How Crumple Zones Work

UH another podcast that we admire for winning the Webby. Yeah, Invisible. Yeah, if you heard our Ted Talks episode, or we interviewed Roman Mars and he won the I Guess panel vote, Yeah, and then we won the People's Voice vote. He's the he's the industry darling. We're the populist darlings. Yeah, as I like when I put it on my personal Facebook page, attacked Roman and I said, we won the one for people's vote and Roman won the one based on quality

and he said, no, they're both quality. He was very sweet about it. Yeah. Um, I also want to say give us special props to reply all who gave us a run for our money for quite a while there the People's Voice Awards, so actually check out all of them, the nominees, nominees, because to to get considered for a webbing, I mean, there's a ton of podcasts out there, and to make it basically what amounts to the top five,

you gotta be pretty good. Hats off to everybody, and thank you again for everyone who voted for us, and congratulations again Into Roman and Visible crew agreed we were in good company, So thanks everyone. So Crumple Zones, I predict this is going to be a correct of an episode terrible. Um. You know what I found out that this fascinates me way more than I thought it would. Dude, totally with you because I'm not a car guy, as

you know. No, but it's not just that it's this is more the history of auto safety, but it also has more to it. There's some physics that we can grasp involved very simple that makes it very attractive. Um, let's kind of like big thing hit, big thing makes boom, right, that's exactly right. But all you have to do is switch out like force and acceleration. You sound smart. Um, yeah, there's a lot to it that that there's even some nefariousness,

corporate nefariousness. So I'm like, yeah, this story is ever sure, you know, agreed? And you know what, this made me want to do episodes on crash test dummies for one, and then maybe even a couple of others. As far as Nator, we should do one on him. Yeah, maybe airbags. Just the whole car safety thing is way fascinating. It really is. And to top it all off, this article was a grabstor article, so well that's why I picked it.

At this point, I'm just searching for his articles. Yeah, we should just be like, recommend some articles that you wrote that we should do. We've done most of them. I know that's the problem. He needs to come back into the fray so sad. And we should also shout out our colleagues here at how stuff works with car stuff Scott and Ben. I'm sure I have covered this at some point. And if you're into this kind of thing, they have a just a treasure Drove of car very specific,

detailed car podcast, emphasis on the treasure. So that's corumple zones. If you want to know more about it, go listen to car Stuff. All right, should we start with that little history bit? Yeah? Why not right. Yeah, so, um, there's actually a lot of history too. I found this really cool Museum of American History, a Smithsonian Museum. They had a like an exhibit years back. It looked like the late nineties, early two thousands, and I just went

through the page. There's this really interesting essay that they had broken up over this webs light. Um, there's a lot of weird history. But initially, the idea of what caused REX has changed dramatically over the years, because at first it was strictly driver error, because the paradigm people were looking through was before you had horses, and a horse could spook and bolt and run somebody down, and

the horse did that, it wasn't the driver. The whole idea of a horseless carriage was that it was just a lump of metal that responded to the driver's commands, and so anything that went wrong it was the driver's fault. And it took many, many years for people to realize like, actually, no, there's some serious design flaws in cars. We can actually make them safer, right, And once people figured that out, they didn't realize that the auto manufacturers had known this

for decades. And then after the public finally realized that. It took a few more decades for people to finally implement it. Yeah, And I think the rationale for a while was and it was the style of the day as well and the materials that were available at the time. But there was a notion of well, let's build these things like Sherman tanks and it will make people safe, right, And what crumble zones proved is the exact opposite. Let's build something that that crumbles and crushes in just the

right way, and that's actually much safer. And you know, it's funny. I remember when this stuff kind of came up, what probably mid to late nineties, when people really started to show up and um in normal cars, and I remember thinking, like, God, they make cars so cheaply compared to how they used to, Like they just come apart. Now I realized, oh, they're designed to come apart, because before it was like the car is not gonna do anything,

but everybody inside is gonna liquefy. Now it's like, how about we keep the people inside safe and just letting the car take the brunt of the impact. Yeah, and one person, there are a lot of people that that owe to this design over the years. But one person squarely in the center as a dude named Ella. That's a nice name. There's a couple of accents and everything. Yeah, I'm not even sure if that's right, but he was a very very very famous engineer and inventor for Domino events.

