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Dec. 1, 2021

029 -Busses, flammability and an unknown force holding good solutions back... with Anja Hofmann-Böllinghaus

029 -Busses, flammability and an unknown force holding good solutions back... with Anja Hofmann-Böllinghaus

This is not a fun episode. It starts with a tragedy, that fueled a whole field of research. Continues into disbelief, that one aspect of fire safety can be at the same chosen as the sole foundation of fire safety within a branch of engineering, and at the same time at a pretty low, clearly insufficient level... And then comes the true shocker - solutions exist and we just don't use them. Because of, who knows why. An unknown force...

Ok, I have spoiled you a bit, but it is absolutely worth hearing the full story that my guest, dr Anja Hofmann-Böllinghaus has to deliver. It is a journey through the world of the resistance to fire and at the same time the frustration and challenges that fire engineers have to go through. And above everything, it is a call for making busses and other means of mass transport safer, by employing the knowledge and solutions we already have!

If you liked it, please take a minute to connect with Anja on her Twitter and LinkedIn 

If you would like to learn more about the fire safety of means of transport, please check out these items:

Also, please check the website of the Fires In VEchicles (FIVE) conferences, which is possibly the best place to learn about the issues and solutions within this sector  - https://www.ri.se/en/five

Transcript
Wojciech Wegrzynski:

Hello, and welcome to session twenty nine of the Fire Science Show. So let's start with the tough question. Can you tell a difference between the bus and a train... Well, I guess it's a horribly posed question because it's little obvious, but yeah, let's, let's rephrase that quite a bit. Can you tell a difference between a fire that starts in the passenger chamber of a bus or a coach and the fire that starts in the passenger chamber of the train? Quite similar environments. In fact, they have seats, upholstered. They, they have some sorts of carpets, linings, ceilings. They are filled with people, passengers who carry their luggages. So in the end, the ignition sources, the materials, the architecture of the compartment. Do they seem quite similar. Yet if you had the fire start in the very same way in the bus and in the train, they would end up completely differently. And, that has a lot to do with the materials used in this two vehicles. And more precisely the way how the fire properties of these materials are assessed and what is allowed to be used on both of the types of the transport vehicles and, uh, to discover what truly makes the difference between those two and, what made one of them so much worse than the other? I have invited Dr.Anja Hofmann-Bllinghaus from German, BAM and she's one of the leaders in testing the material is used in modern vehicles. she's gonna tell me a lot more about how we test our vehicles, how we achieve safety or how we don't achieve safety in some of them. And what's truly missing to create a lot safer world in the world of transportation. It's very interesting because a lot of what we say, can we extrapolate it from buses and trains into passenger vehicles and maybe to in the whole building industry, because so a lot of these methods , are very, very universal. I hope this will be very interesting to you. It was very interesting to me and you really want to hear what Anja has to say. So maybe in our fields, or your fields, we avoid the mistakes done by others. Enjoy. Hello everybody. I'm today here with, Dr. Anja Hofmann-Bllinghaus. Hello, Anja. And good to see you.

Anja Hoffman:

Yeah. Hi, nice to be here. Thank you for the invitation.

Wojciech Wegrzynski:

Thank you for taking the invitation. I'm very happy to have you here. Uh, we've came here to discuss, issues of fire safety in mass transport, because I've heard you've did a lot of research on fire safety of buses and material properties used in the. And, then I was like, well, that's a, quite an unique, research topic. I don't know many bus fire scientists. I do, uh, lots of research on, passenger cars and car parks. So it's actually super interesting to me, uh, please tell me what, what pushed you on this pathway to focus on, on fire safety of mass transport and buses in particular.

Anja Hoffman:

Yeah, it was mainly a very big fire in Germany in 2009. Uh, whereas the whole bus burned down and, uh, had many facilities. We already, before this happened, know that the materials interior materials, uh, were not as good as in other transport sectors. And so we were not that surprised that the whole Bus burned down. yeah, but, it gave us the opportunity to have a project on this bus fire in particular.

Wojciech Wegrzynski:

Was it? The fire of the vehicle? Uh, like alone or was it like in a tunnel or it was just a bus that burned down and people died in it.

