264 - Engineering Firebrand Showers with Samuel L. Manzello

Why WUI Needs Standards

Wojciech Wegrzynski 0:00

Hello, everybody. Welcome to the Fire Science Show. Last week, we've discussed modeling in the WUI, which is the wildland-urban interface, quite an interesting problem, and I think that set up the ground of what the difference between W-WUI areas and wildfires in general is. And this week, we go back to WUI, but this time in a more experimental manner, and, uh, we will also talk about standardization of, uh, the exposures related to, to WUI fires. To do that, I've invited Samuel Manzello from the Tohoku University and Reax Engineering, and Samuel is well known to, to be one of the pioneers of, uh, fires in the wildland-urban interface. He has developed a critical piece of technology which we now know as the Dragon, which is a firebrand generator. And that's something that we largely talk in this podcast episode, the history of the Dragon, what it does, how, how it's controlled, and, how did it turn into a standard. But on top of that, we also discuss the standardization work done at the ISO, at TC 92, which is also, I think, highly relevant and very important as these things turn from the scientific endeavors into practical applications. And we also discuss what firebrands are, because that's, that's an important part of, of, um, being able to generate them. You have to understand what they are, how they work, And this also covers the years and years of research that Samuel did on them. So quite packed with practical information. I hope you'll enjoy that. Let's spin the intro and jump into the episode. The Fire Science Show podcast is brought to you in collaboration with OFR Consultants, a multi-award-winning independent consultancy dedicated to addressing fire safety challenges. OFR is the UK's leading fire risk consultancy that this year celebrates its 10th anniversary. As experts in fire engineering, they are fully committed to delivering preeminent expertise to protect people, property, and the environment. With over 30 chartered engineers and a team of fire researchers at their core, they continually explore the challenges that fire creates for their clients and society so that the best research, experience, and diligence can be applied for effective tailored solutions. In 2026, OFR will grow its team once again and is keen to hear from industry professionals who want to collaborate on fire safety features this year. Get in touch at ofrconsultants.com. And now back to the episode Hello, everybody. Welcome to the Fire Science Show. I am joined today by Samuel Manzello from Tohoku University and Reax Engineering. Hey, Sam

Samuel L. Manzello 3:06

Hey, Wojtek. Great to be here

Wojciech Wegrzynski 3:08

thanks for taking the invitation, and the subject of today's, uh, talk will be the, harmonization efforts in the world of wildland-urban interface. I know you're super involved in the ISO. Uh, you've been developing interesting technologies, and you've been dealing with this problem for, like, very long time. Perhaps one of the first people I know that, that, uh, worked in this space in the world of fire safety. so maybe let's start with some kind of big picture. I think wildland-urban interface is a recognized hazard today and something that's on the mind of all of the people. Could you just maybe summarize the pathway, how we got from recognizing the problem to need of standardizing, technical systems in response, and what happened in between?

Samuel L. Manzello 3:57

Yeah, I mean, I I'm someone who's worked on, on wildfires for a long time and,

Wojciech Wegrzynski 4:01

Oh, yeah

Samuel L. Manzello 4:02

early era, I mean, it was, uh... I can tell you frankly, nobody was interested in this topic. And so, you know, I, after I was, you know, I was graduating with my PhD at the time, and, uh, my PhD was in microgravity combustion, so it's obviously away from WUI fires. you know, I had the opportunity to, to... NIST at the time had a great fellowship, the National Research Council Postdoctoral Fellowship, which is administered, at NIST, and it's a competitive fellowship, but if you, if you win, you could come to NIST and, you can basically, you know, do research for two years of your own interest, basically. So it was a really great opportunity, because the money for the fellowship comes from the National Academy of Sciences and Engineering. you know, I got interested in basically just fire science in general and, having someone who had worked in, like, microgravity combustion, clearly it was an important topic, but, I was interested in doing something closer to the Earth, right? s- you know, I got interested in, you know, WUI fires mainly from looking at the news and, and this was in the early 2000s. Like, you know, there was a lot of news stories about there were fires in California and other places. you know, I was wondering, you know, what kind of research or what kind of activities were going on, on, on, in that space. And so, you know, it started getting interested in that, and then, you know, as you started to dig sort of deeper into it, I found out that, all the news reports kept talking about firebrands embers

What Firebrands Are And Why They Matter

Samuel L. Manzello 5:11

are this really main issue. But then when you start scratching the surface, you see that, surprisingly, there was little scientific quantification of that, of that problem, especially with respect to WUI fires. And, you know, when you look at all these, news reports and things like that and everything is destroyed, it's, it's very, it's hard to take, you know? So I wanted to see, like, you know, I had all this education in combustion science and how could I apply that

Wojciech Wegrzynski 5:31

Hmm.

Samuel L. Manzello 5:31

some- which is much more practical, such as WUI fires

Wojciech Wegrzynski 5:34

And, those early days, uh, g- given this chance to, study that, I guess at that point that's, that's an unstudied phenomenon, the firebrand. Let's, let's perhaps introduce w- what that, what they can be and how they range, and then what's our ability to, to quantify them at that point? Because now I assume it's much better gi- given to your work.

Samuel L. Manzello 5:53

Yeah, I mean, at, at that point, I mean, so one of the first experiments we, we did was that, you know, I went around and I was asking people, "So, like, what do firebrands look like? I mean, have you ever seen firebrands? What, what are the size or the mass?" Those kind of things. And, know, there was a lot of anecdotal stories, but there was no real quantification. So one of the first experiments we did back in the day was, we went out and we actually burned actual scale trees in the laboratory. And, clearly burning trees, you don't think it's really rocket science, right? So,

Wojciech Wegrzynski 6:19

Mm-hmm.

Samuel L. Manzello 6:21

idea was that there was really no research on that. So we were burning trees under different moisture levels and, and trying to quantify the firebrands that are being produced. then, you know, at the same time, then from that data that we got from the firebrand size and mass information, we started to do, like, really basic, ignition experiments in the, in the laboratory, very, very small scale ignition experiments.

Wojciech Wegrzynski 6:39

Mm-hmm.

Samuel L. Manzello 6:40

You know, what we found at that time was that, if you look at a lot of, uh, anecdotal evidence and also any kind of investigation or other post-fire study, firebrands were responsible for causing a lot of ignitions. when, when you were doing these sort of very small scale ignition experiments in the lab, you know, we found that it was very difficult to actually ignite anything with these sort of individual firebrands that we were doing. And so that sort of led to the idea that, you know, when you look at an actual fire, there's always the shower of the particles, right,

Wojciech Wegrzynski 7:05

Mm-hmm.

Samuel L. Manzello 7:06

that you basically see. And so, we wanted to sort of, think about how can we do an experiment to sort of address this showering effect of the particles, because that's something that, nobody had been able to do on a realistic scale.

Wojciech Wegrzynski 7:16

And, for the firebrands themselves, may- maybe listeners are like, they just have a broad idea, this anecdotal idea of w- what a firebrand is. So in, in, in case of real, fires, what's the sizes like? What's the ranges? what exactly is those, uh, i- is in those elements? Is it like thin needles? Is it like whole branches? Like what's, what's the range in there that you can meet?

Samuel L. Manzello 7:40

Yes. I mean, what we, what we found basically from a lot of experiments is that, you know, the main issue i- that's important also in, in wildfires is that, always talk about wildland fires and wildfires, wildfires are distinct in the sense that, you know, when a w- a wildland fire spreads into a community, not only is the vegetation burning, but all the community itself. So the homes, different structures, things like that. And so found that it's very important to quantify firebrand production from both the vegetation and also like, for example, burning structures.

Wojciech Wegrzynski 8:08

Hmm.

Samuel L. Manzello 8:09

when you look at the firebrands that are produced, for example, from, if you look at conifer trees, typically, you know, you get... to the, uh, pyrolysis reactions that occur from the combustion, the needles will basically be, be, be burned, but basically the branches themselves will eventually break up and then form firebrands. And then when you're looking at building components or things like that, we found a lot of experiments looking at the sheathing materials, for example, oriented strand board or plywood, where these kind of building materials can produce a lot of interesting, uh, firebrands that you can, know, sort of easily quantify in the laboratory setting

Wojciech Wegrzynski 8:39

W- what dictates how big the fire brand will be out of, a burning item? Like, uh, either it be a, a house or a tree. Uh, w- what property-- I, I guess that's a, that's a function a lot of, of the properties of materials and how it decomposes, but also the, uh, let's say the thermal strength of the fire itself, because it, it has to throw it and carry it out.