Holds more than patents like this guy. We all owe a debt to this dude. So many more patents than either of us, Yes, than both of us put together. Do you hold a patent neither? This is kind of shameful, really at this point, do you want to hold a patch? Everybody should hold at least one patent. Well, if you could patent things like, uh, you know, stupid stuff that aren't like real, like um Chuck's method for getting out of the grocery store in a hurry, patent it, I

might actually try that. What is it? Are you gonna you say patent pending first before you describe it. I'll just hold on to that. Maybe I could trademark that not patented. No, you can patent a process kenny hh okay, or you can just type a little trademark symbol next to everything you say and it's like back off, everybody. So Bella Mr Barni uh in nineteen fifty two had a patent um It was actually the very first one, uh, the Mercedes Spence W one one one fintail. You didn't

say what the patent was for. I know I was getting to it. Oh sorry, the beautiful car. And it was the first car to hold to have this patent pending. Well, I guess it was patent holding by that point. Crunch zones on the front and rear of the car. The whole reason was these current zones could be designed to absorb the impact from a crash, and if the car absorbed the impact, then the people were less likely to absorb the impact because that impact, the force of the

impact has to go somewhere. Yeah, it ain't going nowhere. And if the car is built to be rigid, the car is not gonna absorb it. It's gonna transfer it. Yeah, like a big ford edseil hitting a Ford fair lane. It's a lot of pounds of metal smashing into one another. And the people inside aren't getting fare too well, especially back then when they're like, what's the seatbelt, dude? Not only what's the seatbelt? The earlier, earlier cars had plate

glass windows. Yeah, there were death machines. They all of like this, the knobs and stuff. Now that's like touchscreen before where they would stick out, so you just take one and go right through your forehead into your brain, just getting paled. Dashboards. Dashboards weren't even padded. It was a steel bar that would just take the top of your head clean off. And then the cars ran on nuclear fuel. Basically it might as well. Yeah, it was amazing.

I know that they've done side by side examples these days where they crashed an old car because people are like, oh, the old cars were built like tanks, and so they would do the same miles per hour for like a Volvo compared to like a nineteen fifty seven Ford, and

you know, the it's obvious what happens. You just like there's a there's a point in time where the common wisdom was you didn't wear a seatbelt, even if you had it, because you would prefer to be thrown from the car because it was so deadly inside the car. And there's actually a very famous injector seat pretty much there's a famous um Reader's Digest article that really captured public opinion back in is called Eds and Sudden Death and it's just like really gory and gruesome, and it's

talking about like these cars are death traps. We need to do better than this. Yeah, and they weren't even going that fast back then, you know. All right, So these days, um, it's all proprietary the exact features and specifics of crumple zones because these car manufacturers they have their own methods and they don't want to share that with everyone. Makes sense, that's fine as long as they're building,

that's right. But in general, what we're talking about our frame designs, where certain parts of the frame of the car bend and collapse in such a way that it keeps the people and things like the gas tank uh safe because you don't want that gas tank exploding either, which we'll get to right, So let's talk about what a crash is, right. A crash is where an object with mass traveling at a certain rate um collides with another object with maths. Yes, and when that happens, force

is created. Right And yeah, Well, I was gonna say, people saying, well, what if you don't hit a car, you're gonna hit a street, You're gonna tumble, you're gonna hit a telephone pole, that something is going to make impact. So what what's happening when you when you have impact is you are technically you're accelerating, but every and logically you should just call it decelerating in the case of a crash, but it's still scientifically, it's still accelerating whenever

you have a change in velocity. Right, Um, So when you hit some thing in your car and you decelerate quickly, that force is transferred force. The force is the mass times the the rate of deceleration. Right. So another way to put is how bad you're messed up equals how heavy the car is and the object that hits times how quickly and suddenly it stops. Yeah, So you can actually take force in that equation and and diminish it tremendously.

