to. It can be adapted to many different areas of fire science, and in my case, we will definitely seek an implementation in wind-fire coupled modelling. So, no matter if you are dealing with the most impressive structural designs crafted for fire, or if it is something not very relevant to your current tasks, please have an open mind and try to understand the workflow and ideas behind this framework, it seems really worth it!

And here are some resources I received from Negar, that may be relevant to you, if you find this topic interesting: 

•  2014 paper by Lange et al. on the application of performance-based earthquake engineering framework to structures in fire
• 2014 paper on a probabilistic model for fire load
• 2015 and 2020 papers on probabilistic material models
• 2016 paper on fire fragility curves
• 2020 paper on probabilistic models for permanent and live loads
• 2022 on the reliability of US prescriptive standard for steel column 

Fire Science Show is sponsored by OFR Consultants.

OFR Consultants is a multi-award-winning independent consultancy dedicated to addressing fire safety challenges. OFR is the UK’s leading fire risk consultancy. Its globally established team has developed a reputation for pre-eminent fire engineering expertise, with colleagues working across the world to help protect people, property, and the planet. 

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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.

Would you rather do 20 published experiments and take your impact factors, or make one that truly changed the world of fire science? Or maybe a different way, would you pursue something that is quick, easy and gives immediate credit over something hard, stressful and requiring maybe years to really change mainstream engineering?

Sure, we all like to see ourselves as heroes, but in reality, very few of us have the courage and vision to pursue these hard-to-achieve goals. But it seems worth it. Today's episode is a statement of that. An experiment designed to investigate a single, most impactful variable. A chain of research, from small, through intermediate, to then full scale, designed with every detail in mind, to truly reveal the physics of a fire in a way we have never seen in a controlled experiment. Finally, a great finish with impactful papers, changing the standards worldwide and the tunnel fire engineering practice for decades to come.

This is what happened in the Runehammar tunnel in Norway. And I am joined today by prof. Haukur Ingason from RISE - the mastermind of this work, and dr Anders Lönnermark, also from RISE, then a PhD student tasked with assisting and processing the findings of the study. The experiments were carried out by SP (now RISE), SINTEF, TNO and industrial partners. In this episode, you will learn their path to these experiments and the environment in which this happened. You will learn how the previous experiences of my guests have been pivotal in understanding the outcomes of the test (truly, fire science is blessed with having just the right people, at the right time at the right place...). We will also try to understand the impact of this research, and dream a bit about 'how would we do this today'. And on top of that, you will learn a ton of technical details of the tests, sprinklered with a bit of tasty fire science.

If you want to learn more about these experiments, the single best piece you can find summarizing it is here.

One of the outcomes of the project is still ongoing - Haukur organized a seminar to disseminate the experimental findings, which eventually turned into the ISTSS conference series. This year, they invite you to the 10th edition of this event at Stavanger in Norway. It is a nice opportunity, as this conference happens just after Fires in Vehicles event, held at the exact same place. Learn more about the event here.

Fire Science Show is sponsored by OFR Consultants.

OFR Consultants is a multi-award-winning independent consultancy dedicated to addressing fire safety challenges. OFR is the UK’s leading fire risk consultancy. Its globally established team has developed a reputation for pre-eminent fire engineering expertise, with colleagues working across the world to help protect people, property, and the planet. 

 Established in the UK in 2016 as a start-up business of two highly experienced fire engineering consultants, the business has grown phenomenally in just six years with offices across the country in seven locations – from Edinburgh to Bath. Colleagues are on a mission to continually explore the challenges that fire creates for clients and society, applying the best research, experience and diligence for effective tailored solutions.

If you wish to learn about the PhD opportunity at the Fire Safety Engineering Group, please follow here. You can also check the LinkedIn post in which prof. Ed Galea explains the proposition here. 

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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.

Three months ago I saw a video of some sort of an electric scooter going off in someone's residential building. That person had absolutely no chance of controlling that fire. I guess they have escaped, but it must have been severe fire damage to their home. Then, I listened to an excellent webinar by IFAB (https://www.youtube.com/watch?v=2vir4_1qSSc) where for the first time I've seen useful measurements of HRR in such a fire... and they are horrifying. A fire in a range of ¬1 MW is in many cases all you need to place your compartment on a trajectory to flashover. A fire that grows that quickly means you have no chance to really react. And these devices are located in people's homes! 