Samuel L. Manzello 9:00

there's a lot-- clearly there's a lot of parameters. I mean, you know, we have a interesting paper about this in Frontiers in Mechanical Engineering, where we talk about these different parameters. It's an open access paper, you know, people could take a look at. But, you know, you have the effect of the buoyancy that's generated, of course, from the fire. But what we've also found is very important is basically the effect of the wind. And so the way that the wind can also, produce the firebrands and also enhance the breakage dynamics of these materials is a very important aspect. And, if you look at the current scientific approaches, even though the firebrands is a, you know, a problem that's been going on for a long time, we still don't have actually good models of the actual breakage and generation dynamics of these, these materials, and especially when you look at building components, for example. So basically, we have very little understanding, you know, in terms of how the firebrands are being produced from different building components. We've done a lot of experiments on that, of course, but it'd be nice to have actual, you know, detailed models to actually look at those kind of effects.

Wojciech Wegrzynski 9:51

do the firebrands for vegetation compared to firebrands from the structures do they vastly differentiate in their ability to ignite? I, I don't know what's the correct word. Uh, like, uh,

Samuel L. Manzello 10:05

You have, you know, different... So for example, typically for the vegetation, the, the sizes and shapes will look different than what you get from typical structures. So structures. will produce, as you can imagine, like oi- O-OSB or plywood, for example, you get much more sort of like these thin but lo-larger shape of veneer materials basically can be generated. And so, and when you look at the vegetation, for example, typically, you know, you get, as I mentioned, branch type shapes, other kind of different shapes there as well. So we've done experiments looking at, you know, both the ignition of different, these different parameters. And what we've basically found, at least in our research, it's very important, is basically the showering effect of the particles.

Wojciech Wegrzynski 10:42

Okay

From Tree Burns To Ignition Tests

Samuel L. Manzello 10:43

'Cause as you know, if you look at the actual images of the wind fire, you have this dynamic process where the particles are basically showering something. And, you know, that led us to, you know, I'm talking to you today here from Tokyo, but that's, that's what led you-- me back to Japan many, many years ago because, I was, uh, in the States and we had, you know, many great facilities at NIST, but we had no large scale wind tunnel to do fire research in.

Wojciech Wegrzynski 11:05

Mm.

Samuel L. Manzello 11:05

And so, you know, it, it, I know it sounds also interesting to readers, but, and people, I mean, people on the call because, you think about, for example, fire in, in sense, I mean, there's never really any wind fire occurring under no wind conditions, right?

Wojciech Wegrzynski 11:15

Yeah

Samuel L. Manzello 11:16

even when we, we have these effects of wind, we, you know, there's very limited places in the world that actually have developed experimental facilities that you can look at the effect of wind on fire. you know, early on when I was at NIST, be-before we came to Japan, you know, we wanted to, um, explored the possibility of doing some experiments in other locations. But, you know, I, I did most of my PhD work at NASA Glenn Research Center in Ohio, and they have some really awesome wind tunnels for like high speed flows. But, you know, most of the wind tunnels are basically wood inside. also if it's high wind speed, as you probably know, it's also like a closed loop system. So it's a closed loop system is not good for fire research. And so, you know, when we asked about using wind tunnels for fire, people thought we were just nuts, right? You know, it's like, "This is crazy. I mean, you, you, well, you're gonna w-destroy our wind tunnel." So, you know, I came to Japan, actually, uh, in 2005. It was actually as part of the IFSS conference. It was actually happening in China at the time. and, uh, I stopped by Japan on the way to China, from DC at the time. And, you know, I saw that they had this large scale wind tunnel that you could burn things in. but it was the same, you know, when I visited, I asked, "Well, if we wanna generate firebrand showers? We have any way to do that in a very simple, safe manner?" And they said, "Well, you know, we don't have that kind of capability, but we have this facility And so this led us to basically, you know, from all these experiments that we've done for the burning vegetation and, and other materials, you know, led us to build this dragon technology, which lets us basically firebrand showers. And then if you insert the dragon in any kind of wind facility, you could recreate this showering effect of the particles under wind. And it's really cool, I think, to, see. And, and I think this is a lot of the research that we've been doing over the last several years

Wojciech Wegrzynski 12:52

brilliant, I was, I was wondering the, the story how you got to, to Japan, but it, it's, it's like, it's so funny that, like, a single piece of infrastructure can spark, you know, enough curiosity to pursue a venture across the world to, to chase research. That's, that's the spirit of science. for the listeners, uh, the papers that, uh, Samuel is referring, The world is burning: What exactly are firebrands and why should anyone care?" And others that are listed in the episode, they will be all linked in the show notes, so feel free to, uh, read them up for a deeper dive. And, for myself, you know, we, we've built a wind tunnel like seven, eight years ago in, uh, in my institution, and I must say the first time we've, set a bid for the wind tunnel to, you know, to get offers from the market how much it's gonna cost, we got some ridiculous quotations. And I went to my boss and I said, "You know, look, this, this steel and plywood structure, like they want so much money for it, we could just as, as well just cast it in concrete." And that, that was a joke. But now, you know, being in, Tsukuba in, in the Building Research Institute out there, because I, I assume that's the tunnel that you refer to, I wish I-- that was not a joke. I wish we did that. I wish w- I wish we did that.

Samuel L. Manzello 14:02

Yeah, I mean, I had-- So, you know, one advantage I had was that, when I was a PhD student, since I was doing microgravity combustion, that's when I first got introduced to Japan. Because at the time, for microgravity combustion, what you need to do is, you know, you need to generate, like, very low gravity conditions for the experiments. And, you know, I did all my work and PhD at NASA. NASA Glenn had, like, two-second and five-second drop towers. But at that time, Japan had a ten-second drop tower. So

Wojciech Wegrzynski 14:27

Mm-hmm.

Samuel L. Manzello 14:27

you can imagine it was a ten-second-- It was an old mine shaft, and it was located all the way in northern Japan in, in really, like, a very small, place in Hokkaido. uh, you know, I came there and, um, that's when I was very impressed with, you know, the facilities that Japan might, um, possess. And so, uh, you know, when I heard about there, there was the wind tunnel that they had built in BRI and also the NRIFD facility at the National Research Institute of Fire Disaster. They have a smaller scaling facility that we used as well. And so the idea was that, you know, initially in the research, we were using this larger scale wind tunnel at BRI, but then, you know, the ultimate goal of the research has always been looking at how can we standardize and also how can we develop more simpler technology that, like, everybody can use in a laboratory. You know, you don't have to have a massive wind tunnel. And so the idea was that, you know, we did these large scale experiments at BRI and at, and at the same time, we were comparing our results at a much smaller scale facility at the National Research Institute of Fire Disaster also. This is located in Tokyo.

Wojciech Wegrzynski 15:23

Hmm

Samuel L. Manzello 15:24

you know, how can we then compare, uh, this? And th-this led us to basically develop what we call, you know, we help-- the iso fire brand generator, which is called the Baby Dragon. And so, the original Dragon was a very large scale, uh, device, but the Baby Dragon is much more smaller scale. And the idea was that, you know, we wanted to develop a technology that anybody could use in their laboratory. They could also generate their own shower of firebrands. And, you know, that was traced back to our years of research of looking at it at much larger scales as well.

Wojciech Wegrzynski 15:51

Okay. Tell me, tell me the story of the Dragon. So how did-- how does one go from understanding that there is an effect of firebrands in wildfires getting, uh, a s- a fellowship at NIST? How does one get from this state of mind in a very scarce literature and a field that's not very popular at the time to building a, a device that is supposed to simulate that?

Wind Tunnels And The Move To Japan

Wojciech Wegrzynski 16:13

Like, w-what were your hypothesis assumptions and, and first steps in building the Dragon, the big one?

