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Hello everybody, welcome to the Fire Science Show.
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When I was recording the last episode of the last year on the New Year's Eve discussing the Hong Kong uh fire, I thought this is gonna be something that we will keep talking for weeks and weeks because that was obviously uh a very huge tragedy and a very medial fire.
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And then on the New Year's night uh the Swiss Cranz Montana nightclub fire happened and the whole media attention of the world has shifted towards that one.
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It's horrible how quickly uh we replace one horrible tragedy with another and how quickly those things shift.
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I've commented some on the Cranz Montana fire on LinkedIn.
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I'm not really used to comment on recent events, I'm not really that much seeking attention, falling to comment on the freshest and the biggest fires and don't feel the urge to be the first one to post about that.
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I rather have my my thoughts made up and provide you with some clean things I have processed in my head that actually can help us strive to be better.
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And so I have planned for this episode to prepare an episode that actually brings some value to the fire safety engineering community.
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And uh yeah, I've invited a nice guest, uh Lazaros Filippidis from the Fire Safety Engineering Group at the Greenwich University.
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Lazaros is a part of um Professor Ed Galea's group uh for ages.
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Uh I I've I remember he was helping me with building Exodus like 15 years ago.
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That's how long I've been professionally exposed to Lazaros.
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And it and since forever I know Lazaros was involved in evacuation modeling and uh and then his group is developing fire modeling software.
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So definitely that's a nice person to talk about this uh particular family of fires in the nightclubs.
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And yeah, what's kind of unfortunate, there's absolutely nothing new in this episode.
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Like in our discussion we are having with Lazaros, we just reiterate through some obvious elements that are not a surprise to anyone.
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They should have not been a surprise to anyone.
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And uh that that's perhaps the most horrible aspect of those nightclub fires, that there is nothing new in that.
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Like we know almost everything.
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We know 99% of stuff that should prevent us from you know having such a tragedy is happening, and yet they occur every few months somewhere in the world, uh, which is the horrible part of this story.
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So today's episode, not necessarily about the Kranz Montana fire, is not that we're gonna, you know, uh dissect the uh recent fire into smallest pieces and analyze what happened there.
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No, we we are trying to present you with a broader context of how fires in such venues look throughout the history and give you some ideas about how to think about uh the scenarios, the design scenarios, the evacuation scenarios in such venues in such a way that we strive to be better fire engineers and provide better fire engineering in the future.
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Not an easy episode, but I think an important one.
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I hope you enjoy it.
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Let's spin the intro and jump into the episode.
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Welcome to the Firest Show.
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My name is Wojciech Wegrzynski, and I will be your host.
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The Fire science Show podcast is brought to you in partnership with OFR Consultants.
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OFR is the UK's leading independent multi-award-winning fire engineering consultancy with a reputation for delivering innovative safety-driven solutions.
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We've been on this journey together for three years so far, and here it begins the fourth year of collaboration between the Fire Science Show and the OFR.
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So far, we've brought through more than 150 episodes which translate into nearly 150 hours of educational content available, free, accessible all over the planet without any paywalls, advertisements, or hidden agendas.
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This makes me very proud and I am super thankful to OFR for this long-lasting partnership.
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I'm extremely happy that we've just started the year 4, and I hope there will be many years after that to come.
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So, big thanks OFR for your support to the Fire Science Show and the support to the fire safety community at large that we can deliver together.
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And for you, the listener, if you would like to learn more or perhaps even become a part of OFR, they always have opportunities awaiting.
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Check their website at OFRConsultants.com.
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And now let's head back to the episode.
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Hello everybody, I am joined today uh by Lazaros Filippidis from University of Greenwich.
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Hello, Lazaros, good to have you in the podcast.
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Hello, Wojciech.
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Uh thank you for uh inviting me to your um forest science show.
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Thanks, man.
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Uh when I was uh going through email uh prepping for this, I found our correspondence from 2012.
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That's how long I know you.
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You've helped me massively with Exodus.
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Uh more than 10 years ago, you know.
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Thank you very much for that.
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Uh I appreciate that.
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It was always uh reaching to you for the support was always great, and I'm really happy we can interact on a different note today.
