Fire Science Show
Fire Science Show
201 - The last fire - a novel set in industrial fire engineering with Joaquim Casal
What happens when a lifetime of studying industrial fire hazards meets the creative mind of a novelist? In this conversation with Professor Joaquim Casal, we explore the unique intersection of fire safety engineering and science fiction through his novel "The Last Fire."
Professor Casal, a retired academic from Universitat Politécnica Catalunya and founder of their fire research group, has crafted something unique – a novel where the protagonists are fire researchers and the plot revolves around fire phenomena, fire research and fire testing.
Beyond the novel on its own, our discussion also takes us deep into the world of industrial fire hazards, exploring phenomena that many building-focused fire engineers rarely encounter. From the extreme temperatures of jet fires that can trigger catastrophic "domino effects" in industrial facilities to the deadly "boil-over" phenomenon that has claimed numerous firefighters' lives. We examine the behaviours of jet-fires, pool fires, flash fires, and the spectacular but devastating fireballs created by BLEVEs (Boiling Liquid Expanding Vapor Explosions).
And finally, I think the greatest imminent value of this novel is in the communication - it is a brilliant example of how you can communicate difficult technical concepts of fire to lay people. I believe many fire engineers could be inspired by this example.
If you would like to read the novel, it is available at Amazon:
https://www.amazon.co.uk/Last-Fire-Joaquim-Casal-ebook/dp/B0F4QYLYSV
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Hello and welcome to the Fire Science Show, episode 201. Let's start the third hundredth of the episodes with a good one. So I'm actually going to violate my promise to you. I've promised you that I'm going to deliver the prime fire science and engineering. But today actually I'm going to bring a little bit of science fiction into the podcast, because my attention was brought into a science fiction book, a novel, into the podcast.
Wojciech Wegrzynski:Because my attention was brought into a science fiction book, a novel written by Professor Joaquim Casal, and the novel is called the Last Fire, and it's actually a novel book but settled up in a fire safety engineering world kind of. And I had to call Joaquim and interview him about his story as a fire researcher, as a professor. So he's a professor at Universitat Politécnica Catalunya, he's Catalan and he's one of the founders of the fire group at UPC. In his free time his passion is writing novels and he just combined those two passions together and wrote a novel book in which the characters are fire researchers, in which the setting of the novel largely is related to fire safety engineering, world, fire research. And it was very interesting for me to discover this novel and read through it. So in this podcast episode we will talk about the novel, but actually not that much. We spent a lot of time in the interview talking about his background in industrial fires because he has an interesting view on fire. He's seen a lot of fires. He specializes in high-risk events in industrial facilities, so in this episode I guess we have never talked really about industrial fire hazards in the podcast yet, so having him in the podcast was a great chance to cover those. So in this podcast, a lot of fire science about industrial fires and also enjoyable novel in the background. I hope you will enjoy this twist of the fire science show. So let's spin the intro and jump into the episode. Welcome to the Firesize Show. My name is Wojciech Wigrzyński and I will be your host.
Wojciech Wegrzynski:The FireSense Show is into its third year of continued support from its sponsor, ofar Consultants, who are an independent, multi-award-winning fire engineering consultancy with a reputation for delivering innovative, safety-driven solutions. As the UK-leading independent fire risk consultancy, ofar's globally established team have developed a reputation for preeminent fire engineering expertise, with colleagues working across the world to help protect people, property and the plant. Established in the UK in 2016 as a startup business by two highly experienced fire engineering consultants, the business continues to grow at a phenomenal rate, with offices across the country in eight locations, from Edinburgh to Bath, and plans for future expansions. If you're keen to find out more or join OFR Consultants during this exciting period of growth, visit their website at ofrconsultantscom. And now back to the episode.
Wojciech Wegrzynski:Hello, everybody, I'm joined today by joachim kazal. Hello, joachim, nice, nice to see you. Hello, boy, chef. And joachim is an author of a novel, a fiction book, science fiction book, we could even say that is set in the realm of fire safety engineering. First time I've read a book in the universe of fire safety engineering, to be honest, and I felt very happy reading it because it's so well captured my life, in a way, as a fire safety engineer, fire safety scientist. Jacquem, first question I have to ask you so it's not your first novel. Uh, I assume this is, this must be some hobby of yours, but tell me the story. Like, how did you come up with a book that is so strongly connected with fire safety engineering?