To learn more about those threats, I've invited dr Adam Barowy of UL FSRI. Adam has thorough experience in testing and experimenting with these exact types of fires, and is a priceless source of knowledge on such incidents. I am not able to summarize all the amazing information shared by Adam - you really have to listen to the episode. It is absolutely worth it. But what is also worth your time, is to go through amazing UL FSRI resources:

• Online course - Fire Service Considerations with Lithium-Ion Battery ESS https://fsri.org/resource/fire-service-considerations-lithium-ion-battery-ess
• Examining the Fire Safety Hazards of Lithium-ion Battery Powered e-Mobility Devices in Homes
• The Impact of Batteries on Fire Dynamics

And the most important resource - Safety tips for devices with lithium-ion batteries

Fire Science Show is sponsored by OFR Consultants.

OFR Consultants is a multi-award-winning independent consultancy dedicated to addressing fire safety challenges. OFR is the UK’s leading fire risk consultancy. Its globally established team has developed a reputation for pre-eminent fire engineering expertise, with colleagues working across the world to help protect people, property, and the planet. 

 Established in the UK in 2016 as a start-up business of two highly experienced fire engineering consultants, the business has grown phenomenally in just six years with offices across the country in seven locations – from Edinburgh to Bath. Colleagues are on a mission to continually explore the challenges that fire creates for clients and society, applying the best research, experience and diligence for effective tailored solutions.

If you wish to learn about the PhD opportunity at the Fire Safety Engineering Group, please follow here. You can also check the LinkedIn post in which prof. Ed Galea explains the proposition here. 

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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.

Welcome to Questions & Answers session 02 covering the recent sponsorship opening in the podcast and how the podcast is turning from a hobby project to something more professional, and the summary of the 2022 listener experience survey.

In this session you can find answers to the following questions:

What does it mean to have podcast sponsorships for the podcast, the audience, me and the sponsors? 2:15
Summary of listener experience survey. 15:29
Types of content you would like to see in the show. 30:16
Direct answers to some of your comments. 37:08

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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.

In my first episode, I mentioned that I'm doing this podcast to preserve some amazing conversations and share them with a larger audience, as sometimes it is a huge waste of interesting thoughts that remain just between the few people participating in a talk. This part of the podcast mission is what I'm trying to achieve with today's episode. I had the privilege to be a part of an amazing discussion between fire science giants Steve Gwynne from Movement Strategies and Mike Spearpoint from OFR, who also happen to be amazing amateur philosophers. I throw them some difficult questions on why the industry is driven to do science. How is the industry doing science? Does it differ from the world of academia? What are the metrics the industry would measure the value of research? And they give me simply amazing answers, based on their very long practical experience.

This is a little different episode than the usual fire science, but it shows a lot of 'why' we do fire science. I think understanding how and why we do science is as important as the science itself, and some of the thoughts in the episode such as that the biggest impact is entering the building code with your research or the scrutiny and reputation related to research, are just profound. I think it is critical to understand how the world of science works if we are to trust the research that comes from that world. I'm aware this episode is not for every fire engineer, but I hope that those who find it interesting will find a lot of value within it. Just as I did.

This episode is also historical, as it is the first episode created in partnership with OFR Consultants, who are the diamond sponsor of the podcast for the year 2023. Please allow me to introduce OFR to you. And you can learn more and connect with them at their website. 

OFR Consultants is a multi-award-winning independent consultancy dedicated to addressing fire safety challenges. OFR is the UK’s leading fire risk consultancy. Its globally established team has developed a reputation for pre-eminent fire engineering expertise, with colleagues working across the world to help protect people, property, and the planet. 

 Established in the UK in 2016 as a start-up business of two highly experienced fire engineering consultants, the business has grown phenomenally in just six years with offices across the country in seven locations – from Edinburgh to Bath. Colleagues are on a mission to continually explore the challenges that fire creates for clients and society, applying the best research, experience and diligence for effective tailored solutions.

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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.

Let's start another mini-series! This time 'fire fundamentals' where we are going to learn some basics from the world's best. It is usually fascinating to do that! Not sure how you feel about it but I would kill for a chance to listen to the principles of fire science from Quintiere or Drysdale, even though I give these lectures on my own...