Anja Hoffman:

Um, it was a bus on the motorway. And, , the problem was that your fire was not detected in the first part of the development. So it developed, , in the toilet and luggage area for some time. And, the bus, has an air conditioning, which sucks, air from the top and push it through, she was a floor so it was a smoke, came out of the bus underneath. So it was a bus driver. Didn't see that there was. And, um, the cars behind the bus try to alert him, that there is a problem and that there is smoke. and then he stopped, but, it is assumed that one passenger opens the toilet door and gave the, uh, fire oxygen. And then, , the whole cabin the whole passenger, cabin was on fire very quickly. And then, um, there's a toilet is, close , to the rear exit. And so it was a rear exit was not, usable. And so, , the passengers could only use the front, exit and all the passengers who were behind this rear exit had no chance to leave the bus because it was so quick, the development of the fire in the passenger cabin Uh, the people who survived, say they could tell that they couldn't even, , rescue the ones which are really close to the exit because it was so hot. And so much smoke that a, couldn't even grab the uh, people who were very close to.

Wojciech Wegrzynski:

That is such a horrible, , Combination of, unfortunate events because you have a concealed fire that's undetected, you have a space with the ideal ratio of ventilation to fuel, to a, let the fire grow, but stay in this, let's say in incepient stage So , it's heating up, but not flaming to give warning, but again, not like going out. So it's just smoldering. So it must have been like quite the big fire in there. And then a quick opening, a quick gulp of air and you like almost have an internal backdraft inside the bus,

Anja Hoffman:

Yeah, we some FDS calculations at the time. And we could show was that if you have a fire, which develops in this area where it's not that much air and then you give air to the fires and then you have a very quick, filling of the whole passenger cabin with flames and smoke. In a way, shows that this scenario is likely that someone opened the was a toilet door and, that is a made the situation so bad

Wojciech Wegrzynski:

This scenario is nothing very uncommon in buildings. Like this is how, backdrafts happened. This is how many firefighters train, uh, these situations, but we're talking about buildings not sitting comfortably in a bus, on the motorway. So we probably had, and also you would not like to jump from window to motorway

Anja Hoffman:

we had two fires actually. It's funny that you say that we had two fires with this younger people, in i think as, uh, two three years after this incident and they survived because they smashed the windows in the upper deck and they jumped out of the window, but I don't think a normal passenger can do that because it is quite high and you have to be really fit to do that. So it was only lucky that his passengers were so young and so able to do that. If you have elderly passengers or passengers who are, have a reduced mobility, I don't think it's possible.

Wojciech Wegrzynski:

And before we jump into the material properties, because that that is that interesting topic, if this happened on the plane, for example, you would have the cargo smoke detectors, most likely. I would pick up the incipient stage of the fire and so on. Did this tragedy led to some sort of introduction of, , detection in, buses afterwards?

Anja Hoffman:

Yes. , a lot of, companies, introduce this smoke detectors very quickly, but it became mandatory. Then after a few years that you have smoke detection in areas as a driver you cannot see. So, um, this fire probably would have been detected earlier if there had been a smoke detector, it's a time in the toilet or in the luggage area.

Wojciech Wegrzynski:

So, with, new regulations, it may be less possible for such a deadly fire to occur because, the, Fattal outcome of this fire seems to be a combination of many things, but, one of them has not really changed that much, or I will. How much it changed and that's the material properties. And, no matter if the fire is detected or not, no matter if the bus is on the road or parked in the lot, we know that these vehicles can burn. They are quite dangerous. Especially when you have like a hundred of them parked next to each other. And we had this fires , of like large bus depots we had some in Poland. I know, I think in Stuttgart, there was a recently a large fire of this type

Anja Hoffman:

Yes. We had several, I guess, this year in Germany and bus depots where you see that. Yeah, that just spread from one bus to another very quick.

Wojciech Wegrzynski:

And, the consequences of such a fire are well beyond the, just the loss of a vehicle, because it's a huge disturbance to the local community. If you lose a hundred buses, the city can have quite a big issues, uh, operating. Like we would just buy old buses from Germany, but yes, you, you have to manufacture them, I guess.

Anja Hoffman:

Yeah, I think, if they can't operate them for the insurers, that is sometimes a bigger problem when they can't operate the next few weeks or months, then there's the actual loss of service. But if you have bus depotsand you have 20, or even, I don't know, we had a fire in 2011 with nearly 70 buses in one incident.