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Indeed.
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And I think we've only met uh in person once.
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Yeah, probably exchange like versions once.
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Yes, we'll exchange lots of emails and messages.
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This is hilarious.
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But uh anyway, the the topic I've invited you for is is not not as funny as our interactions because we're gonna talk about, I guess, a family of fires, and obviously the attention of the world was on the Kranz Montana fire just after the New Years, and uh this to some extent triggered this discussion.
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But there was another one, right?
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Well, there are the many incidents that um follow the same kind of pattern, and uh there are lots of uh near misses that uh probably don't take up immediate time.
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The latest one that I've heard about was in uh Madrid in a restaurant where uh again fireworks ignited curtains.
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Fortunately, in that incident, uh they used the fire extinguishers and they put out the fire within seconds.
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So that was uh, as I said, a near miss.
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Nothing really happened.
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But it's the same kind of incident.
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You have fireworks in an enclosed environment with flammable materials that puts people at great risk.
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People that go to a place to have fun and not to be vigilant.
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They're not going they they're not entering, you know, um a chemical facility or nuclear plant where they know that okay, they have to be careful.
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They enter a restaurant, uh discotheque, a nightclub, so they forget about the problems.
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Yeah, I mean when they see you know fires like the one that happened in Hong Kong, which obviously was a huge tragedy.
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When when I look at it, there are things that were not obvious.
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There is some interesting fire physics out there, there are things that I probably have never seen uh happen.
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When I even when I see things like uh King's Cross, that's that's some new physics, there's interesting interactions, like it's complicated.
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I mean, fire science is complicated, and many of those fires are very, very complicated.
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And and you know, the specific uh set of physical conditions that promote those fires are not that easy.
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And and so when I look at those you know, nightclub fires, there's no interesting fire physics to me.
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It's like a brutal compartment fire within in a compartment with a lot of people and most likely insufficient means of escape.
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It devastates me, really, because like I I I'm hopeless.
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Like I I I I don't know how what what more a fire engineer could do to to prevent those at large.
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Yes, indeed.
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I mean uh the examples you gave initially actually did provide new physics and new type there were new types of incidents.
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Uh but what we see with uh discotheques and nightclubs, it's a recurring pattern.
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Again and again we see the same thing.
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Uh small spaces, typically overpopulated, typically with uh limited escape routes.
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Uh sometimes they're even locked the escape routes.
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So to prevent people, you know, for uh getting out without paying uh what they bought, with uh typically badly installed uh flammable material and fire sources that shouldn't really exist within those venues, pyrotechnics and fireworks.
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Let's try and go back in time.
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Um because it's not also a uh a new thing.
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Like those those fires happened throughout the history.
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Going back, like what will be the worst one?
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The coconut groove?
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Coconut groove, I think, is the worst one uh in 1942, with just under 500 uh fatalities and a few hundred injured people.
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I I think this was the deadliest, uh deadliest uh uh incident in history for a club.
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Maybe maybe let's try to unwrap that one.
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Like do you do you know what happened there again?
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Well, there was ignition again of flammable uh decorations.
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Uh there were obstructed exits, locked exits.
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The incident actually led to the adoption of uh new fire safety measures.
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So based on that, the authorities designed new regulations.
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Um panic hardware to doors was uh uh became a requirement after that incident.
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Illuminated uh signs, I believe, became uh requirement after that incident.
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And uh there was I think a ban on uh some uh materials within within these establishments.
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But we see though with we see flammable materials appearing all the time.
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So I guess there was like a small uh well quite large actually, space, because you have to have space for for a lot of people, uh, with uh most likely insufficient insufficient exit capacity.
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I mean, if you think about it, the architectural features uh of a nightclub or or a venue uh kind of promote this environment because you like you most likely want it to be dark, that's that's a theme.
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You want to have a control over uh who comes in, who comes out, and as you as you mentioned, they they pay.
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So this pathway is kind of closed.
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Um you probably don't want to have alternative pathways inside and outside.
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So people sneak around or and and do some perhaps ill illegal activities, uh which in uh well-refreshed venues sometimes happen.