Samuel L. Manzello 16:19

So yeah, that, that, that's a, a great question. I mean, I think, uh, so the funny story was, you know, I joined NIST and, uh, I was doing this, uh, NRC postdoc, and then, you know, of course I, I liked working at NIST at the time, so I wanted to become a permanent staff member. So luckily they, they decided to hire me as a permanent staff member. But, I was interested in this wooly. I said, "I wanna work on wooly." And I remember at the time going to the NIST management and they're like, "You know, we don't really-- we're not interested in this," basically. Like, you know, "Nobody cares about this," basically. And like, but I'm like, you know, you probably can guess from my personality I'm like a really persistent guy. So like I don't give up. So I kept going back. So, finally one of the program managers at NIST, they, they showed me a picture of an actual, a firebrand shower in a wooly fire. then he joked to me and he said, "Look, if, if you can make that, experimentally, you know, that would be really useful, right?" And, but of course, you know, everybody was laughing, "Ha ha ha," like, you know, "You're never gonna be able to do that." So then I was thinking, "Okay, well, we need wind and we need to have a technology to do this." And then that's when I started thinking about, you know, knowledge from combustion, because my PhD was in droplets basically.

Wojciech Wegrzynski 17:17

Oh, okay

Samuel L. Manzello 17:17

think about firebrands another kind of particles So we, basically, at NIST we built this like dragon, in, in, the original version in the laboratory. And then I was able to convince the NIST management, "Okay, look, I wanna go to Japan and I wanna test this out." And then they told me, "Okay," like, that time I think they said, "We'll give you like a week to go to Japan and you can try this out." So, you know, we flew all the way from DC and like you can imagine with jet lags and all this kind of stuff. but you know, we came back with the video of the dragon and, uh, I guess the rest was sort of history because after that, you know, they were, the management was convinced, okay, you know, clearly this was something that looked like important uh, you know, how can we continue to do this kind of, research? So I think it's also a good story probably for your listeners because,

Wojciech Wegrzynski 17:57

Mm.

Samuel L. Manzello 17:57

you might have a lot of like, you know, let's say newer researchers or things like that. And my own experience from it was, I went from people kind of laughing, you know, "Good luck doing that," to try to create it. And, you know, it's important I think to have persistence and, and not give up easily on something. And, and you know, I felt that, even at that time there were, there were wooly fires that were occurring. It was nowhere near as bad as now where you ha- it's happening all over the globe. But still, you know, seeing all the destruction from those fires was very hard to take as a, as a younger person at that time. And I wanted to try to do anything I could to help it, basically.

Wojciech Wegrzynski 18:27

I think, uh, those, those traits of, of persistence, uh, fighting for your own idea, in my personal, uh, opinion even, you know, audacity to, to some extent is necessary if you need to do great science. Because, uh, of course, if you, if you just do science that, that fills someone's, five-year plan or, or whatever, you know, and you're just ticking items off that list, I mean, that's great and likely useful and likely moving us all forward. But, uh, usually the, the stories of great discoveries start with, "Oh yeah, they didn't want to do this, and for five years I was fighting and then I got chance and then we... The rest is history." So I, I appreciate the persistence of, of that, Samuel. Uh, in terms of what the dragon does, because obviously you said it generates showers. So, what does it shoot out, out, out of the, the dragon's mouth? What, what are the artificial firebrands that you're shooting?

Samuel L. Manzello 19:25

So basically what we, from, as I mentioned earlier in the, in the discussion, from the, you know, years of research of looking at vegetation and also structures and, and also we did investigation of actual wildfires. And so the idea was that, you know, the Dragon can basically reproduce showers that you see characteristic of actual wildfires in specific vegetation and structures. So you can basically engineer a distribution that you'd like depending on how you feed in the conditions. basically then, you know, you can, you, if you want, you can make a shower very representative of burning vegetation. You can make it very representative of burning structures. You can make a mixed shower, for example. So, one of our most recent papers that we published for the, uh, ISO, firebrand generator w- w- was published in Applications in Energy and Combustion Science. And that paper, um, looks at, effects. So basically you have like a, a shower of both vegetative and structural firebrands, which are very different in their nature. And so you can do that in the same time as, you know, what you'd see in a real wildfire would not really necessarily be only the vegetation, 'cause everything is burning all at the same time. So it makes, I think, the process, uh, very, uh, complicated. And of course, I'd like to give a shout-out to my, uh, main collaborator for the, the past 15 years is Professor Suzuki, who's at the Institute of Science Tokyo. she worked with me, initially at, uh, NIST. she was a, a postdoc at the time and, um, uh, you know, we developed these, these technologies and then when she came back to, uh, Japan, she was from the University of Tokyo as a PhD, then we continued our collaboration in, in this area for, for many, many years.

Wojciech Wegrzynski 20:51

By engineering the firebrands, what do you have in mind? Like, do you feed the machine with a specific mix of, pre-burning firebrands and then it's what's released? Or the machine does the processing itself by some sort of, I don't know, uh, mulch, uh, processing, uh, technique, uh

Samuel L. Manzello 21:09

So we basically, you, you know, you can feed any sort of material that's basically combustible into the device, and depending on how you, you know, adjust the combustion parameters, you can basically tailor different firebrands. So as an example, initially what we did was that, you know, we were doing, for example, we would do actual simple experiments where we'd actually mulch a tree, and then you'd tree mulch into the firebrand generator. But then when we wanted to look at more precise control of different parameters, for example, then we would fix with, for example, specific sizes of different materials. And then, you know, you could just generate any sort of material that you'd like. So,

The Dragon Origin Story

Samuel L. Manzello 21:42

and I think what's interesting in, about it, as you mentioned earlier, you can also generate a shower of either flaming firebrands or basically, you know, glowing firebrands, depending on what you understand. Because the way you, the way you adjust the airflow through the device, you know, you can imagine if you, if you, you provide a very high airflow, the firebrands will come out in a flaming state. But if you provide a lower airflow, you can get firebrands coming out in a glowing combustion state. So depending on what you'd like to tailor and generate, you can sort of do, you know, whatever your heart desires.

Wojciech Wegrzynski 22:10

Do, do you have a full control of that as a person running the experiment? through a knob, uh, velocity and that's it, you, you change the fl- flaming behavior or is it more complicated?

Samuel L. Manzello 22:20

so for the ISO Dragon, the Baby Dragon, what we have basically is, y- you feed it with a conveyor system. So what it is, is you're loading these m- materials on a conveyor, and then you could basically adjust the flow parameters of the device. So for example, you know, if you'd like to increase the velocity, you can increase the velocity, which would give you, you know, uh, flaming fire brands, and you can also, you know, adjust those parameters depending on what you'd like to do with it

Wojciech Wegrzynski 22:42

Uh, how about shapes? Because I, years ago I was mesmerized by a paper by Ali Tohidi about, six-degree function, uh, model of, uh, firebrand aerodynamics. I, I, I just found it very interesting. Uh, how, how much do you care about shape of those particles? Like, do, do you want them to be like balls, cubes, disks, or it doesn't matter that much?

Samuel L. Manzello 23:01

mean, I think for the, for the research we've done really with respect to like a, a mainly the structure of fire brands, I mean, you'd like these to be different shapes than what you get from the vegetative fire brands because in their texture, in terms of what you see, they're, they're basically different. And I mean, one thing also we did, uh, many years ago as well is that we had a collaboration at that time with CAL FIRE, the California, Department of Forestry and Fire Protection in, in California. And basically, they did an investigation where they collected burned, materials that were exposed to fire brand showers. For example, there were trampolines and other kinds of materials. then from that, what we did is we then used the Dragon to recreate those burn patterns on these different materials. So then we could see, for example, you know, what would fire brands actually look like from a very realistic wildfire situation itself. And so, you know, I think that, uh, uh, it's important especially, and I know it's somewhat of a tangent here, but I mean, in terms of like, you know, actual research as well, is that, more data collected from actual wildfire disasters is also needed because as we collect more data, you know, then we could also tailor the Dragon to different kind of situations. And this also, leads us to another project, um, that we're also working on recently now with, in Africa um, which was that, you know, in Africa also we're working with, you know, characterizing local vegetation there. And then the idea is then the Dragon will be producing like, uh, African fire brand showers. So looking at the differences of the vegetation from Africa, for example, versus what we see in Japan or what-- versus what we see in the United States or Europe or other countries.