Joaquim Casal:Well, look, I arrived at this point because essentially two facts. The first one is that I like writing and, yes, I have probably something about fiction and science fiction before.
Joaquim Casal:And the second reason is the fact that I have been, during the last, approximately large fires, full fires of different diameters, up to six meters in diameter of diesel oil and petrol jet fires, and so on, and so at a certain moment, I started to think about the possibility of writing something about fire, because I have seen that fire is a complex phenomenon. In fire, you can see, sometimes, strange things, strange things that have really a scientific explanation, but also could be seen and interpreted in a way of fiction or science fiction, and this is essentially why, finally, I decided to write this novel.
Wojciech Wegrzynski:As a fire engineer, I often come to an observation that fires are very non-intuitive. It's very difficult to have this intuitive understanding of the nature of fires. You think you understand them all and then you see a fire you have never seen and it completely escapes your imagination. Uh, is this also something you've observed in your career?
Joaquim Casal:yes, yes, well, because, uh, look, most people know some types of fire, which is, I don't know, the fire in in the kitchen that we use every day, and the fire may be a wood fire. But there are many more different types of fire which show a different behavior. For example, there are jet fires, when there is a fluid, a combustible fluid, which leaves from, for example, from the hole of a pressurized pipe or a tunnel. This fluid leaves at a very high velocity, often the sonic velocity, and then, if it gets ignited, we have a jet fire, which can be small, which can be large it depends and which has a certain behavior. Of course, the fire and the flames and the behavior can be different. If, instead of a jet fire, we have a pool fire, for example, we have a release of a liquid which is flammable, disavoid petrol maybe, and that is a pool and there is an ignition point, you have a pool fire.
Joaquim Casal:Okay, I work with pool fires and with the fires, and what have been these types of fire is very interesting because they show different behaviors. You can have as well another type of fire, which is the flash fire. Then we need a flammable cloud, so we have a gas or a vapor which is flammable, for example from petrol, and it is mixed with air and then at a certain moment the concentration is between the flammable limits. So that is an ignition point. We have a flash fire which lasts barely one second, maybe two seconds, and which is complete as different essentially from the pull fire, from the jet fires. Hardware is an interesting world with many possibilities.
Wojciech Wegrzynski:Okay, I will tell you a story of my biggest professional failure perhaps, where I really learned how surprising and non-intuitive fires can be. So we were doing this demonstration for Polish firefighters in a car park about smoke control system and we were using those small trays of 0.5 by 0.5 meters, so a quarter of a square meter, and we were filling them with propanol and we used four of them and like one meter above them we just built a small ceiling with gypsum plasterboard, just to, you know, imitate the plumes going on the sides of the car, so just to break the dynamics, you know, and on the sides of the car, so just to break the plume dynamics. And on the day before the demonstration the car park was sprinklered. So we've protected the immediately nearest sprinklers and we've protected one row of sprinklers around our fire, like further away. We've run the test. It acted like always, so we had it under control. We were very happy with the test. It acted like always, so we had it under control. We were very happy with the demonstration.
Wojciech Wegrzynski:Next day we did the demonstration live for the state fire brigade in Poland, including the chief commander of the Polish fire brigade. But we came to an idea. You know what? Perhaps let's just add one more tray, fifth tray, to the setup. Each tray was 150, 200 kilowatts of fire. Not very much, so we thought, ok, we will. Was 150, 200 kilowatts of fire, not very much, so we thought, okay, we will go from 800 kilowatts to a megawatt.
Wojciech Wegrzynski:That's not a big difference we put that fifth tray and when we started the fire it was completely different. Suddenly the radiation from the fire underneath this little ceiling created such a strong boiling effect on the propanol trays. It was not a plus 200 kilowatts, it was double the fire size we had previously. And what happened is the sprinklers in the third row which we have not protected. They went off directly over the head of the commander chief of polish fire brigade.
Wojciech Wegrzynski:I was absolutely sure my career is done at that moment and actually the firefighters were very happy because the first time they've seen you know how sprinklers operate in the car park in real fire. So they were very pleased with the demonstration. But I have really underestimated. How big is the difference between small and larger? They do not increase gradually in size. It was a completely different phenomenon.