If you can diminish tremendously the rate of acceleration, if you can make if you can extend the time it takes to decelerate, and you you can understand this a lot more easily if you think about when you come to a stop slowly at a stop sign, as opposed to when you have to slam on the brakes and you come to a stop. Now, the next degree above that is when you hit like a pylon and come to a complete stop. So that's what an accident is. It's that transfer of force from one to another through

this deceleration, this rapid deceleration. Yeah, and in the case of a crumple zone. Uh, there are two things that is trying to do. Their one is to reduce that initial point of force, initial force from that first point of contact when you hit that phone pole or that

other car or whatever. You want to drop that force and then redistribute that away from the people, right right, So the way you drop that force is to extend the rate of deceleration, even by tenths of a second, makes an enormous impact, Like that's all you have in the case of a crash. Right. So Ed points out, um that if you take if you change the deceleration time from point two seconds to point eight seconds, you

reduce the total force by huge difference. Yeah, especially if you're in a car accident, like less force being transmitted through the car, is that's preferable, yeah, right, So, Um, the whole point of crumps, the whole thinking behind them, is to basically build an area that can change this deceleration, lengthen it out some so that the forces. Yeah, and then also to kind of redistribute that force throughout the car away from the passengers. That's the whole thing behind

it makes total sense. All right, let's take a quick break here and we will come back and talk a little bit about how they're doing that stuff. All right, So a car is it can't be one big crumple zone. There are parts that need to be rigid, Like the if you picture a car, picture the four seat. Let's just talk about a four seater. Let's do it. I know people will be like, what about the third row, there's seven of us in here, whatever the case. Just

picture a small box where the people are actually sitting. Yeah, that's the called the passenger compartment. The passenger compartment, that is that box that needs to be rigid. You don't want that crumpling. You want everything before that and after that crumpling to reduce that force and that decert rate of deceleration. So you want that middle to be super strong, and you don't want to because if that crumples, the people aren't protected any longer. They're exposed all sorts of

terrible stuff. So it does have to be rigid. But again, before they made the whole thinking was, well, just make the whole car super rigid. And the problem is there has to be something that's absorbing into redistributing that force. Um,

and that's what the crumple crumple zone does. So they took that tank of a car and rather the whole car being that, they shrunk it down to just the passenger compartment where it's really needed, and then made the rest of the car a big crumple zone and then surrounded that part with air bags, side curtain, front and all that stuff. So that's what protects the people. But um, the way this article put it in Man sure has

a way with words. He talked about thinking of it in terms a car crash in terms of a budget, like a monetary budget, and that's what that forces. And everything that happens is paying a little bit of that budget.

It's spending some of it, yeah, spending some taking away from that budget, like like on glass breaks, when the door, you know, when anything any kind of damage happens, that's spending a tiny little bit of that budget because that's energy, right, And then eventually the budgets entirely spent and all the force has been distributed in the accidents over the crash

is over right. Um, if you can get other parts besides the passenger compartment and even more importantly the passengers to distribute that force, then ad can be distributed before it gets to the passengers. Yeah, you wanted to be paid down to almost nothing by the time it gets to you. I don't think it's get the imperson. I don't think it's possible to distribute a percent of the force.

Probably not, because in that case, like the person wouldn't even you wouldn't feel anything, right, So, but I mean, is that possible? I guess could you design something to where somebody could come to a complete and sudden stop in an impact and not not experience any force whatsoever because all of it was distributed away from the person. Probably not. And that's the point the article makes. Probably not like a drivable manufacturable car, because that's the delicate balance.