Wojciech Wegrzynski 24:28

as you talk about this, uh, the image builds in my m-- I, I mean, I obviously know the, know the dragon, uh, f-from, from previous studies that we've also done. Uh, n-never built the device, but, but I'm familiar with, with, with the outcomes. It, it's interesting because you here solve like three separate problems in one go. Like first you have to generate something that reassembles a real firebrand, burns like a real firebrand, and, uh, it's, it's just a good representation of the firebrand. That thing needs to follow the aerodynamics of the firebrand and fly with the wind, land like a real firebrand, behave like, like if, if it's heavier than a real firebrand, it's gonna land sh- closer. That, that, that's simple physics. And, and accumulate differently. So that's a aerodynamic problem you have to solve. And the third one is once it lands, it has to reassemble the, ig-ignition or combustion, uh, properties of a landed firebrand to lead to the same kind of ignitions. So we not only have to create something that flies like a firebrand, but behaves like one when it lands. That, that's actually quite challenging, especially the third part, because from wildfire investigations, assuming they've ignited the structure, you're not gonna see the, uh, ignition scene because it's gonna be destroyed by the fire. That, that must be very challenging to get, how, how did they really accumulate and ignite?

Samuel L. Manzello 25:53

Yeah. I mean, I think that, what I think is really cool about the technology and, and, you know, th- that we developed it is that like, you know, so once you can actually generate these firebrand showers, you know, you could put it in, in a, in a realistic scale wind tunnel, and you could actually see for the first time, you know, what the flow does, right?

Wojciech Wegrzynski 26:08

Mm-hmm.

Samuel L. Manzello 26:08

the thing I always talk about it whenever I talk about this research is that like, you know, what inspired it was that, you see these pictures on the TV or you see these kind of things, but you really wanted to say, "Well, you know, can I just be sitting in a laboratory and try to create a situation where you see what, what's actually happening," right? In a controlled way. And so that was, you know, the main motivation. For example, a lot of the experiments we've done is that, you know, you can also basically place, like for example, different obstacles downstream of the firebrand generator. And then you could look at, for example, how like a, a particle-laden flow of like burning particles, how, how it accumulates, what it does. And I mean, I think that, you know, that's, a, a very also cool, interesting experiment to basically see. Because, I mean, without this kind of technology, there's no way to really, to generate that. I mean, you know, before this, the only way that I was aware of that people were generating any kind of so-called firebrand shower was, you'd burn a wood crib. So if you burn a wood crib, and then you have some capability of doing any kind of airflow, but you know from, you know, years of also research yourself, I mean, wood cribs, it's very uncontrolled, and it's also just very difficult to deal with it. And, you know, but the difference with the, with the Dragon is that, you know, as long as you-- It's a continuously feedable device, so as long as you're feeding it, you could keep generating showers as long as you want. then you could just play with it and see sort of what's going on w- w-with this technology.

Wojciech Wegrzynski 27:24

Yeah, th-th-that part I'm especially familiar with because I, I've c- supervised, Dr. Simona Dossi, who was doing a PhD at Imperial, uh, some years ago, on firebrands as well. I always had a hypothesis in my head, that, you know, a lot of the images that we were getting out of those accumulation patterns were kind of reassembling the, the, the static pressure distribution around the building in wind. Had you ever had-- I, I, I know today you've moved already to super advanced methods, like you, you have a great paper on, you know, prediction of firebrand transport using ma- using machine learning and, and physics-constrained neural networks that's also in the show notes. but, uh, have you ever tried to study firebrands but just looking at the wind fields around the buildings or around, uh, uh, whatever obstacles you find?

Samuel L. Manzello 28:12

Yeah, I mean, that's a great question. I mean, you know, early in the research, what we did is that, from typical, let's say, stagnation zones in a corner of buildings or these kind of things. So what we wanted to look at basically was that, you know, there's a stagnation zone, you would think from a hypothesis point of view that these should be places where the firebrand would sort of drop out and, and basically potentially accumulate. And so before we did a lot of the initial experiments, you know, we basically did a, a just simple modeling of the wind tunnels. And then basically from the simple modeling, we looked at, okay, you know, what if we place this obstacle at this distance from the dragon? You know, what kind of stagnation zone would develop? And we wanted to compare, for example, then, you know, how does it actually compare when you actually like, you know, see the flow with the actual burning particles themselves. And so that, you know, led us to do

How The Dragon Controls Firebrands

Samuel L. Manzello 28:54

a lot of, you know, different kinds of experiments. We look, we looked at also like, you know, mocks experiments where we simulate the, the separation issues from structures. and you know, I know that also with re- with respect to the work of Simona, I mean, a lot of the great work that she did. I mean, I know that she was also interested in those kind of, you know, mitigation strategies as well. Because, for example, you know, if you know that the firebrands will accumulate in certain zones within a community, can you come up with some strategy to either, you know, mitigate that or get it to not happen or, or those kind of things, so. And I think that, you know, that was the initial thinking when we first built it, was that if you have that kind of technology, you know, you could play with these kind of things. And, know nowadays everybody loves modeling, of course. And I'm, I'm not against modeling, but you know, experiments, I think another plug for the listeners is that experiments are really, really awesome, and it's very, you know... I mean, I feel it's really a gift to just be able to observe the nature, okay?

Wojciech Wegrzynski 29:42

Yeah

Samuel L. Manzello 29:42

I mean, I don't disagree that, you know, people always tell me experiments are expensive and it's hard or whatever, but I mean, literally, like, you know, all the papers I've published, I've done all the experiments myself. And so, I mean, I've done like thousands and thousands of experiments and that what, you know, motivated me to keep doing it. And I know, I know that we're in the era of, you know, machine learning and AI and all this stuff, but I mean, it's important. We really need to do experiments right? I mean, that's, you

Wojciech Wegrzynski 30:06

Yeah

Samuel L. Manzello 30:06

that's a plug that I wanted to give on this show 'cause I was excited, you know, when I was looking at all your previous talks. I mean, I know you've had some great experimentalists as well, but, it's hard to convince, I think, nowadays younger people to work on experiments, right? Because, you know, there, there's a lot of interest in modeling and these other t- technologies.

Wojciech Wegrzynski 30:23

You know, it's, it's the constraints of doing science today. I think a lot of younger people just, you know, uh, and that's why I said it's so great if you have, you know, the audacity to fight for your own idea and case and get it done. Uh, because you often get stuck in this, in this pathway of, doing a chunk of somebody's else, uh, big idea, and then you move to your postdoc and you do a chunk of somebody's else's idea, and then you enter, you know, your permanent position and you have to fight for everything, and you get a little lab. You got a cone and, and they don't want to buy you anything larger. It's difficult to, to become experimentalist in that setup. But then again, you can realize that a good experiment is, is mostly an idea in your head, and you can do so much with five thermocouples, uh, a little fan and a bit of space, way more than you would think, I know for some experiments, of course, you need to have sophisticated measurements and, and weeks of setup and everything. But sometimes it's just, you know, about having a really, really good idea, finding someone who shares, uh, this same enthusiasm, finding a piece of equipment on the other part of the world, socializing, building friendships, fostering that. And, and I think all the people I know in the science who got the furthest got there this way, kind of.

Samuel L. Manzello 31:52

Yeah. I mean, I remember the, you know, one of the things I was very proud about at the time is that, you know, uh, 'cause w- we recently came together from the IFSS conference, right? That was in La Rochelle. But, you know, back when they had the IFSS in, it was in, in New Zealand, in

Wojciech Wegrzynski 32:05

Hmm?

Samuel L. Manzello 32:06

Christchurch, uh, I was very honored to be an invited speaker at the time and, you know, we presented the, the paper, which was a summary of what we had done so far, more or less, with the dry head. And, you know, I remember that, um, you know, presenting that and, uh, there was a lot of interest from the participants because, you know, it was like had spoken that time to a lot of really senior fire scientists and, you know, they talked about, firebrands. Everybody was interested in that topic for a long time, but nobody could actually see what it was really doing. And I remember having conversations at the conference with, you know, very eminent fire scientists at the time, and they're like, "You know, this was just fascinating because, you know, we, we imagine what might be happening, but we could actually see it," right?

Wojciech Wegrzynski 32:41

Mm-hmm.

Samuel L. Manzello 32:42

so, um, you know, those kind of compliments, I mean, always stuck with me for a long time because, I mean, you know, that was the same kind of thinking that I had that like, you know, y- you wanna see something, but how can we do it? And, you know, I think for future experimentalists or other people also doing experiments currently is that, you know, if there's some interesting physics or chemistry of something that you'd like to really see that nobody's seen, I mean, don't give up on it. Try to see if there's some way to actually see it. And, you know, modelers will always tell you it's easier to model this or whatever, but like, you know, in my opinion, I mean, a model is only a model, right? So the model can only model what, you know, we know about the physics, but if we don't know anything about it at all, then really it, it's a model is anybody's best guess of really what's happening.