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And at the same time, I think the ratio of height to the volume, I don't know even know if that metric exists, but they all seem not very not very high, not very huge venues, but just l large in space, right?
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Indeed, normally they would have low ceiling.
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I guess acoustics to some extent must promote that, right?
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Probably uh normally you'd see low ceiling venues.
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Uh but as you said, normally and typically what you have is you'll you'll get um a managed ingress of people because they have to pay to get in.
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Uh and also because it takes uh this the this process takes over a long period of time, it takes maybe a couple of hours for everybody to get in.
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They don't arrive all at the same time.
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So for ingress, the the means of getting into the venues are sufficient.
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Then for security reasons, as you said, they do many times uh restrict quick ingress.
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But of course, uh in an emergency that's exactly what you want.
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You want you want to have access to appropriate number of uh escape routes.
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These escape routes must not be locked.
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In many cases, we we know that uh the windows were closed with uh and locked with uh metal grids so people couldn't escape.
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So, yes, while they are designed for a good flow of ingress, they're not definitely not designed for um efficient uh evacuation during an emergency.
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And and another thing is the um acoustics, because like okay, people do those choices, a lot of those design choices, for a reason.
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And there there is actually a good reason why you want to have uh insulation on uh on your uh ceiling in in such a venue for the same reason why I have an insulated wall in the space where I'm sitting in here.
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Absolutely, uh reverbation and acoustical effects in because it's quite a large space.
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Like engineers should should understand that.
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If you have a space that has 30-40 meters length, that's uh the sound takes uh 0.1 seconds to travel that that length.
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The sound is not that fast, and and that creates a very annoying reverbation and acoustic effects that will be very obvious in a setting where people enjoy music.
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And this means that a space that is not acoustically insulated if you have a low ceiling, there's a lot of space to bounce from the sound.
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And if you don't have that insulation, the space will not fulfill its primary goal of delivering uh music to people as a a way of operating.
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I mean, because a lot of uh blame after those fires is of course that you can make this type of insulation without flammable materials and will reach the flammable materials in a second.
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But the point is like you need that, and and and the engineers and everyone around should should respect the fact that this is actually a quite important feature of such a facility.
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It's actually a requirement.
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I mean this is true.
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Uh you you need to have some type of acoustic uh insulation in these uh establishments that goes without saying.
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However, they have to choose appropriate materials that are fire retardant.
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And uh we know that in many cases this was not the case.
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For example, in the Station Night Club and the KISS Club, uh these materials were highly flammable, and they they ignited through pyrotechnics and fireworks.
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Um But yes, the engineer does do that uh you need to have you need to install acoustic insulating materials to enhance the experience of uh the patrons.
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That's why they go there.
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They go there to have fun, they go there to hear to listen to their music, listen to their favorite band, and of course all this adds up to the experience.
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And and another uh aspect that that is quite typical for such a facility is and that that actually I think is outside of the engineer's ability to act, is is how the internal furniture is distributed among the places.
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I mean where the tables are, where the seats are, and and and how the venue operates every day.
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Because I also feel this is something out of control of engineering.
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I I design walls, I may design the main area, I may design the staircase.
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I can tell them where you can put tables, and I will most likely receive some kind of uh you know drawings that will show me the table layout.
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Yes, but you never know what's gonna happen.
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I mean, in in many cases, again, you can have a compliant uh structure, you can have a compliant building.
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But how the operators will actually furnish the venue, it's out of the control of uh the engineer.
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And in many cases, they do put tables that block the exits or restrict the effective width of the exits or the corridors.
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Well, they they want to make money at the end of the day, so they try to allow as many people in as possible.
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That is another issue.
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Let's perhaps talk about bottlenecks and how bottlenecks work uh from the perspective of crowds and and uh evacuation.
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Because if you put too many elements in front of that or nearby the exit, you may not even block the exit, but if you create you know like a narrow corridor leading to an exit, you dramatically reduce the amount of people who can move towards the exit, etc.
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And I I think this bottlenecking problem is also a massive.
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Maybe you can comment on on how women the um exits lose their desired uh capacity, perhaps.