Wojciech Wegrzynski:

Now that is quite the disturbance. So I'm going to them material issue. I assume you've started interesting in materials after this big fire. And what was your first surprising finding regarding the materials? What did you expect when you've entered the study and what did you find out about.

Anja Hoffman:

Yeah, we were really surprised that's a requirements for the automotive sector, are uh, really below all the other transport sectors. The requirements are going back to the 1960's and, they consider mostly very little ignition sources like lighters or matches. They're supposed to be smoker equipment. It was b ased on the assumptions that someone who smokes in the car doesn't set the car on fire. But over the years, I mean a car or a bus from the sixties is not really comparable with something we have today. So there, the amount of plastic is really not comparable to these older buses. And, it seems unreasonably, you said it's, um, Plastics than before for comfort and for other things. And, so it was the materials behave quite different from say train materials. And because the requirements are so low, you have, total different fire behavior as materials if you compare a bus seat and the train sit, they burn completely different. So it's not only the material itself, but if you have a component like a sit that it burns totally different. If you have a train seat. And we made a lot of experiments with, paper cushions and, cushions, we ignited this paper cautions on top of the seat or a seat mock up and the train seat is. So that it's not burning, there's a paper cushion is burning and then it's not burning further. And, if you have a bus seat and within two minutes, a whole, the whole seat is burning and it, doesn't stop.

Wojciech Wegrzynski:

Yeah, I have in front of me your report, buses, and there's like an array of, pictures showing, the calorimetry tests of train seats, coach seats, city bus from 95 and city bus from 2005. And I assume, from the pictures itself, you can clearly see, , how different each of them behaves and how bigger, the fire is when it's, in the city bus. And it actually develops after the initial of the fire source , is removed. So. This, concept of resisting the ignition sources is east clearly feeling here. I know my colleagues, we have similar issues with testing, building materials, and I know they have some tests where you have, for example, put, cigarettes against the material to test. And we were actually running out of cigarettes that meet the requirements of the standard is a quite quiet, difficult to obtain a, such a horrible cigarette.

Anja Hoffman:

Yeah.

Wojciech Wegrzynski:

As the test standard requires, here, I always had this, I know no doubt interest in understanding these tests because for me, when you define the ignition source, so well you can, I was a producer I could play around it. You know, I could make a material that, resist this particular ignition source and just stop my development after that because I've passed the test and I'm good. And if you look at the that from, scientist perspective, if you go into like material science, even at the simple concept of activation energy or ignition temper, It's not that it doesn't ignite you just move the boundary of what is necessary to ignite that. So my next question is, did you go beyond the ignition properties and, and kept burning these items to learn more about them?

Anja Hoffman:

Um, yes, we, we compared them to the tests from the train sector. So we put, bus materials. We obtained from suppliers or, , one , from a real bus. We could take , some specimens and we tested them against the train regulations, European train regulations. And you can see a very big difference because none of the materials we tested, from the different sources would be allowed in a train. So we found not one single material which passed, the European tests for trains. and, I think trains and buses, some of that different if even many look yeah. How they operate. So, the argument often is that the bus is, easier to stop on the street and that it can stop everything. But on the other hand, you need some time. I mean, if you're on a motor way or if you're in a tunnel, you need some time to stop and you need some time to evacuate, so I think if you compare, a city, tram and city bus. It's it's not so different

Wojciech Wegrzynski:

And was, it was like all flammability characteristics. Like it was both the heat release rates smoke production, uh, the yields of toxic materials, or just some particular ones that went out of range.

Anja Hoffman:

It is more or less everything, unfortunately.

Wojciech Wegrzynski:

that's very positive.

Anja Hoffman:

Yeah, I'm sorry. These are the main test in, the automotive sector is a horizontal test and, I think I don't have to explain to you, I mean, if you're, if you

Wojciech Wegrzynski:

Yeah, but you're very, very welcome to explain it to the listeners.