Joaquim Casal:Yes, because when you have cool fires, after a certain time, at a certain moment, the liquid starts to boil and this implies that the aspect and the size and the turbo length of the flame changes completely.
Wojciech Wegrzynski:It's completely different.
Wojciech Wegrzynski:Yes, completely, it is another type of fire I'm bringing this up because, uh, this is the type of stories that you also, uh, share in the book, and this is the way how you describe fires. I'm uh giving you this uh description. I'm inspired by, by your work. I think it's beautiful to talk about fire in those simple manners. Perhaps let's let's tell a little bit more about the book. Maybe you, as an author, would like to introduce the book to the reader. So if you could just say generally what it is about and what you would like the reader to find in it, and then perhaps I'll complement that with my healing.
Joaquim Casal:Yes, well, not the book. The book has essentially two parts. I will not explain much about the book.
Wojciech Wegrzynski:Yes, let's not spoil it. No.
Joaquim Casal:The first part occurs in Barcelona and it deals with the research on fire okay, research on certain types of fire. Then some strange things start to happen and due to these strange things and to the people involved, then there is a second part of the book which happens very fast from Barcelona, which happens in Iran. Okay, In. Iran in Barcelona. Which happens in Iran, in Iran. I have been several times in Iran as a visiting professor at the university there.
Joaquim Casal:Iran is a very beautiful country with, I must say, a very beautiful and kind and hospitable people, and in Iran there is a minoritarian religion which is also in India. There is a minoritary religion which is also in India, in which it is called the Zoroastrianism, in which fire plays an important role. Okay, fire is related to God and in this religion there are the temples of fire, which are temples in which there is a fire which is never extinguished, which is always burning. And well, the second part of the book occurs in a completely different situation and country and strange things happen related with fire, and I'm sorry, but I cannot tell you anymore. Okay, if you want to know these things, sorry, you should read the book.
Wojciech Wegrzynski:Yes, so I'll compliment that, explaining a little bit of the setting, because the setting is so fascinating to me. So when you talk about the part in Barcelonacelona, it actually happens, uh, in a fire laboratory.
Wojciech Wegrzynski:The main characters of the book are fire researchers working in the fire laboratories yes, I find that very interesting, and the plot uh in, in a way a criminal plot or just the interesting plot of the book revolves around a technical problem they are trying to solve using different types of fire research and then, as you mentioned, the plot changes to Iran, also introducing the reader to some interesting concepts coming from Zoroastrianism about how cultures celebrate fire, about how cultures celebrate fire, how people feel fire is not just a chemical or physical phenomenon, but also a mystical thing, also bringing this element of mysticism or science fiction perhaps even to the book. I like how you in the introduction, said that there are many aspects of fire that we can explain with physics, but yet they look mystical or they look mysterious to some others. So I think this interplay was something you could take in a very interesting direction in the book. Also, now that you mentioned about the temple that has a flame burning for centuries actually I've been in such a temple.
Wojciech Wegrzynski:In Japan. There is an island, miyajima. It's near Hiroshima, a very beautiful place. I highly highly recommend anyone who ever visits Japan to go to Hiroshima and then go to Miyajima, and on that island there is a mountain called Mount Misen, and on Mount Misen there is a temple in which there is a cauldron. Underneath it there's a fire and that fire is maintained for 1,000 years. It's ongoing burning and I think the flame that is burning in the Peace Memorial Museum in Hiroshima there's a big flame in the middle of Peace Park in Hiroshima that was set up from that fire in Montmissen. So it's very interesting that the culture, you know, just, you know the fire is not the 1,000 years old because of the mass transfer phenomenon and everything. But it's very intriguing that the culture can do that.
Joaquim Casal:Fire has been always very interesting and useful, and also dangerous, maybe for people, for humanity, and probably this is why in Zoroastrianism, fire plays a quite important role. Look, sorvastrizo was created by Sorvasta about 3,000 years ago or 3,500 years ago. It is the oldest monotheistic religion and it is few years old because in it fire plays an important role.
Wojciech Wegrzynski:Exactly exactly. I've described to you my experience with fires also for another reason. Uh, in the book you do a lot of things very cleverly and, uh, I see them as a fire safety engineer. Usually if I read a book and there's an element of fire, it's good, good, good. And then something happens in a, in a, in a way that is completely unphysical for me as a fire scientist, and I'm disappointed. In your book, everything was spot on. And on top of everything being spot on, I also captured those little tiny details that made me a lot of joy. One of those details is your description.