Wojciech Wegrzynski 33:24

Yeah

Samuel L. Manzello 33:24

know, it's just important, uh, especially in, you know, in, in fire safety science, I think this is... You know, what dragged me to the topic, as I mentioned in the beginning, was that there was a lot of just, like, problems that we know of, of in fire safety science, but there's a, there isn't a lot of experimental quantification of them. Mm-hmm. You

Wojciech Wegrzynski 33:42

I

Samuel L. Manzello 33:42

whatever reason. And so, you know, how can we do that? I mean, WUI is one example, but, you know, there's many other things that, you know, we need a lot, a lot of detailed understanding, I think, that we just... It's difficult to achieve without having good experiments, I think.

Wojciech Wegrzynski 33:55

I fully agree and, you know, going back full circle to your recent papers on neu- neural networks and using, uh, AI, I had, uh, Amzin Nasser in the podcast five years ago. I had him a few months ago. Years ago, we were talking about, you know, opportunities, how it grows, what can you achieve, like, you know, all this horizon of, of opportunities in front of us. And a few months ago when we've talked, it was-- I, I hope I, I don't, butcher the message, but in the end it was like we really need good experiments to feed those models be- and, and that's the, the, that's the cornerstone and that's the, the bottleneck we have. Like we need good quality experimental data because i- if we don't have that, the machine learning models are not gonna work.

Samuel L. Manzello 34:45

Yeah, I mean, I think in our case, like, you know, as someone who's done thousands and thousands of experiments, so, you know, I became interested in

Accumulation Patterns And Flow Physics

Samuel L. Manzello 34:52

getting in the machine learning and those technologies after I had a lot of data.

Wojciech Wegrzynski 34:56

Hmm.

Samuel L. Manzello 34:57

So the, the thing is, I think it's important, you know, I'm, I'm glad you bring up this point because like, you know, those technologies are great, but I mean, without a lot of data and good understanding of actually what's physically happening, you know, because model's just gonna learn whatever it learns, right? But the thing is, if you don't have the ability to really train it to something that actually is embedded in the physics, you don't really know what you're gonna get from it. so I think that those are, very important things. And I think, you know, probably I sound like I'm too old now, but like, you know, it's like, you know, it's just, uh, uh, you know, when I, when I'm at a conference, I mean, I always do feel that like, you know, I'm excited to see people doing experiments, but also like, you know, it's important that we, we don't lose, lose sight of the track that like, you know, you know, all these models are only good as, as good as the experiments that we have, right? And so if we don't have good experiments in most of this stuff, I mean, you know, the, it's just models for the sake of models in some sense.

Wojciech Wegrzynski 35:45

Uh, th- there's a whole modern school of using machine learning applications based on FDS simulations, because you can get a structured data output out of FDS simulation much more dense and much more structured than you would get from, get from an experiment unless you put you know, devices in your experiment in a very, like, nice network, which is difficult obviously. And, uh, by-- I, I mean, they get us somewhere, but again, it's just a simulation. And, and even coming back to the work of Simona, when she was doing the PhD, the FDS version changed a little bit. A, a tiny minor change like third significant digit in the number of FDS, but it changed completely the behavior of how firebrands responded to the surface, you know, and suddenly the simulations are up like 100% different. So yeah, it, it, uh, th- there's a whole world of, of challenges. I would like to go back for a second to that, aerodynamic problem of buildings and structures and, and, things around, um, obstacles. So if there is a strong relationship between the aerodynamic response of the objects to wind, it also includes a new challenge that's literally the wind distribution speeds and, uh, you know, angle sensitivity of the wind, because wind is a very complex phenomenon, and you can have like i- you're not able to solve the problem for a single setting of the wind. And also when you get into a complicated, uh, aerodynamically setting of buildings like a village, you will also have, a huge variety in outcomes dependent on from which side the wind blew and how strong it was. So, so th- that must be a challenging problem, to solve and, I assume you also can use this dragon technology to look into those distributions in kind of a transient things, but you need a good wind tunnel for that, I guess.

Samuel L. Manzello 37:43

Yeah, I mean, you know, for, for-- that's a great question. I mean, for, for those aspects, you know, what we were doing is like looking at really, really simplistic experiments. So the idea is, you know, we'd put a very simple, like, just like a simple wall, like different orientations downstream of the dragon.

Wojciech Wegrzynski 37:57

Hmm?

Samuel L. Manzello 37:57

In that way, if you just, you know, fundamentally look at these accumulation patterns. And then, you know, we did that initially in the large-scale wind tunnel, then we did it in the smaller scale facility to see can we replicate those kind of behaviors. And so, you know, we have a paper about that in fire materials. and, uh, we could find some interesting results basically trying to replicate those, those kind of behaviors. But the idea, you know, I remember when we were first doing it, you know, getting also, you know, support from NIST to do that was difficult because, you know, it was like, "Okay, you, you, you're gonna go to Japan and you're gonna put, like, just a wall downstream of the wind tunnel. What, what are you gonna do basically?" Like the idea was that, you know, we already had the vision that like, you know, so we need this really high-quality benchmark data to basically understand really just the flow physics of what's going on. And of course, there's gonna be an end use to it, but, sometimes it's, you know, when you're doing certain research, it's, it's not always apparent for everybody where that's gonna go, right? Even as a researcher, you have the idea where you wanna go with it, but, you know, just trying to convince people how to do those things is always a, a challenge, I think.

Wojciech Wegrzynski 38:51

Uh, let, let's move now to the world of, of applications and, uh, developing standards. So, uh, y- you are the convener of ISO TC 92 Work Group 14, and, I understand that this is the work group that eventually produced the Baby Dragon standards. Um, l- let's talk a little bit about that. how does the knowledge and the years of experience as a researcher turn into, uh, useful technology? first, uh, I'm not sure if everyone's familiar, if you can broadly introduce ISO TC 92 as a whole, uh, for engineering thing, and, and then tell me where your, where your group lands in the I- ISO committee and, and what it does.

Samuel L. Manzello 39:32

Thanks. Yeah, I mean, yeah, ISO TC 92 has been around, I, I think everybody might be aware, I mean, for many, many years, basically. And so, um, ISO TC 92 is, it's fire safety that's handled in ISO and, the interesting thing is that, you know, I got involved with it because, for a long time, basically, ISO was very focused on fire standards for fires inside buildings, And some of the... Uh, it's a somewhat of a little bit of a long story, but some of the brief history was that, you know, in 2015, actually at the time, ASTM had asked me to organize a, a workshop to look at, you know, how are we doing with respect to fire standards for WUI fires? if you look at the history of just standardization, for example, you know, before there were building codes and standards, I mean, you know, most of the major cities in the world were just burning down, if you look at Chicago and these kind of things. so the development of the fire standards for, you know, buildings has really been a, a huge improvement, I think, in terms of mitigating these large-scale destructive fires. And so, ASTM E5, they, they recognized at the time that, you know, probably the, the WUI standards are not really good, right? And so we had this workshop and, you know, one of the main focuses at the time was, know, how can we, first of all, get the researchers to come to the ASTM meetings? Since I can tell you, frankly, researchers didn't wanna go. And I mean, how can also we get the code officials and o- other standards s- s- people to talk to researchers? So we had the workshop and, you know, what we learned at the time was that some important things. One, like, the s- the, the standards people in different organizations really had no idea what the researchers were doing, and the researchers had no idea what the standards people were doing. So bringing them together was a great thing. And what we learned also at the time was that, you know, the research community, even all the way back in 2015, we knew that fire brands were an important issue, but there was nothing in terms of the standards for fire brands in, in the, in the building codes. And so, of that activity, we published some reports, and we had a special issue in fire technology at the time as well. And, you know, eventually this got the word of ISO. So ISO TC 92 at that time, it was, uh, Patrick Van He was the chairman of ISO TC 92. And, you know, everybody knew I was in Japan, so Patrick said, "Look, there's gonna be ISO TC 92 in Tsukuba." This was in 2017.