They they still have to drive and handle in a certain way. And like when you that's what it fascinates me about this is car design. You have to take all these things that are knocking heads against one another into consideration. You know, it's got a gas think in there, things full of flammable fuel and it's crashing into things like it's amazing. It's really like that delicate balance they've walked these days to make cars as safe as they are as astounding to me. So so there are some

things that they have to trade off. Like if you have a really good um crumple zone, a big one in front, you're gonna have to do something with your engine. And you can only put an engine so much on top of itself before it needs to just kind of go back toward the passenger right, And you can only move it back so much. And the problem is with an engine. An engine is one of the few things in the car aside from the passenger compartment that is

rigid and basically immovable. Like an engine is not going to crumple and bend. It's going to transmit that force. And if that engine comes into the passenger compartment, it's going to say hello and transmit that force right into the people that it runs into. Yeah, and that I mean I remember old car Wrex where the engine is like in the front seat, you know, where the person used to be. That's not a good place for an engine,

and that's not a good place at all. So there are considerations you have to you have to do in making a crumple zone, um Like, so in that case you would be like, well, it's likelier that the engine is going to kill the passenger by getting pushed into the passenger compartment. We're just gonna have to make the crump zone a little less um And then another thing, like you said, that they have to deal with is gas tanks. Thought that most cars fuel tanks are in

the back, and this is really cool. Most modern cars, when you getting a rear end collision, it's designed the rear crumple zone is designed to go up so that the gas tank is actually lifted up and away from the point of collision, which is usually the hood of a car behind it, right, which happens in a fraction of a second, right, So it's designed to do that. That's part of a crumple zone as well. And that's a huge improvement from the seventies, specifically with the Ford Pinto.

So the Ford Pinto. Man, this is this one may even deserve podcasts in and of itself, but I think in like ninetevent definitely the seventies people were dying in fairly low speed rear and collisions because the Pinto's fuel tank would break and catch flame and burn people alive. These cars were exploding in minor collisions, and then the autopsy would show they had like basically not even a bump or a bruise. They had just been burned to

death because the Ford Pinto gas tank blew up. And Ford got caught very famously with some internal memos where they calculated the cost benefit of a recall as opposed to paying out lawsuits for human lives, and they said, the human life we're going to say is about five hundred thousand dollars, So if if you know X number of people see us will end up probably spending forty nine million. But it cost us a hundred and thirty seven million to recall these things and actually make them

safe to protect people. So they went with the just handling lawsuits and it was a big deal, and finally there enough of a public outcry came out about it that they finally did something. Um and I think they did recall some Pinto's and then they were like, oh, we'll just put the guess thing in front of the rear axle so that's not exposed during crashes, and a couple of other improvements that cost like a dollar a piece, and they at that point it was kind of um,

the Pinto was dead. Yeah, they weren't selling longer. No, I mean, like you want to get a bad name for your car, fiery death is a good way to do it. There was a movie, what was it. It It was one of the spoof movies. Oh it was. It was don't don't talk top secret, Secret barely tapped the tree. It was a Pinto that exploded like it slowed down and went and then went boom. I didn't think it was top secret. So when that World War two, it was an anachronism. I'm I'm nine point nine. That was

my first thing too, my first guess. Alright, so, uh, not only gas tanks, but these days with these fancy schmancy electric and hybrid cars, you've got these big battery packs and you've got toxic chemicals, and you know it's you've got to protect that as well. If you, in the case of a Tesla Roadster, if you get into an accident, elon Musk himself comes and pulls you to safety. That's the level of service. Yeah, oh wow, I might be worth it. If you need it. Uh No. In

the case of a rodster though, it is pretty neat. Though, Um, it's got a safety mechanism. It shuts off the battery packs, drains all the electric energy from the cables the instant it senses an emergency. Pretty rad. It is pretty rad. What about if your car is tiny, though, it's pretty easy. If you've got a stretch limo, you've got plenty of things to crumple, Yeah, crumple away. But what about like a Mini Cooper. What's this thing? Smart car? Yeah, like

a smart car. Um. So the grabster says, well, let's use a smart too as an example. Um. They came up with crumple zones that they call crash boxes, one in the front and one in the rear. But the problem is these are extraordinarily small cars. You've seen smart cars before. It's like the kind you could put like a giant penny in the back and like pull it backward and it takes all It looks like a McDonald's

happy meal very much, except a very very expensive one. Um. But the smart cars very small, and when it does get in the crest, it does have these crumple zones, and they do do something, but they The engineers also had to like get kind of clever to like, for example, I think, um, the transmission actually turns into its own crumple zone to redistribute the force, right, Yeah, it's amazing.