In this first episode, I've invited dr Rory Hadden - an emerging legend of fire from the University of Edinburgh, to discuss some basics of flame and combustion. We have covered the following topics:

• diffusion flame;
• flammability limits;
• role of heat transfer in solid and liquid phase fires;
• ignition sources and ignition energy;
• fire retardants;
• effects of scale in flammability;
• and the ways to measure the fire.

Quite a lot for a first lecture, and it is a little longer than the usual Fire Science Show episode, but I'm sure it is worth it. Let me know what you think about this mini-series and send me ideas for future episodes.

I also promised to link to three masterpieces you need to read as a fire engineer, these are:

• An Introduction to Fire Dynamics, Third Edition by Dougal Drysdale;
• Fundamentals of Fire Phenomena by James Quintiere;
• Enclosure fire dynamics (recently revised!) by Bjorn Karlsson and James Quintiere 

Learn more about the Fire Engineering Science MSc at the University of Edinburgh here.

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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.

Fire science is often accelerated by tragedies. The same goes for the tools we are using and the methods we know. In the early 2000's we already had some great tools, in fact, it was the era where the paradigm of fire modelling shifted from zone models to emerging CFD (listen to episode 81 to learn more about this shift). But these new capabilities soon went through a significant test - a terrorist attack in New York, bringing two iconic skyscrapers to collapse. An overwhelming media turmoil. Can jet fuel melt steel beams? Can fire take down a skyscraper? Why both have collapsed and why in this order? And on top of that, everyone suing everyone.

To appreciate the challenge, let's contemplate the tools of that time (FDS).
You have a giant building to model - what do you do? You cut it into smaller meshes and run on multi CPU's. Easy right? Nope. Not there yet.
Defining parameters of fuel? Pyrolysis model? Nope, not really.
Transferring data out to FEM software? Ha, you wish. Go and program that from scratch.
At least you have it easy with Adiabatic Surface Temperature right? (...)

Yup, it was a very young solver given a very mature task. But they did it. They programmed what was needed to program. They used the cleverest techniques to calibrate models. They have used fire experiments to approximate the fire growth... and in the end, they achieved something they can proudly call a reconstruction of the WTC fire. All in the shadow, not talking to anyone (remember everyone suing everyone part?). I think even today this would be a massive and challenging project. But for the early 2000's it is an engineering masterpiece.

Join me and Kevin McGrattan and listen to the full story.
A summary of the inquiry is available here.
Cover image credit: https://www.nist.gov/image/wtctowerfiretest2003jpg

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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.

Has it ever crossed your mind how would our discipline look like, if we did not have Fire Dynamics Simulator? Maybe you had an opportunity to discuss CFD with colleagues from other disciplines, to find their faces in shock and awe that the fire community actually has its own, FREE AND OPEN SOURCE, validated and fully recognized solver? A testimony to the impact of FDS may be the citation count on its user guide, which has recently exceeded 5.000 citations! The FDS code is something special and our little scientific community can feel proud that a tool of this magnitude was built just for us!

But it did not build itself. There is a history of giants paving the route with their low-Mach number approximation of Navier-Stokes. There is my today's guest - Dr Kevin McGrattan who saw the need and built the first iteration of FDS (and still leads its development 20 years later). And there is a team of brilliant scientists at NIST, VTT and other parts of the world, who shared this dream of a robust, open-access fire simulator, and volunteered their hard work into making this dream a reality.

In this podcast episode, we focus on the very early days of FDS (or even before it came to life). My mission was to learn how FDS was built, what the landscape looked like back then and how it was growing. When particular important sub-models came into existence and what triggered that. We also learn what were the goals for the tool development and how did they evolve over the years as the project got more and more serious.  You may be surprised by some very simple explanations beyond some very tough design decisions!

I hope you enjoy this episode. Please appreciate dr Kevin McGrattan and the hard work done at NIST, VTT and other places, that enabled us to have something really special. Our solver. Fine tuned for fire and open to all.

Learn more about FDS at the project website at NIST or the GitHub repository.

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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.

Today is a great day to celebrate with Prof Ruben van Coile of Ghent University, who is most likely the first representative of Fire Safety Engineering to receive a grant within the European Research Councill Starting Grant scheme.  It is not common to celebrate a grant award this much - usually, we would wait till the work gets done and we see the effects... But not here.  ERC is something else. ERC is a place for the bravest proposals brought by the brightest minds of science. And even that does not guarantee success when you have to pass 9-12 independent reviewers and a multiple-stage recruitment process... But it seems to be worth it. A five-year funding scheme that allows a truly grand design to be pursued.