Wojciech Wegrzynski:So the characters perform different fire tests. They use pool fire as the method of them to study the thing they want to study. They can do some pool fires in a warehouse in Barcelona, near the airport, small pool fires. Then they have to go to a different place to make a larger pool fire and then they move into a different place, a different location, far away from Barcelona, to make those very large pool fires.
Wojciech Wegrzynski:And there is also a person observing those fires, those very large fires, and that person is able to come close to the fire, look into the fire. They're not how to say it scared of the fire and the other characters in the book say oh, this is very odd, that a person who never seen fire acts like that in the front of a fire. It's a very interesting observation that must come from your life. So what made you do this spin? And how do you observe people in the laboratory professionals behaving in front of the fire? Is it really something you could observe in your lab that, oh, this person must know fire because they don't act normally in front of it?
Joaquim Casal:Yes, yes, this can be seen and I saw it and I observed it, not much in the laboratory, because in the laboratory we worked with relatively small fires, of course, but when we had large fires in the open in the country. If you are not used to see this type of fire, you get an impression, you know yes, use it to see this type of fire, you get an impression, you know yes. So people and I have seen, really, that people who don't know this and who are using it to see and to be near these large fires the first time they see them, they are affected and you observe that they are not quite, they don't feel to be much safe close to these large fires and these turboling flames you know I see that in the laboratory even myself you have to get familiar with the fire.
Wojciech Wegrzynski:We often joke that when we run a set of experiments we grow in our courage. So the first fire, oh my God, this is a huge fire. We need to take it down. After a few times we get used to this fire and perhaps we can let it go for a little longer, for a little larger, and eventually, at the end of the experimental series, we are very comfortable running an experiment.
Joaquim Casal:Yes, but you must be aware that the tire can be dangerous.
Wojciech Wegrzynski:Of course, this is not a recommendation for people to do fire experiments in their homes or garages. We're talking about fire laboratories that make a living out of testing things with fire. So the book is set in the fire safety engineering universe, as I said, but it's very strongly connected to industrial fire safety because that is where your background lies and my audience. Many of the fire safety engineers in this podcast are used to more compartment fire physics. You know compartments, car parks, tunnels. This is the stuff that is mostly discussed in the fire science show.
Wojciech Wegrzynski:So, even though we are discussing your novel, I would still like to talk with you about your knowledge and experience with industrial fires, because this is also highly important to the book. You mentioned the different types of fires jet fires, pool fires. There's also boiling liquid explosions, gas explosions, flash fires different types of fires that are very relevant to industrial setting. Perhaps let's spend a few minutes and discuss those fires one by one. So first, maybe, jet fires. If you could characterize a jet fire as a fire and also as an industrial hazard, what exactly is so hazardous or so dangerous about a jet fire?
Joaquim Casal:Yes, jet fires are hazardous. Jet fires are often relatively small. Okay, there can be large jet fires.
Wojciech Wegrzynski:Can you define small and large in your mind? A?
Joaquim Casal:small fire would be between one and four meters, for example. Okay. However, there have been jet fires of about 30 meters length. Okay, that's huge left. The problem with jet fires is that the jet, which is originated from a hole or from a flange, lives at a very high velocity, very turbulent, and this turbulence implies a very good mixing with air, and so this implies good combustion. Okay, when we have a jet fire, you can see that the combustion is good because there is not much black smoke, not at all well, and what does imply this good combustion?
Joaquim Casal:this good combustion implies very high temperature. So the problem with the jet fire, even if it is relatively small, is that if it impinges on a surface, on the surface of a tank or the surface of a pipe, in a very short time the temperature of this wall will increase, of this metallic usually metallic wall will increase, and if inside this tank or this pipe there is a certain pressure, it can fail. So we can have here the so-called domino effect. It means that the first small accident, a jet fire, will imply a larger accident, which is the release, a massive release, from the towel which has failed or the pie which has failed. So this is the problem essentially with jet fires. Even if they are smaller often than other types of fires, they can be very dangerous.