Wojciech Wegrzynski 41:36

Mm-hmm

Samuel L. Manzello 41:37

you to come and present to the ISO TC 92 about WUI." And I said, "Okay, you know, I'm excited to do that." So, you know, I presented it, and after that, you know, the people at ISO were like, "Okay, you know, this is clearly like a... W- We're not dealing with this at all, right?" I mean, you know, you know, most of the people that were in the audience. And so, um, what we did from there is that, you know, we developed first what's called a, a, a task group. So we made what's called ISO TC 92, uh, WG 3. And what it was

Experiments Versus Modeling And AI

Samuel L. Manzello 42:03

is, I mean, I mean, TG 3. So TG 3 is a, a task group can't really write standards to do anything. But basically the idea is they can report to ISO TC 92 like, you know, is this problem worth working on or not?

Wojciech Wegrzynski 42:13

Mm-hmm.

Samuel L. Manzello 42:14

So, um, ISO TC 92 had a workshop in Delft in 2018, and also we have another special issue about this in fire technology. And, uh, basically, you know, from that discussion, you know, everybody was like, "Look, this is an important problem." And this is, I think, before WUI fires really became even more of a major global issue. And so then, you know, we balloted and, um, got approval to make what's called ISO TC 92 WG 14, which is a large outdoor fires in the built environment working group. then, you know, we started working on this basically in terms of, you know, the first thing we did basically was that, you know, we issued a report to look at an overview of global standardization processes for outdoor fires. You know, what exists basically all over the world. And this is called ISO, TR 24188.

Wojciech Wegrzynski 42:58

Hmm?

Samuel L. Manzello 42:59

and we published this in-- initially the b- the first version was in 2022, and then we updated it in 2025. But one of the first discussions from that was that, like, you know, after we looked all over the world about what was going on, there was no fire brand-related methods, And so, since most of the committee and other people in ISO were aware of the Dragon, basically the, the Dragon moved through to become device for, ISO TC 92. And, reason we made this initially as a standalone device was that, you know, the first thinking was that, you know, in order to implement it to existing tests, it's gonna take much more time. So it'd be much more quicker to basically have it just published as a standalone device that everybody could just use.

Wojciech Wegrzynski 43:39

Hmm.

Samuel L. Manzello 43:40

And then, you know, after that, we are now considering how can we implement that with different kinds of tests for different materials and also, um, Even, for example, a big need, I think, in ISO, 92 is also standardization needs for, you know, how do we quantify the hazards from vegetation? So, you know, you asked me early in, in, in the podcast about, the initial work with the trees or those kind of things. And so, you know, some of the work we're doing now, as a research point of view is, you know, how can we develop a methodology such that, you know, they could compare hazards of burning vegetation across different continents? So example, how does African vegetation compare to European vegetation versus, US or Japanese vegetation? And so, you know, we're working, um, with partners across this to do these kind of things. And, um, some of the other work that also ISO TC 92 WG 14 is doing is that we now also are working on a, a standardized methodology for post-fire data collection. So, you know, when you're trying to compare, for example, the disasters across different countries, we don't have any standardized way to do this. And so we have a, a document that, um, we're working on now. It's, it's now entered the draft international standard phase. And then the other work that we're doing is, um, the committee is working on a technical specification to try to harmonize the thermal flux exposure. So, you know, I talked a lot about firebrands, but you know, in the, in a wildfire situation, you have the direct flame contact, you have radiation, and you have firebrands. And so there are various tests that exist for radiation and, and, and, direct flame contact. So the idea is that we wanna try to see how can we harmonize at least what exists globally for these different kind of situations. I think the, one of the most exciting things that we've just added to the work program is also we're gonna be developing a document comparing different models for large outdoor fires. So to our knowledge, this has never been done on a global scale. So the idea is that, you know, there'll be a document that's just started. It will have three years to finish it. Um, but you know, also for your listeners as well, if you're aware of any models that we should consider as we're developing this document, um, that would be very helpful because, you know, there's been an increase in, let's say, modeling approaches, but we wanna have a, a critical document actually that basically talks about like, you know, are these models validated against experiments or, you know, what are the methodologies that are being used for these different models? And so, I know that's a mouthful, but you know, probably after, after the podcast, maybe we can list some of those because they're all on the web and, um, you know, you can sort of see what we've done

Wojciech Wegrzynski 46:00

Oh, yes, yes.

Samuel L. Manzello 46:00

so far with this.

Wojciech Wegrzynski 46:00

and there's also like the short piece you wrote for SFP, uh, was it SFP Europe or, there's a note online that I'll, I'll link, uh, uh, which, which summarizes a lot of those activities with links that lead you further. So if anyone wants to, to go into j- the rabbit hole there, that you're, you're very welcome to. Um, is this somehow linked to the IFSS group on large outdoor fires and built environment that you're also leading, uh, in the s- in the world of science?

Samuel L. Manzello 46:31

Yeah, I mean, so what it is, is, you know, as you probably know, in ISO's case, I mean, even though I'm the convener, the way the ISO rules work is I can't appoint anybody to become a member of ISO. You have to be appointed by each country's standards body. And so, you know, as the convener, I can't get involved in those processes. And so what we did is when we developed this IFSS, what's called LOFBE, the Large Outdoor Fires in the Built Environment working group, you know, this is something that basically, you know, uh, we now have like more than 200 members that are there. And, you know, and every time we have an ISO meeting, I report the progress of what LO- IFSS LOFBE's doing. So the ISO members are aware of the sort of state-of-the-art of the science and tho- those kind of technologies. And, I think it's, you know, a good opportunity to basically sort of cross-feed and germinate the diff- And, you know, th- therefore, the ISO people are aware that there's a lot of research going on, for example. And, we had our most recent LOFBE workshop also in La Rochelle, before the, the IFSS itself, And, uh, it's, main focus, I guess, for the standardization for a long time, p- going all the way back to the ASTM, was that it's important for me to get everybody at the table. So, like, you know, we can't only have people who are just developing the standards because in-- for whatever reason, they might not be aware of research or... And I know now, you know, we're entering the world of AI and the-- it's easier to find research, I think, than it ever was before. you know, you're-- I mean, I got my PhD in 2000, so you know, back in those day, I mean, like literature review was more painful than it is now, Ron. And so, I mean, like, uh, it's like, uh, how can we just make sure that everybody's aware of what's actually happening and, and what's going on with them? And that, that was one of the main ideas of trying to get these two groups to, at least be aware. So, you know, every time we have ISO TC 92 WG 14 meeting, I provide a very brief overview of like, you know, this is what we are doing in LOFBE. This is what the LOFBE people are doing. And, and now, for example, LOFBE group has developed like various papers and other things that actually have been u- that are being used now by the ISO group as well. And so, it's obviously it's exciting, but I also can't deny it's a lot of work. I mean, 'cause like, you know, leading the ISO group and at the same time the LOFBE group. I mean, you know, I have a passion for this, I mean, of course, but it's just still a lot of gr- you know, work to, to try to bring more science, I think, into the standards process because, I'm still relatively new to ISO, but I, I was involved with ASTM for a long time. And in ASTM, I first went to it, I remember, you know, there were very few researchers there Basically. So, you know, you go to an ASTM meeting and, you know, even

ISO TC 92 And WG 14 Explained

Samuel L. Manzello 48:51

people would ask me, like, you know, "We don't talk about research. Why did you come here?" Like, you know? Like, and those are kinda like hurtful comments, right? But like, you know, it's like, uh, So in, in ISO we-- I know we have, I would say, more, there are more research-related people, but still it's hard to get these communities, I think, uh, talking. And so, you know, what we've been trying to do in IFSS with the LOFBY is try to bring more, like, uh, applications-driven people to the conference, right?

Wojciech Wegrzynski 49:16

Mm-hmm.

Samuel L. Manzello 49:17

well, I think now we have a lot of focus in IFSS. There's a lot of professors and more academics and, you know, I don't wanna take anything away from what they're doing, but, you know, normally academic research is, is, it's not necessarily directly focused on, let's say, practical problems in many cases. And so, and, and the practitioners sometimes, you know, look at it, "Okay, this conference is so scientific, I don't know what they're talking about. I don't care about it," So like, you know, how can we get sort of, um, uh, cross-discussion amongst these different groups?