Anja Hoffman:

if you have a match and you hold it in horizontal way it will not burn very much. And if you, have it in a vertical direction, it will burn much more. So it was the horizontal test is not merely discriminating, a lot of materials, which means in the end that you can use a lot of materials. You are not allowed in other sectors. I mean, even in the building sector, you have a vertical test is a minimum flammability tests. And this is the same in the train sector in so ships and we say aircraft. I think the horizontal test as a minimum requirement is not working very well because, , it's not discriminating enough materials. So at least it will be good to have, vertical tests as a minimum requirement as it is in, in others sectors. In all the, as a transport sector, as you limit the heat release rate and, the smoke production and the toxicity and , In the bus sector or in the automotive sector, you only have the flammability more or less. You have the vertical tests and the horizontal tests. And you have one which is a smelting, the specimen, but you don't have anything which measures the heat release rate or limits the heat release rate. And you have nothing which limits the smoke production or is it toxicity?

Wojciech Wegrzynski:

This is interesting. So, so you said that, in this particular area the whole, fire safety of the, vehicle\ actually was brought down to the concept , of pretty much ignition. So, that's the one and sole layer of protection that it's actively verified with these horizontal tests and melting to some point, I

Anja Hoffman:

Yeah.

Wojciech Wegrzynski:

a, but that's also a characteristic that I would put into the bracket of fire spread. more than anything else. Uh, because before your, ceiling starts melting on passengers, they're probably already dead from the smoke anyway. It's very, ignition oriented where. Uh, from the test that I know where you would do heat release rates in any form, even simple heat of combustion. That's an indicator of, let's say the amount of heat or the size of the fire that can be produced. If you do cone. You look at the very beautiful picture of the fire behavior of the material, including reaction to heat feedback. Ignitability into the production of toxic products. When we go into, into buildings and how we would verify many of the features for the buildings, you would enter this , single burning item tests SBI, where, you would holistically look at the fire behavior of an element. And I can clearly imagine myself putting a, bus chair inside SBI that's perfectly viable and could be. And, if you go up there's room corner, maybe not, , as used as many years ago, but also holistic view on, the characteristics of your, but materials in compartment. Your view and your possibilities of understanding the fire behavior are like infinitely bigger than just flammability. Do you miss this features in this simple tests?

Anja Hoffman:

Yes. Several aspects. You have a very small ignition source, like a Bunsen burner. So even the flammability test is not very strong. And, in the recent regulations, you have more of the vertical test, but only for vertical mounted materials. So something like the ceiling. Not vertical mounted would not have to pass a vertical test, but it, can promote the fire very well because you ignite ignites a ceiling very fast and then it spreads very good. And, then on the other side the heat release rate and smoke production rate would tell you something, obviously your ability to, to spread the fire. And if you don't limit the heat release rate Really really high heat release rates. And it will tell you is it's a fire propagates through the passenger cabin very quickly. And if you don't limit as a smoke production, you will have less visibility very, very quickly. And so if the passanger just can't see easy, easy exit, so I probably won't be able to reach it. So, with this fire in 2009, um, they found passengers which were still stripped on their sits, so they didn't even lose the seatbelt, because it, it was so fast. So, and that yeah. Tells you something about the, the timeline in this development. And that is, if you look at pictures from bus fires, you very often you sees the same picture. That's, there's no combustible material left. You only have the metal parts of the bus. And this goes really, really quick. So if even if the fire service is relatively quick and is at the scene at 10 minutes and they don't have any chance to rescue. Somebody. So you have a situation when you accept that's a fireservice, can't rescue anybody body. And there's this for me, that is a strange situation.

Wojciech Wegrzynski:

I took you here on purpose because this particular issue. It's like a microcosm of the issues of fire safety we have in all sectors of fires. That's the methods driving the development, not the fire safety focusing on one particular characteristic of a material. Also in the context of passing a test without having a holistic view over the use of the material and the environment in which it will be used, focusing on small scale. Events such as an ignition of a chair Without considering, uh, how this behave when it was a group of buses parked next to each other, where your heat release rate or the size of a fire next to your bus is so tremendous. You're, doesn't matter what your, ignition temperature was of your material. It will ignite. And, I guess in your very deep work on this subject, the government asked you to investigate this, to prevent this, in your study. did you reach these conclusions? Like, this has to change otherwise this large-scale evens will continue.

Anja Hoffman:

Um, yes, I think we had several recommendations. It was a smoke detection. It was the engine suppression, because a lot of fires, at least in the, classic busses are starting in, engine area. And so a suppression system is, is very, um, useful to, Slow down the fire until the fire service is on scene. One aspect we recommended, I think we are recommending this for 10 years now or something like that to do something about the materials. And there is very slow change. I mean, there is this change that you use a vertical mounted of materials now have to be tested vertically but this is more or less the only thing which has changed with the materials.