Wojciech Wegrzynski:I have three follow-up questions. One the hazard comes only from the impingement of the flame or also just the radiation from the jet fire?
Joaquim Casal:If the jet fire is relatively small, as often happens, the problem is essentially associated to the impingement. If that is not impingement, okay, in certain circumstances there could be a problem, but usually not.
Wojciech Wegrzynski:And the second question earlier in the interview you said that the velocity can be supersonic.
Joaquim Casal:No, not supersonic. In order to have supersonic you would need a special design of the exiting hole. No, no, sonic velocity can be reached relatively quickly if the pressure inside the pipe or inside the town is approximately twice the pressure outside. That would mean, if the pressure outside is one atmosphere, if you have inside the pressure of two atmospheres, you will have sonic velocity.
Wojciech Wegrzynski:The reason why I ask this question is of practical reasons, because I know many researchers try to study those and I know many researchers try to study those and I know many researchers try to model those jet fires, for example with FDS software, and it has limits of velocities that it can handle. So it must be very interesting to study those. But let's keep this away. My third question is how do you extinguish those fires actually?
Joaquim Casal:In our textbook, the extinguish a jet fire. The only solution is to close one veil, to close something, and if you do it like this, for example, if there's a problem, the jet fire is released from a pipe. If you close a veil or a safety veil, it will automatically close it. The fire will be extinguished in a very short time.
Wojciech Wegrzynski:Okay, let's move to pool fires. Pool fires are essential to the plot of the book because this is the method used by the scientists in your novel. So tell me about your experience with pool fire experiments.
Joaquim Casal:I worked a week with my team, we worked with pool fires of diesel oil or petrol, which are much more dangerous. Pool fires with diameter varied from half a meter up to six meters in diameter. So when we worked with the larger fires, five, four, five to six meters in diameter. So when we worked with the larger fires, five, four, five, six meters in diameter as we worked with diesel oil, no problem, because diesel oil is not easy to ignite, but we needed to put some petrol, a little bit of petrol, to start the fire. However, when we worked with petrol, it was dangerous. It was a dangerous situation because we needed some time to fill in a pool of five metres or six metres in diameter and during this time, as in petrol, there are very volatile substances. In petrol there are very volatile substances, components.
Joaquim Casal:Immediately, you are having a flammable cloud above the pool, you know. So you must be aware that when you will ignite it, you will have a flash fire originated by the combustion of this coal. So well, you have to take. The person who ignites must be very well protected, dressed as a firefighter. And, okay, you have to take the person who ignites must be very well protected, dressed as a firefighter. Okay, all the team when we work with these flash fires. All the team were dressed as firefighters. Okay, completely protected.
Wojciech Wegrzynski:We'll come back to flash fires to subject that material. For me that was, for example, an odd thing about the book, because I'm a fire researcher and I have my furnaces. So I would just put the material in an industrial furnace for fire resistance testing. That's the way we do it. Material in an industrial furnace for fire resistance testing, that's the way we do it. But now, knowing your background and your professional career, I completely understand why pull fires are of the choice, and of course it gives us a possibility to nicely explain the fire instead of just oh yes, we looked at the wall of the furnace for two hours, which is perhaps not as exciting, for two hours, which is perhaps not as exciting.
Joaquim Casal:Well, in fact, if you want to analyze the effects of a pool fire on a certain material, a certain isolating or protecting material, it's not necessary at all to work with fires, large fires, large pool fires of six meters in diameter. On the contrary, it's much, much practical to work with much smaller pull fires half a meter, one meter in diameter. It's not necessary to go to larger diameters. It would be more complicated, more expensive, and so on.
Wojciech Wegrzynski:In the book it's explained that they really wanted to put the material to the furthest because previously a company has suffered a loss because of the material they used. So the plot explains the reason to go that far. In the industrial setting the mine hazards from pool fires is it fire spilling over different facilities? I think they have the catch spaces where they catch the liquid, so I don't think spillage should be a big issue in a well-designed facility. I assume radiation in this scenario would be a big issue of the very large fire.
Joaquim Casal:Yes, okay, if you have a kind of pull fire, yes, certainly, the radiation can be strong and if the pull fire lasts a relatively long time, the radiation can originate a domino effect. However, of course, if there is direct contact of the flames of this pull fire on another equipment, then the disaster or the domino effect can arrive, can happen in a much shorter time, certainly.