And um they use the wheels and the tires. They were like, well, these things they're gonna be getting a lot of impact right away, so why not design the wheels, the suspension, the tires, uh two deform and breakaway or even rebound and distribute that kinetic energy elsewhere, which is pretty awesome. It's amazing. Yeah, And so again we should say this is proprietary stuff for the most part, but you can really let your imagination run with these things.

Like all you have to do is say, um, you know, like really high end sports cars, they'll use like honeycombed structures which give great, excellent strength under normal conditions, but when they're dented with enough force, they just completely give and crumple and that force gets redistributed throughout the honeycomb. Imagine more lightweight too. Yeah, I guess you think trains,

even trains just technology, which is pretty smart too. What they put them on the front and rear of each car compartment, right, each passenger car, and then when the cars to start stacking up, it just gets distributed throughout the train rather than into the people who are trying to eat their seals. Very steak. All right, we let's take another break and we'll come back and finish up with a little bit on everyone's favorite topic of the stuff you should know Army Nascar No So Chuck the

Grabster mentions a crash in this article. Michael waltrips Darryll Walt trip No. Michael waltrips crash at Bristol. You look it up. It's pretty bad. It's insane that he not only survived like they show him right after the crash, like waving to the crowd like, hey, I'll be at the bar. Yeah, he probably was too. Oh I would have been have been like give me a flask right now. This is a and it was that the Bristol track in Tennessee. And um, Bristol is a it's not. It's

the one of the slowest, thankfully. It's not a superspeedway. It's really small. But he was going fast. Well, you're still racing cars, but it's not like he was. He wasn't going like two hundred miles an hour or anything like how fast is he going? Nina, I don't know. At Bristol. I'm gonna get this wrong. I think. I mean, the top speeds are in the lower one hundred, twenties and thirties. He's still going over one mile an hour,

which is several kilometers per hour. And he just stopped all of a sudden because he hit a pylon, a concrete pylon. Yeah, he hits uh. Instead of like another car that will move with you, or offense that will break away, he hits something that had zero give. Now um something else that may have saved him, but it seems it's so slight, it seems minimal. He actually hits the guardrail a fraction of a second before he hit the concrete, and you see some stuff kind of come off.

And again, when you look at force, that force of the collision. As a budget, that spent some of that that force when those things takes force for those things to be thrown clear, But it was probably just miniscule compared to the actual impact that came right after that when he hits the concrete and just the car just disintegrates. Well.

And this was in before they had done a lot of the safety advances that they have today in NASCAR, and they head points out in this article like he got lucky, Like he shouldn't have survived that crash with the kind of cars they had. He got super lucky. But even if you're not a car race fan and you see these rex on TV where the car just flies onto a million pieces, that's exactly what it's supposed to be doing. And every little piece of that car you see flying off is something that has kept that

driver safe. It's so funny to think, like before they designed cars to save you money in the shop after a wreck, but it didn't matter because there's really just saving your a state money because you're dead. Now it's like this is gonna this is gonna cost you a billion dollars to replace this this car. It's basically just told old but you're fine, right, Like that's the thinking

behind crumple zones. Basically, yeah, that human life was more important than a bumper that you don't have to replace. Good move. UM in two thousand, In the eighties and nineties, UM, actually, all throughout NASCAR history up until the two thousand's UM, the idea was a little more that old school approach. They wanted these cars to be rigid and stiff because they performed better and they were heavier and you could