Wojciech Wegrzynski:

From my perspective, I'm very interested in the topic of fire sources and size of fires and, plastics in relation to the size of the fire, it's also something that is, I'm really curious. And maybe, , we can talk about that. The use of the plastics in our vehicles, over the decades, how it's changed and, Does this invalidate our assumptions for fire safety in many of the infrastructure projects, because I'll give you my example. We do design car parks for passenger vehicles. And, because there is no. Very much research on the fires and passengers vehicles. There is very few holistic projects on that. We still would base our design from a fire, tests by TNO in 1999, because they were very well documented. They were done in the car park. They were very well. Performed experiments. Of course there were further experiments in BRE , there were some in Japan recently, not saying that there was no research, but I still find it very hard to replace my 20 year old design fire, because I feel confident regarding the setup, not this is really the vehicle and now. 1999. So they've burned vehicles, like not fresh from the factory. They must have bought like few years old cars, like VRE, both 10 year old cars for their experiments. So I'm basing on like beginning of that, of the nineties. So vehicles from that period would now be considered classics and they increase in value now. And, , the. Completely different from what I have and what I see in my carpark. Like it's a totally different planet, a completely different, every, everything is plastic, everything. So maybe you have a number for that, or maybe just rough assumption, but to what extent, this increase in how much it changes the holistic image of the vehicle fire.

Anja Hoffman:

no, I, I can't quantify it. I'm sorry. but what I can say certainly is that it's a cars up totally different from, from the curse 10 or 20 years ago. So they burn quite different. So you see sometimes if you only look at the parts there, they're a very big difference. And, , we did this, seat, experiment you mentioned before. And unfortunately the newest seat burned much more than the older seats. So even in this bus, you could see that after a few years, the situation got worse and that is not something you would expect. I mean, you would expect that the more modern seat, burns, not as much as the older one, but it's, that's not the case. Your old seat has a wood parts and the newer seat didn't have any Woodpro parts anymore. And, there was a foam. Totally different. can't say what it is because we, we don't know it was from, from two actual buses, but, it was, um, thicker and it was more material it looked and felt different. So there is a lot of change in this materials and that, leads to, to a totally different burning behavior.

Wojciech Wegrzynski:

and it's um, more material. It's easier to ignite. And, from your report, I also assume it's, also more toxic, right?

Anja Hoffman:

We found that so smoke production is very high and let's say toxicity is very high in, was it toxic components are very present. And, we try to find out whether you can, , limit one perimeter so that you don't have to look at everything. And there's a train regulations are quite complicated because you have to limit the smoke productions, the heat release. And the toxicity. And so you have yeah, a whole set of experiments and then we saw maybe it can be easier, but unfortunately it was all the materials we tested. We found that, , if you have a material, which is okay, in terms of heat release, then you can have a very toxic gases or very high smoke production. So you need to look at all those three parameters. Additionally to the flammability to, , have really of material which behaves better. So, , it is not enough to, look at one of these three parameters, but you have to have a limit on all of them so that you really have materials, which are better than sense of once you are using.

Wojciech Wegrzynski:

I also have my eyes on the graphs from the toxicity, of your reports. And one thing that's really stressful to me is that even if, some materials perform well in them. There are other materials who will perform horribly bad like in one of your tests, HCl is produced not in a, such a bad moment for like, seatfoam or insulation materials, but then you have floor coverings , or ceilings. which go crazy. And, on other graphs it's opposite. And yet in the vehicle, you have the perfect mix of all of them. Did you try, or maybe, you know, any tests where it would be tested like holistically, like the whole vehicle would burn and these would be measured or, or it was not

Anja Hoffman:

No, but I think you need, , at first you need, um, a scenario you want to address. I think with all the asset transport sectors say they have. A scenario in mind, which they want to prevent. I mean, they have minimum escape times we didn't even agreed on that so far. How many time do you need to leave your bus in the case of fire? And so no test is really addressing this and, um, I think, yeah, we, we need to concentrate in what do we want to, to reach? Do we want to have, say 10 minutes or 15 minutes for the person just to, to leave the bus. Okay. You need to test, which shows you in the end that this is possible. I mean, we, we try to combine numerical simulations with our small scale tests. Um, what the benefit is of some materials. And I think you, you could do this. If we had one calculation where we, put in our, , model, train seats, and, then we looked out, I was a fire with develop. If you have a train seat instead of a bus seat in your bus, and then you see that with this, , Paper, cushion I mentioned earlier then your, , development is so much slower that you have so much more time to escape. So is that would really give a very big benefit. And I think if you would have better requirements for seats you probably what have really big Bennett benefit, for the passangers

Wojciech Wegrzynski:

I also find this really interesting because for me, it's very difficult, to change my point of view. Into the safety of the vehicle and vehicle users, because I'm so used to car parks and tunnels where I would care about the infrastructure and everyone else basically. So it also shows how we're like. In kind of separate bubbles, uh, like I, I enjoy talking to you and you most likely enjoy talking to other fire scientists, but there is no industry to industry discussion. I feel there is no discussion between the car industry at a whole, with a built environment industry as a whole.

Anja Hoffman:

true. Hmm,

Wojciech Wegrzynski:

and you cannot separate the world of vehicles from the world of buildings, which are full vehicles to, use. And I find lack of, connection here that's really, really bad for us all, because, there is so much we, as, as the building industry, could help with the other industry, like identify with all the test methods with cone's with everything. I mean, we've been there. We had combustible linings in buildings. People have died and we fixed that. We had a horrible flammability issues and one way or another, they were controlled. We're battling with. Burning facades and it's also a similar issue. So it would be great. And then we have to design our buildings for the dangers that this industry is preparing for us. And now on this topic, on the dangerous that industry is preparing. So let's go into the world of electromobility and I'll start this by a very bold statement of my own. I would claim. That the change in the amount of plastics in the vehicle and their burning behavior is a far bigger risk factor than just using a battery or, electric motor inside. I personally, if I see these two problems and I would have all the money and resources to solve. I would go materials, not batteries. And what would you pick

Anja Hoffman:

Um, I agree to a point, I think, , if you, uh, compares of fire the engine fire from a battery and, , and a gasolien, fire. it is comparable. So it just, uh, I mean, you have some additional problems in, in both of them. I mean, if you have fuel and it can, distribute itself on the floors and you have other problems as with, as a battery where you have more toxic cases maybe, or some other, yeah. Something like that. But,i think the materials are quite a big problem in both. And, um, often they are not addressed. Often you were talking about the, , the engine or the battery. And then you think, okay, that is really comparable. And I agree, but there's a whole part of the materials is not addressed and you have a lot of problems in this area and I agree that they should be. I think one month problem you have with your better uses, if you're charging them, you're introducing another possible ignition source. And we saw this in some of these depot fires that, sometimes the battery it causes the fire. And so if you have a car park or a Depot and you are charging, then you're adding more possible ignition sources.

Wojciech Wegrzynski:

You know, it's frustrating. There is this debate on, on electric vehicles and everything in the. Vehicle's side of fire safety is now so electric vehicle oriented and there that's the next big thing, but you go over the fact that you have one ton of, highly combustible plastic in your vehicle. And this battery is, is not really changing that much. From the infrastructure point of view, the largest fires in car parks that happened recently, , Stavanger airport fire the Liverpool, uh, Echo fire. We had a huge fire in the Warsaw we're a large carpark as burned down. This were not so devastating because we had a vehicle with batteries. No. they were devastating because, cars are very flammable. They contain hundreds of kilograms of plastics. and they're in a compartment that essentially is designed to be quite well ventilated because you need to remove the fumes from the vehicle. So essentially you're putting, uh, Fuel into well ventilated space and , that's what you get. Yeah. So, , so I assume from our perspective in our infrastructure, it's so highly underestimated the flammability of cars. And I guess from this talk and how you described it, the testing and, uh, the safety procedures in the world of large vehicles, I guess, is the same for you.