Wojciech Wegrzynski:The pull fire may also occur inside a tank, even if the tank is undamaged, for example, if there was a floating roof and the Well yeah of course, yes, you can have.
Joaquim Casal:If you have a problem with the tank, for example a floating roof tank in which there is an explosion and the tank loses the roof then inside the tank, if you have certainly a combustible liquid, you can have a kind of fire, a town fire. A town fire is more or less like a pool fire which takes place at a certain height, maybe four metres of the soil, or more 10 metres, it depends of the soil, or more 10 meters, it depends. Yes, it is that a tank fire has originated flames and radiation, more or less similar, more or less to a pool fire.
Wojciech Wegrzynski:One thing that we were learning in Poland about those types of fires, and I'll tell you in a second why it's important for Polish people that if you have a layer of water on the bottom of the tank and the fire is occurring on a liquid that's lighter than water, the heat can move through the liquid, reach the water and immediately evaporate it.
Joaquim Casal:You have the so-called boil over, and this phenomenon, this boil over, has killed many firefighters, because this takes place. Let's suppose that we have a fire in a town, a town fire, which has a town which has most its roof. Okay, firefighters arrive and try to extinguish the fire, and maybe this can take a relatively long time. So firefighters are there, nothing happens. They have a fire which is at a stabilised regime, I would say so. Firefighters are trying to extinguish it. Nothing, not a problem, not a dangerous situation, apparently.
Joaquim Casal:However, as you said, after a certain time, when the temperature has increased through the whole head of the flammable liquid, of the oil, diesel, oil or petrol, and it reaches the water, the water can boil. This boiling of the water will throw turbulent. Small particles of the petrol or of the combustible fuel are feeding the flames and this is called boil over. Boil over means that in a moment they will have a kind of mixture between flames of the pool fire and flames of the flash fire. Flames of a flash fire and some burning liquid will be thrown up to relatively large distances in which there will be firefighters, and this has killed more firefighters. Now, firefighters know very well that this can happen and and they take cautions and, and they know so, the situation has improved.
Wojciech Wegrzynski:But years ago, many years ago, many, many firefighters were killed because of point lower phenomena an incident like this happened in poland in 1970s in cehovica jiu-jitsu, a very big uh industrial facility, and and many people have died in that incident and it is by some of older colleagues. It is claimed that this is one of the triggers for professionalization of fire safety engineering in Poland this type of a boil-over fire in that oil facility.
Joaquim Casal:Yes.
Wojciech Wegrzynski:Definitely an extreme extreme thing. Another extreme phenomenon related to liquid fires are boiling liquid, evaporating vapor explosions we call them blebe.
Joaquim Casal:Well, look blebe in fact is an explosion. It's not a fire. Blebe is an explosion.
Joaquim Casal:For example, there are relatively frequent blevies in playing water and steam from the water. Okay, because steam is used in many, many industries, because we need pressure steam to heat, and so on. This type of equipment which produces this pressurized steam is not especially dangerous. But as there are a large number of these equipments, some explosions keep occurring.
Joaquim Casal:Okay, well, and these explosions? Not with a tank containing water, but with a tank containing a fuel, for example petrol or for example diesel oil, which has been submitted to a strong heating by flames, by the contact of flames, and it explodes. Then we have first an explosion, a blabbing, and immediately this is followed by a firewall. A firewall is the fact that when the tank explodes, because of this more monolithic, expanding vapor explosion, the liquid, the combustible liquid, is thrown up mixed with air, small droplets vaporize it and the same explosion originates the emission. So it's not exactly a flash fire because it can last more. We have here a fireball, a ball of fire which lasts several seconds, maybe 20 seconds, it depends, and this is a dangerous, a very dangerous phenomenon as well.
Wojciech Wegrzynski:This brings me. I forgot to put one thing that is very particular about those fires in industrial setting. In my residential commercial applications my fires would usually last an hour, two hours I design my compartmentation for two-hour rating, for example Whereas in industrial setting those jet fires or giant pool fires can last days. I know fires that lasted multiple, multiple days, if not weeks. So also the timescale of this hazard is absolutely different than we often deal with.
Joaquim Casal:Yes, this can happen also with tunnels containing propane, for example.