Wojciech Wegrzynski 49:44

So, you know, uh, we, we have similar experiences in here which, which are kind of funny because at CEN it's even more rigid, I feel. But recently my colleague was intending to do a change in one of the Eurocodes, and what, what he learned is that, "Oh, you want to propose a change? Come back with a peer-reviewed research paper." And we're like, "Whoa." Now y- y- you didn't need a research paper to put stupid thing into a standard 50 years ago, but now we, we have to, you know, go through science, like an escape, from this, uh, rigid world of, of standardization. Now you need a proof, whi- which I find interesting, and it also means that the-- if this is a shift in thinking in the standardization bodies, they will need the researchers more and more. And, things like LOFBY and, and other wo- uh, other standing committees of IFSS are just, you know, ways to gather scientists around a technical topic and, show them the, the relationship between science and reality. That's great for scientists, but also I see, see that standardization will need this, you know, proof-based science, uh, more and more. In, in terms of the, the Dragon and the outcomes, what does standardizing Dragon now mean for the industry, and what does it allow now? Do, do you foresee a new generation of standards that just use Dragon as standardized exposure tool and then can measure response in, in some various ways? Where, where would you like this technology to go from now?

Samuel L. Manzello 51:11

Yeah. I mean, I think that... Thanks. That's a great question. I mean, uh, we, we developed it, as I mentioned earlier, as a standalone device, but, you know, for example, there's a lot of, of methods currently that are, that are not very good in terms of fire brand exposure. So one thing, uh, I know we don't have so much time, but I'll talk very briefly about roofs. So when you're looking at roofing assemblies, for example, like, you know, of the early experiments we did many, many years ago was that, you know... So if you look at ceramic tile roofs, these are generally, you know, have a very high ignition resistance because, uh, as we know, I mean, ceramic doesn't burn. But, you know, we were told at the time, you know, uh, looking at different post-fire studies and things, okay, you know, you know, fire brands might be getting under these tiles and igniting the underlayment or this kind of stuff. And so, um, you know, we did experiments on this and basically, you know, we found that, yeah, I mean, you know, the fire brands will just blow under the tiles, and then depending on what's underneath, I mean, you could easily get ignition on these kind of things. And, you know, we did experiments both for like US kind of style roofing materials, and then also we looked at Japanese materials. And what we found actually in Japan is they also have ceramic roofs, but, you know, their tiles are much worse in terms of the penetration than the US ones. I mean, the stuff was just going under there like crazy. so, thing that we envision, I guess, hopefully in the near term probably would be like, you know, can we interface the Dragon with a new, with a roof test such that we can actually start to look at the penetration? Because, you know, only rating... You know, the way they rate for the current roof test is, you know, you put a wood crib on top of the roof. But you know, if you have a wood crib, it doesn't do anything to the ceramic tiles, right? you know, 'cause it's a static test. And so the idea is that if we have a dynamic test where you actually have the flow of the fire brands under the roof, you know, then that would lead to, I think, new designs of roofing or other ways to stop those kind of penetrations from happening.

Wojciech Wegrzynski 52:50

Yeah, that's very interesting. I, I agree with our B roofs, that's something that you don't really test much for. I assume the same could be for all the outdoor ventilation devices, chimneys, all-- Like, basically any pathway that the firebrands could get into a building could now be studied in some way with this technology in how does it delay or prevent that, that, that transfer of firebrands into a building

Samuel L. Manzello 53:17

Yeah. I mean, I think that, that's great too. I mean, you know, in terms of-- One of the early experiments we did basically was that, you know, looking at firebrand penetration into building vents. And so, at the time it was like, uh, you know... I remember, and this was many, many years ago, but we went to, you know, Cal Fire at the time, and they said: "Look, you know, I, I see you have this requirement having a mesh behind the vent. You know, how did you come up with that? Do you do any tests?" And they said: "Well, you know, no. The original design was based on keeping rodents out of the building." And so, then we did the dragon test, and we found that, you know, the firebrands would easily penetrate, you know, behind these meshes. And I mean, this comes up, I think it's an important discussion also for, you know, your, your listeners in Europe is, you know, people always tell me that, like, you know... So when you look at housing construction in Europe versus, let's say, other countries, you know, Europe has much more, let's say, durable construction. There's using of less wood or these kind of materials. So, you know, in Europe, maybe we don't need to care about firebrands. But then I said, you know: "Are you aware of the building ventilation?" Because basically, like, you know, there's no test for that. So basically, firebrands will just penetrate into those ventilation situations and, and cause these type of effects. And, and so there's a whole litany of things I think you can sort of look at in tests. And also, I know what's very common nowadays, and I know you, you also worked on this as well, is the green facades, right?

Wojciech Wegrzynski 54:29

Yep

Samuel L. Manzello 54:30

for example, I know like, you know, in-- I was in Milano a couple of weeks ago, and,

Wojciech Wegrzynski 54:33

Oh, you seen the big green building?

Samuel L. Manzello 54:35

you know, a very-- there's some very famous buildings in Milano of

Wojciech Wegrzynski 54:36

Yeah.

Samuel L. Manzello 54:37

facades and, you know. So when I

Wojciech Wegrzynski 54:38

Wow

Samuel L. Manzello 54:39

there, like, you know, the, the audience asked me like, you know: "So what do we think about these firebrand showers and these green facades?" And I said: "Well, you know, we need tests on this, basically," 'cause, you know, I understand that people would like to use tho-that beautiful construction, but also like, you know, if there... You know, I was explaining to the audience, you know, I was giving a seminar at the Politecnico di Milano and like, you know, if there's a, uh, you know, exposure of firebrands, this, this is gonna be a-attacked with this stuff. And like, it's gonna depend how that's gonna perform. Like, you know, nobody really knows, right?

Wojciech Wegrzynski 55:07

And it's gonna create even more firebrands if it, uh, burns because that's an at height elevated, vegetation and a lot of, substrate ground that, that is pretty much a compressed firebrand

Samuel L. Manzello 55:21

Yeah, exactly. So, I mean, and I think that what I found interesting from my, my visits to Italy was that like, you know, there was a lot of, I think, wouldn't say constipated, but just kind of a, uh, very worried faces like, you know, when... 'Cause if people never really looked at the effect of these firebrand showers and then they start to think about, okay, there's, you know... 'Cause I was explaining, you know, the, the fire could be happening at this location and coming into the city and basically like, you know, or, you know, locally you can get these other like firebrand showers also from these green, you know, facades. And so it's, it could potentially compound the problem in something even more complicated than you already have, right? So I think there's, you know, a whole thing of, of, of tests that need to be developed basically that, you know, that we haven't really thought about. And I think it's just mainly because the fact that like, you know, the research community also, and, and ISO itself, you know, really focused on indoor building fires for a long time because, I mean, you know, there was an initial focus of building the science

What Standardized Firebrand Exposure Enables

Samuel L. Manzello 56:10

that's needed for that. and you know, I mean, as you mentioned, NIST played a very important role with the development of the FDS and I mean, uh, various organizations and, um, you know, Jim Quintiere is someone who I respect a lot. For example, I know Jim was on your show a lot and, uh,

Wojciech Wegrzynski 56:23

And he he spoke with great joy on his, uh, collaborations with Japanese researchers, and also he mentioned he, he, he really misses the NES Japan, uh, collaboration workshops, and he was very, very disappointed that there was not that much collaboration these days. So that, that's one of memories from-- of Jim of-- and his interviews.

Samuel L. Manzello 56:44

So, I mean, yeah, I mean, Jim, you know, uh, yeah, I mean, we had that, you know... Now that you mention that, I mean, one thing that we are working on a lot is I developed, uh, this, we called it Operation Tomodachi Fire Research. And so, like, you know, back in the day, there was a lot of work between US and Japan on the UGNR.