Anja Hoffman:

If, if you look at this Liverpool car fire, you saw that the structure was really destroyed after this. So it, it was, so it was not made to, to survive that. , and if you look at, bus depots, at least there's a fires we had in Germany. A structure was, destroyed as well. And with the buses, you have the additional problems that if you try to extinguish them from the outside, they are rain safe. Of course they are made to be rain safe. So, you have really a problem. If you have a, bus Depot, which is really packed and they normally do this because. They don't have that much space and they want you to make use of this space. So their buses are very close to each other. And then, if you have one fully developed fire in one bus, normally it's very difficult to save the, others because you already have so many, um, hot gases and smoke. , you release with this one bus on fire, and if you have a ceiling then you distribute a whole hot gas layer, over all your buses.

Wojciech Wegrzynski:

Okay. let's make a full circle at the startyou've said that, uh, you've observed it being quite different from the other transportation, , industries like trains and I assume aircraft as well and Marine as well. , Do you think, eh, that, for example, in terms of trains, , the issue is solved and the same methods would work in buses and potentially in other industries. And if yes, how would you rank them? What would it be the best to implement the quickest, to, to get the best return?

Anja Hoffman:

um, I think from my perspective, the easiest would be to say, we use as a train materials we already have from some marketing buses as well. That would be a very easy and very.

Wojciech Wegrzynski:

like black, like your plastic seats, cautions linings, like these cusions of materials? Yes.

Anja Hoffman:

Yes. So if, if you would say you need the same requirements as in trains, I mean, the trains and the buses have, , different levels, they address. If you have a train, which is only on yeah. Like a city train. Less restrictions. And if you have a train, which is going long distance and using tunnels, and you could apply the same approach on buses as well, I do think that you don't have to be as strict with a city bus as with a, , bus, which is, uh, doing long distance, whereas the people are sleeping and which is much more comfortable. So you have this differences in buses, in training. Would be relatively easy to find something which satisfies the needs of different buses in the same way as it is done with trains but it would of course, make the materials more expensive

Wojciech Wegrzynski:

I'm surprised because I thought that you would say it's a to implement the same, , testing methods or, , transport some let's say approaches from the industry. But, what you've said is actually so much, so much smarter , the good materials already exist. It's like, it's not that we stand at the end of the. The road and we have to invent a new material or we fail. It's just, they exist. It seems the issues with the ranking system and, how we let some materials be used in a certain way and, how some other materials are not promoted. And when it comes down to economic incentive, it's always the. The cheaper one, uh, will outpaced, the more expensive one. That's quite sad that it's in the end, it, it comes down to, to, to the money because it's society that pays for mass transport. And I guess it wouldn't be such a big deal to transfer that.

Anja Hoffman:

No, I don't think so. I mean, if you, if you compare a, , example from a different area, if you see mattresses in the UK and mattresses saving in Germany, but I think most of them in most European countries, it's the same. We don't have in Germany, any, requirements for mattresses in the UK is, are requirements are relatively high. And, if you go to, uh, this speak Swedish, uh, shop how's you there was a price it's really comparable. It's not that the UK mattress is so much more expensive than if you buy this in Germany or another European countries. I guess if you would have a new regulation, and it is mandatory for the buses and, I don't think the price would increase as much as you now estimate if you only look at the difference between trains and buses.

Wojciech Wegrzynski:

So in the end, it's all about, it could be all about smart legislation and just promoting the, the good rules. I have last question related , to the best of your knowledge, these regulations related the flammability and the use of materials, are they also applied in like, , passenger cars or does a world that's completely different or.

Anja Hoffman:

No, that's, that's very harmonized. The whole automotive sectors is that this is good. It's very harmonized, nearly worldwide, very harmonized, but.

Wojciech Wegrzynski:

Just with w just with the wrong standards.

Anja Hoffman:

But that's a pity. That's a requirement. Not so high. Yeah.

Wojciech Wegrzynski:

So, so this, like issues with flammability, plastics, toxicity in everything, it's the same, like pathway us as the large vehicle and it would, it just a different scale, but the methods would be the

Anja Hoffman:

yep. Yes. You have more or less the same tests with the user cars as well. I mean, normally. Less passengers. So your problem might be smaller, but even with the cars, you see that after a, you really have a big danger for the passenger to die in this in this accident. I think it is an issue with the cause as well, only on the, on a, as a scale because you don't have this single. Uh, severe incidents. You have more, a lot of smaller incidents. And so it's not so visible, but if you look at the news, you see very often they said that a car had an accident, a collision, and then a fire, and then it was impossible to save.