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Well, it all depends on uh the number of people you have in in the venue.
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So normally there are guidelines that uh d dictate the maximum number of people that you can have within a building.
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But of course, uh the behavior of the people plays a significant role.
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Now, when uh you have an urgent emergency situation and uh everybody urgently needs to evacuate, then obviously most of the people will try to go towards the exits.
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Now we know from re past research and literature that most people will try and escape through the entrances that they're most familiar with, and that's typically the entrance to the building.
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Uh in many cases they ignore the emergency exits.
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They may not be aware where these emergency exits are.
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Maybe they want they maybe the emergency exits are behind or within other rooms, which they don't have access to anyway, so they wouldn't know about them.
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So when you have a certain uh rush of people going to towards the same escape route, same exit, we have observed that uh the capacity is not enough.
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And we're not talking about um here we're not talking about drills.
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During a drill, people are more relaxed.
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The capacity seems to be uh appropriate for the population you have in your building.
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But during uh an emergency where you have fire products affecting you and you need to escape as quickly as possible, this creates bottlenecks.
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Uh usually creates bottlenecks at the exits because they're they're they're not they're not wide enough.
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And you have a rush of people of people that are trying to escape as quickly as possible.
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Does the capacity of exit decrease when the when the density of population increases?
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I think that's the part of the fundamental diagram for doors, right?
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Yes, I mean you could you could you could say that.
00:18:04.640 --> 00:18:05.519
You could say that.
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I mean the greater the density, the uh the the more difficulty the people have to are able to move.
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The more difficulty they have to they can't move as easily as obviously as when the density is not as high.
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And and and especially tragical when you have uh another bottleneck like a few meters ahead where where there's another group of people.
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And I think we've we've seen those horrible images.
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I think it was station nights that were something where people were trying to the station, yes.
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They they were literally in the doors and they were just stuck in the doors and then you were unable to exit.
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This is like really, really horrible.
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Yes, it it is because uh the the people are affected by uh the fire products.
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I mean uh all this insulating material, uh the acoustic form generates uh hydrogen cyanide, carbon monoxide, uh carbon dioxide.
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Hydrogen cyanide is extremely toxic.
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And we're talking about sometimes seconds make uh the difference between uh life and death.
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So in many cases, uh unfortunately people reach the exit but they uh they become incapacitated at that location.
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And of course, then the next person that comes has difficulty to get out, then the next one has a greater difficulty to get out, and that's a cascating effect taking place at those locations.
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And and and letting me just add something else, and it's not just that, in some cases, outside the exit, there are barriers as well.
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And and I think in the station uh nightclub it was also elevated, so there were staircases on that elevated platform outside the exit.
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Uh that can cause extra problems as well, because that's another element that you have to get away from.
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And you're restricted there as well.
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It's not just you know uh level surface that you just get out and you can go away from the building.
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You have another obstacle to overcome.
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And I think it's the same uh in the in the recent uh Swiss uh club as well.
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Yeah, it's actually exactly the same.
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Yes, we had uh a staircase going downwards a bit.
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Once they exited from uh the building itself.
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At this point, I like struggle with one thing.
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Like, what would be a sufficient size of those doors?
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Because I I I you know I it's hard for me to imagine that I have a door of, let's say, whatever width one and a half meter, let's say I had, and that promoted um a catastrophe.
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Would this additional half a meter of the door width like really solve the case?
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Or I would need it like multiples of that.
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Is there a safe target?
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I think the idea is to have multiple escape routes as well, not just uh wider exits and unobstructed exits.
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Uh you need to have multiple escape routes.
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And further to that, the exits have to open outwards.
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Yeah.
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Not inwards.
00:20:46.640 --> 00:20:49.200
This is a very, very important point.
00:20:49.519 --> 00:20:56.640
Yes, I mean that is actually a a door that opens indoors will prevent uh efficient evacuation.
00:20:56.640 --> 00:20:59.039
It will actually be part of a problem.
00:21:00.640 --> 00:21:12.720
This is something uh that that especially in the tunnel space is quite challenging for us because we will always want to have uh doors opening outwards, but we have two tunnels to evacuate from each other.