Wojciech Wegrzynski 57:00

Hmm

Samuel L. Manzello 57:00

that sort of went away in terms of fire research, and then we made a lot of efforts to re-revisit that in the Operation Tomodachi. And of course, once again, special issue in fire technology, so clearly we'll have to give a plug to Guillermo, of course. But Guillermo supported a lot, a lot of special issues we had on this. Uh, but, um, you know, also I found in research too that, you know, people forget about this. So, you know, when they talk about, these things, I mean, you know, especially when WUI fires, we had a huge workshop series looking at fire structure action, urban fire spread. How does that influence WUI? And, Japan was never interested in the WUI problem, but like, you know, they had a lot of experience in urban fires. And the idea was, you know... But we knew from a physics point of view that, you know, once a WUI fire, you know, a wildfire gets into an urban area, you just have an urban fire, right? So, you know, stuff was known for many, many years ago, but I think nowadays it's, it's also forgotten for whatever reason. And, you know, I won't go into specifics, but I mean, I read a lot of papers nowadays and, you know, I see that people just forget about this and like, you know, are presenting it as something like their new idea. But if you go back in the literature and like, this was recognized many, many years ago. But I think part of the, the, uh, um, issue, and I think what's great about your questions, Wojtek, is that, you know, it gets back to the original thing that even though we were developing these workshops and other series, just people were not interested in WUI fires.

Wojciech Wegrzynski 58:18

Hmm

Samuel L. Manzello 58:18

You know, I was going around and talking about this forever, and everyone's like, "Who cares?" I mean, like, you know, maybe it's gonna happen, maybe it doesn't." And like, you know... So someone who's worked on it for so long, and it... know, I mean, I, I get frustrated when I just see the problem becoming worse and worse, but it's like there's a lot of knowledge that we have that we've developed for years, but it's like forgotten. And, it's just there, there wasn't the focus on, on the problem at that time. And, you know, it's just unfortunately, it's, I think it's taken just many fires all over the place, and especially fires that you normally don't happen, right? Like, you know, I went to Germany. Germany has a problem now. I mean, I know, you know, Poland. I mean,

Wojciech Wegrzynski 58:54

We just had a wildfire outside of Warsaw. we,

Samuel L. Manzello 58:57

even

Wojciech Wegrzynski 58:57

we...

Samuel L. Manzello 58:57

this kind of stuff now have

Wojciech Wegrzynski 58:58

Yeah.

Samuel L. Manzello 58:59

right?

Wojciech Wegrzynski 59:00

Yeah

Samuel L. Manzello 59:00

and, uh, you know, people always ask me just in the US case, I mean, you know, California had it, but no reason that they get should be limited to California. I mean, you know,

Wojciech Wegrzynski 59:07

Yeah

Samuel L. Manzello 59:08

historical fires have actually never been in California itself, so, and I'll get off the soapbox. I mean, complaining about it, but it's just, you know,

Wojciech Wegrzynski 59:15

that's an example of a very sad I told you so, and, uh, I mean, it's great that we, we have this interest right now. But it, it, again, we, we can, uh, we can be disappointed about the, the way how science is carried, but it is kind of, you know, thematical. What, what, what's kind of sexy topic right now? What's gonna get published? What's gonna get citations? And, uh, I mean, those topics, of course, trend in popularity right now, but I assume 20 years ago it was not a subject that's gonna immediately get you all the citations you, you would like, and probably compartment fires and, you know, uh, physics at the level of compartment and building was that thing back then, explaining why NIST some years ago was perhaps more building-oriented at, uh-- and, and less, you know, open to, to wildfires. Now they do great wildfire science, so, uh, everything shifts. It's, it's sad you have to move the whole machine to, to, to get there. Um, Samuel, with respect, uh, to your time, I think we're gonna f- finish here, and I'm, I'm, I'm really thankful, uh, that, that you, you came here. If you would like to leave like a, a, a final summary message to, to the listeners or perhaps, uh, what's the top one priority to focus right now on, or maybe, I know, a call for more collaborative efforts. I know, uh, that's also important to you. Uh, th- this is the time to do that.

Samuel L. Manzello 1:00:40

Thanks. I, I appreciate being here and, um, uh, I, I really enjoyed the conversation, and I think it's important that, you know... My message probably is woomera fires are important. I mean, you know, even in the most recent IFSS in La Rochelle, I mean, we don't have a lot of focus on, on woomera fires, actually. I mean, and like, you know, it's still, in my opinion, very, um, building fire driven basically, and I don't ha- you know, have an issue with it. But, you know, one thing that we issued, uh, many years ago for the, the, the former fire research directors is we made an opinion paper about, you know, what we need to do for woomera fires. And, you know, at that time, we were basically saying in a very, I think it was direct, but a very direct manner that, you know, we've done a lot on, on, on fires inside buildings, but we need to do stuff on outdoor fires. And this is, I think, really important, especially in woomera fires. So, I mean, I think we need more research and also I, I don't think I have to so much convince people that it's important anymore. But I mean, like, probably take a lesson from me hopefully that, you know, as someone who's going around for-- talking about it for more than, like, you know, two decades, I mean, don't give up and like, you know, it seem, you know... And I mean, we keep working on it and, you know, e- eventually, I mean, I think it's a... You know, it's become important globally and, uh, I, I hope some of it is also because I've been going around and complaining about it forever. Like, you know, I complain about them. If you don't know me, I mean, some people will tell me that I'm a, maybe I'm a, a hard pill to swallow and whatever. But one thing you have to understand is I don't, I don't mean anything, you know, by it. It's just that, you know, when you see something happening that I think that as a community we, we could do a lot for, know, e- every time I see somebody's house is destroyed or something is happening, uh, it really hurts me personally. So, so

Wojciech Wegrzynski 1:02:13

Mm-hmm.

Samuel L. Manzello 1:02:14

that's what keeps me going on because I don't, you know, I don't wanna lose my entire family's photographs or, you know, your pets or a loved one or those kind of things. I mean, it's a very disturbing thing to me, so it affected me a lot personally. So I just wanted to try to do the best that I could for this. And I know I'm probably failing, but the thing is that like, you know, I, I still think it's important to try to

Final Message And Why This Work Hurts

Samuel L. Manzello 1:02:35

do the best that we can for, for, for something that you believe in.

Wojciech Wegrzynski 1:02:38

Thank you. Thank you, Samuel. Big props to, to your collaborator, Professor Suzuki. I'm looking forward to see you, somewhere, somewhere soon and catch up again, and I hope, uh, y- you will be willing to come back to Fars Science show in some time to maybe dig o- into some of those problems in, in more details. Thank you, Samuel.

Samuel L. Manzello 1:02:58

Take care. Thank you

Wojciech Wegrzynski 1:02:59

And that's it. Thank you for listening. I actually had the pleasure to meet with, uh, Samuel and Professor Suzuki last week, and, uh, we had a very nice conversations about life in Japan and all, all things wildfire-related. Thanks-- thank you for, for that, Samuel. Um, in regards to the episode, I think the standardization of the firebrand exposure is exactly what we need to develop a more robust solutions for protecting against them. While they come in variety of shapes and types and can be generated by different fires in a different way, the wind will shape them differently. Quite a, quite a challenging problem if you want to, to deal with it. However, once a standardized source is defined, a lot of this variability goes away, and you can actually work on practical solutions. Yes, it will not cover every possible outcome or scenario, but at least it gives you a chance to, to start working on something, and then with sensitivity analysis and, you know, more testing and, and verifications, you can improve those solutions. So a very, very important effort to, to, to have the first step, this, this new dragon that is defined by the ISO standard. I hope it will become the golden standard in generating firebrand exposures, and perhaps it's gonna get somehow incorporated into the existing standards. I think that would be a very much needed development that this thing becomes a part of the roof standards, of the facade standards, of the doors, windows, ventilation openings, all the f-fragile elements of our houses and buildings that lead into WUI fire vulnerabilities. So a very important development, the first step in that, and you've heard some history behind that. It's not an overnight thing that happened. It's years and years of experiments and testing and building, uh, new iterations. And also, I have to highlight that, that Samuel is very, very active in ISO, very active in IAFSS. We've touched a b- a bit on that in the episode. I'm not sure if we gave it the justice. It's really huge work to lead the ISO group, and it's a huge work to, to lead the LOFBY group at the I- at the IAFSS, and he's doing both. So thank you, thank you very much for, you know, merging those communities. Samuel is also involved in JRC, the European, uh, in Joint Research Center expert network, where we meet, uh, every now and then, where he also updates us on the developments in, in the WUI. So yeah, very, very active man. Anyway, I think that would be it for the today's episode. I hope you've enjoyed this experimental view on the wildfire problem and, uh, learned something today, and I will be definitely looking into the dragon technology and how to incorporate it in my testing. I've I've been looking at it for a long time, but I think it's time to, to finally build one. Thanks for listening to the Fire Science Show, and if you want more fire science, it's gonna come your way next Wednesday. Cheers. Bye.