Wojciech Wegrzynski:

I I was quite aware of the issues with plastics and everything and how the vehicles changed because there was recently a very good report by NFPA on the evolution of, of vehicle fires. And I know there's a follow-up to that one, with full-scale, uh, electric vehicles, experiments. From my perspective, that's exactly what we need to build better infrastructure, this holistic testing. And from your side, , it's also seems optimistic that if you only could change the testing regime and standards and promote this better methods. Yeah. I hope you eventually will unleash on the industry. And then if Germans do that, that's like half of the cars in the world already. So we can, we will be, we will be much, much safer, thank you very much for this, , interesting talk with some really, uh, sad conclusions that the solution may be simple it just costs a, uh, maybe not even too much, it's just the customer doesn't want to pay. That's

Anja Hoffman:

Yeah, I think it's is a willingness is not, not there. It's a moment to, to change. So I dunno. Don't hope said there is another big fire, which changes, but yeah, I still hope we can have some change result. And that was a major fire.

Wojciech Wegrzynski:

Maybe, , Episodes like this one will help, uh, promote the movement. , towards was the better that's that actually is the point of doing this.

Anja Hoffman:

Yeah, very good. Very good. I will really appreciate that.

Wojciech Wegrzynski:

I, I hope so. Thank you so much. Anja, for your time, , talking about this important issue and yeah. All the best. If you change the industry, please let me know. I would love to make a very optimistic follow-up episode to this one. . Anja Hoffman: Yeah, I'm, I'm the building sector as well. So maybe that is, I mean, I don't know, and with facade, so, but that is not a funny topic either. thank you so much once again. And see you around.

Anja Hoffman:

yeah, thank you.

Wojciech Wegrzynski:

So after this talk, I feel slightly depressed. We have identify the quite the problematic field of engineering. We've identified quite a significant problem for the, for the environment, for the people with, flammability of materials used in modern vehicles. Buses. We have identified quite a problematic area, where the flammability standards or reaction to fire standards may not be doing the best job filtering good solutions from bad solutions. And then. On the other hand, just next doors. There's a very similar industry in which similar issues have been solved for years and years. And. They are so, so similar to each other, but yet there is no transport of knowledge from one to another. Why I don't really get, why cannot we have the same materials that we have as we have in trains in our buses. I mean, if it's identified that it is a problem, if it's identified. People literally die in fires because these materials are not good enough. And from the research Anja was quoting and I'll link some of that in the show notes. It is obvious that materials are a significant part of the issue. So if it is so obvious, why cannot we just change the materials? There is this unknown force that is holding us back and, I'm depressed because I see this, invisible force or glass ceilings everywhere in fires. Everywhere where we have a bunch of legal testing frameworks that are so coupled with each other in ways that it's impossible to decouple them anymore in, in ways that prevent us from really engineering the correct solutions, because they would suddenly not meet the requirements of the law. Why. Are we forced to stand with these regulations instead of choosing a pathway that is known and is known to be efficient, working and providing safety to the users, it's horrible. And I really appreciate that people like Anja exist, who researched that, who show this, , disturbance on paper. Proofs. It's just sad that it is so hard to reach the people in charge with this message And I would love to make a call to action to all of you, so you can reach out to your authorities or something, but I understand it is unrealistic. So yeah, maybe the best thing is just to share the knowledge we have, seek for the best solutions and promote them , wherever we can. And just used science based evidence as the foundation of our engineering. And , let's just try to create a fire safe world, one project at a time. And when you have a chance to talk with the authorities, if you see an issue like in here with the materials used in buses,take action, educate, and maybe this will help solving one of. Issues of the world Which for some reason are still unsolved, even though the solutions exist, it's actually mind blowing that the solutions are there. The materials are there. It's just not being used because the regulations don't promote them. Anyway. it was interesting to talk with Anja about that. I've learned a lot about reaction to fire a learned a lot about how, , Test methods the goal within the regulation can really change the holistic image of the whole sector of the whole field fire engineering. And I'm very glad to have received this lesson from, from Anja. And yeah, in the next episode, there's more lessons to come. I have a very exciting thing to share with you that recently happened to me in one of my friends. And we were going to spend a whole episode discussing that and what interesting pathways that opens. So I hope you join us, , the next Wednesday we'll be here and yeah. Thank you for listening to Fire Science Show and see you next Wednesday.