00:21:12.720 --> 00:21:17.359
So uh and you cannot pick the lucky tunnel uh that has the correct one.
00:21:17.359 --> 00:21:21.519
So you have to basically have a full redundancy of all evacuation doors.
00:21:21.519 --> 00:21:24.880
So each tunnel has a main door that opens outwards to the another one.
00:21:24.880 --> 00:21:31.839
That's quite a big design struggle, but we we believe that this is uh this is necessary to promote good good evacuation.
00:21:31.839 --> 00:22:00.960
When I was I I I'm not aware how it works around the world, but I remember uh one day I've done um analysis for the Polish uh regulations because the Polish regulations connect the number of people in a room with uh with uh capacity that is expected, and we do that in 0.6 meter increments, so perhaps per every like you have a basic minimum, like let's say 1.2 meter, and then you add 0.6 meters for every every another 100 people.
00:22:00.960 --> 00:22:05.519
And what's interesting when you do the math, it converges at 180 seconds, you know.
00:22:05.519 --> 00:22:16.079
So uh you basically get up to a 180 seconds time that you need to evacuate this space, you add uh another meter, so it drops to let's say 150 and then then goes up all the way to 180 again.
00:22:16.079 --> 00:22:17.519
Yeah, yeah.
00:22:17.519 --> 00:22:21.119
So so I in in some way, yeah, in three minutes.
00:22:21.119 --> 00:22:37.680
So in some way, this three minutes is my hidden but explicit target for evacuation time, because when I design my means of escape, three minutes is what I'm gonna get at fully uh uh like used up uh capacity of the venue.
00:22:37.680 --> 00:22:42.319
But this is my minimum, and I don't feel like three minutes that's quite a lot actually.
00:22:42.640 --> 00:22:43.440
It's quite a lot.
00:22:43.440 --> 00:23:01.119
I mean, if you consider that uh the response time of the of the people, once they realize that something is going on, or once they hear the alarm, um you can expect um response times in the range of 30 seconds, which may sound uh a little, but sometimes it can be longer than that.
00:23:01.119 --> 00:23:02.880
Many times it's longer than that.
00:23:02.880 --> 00:23:09.519
But then for establishments like the ones we're talking about, nightclubs, there is the issue of uh fire.
00:23:09.519 --> 00:23:18.079
So it's not just you know you have uh how quickly the people respond, but what happens with the fire physics as well and the fire dynamics.
00:23:18.079 --> 00:23:26.960
In some of the uh examples, uh I think the station uh club, the kiss club, uh flushover occurred within uh a minute and a half.
00:23:26.960 --> 00:23:33.680
So that is way, way, way below the three-minute mark like you just mentioned.
00:23:34.000 --> 00:23:55.039
And three minutes would be just you know, just the time to exit minus the the detection, the pre-evacuation time, exactly, decision making, arrival to the exit, like all the other all the other like I I I I seriously wonder, like in fire engineering we we tend to do uh it as a part of acid arson analysis.
00:23:55.039 --> 00:23:57.920
This is the paradigm that we have in fire safety engineering.
00:23:57.920 --> 00:24:03.279
Well, do you have uh more time to escape than you potentially uh need?
00:24:03.279 --> 00:24:14.640
I wonder in in such a difficult setting, can you actually achieve that without using hyperoptimistic assumptions?
00:24:14.640 --> 00:24:31.039
Because if you use hyper-optimistic assumptions like uh let's say 50% occupation or like medium fire growth, what that you you'll get your acid acid, yes, you you you will have your engineering analysis, you'll clear the project, you it will go for for go.
00:24:31.039 --> 00:24:38.640
But as you set flashover in one and a half minutes and explicit targeting low three minutes for evacuation, yes.
00:24:38.640 --> 00:24:41.039
This is failure by design.
00:24:41.359 --> 00:24:42.319
Indeed, exactly.
00:24:42.319 --> 00:24:47.680
And as you said, I mean yes, ASET and RSAT studies are conducted uh uh habitually.
00:24:47.680 --> 00:24:52.960
The issue the issue with that is that uh the pro the the these two processes are not independent.