Wojciech Wegrzynski:You know, fire propane under pressure it was brought many times, the flash fire, and whereas the blets and these boil-overs are just something that is fascinating to me and I really wanted to ask you, as an industrial fire expert, about them, they are not highly relevant to the plot of the book. The flash fire is very relevant to the plot of the book. So if you can tell me a little bit about the flash fire phenomenon and what's your professional experience with those types of fires, Well, I must say that I have worked experimentally with fires, with jet fires, but not with flash fires.
Joaquim Casal:I attended once only attended once an experimental work with flash fires. The problem with flash fires is that a flash lasts a second, maybe, or two seconds, so it's not easy to do it. It depends, for example, if you have some wind, it gets complicated to get a cloud, a flammable cloud of a certain shape, because you need to know this if you want to try to check a model, a mathematical model, things like that. So I never worked at Perseroy and in my team we never had experimental work on flash fires. Once I attended, many years ago, experimental work with flash fires. I was one morning. They tried to do several and one was relatively useful for them. And of course, then when you have a flash fire, you have to film it, registrate it and things.
Joaquim Casal:But it's a more difficult experimental work, much more, in my opinion, much more difficult than working on pull fires or or project fires etc what are the the hazards to people?
Wojciech Wegrzynski:uh, from flash fires. In the book you put this distinction usually it is.
Joaquim Casal:it is accepted that people which are inside the flash fire are killed and people who are outside nothing happens. This is usually because, as it lasts, people outside receive, yes, no contact with the flames, but some radiation, but it is very short time. So, okay, maybe, yeah, there can be some people more or less wounded, but not much important. So it is usually assumed that nothing happens.
Wojciech Wegrzynski:This is related to the length of the fire right. So if you have a blever type fireball which lasts several seconds, it's different.
Joaquim Casal:This is different because from a fireball the radiation is very strong and it can last a certain time, so it is different. Then you must calculate which is the radiation to predict what would happen in a certain case, and in this case you must calculate which is the radiation to predict what would happen in a certain case, and in this case you must calculate which will be the radiation function of the distance from the contour of the fire. There are mathematical models to do this?
Wojciech Wegrzynski:Fantastic. And this flash fire phenomenon? You also mentioned that when you start the pool fire with the gasoline, the vapor that is above the gasoline would create. That Is the flash fire, also connected with some sort of pressure wave, pressure event, or this is not a?
Joaquim Casal:signal no, no, A flash fire it should not. Well, yes, if it is a large flash fire, in certain conditions it can be a kind of explosion. Yes really what is?
Wojciech Wegrzynski:not a deflagration type of explosion. It depends.
Joaquim Casal:In certain cases. Yeah, you can have deflagration and even you can have a blast wave. Okay, Explosion Physical, not physical effects yes, Very interesting.
Wojciech Wegrzynski:I bring this up because this is actually the flash fires are relevant to the plot of the book. We're narrowing the end of the time, but I really want to talk some things about the book that are not immediately coming from the book but my thoughts about after reading this. So one thing that I really like about the book is that you describe fire phenomena, fire testing, the whole concept of thinking about fire protection and providing fire protection to the society in a very easy way. So I really believe that if I gave this book, for example, to my wife, who's not a fire engineer, she would enjoy it and she would understand what do you mean describing those fairly complex physical phenomena?
Joaquim Casal:well, I have wrote this book, uh, thinking not in people who specialize on fire or engineering. No, no, no, I wrote it thinking on usual people. I think that it is not to read, and maybe even to enjoy the book, it's not necessary to have an important knowledge of fire. No, not at all Either, or is it at all?
Wojciech Wegrzynski:No, exactly, it's like you say, and I think this is a very huge strength of the work that you have created, because it gives us an example of how to communicate fire to those who are not familiarized with it. It's a skill that a lot of fire engineers does not have. It's something that is very difficult actually to discuss this fire phenomena with people who are not fire experts, and yet every day you have to do it. You have to explain the fire to architects, you have to explain it to your local government, you have to explain it to the insurer, you have to explain it to the owner of the building, to the user of the building, whoever that may be. This is our job, our everyday job as fire safety engineers, and I'm very strong on highlighting the need for good communication about it, and I think your book gives excellent examples of how that communication can work.