And this exactly is the case with the framework proposed by prof. van Coile. He is not the first one to recognize we need a new foundation stone for fire safety, but he surely is one of those who give the clearest and most achievable pathway on how to get there.  I highly recommend this episode to all fire safety engineers, not to just learn about the grant Ruben has just obtained, but to view the current state of FSE through the lens of this proposal. As it does, in an excellent way, highlight the shortcomings and failures of modern fire engineering.

Join us in this talk, and if you would like to read more about the grant, here is its official abstract (and near future will bring material for sure!).

Proposal Summary
Adaptive Fire Testing: A new foundation stone for fire safety (AFireTest)

The current fire safety paradigm is based on a set of standardized tests which have been developed as part of a prescriptive design framework, and do not provide in-depth understanding of construction products’ fire performance. The resulting incomplete fire performance characterization hampers the much needed innovation in the built environment. The current fire safety paradigm also places tremendous emphasis on the expertise of controlling bodies (AHJ), making them responsible both for the specification of detailed prescriptive rules, and for the acceptance of performance based designs. This is unsustainable in the face of innovation.

AFireTest strives to induce a paradigm shift in fire safety science and engineering (FSSE). The core of AFireTest is the development of Adaptive Fire Testing whereby optimum fire tests are determined from the infinite number of possible test specifications through the maximum expected net information gain (Value of Information, VoI). This will be developed using modern glazing and load bearing glass as innovative case study, resulting in breakthroughs in fire performance understanding. Secondly, a framework for advanced ‘grey’ surrogate modelling will be developed, combining the pattern identification strengths of machine learning with fundamental FSSE constraints. This will introduce a powerful new tool to FSSE and enable the VoI optimization. A grey modelling approach will also be developed for quasiinstantaneous building specific risk evaluations, allowing a new approach to the AHJ acceptance of fire designs. The future operationalization of the new framework for fire design acceptance will require large follow-up investments. Thus, stakeholder buy-in is crucial. Therefore, AFireTest will develop a methodology for the cost-benefit evaluation of fire safety frameworks. For the first time, fire safety approaches will be evaluated from the perspective of Law and Economics, laying the groundwork for an entirely new field of study.

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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.

When the flaming combustion stops and the raging inferno disappears, the environment is still far away from a stable, stationary state. The heat emitted by the fire and accumulated by the structural elements is still on the move, travelling through the members until it gets eventually dissipated. As parts of the structure get heated, some processes will occur, that may influence their load-bearing capacity and other properties. This is nothing new, we recognize this as an obvious process within the so-called "decay" phase of the fire.

What is new, though, are some recent observations related to the behaviour of timber elements in this phase of the fire. Today's guests Thomas Gernay and Jochen Zehfuss (along with a team that I call EU Fire All-Star Team) have performed a very precise study in which they have shown on one example the exact conditions in which the load-bearing capacity is lost in the decay phase by a column. If you missed that, they made quite an impression on LinkedIn (check the post and discussion here). In their experiments carried out within a well-controlled furnace environment, the variable they played with was the duration of the heating phase. It allowed them to find out two separate behaviours - one in which the column collapses in the decay phase, and one (not very different) in which the collapse does not happen.  To learn more, please join us in the episode, and for sure - read the research paper provided in here.

If you would like a quick insight, I will also steal some text from Thomas's post on LinkedIn, as he did a great job summarizing their research. So here is his short comment:

"Two of the columns were subjected to ISO 834 heating until failure. They failed after 55 and 58 min (-> standard fire resistance).

Two other columns were subjected to 15 min of ISO 834 heating followed by controlled cooling. Flames self-extinguished after 40 min. But the columns still failed during the cooling phase, respectively after 98 and 153 min.

The load on the timber columns was constant throughout the tests. What changes between 15 min (end of heating) and 153 min (failure)? Heat transfer. The temperature of the inner parts of the column section continues increasing. Hence the strength continues decreasing.

Flaming and charring are not necessary for this inner temperature increase. And the absence of flaming is not a good predictor that the column is safe (see video).

By better understanding these phenomena, we can design to account for them - and achieve safe and resilient timber designs, including for burnout resistance when needed. Numerical modelling can support this objective. But simple methods based on charring rate fall short because they don't account for the slow heat transfer processes during the cooling phase."

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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.