Wojciech Wegrzynski:Thank you, I try it, but thank you very much for encouraging me like this Thank you Actually one thing that came to my attention in the book and again now as I talk with you in person. I understand where it comes from, but when you describe the fires, you use a very specific type of adjectives describing fires. When I would try to describe a fire, I would call it it was extremely hot, or it was very bright, or I could feel immense heat on my skin. But you use a different word. You very often say the fire was very turbulent and loud, and this caught my attention because, oh yeah, you could. Perhaps my files are not loud, so that was perhaps surprising to me. But turbulence, there is something about that. Where did it come from?
Joaquim Casal:Well, I must say, okay, I did translate the book to English. It was a lady who was this professional, because this is not at all good enough to read and well, she translated the words I had written in Catalan. Okay, the book is published in Catalan and in English. And, yes, turbulent and I don't know. I use the words I consider logical to use when talking about this type of fire.
Wojciech Wegrzynski:So by the turbulent you mean this rapidly changing mixing phenomenon. There's a lot of happening in the flame, right, If you look into a laminar flame of a candle. It has a shape, it's stable, nothing happens, it's not at all turbulent.
Joaquim Casal:Yeah, you're right. You're right, Not at all turbulent. Yeah, you're right, but an accidental fire usually implies turbulence in the flames.
Wojciech Wegrzynski:Especially when you have this fireball. You can see one giant vortex of the fireball and you look closer and they are smaller, like a fractal structure. Yes, fireballs and flash fires are very, very mesmerizing to an extent and I will also tell you the most improbable thing that happened in your book for me, Most unrealistic thing. So the researchers come up with the research plan after a few hours. One week later they are ready to start the tests, the samples are delivered, Everything happens on time. It doesn't work like that in fire laboratories.
Joaquim Casal:Well, it is a book. Okay, it's a fiction. A fiction book. Attention, a fiction book.
Wojciech Wegrzynski:It's clear. This brought me a lot of joy. It's a high yeah, if we only work like those, like those are, and they only had one project. That was also interesting.
Wojciech Wegrzynski:They only work on this one project and they they had full attention to that. It was very, very interesting to me as a fire researcher. I would I would love to uh live in the world when I can uh work like that. Uh, and I will. Joachim, thank you very much for this fantastic conversation about industrial fires and the world of novel that you've created for everyone and I am certain that fire engineers will enjoy. Perhaps one last question any more fire engineering related books in your mind? I mean today, as we talked, the pool fires, the domino effect, the blivers. There is so much more you could write on loud and turbulent flames, I think.
Joaquim Casal:I haven't. In fact, from the moment in which I finished this one, the Last Fire, I have been very busy. I want to write something more in the field of fiction, but I don't have a still defined new project. If one day I publish something, you will be informed, thank you.
Wojciech Wegrzynski:Thank you very much, and maybe one day we'll also see a Netflix adaptation of the book. If they need a fire laboratory to record the massive pool fires, I volunteer to run the pool fire experiments.
Joaquim Casal:All right.
Wojciech Wegrzynski:Joachim, thank you very much for coming to the Fire Science Show and crossing fingers for your future novel books and future research items. All the best, thank you.
Joaquim Casal:Thank you very much, Wojciech.
Wojciech Wegrzynski:It's been a pleasure and that's it. I hope you've enjoyed this interview with Joachim Casal. I've never expected to be reviewing or talking about a fiction novel in this podcast, but here we are and I think it was still quite interesting to the audience. We've still talked quite lengthy about the physical phenomenon, so my consciousness is clear We've done a good job, covering both physics and the novel itself. What else to say about this episode?
Wojciech Wegrzynski:I guess if you got interested and you would like to see how the novel looks like and you would like to read a story that is nested in the fire safety engineering world or fire safety engineering universe, well then, look for the Last Fire. It's available on Amazon. You can download it for Kindle, so it's very easy and accessible and it's a good few hours of of reading and, uh, I've enjoyed it. I've liked it, especially the fact that for the first time in my life reading a fiction novel, the main characters had so much in common in their normal lives as I do. It's really for the first time I felt to some extent so connected with with the people in the book. Um, that would be it for today's Fire Science Show episode. Next week, a little less fiction, pure science heading your way. So let's see each other on next Wednesday. Thank you for being here with me. Cheers, bye, thank you.