drive faster and hug the road and handle better. But then in in two thousand one and you know, it's, well, it's not funny at all. I followed NASCAR one time for one season and the very first because I had friends that did it, and I was like just driving in a circle. They're like, no, no no, no, just watch Chuck. It's much more than that. Just watch. You're smart guy, you'll get it. And so I was like, all right. I watched the Daytime five hundred and two thousand one,

and that's when dail Ernard died. That was the first race I ever watched, like all the way through, like, does this happen a lot? Well, I was scared I had something to do with it. I don't know if you did. I don't think you're a jinx no. But it was very sad because if you saw that wreck, it didn't appear to be that big of a deal because the car didn't fly into a million pieces. Yeah, he just kind of turned up into the wall and

all of a sudden, Dale Earnhart's dead. I think they even like they played like a wall sound effect before they realized like, oh wait, yeah, it was awful. So what happened in that case is he had what's called a Bassler skull fracture. So did you look these up? Yeah? I mean this is when you're going really fast and you stop immediately, and in the case of a race car driver, their bodies are completely strapped in, but their heads at the time weren't, and your head goes forward

and your body doesn't. Yeah, and you get a fracture, a snap where your spinal column meets your skull. That's the basilar skull fracture. Did you look it up on Google Images? Yeah, it's Man, did you see the raccoon eyes? There's actually, Ah, you can if you're doing an autopsy or something. One way to too if the person has like real dark circles around their eyes and especially under their eyes. Um, that's called raccoon eyes, and it's a

symptom of basilar skull fracture. Um. It's pretty crazy stuff. You probably shouldn't look that up because there's some really awful pictures of just dead people with raccoon eyes and the tops of their heads removed and stuff. Man, well because that wreck, because they are in heart with such an icon of the sport. I mean, you know, anytime

someone dies it's a tragedy. But he was like on the mount Rushmore of race car drivers, So for him to die in a crash, they really started taking things seriously. And um they created what's called the Car of Tomorrow, which is what they've been racing in I think since two thousand eight. Uh, and that is uh, well, it's essentially just a card that's way way, way safer. We won't get into a lot of the particulars, but there's more styrofoam involved that are crumple zones. It was just

a big one. I think the I think it's called the Hans Device is what they started wearing after that, which keeps your head attached to the seat smart so it doesn't snap forward. The drivers didn't like it as much because they couldn't look around as easily, but you know, it's like a give and take with safety. Sure you don't want to die out there either. Let's put some mirrors in there. I got a rear view mirror. We'll put a bigger one up. Uh. I got nothing left, No,

you got anything left? As crumple zones part of the growing auto safety suite. Uh. If you want to know more about crumple zones, type the word those words into the search part how stufforks dot com. Since I said search parts notap for listener mail, I'm gonna call this hundreds of doll heads? Did you read this one? Hey? Guys love the show. The lead episode hit home because I worked for a consumer product certification company. We test everything from guitars to pacifiers to chainsaws, and one of

our responsibilities is certifying low lead content. UM. Part of our federal code mandates that surface coatings paint on children's products and furniture contained no more than ninety parts per million of lead at This limit was originally six hundred parts per million, but it was lowered after the lead toy panic of two thousand seven. Remember that one, the Great lead Panic of two thousand Do you know? Yeah? Remember the Chinese toys turned up with lead in it

and everybody's like, get those things out of here. I think I slept through most of two thousand seven. Yeah. Did you have mono mature? Okay? Uh? And our trace Metals Analytics lab we test thousands of products every year. Uh, for heavy metals, lead, mercury, arson, etcetera, and other restricted substances. My first job at the company was to use a razor blade and physically scraped surface coatings off toys for

lead testing UH. This job was quite tedious due to the amount of UH scraped surface coating needed for acid digestion and chemical analysis. The early days of your podcast definitely helped. In one instance, our lab we asked was asked to test only the painted eyebrows of a doll. You can imagine how little surface coating can be collected from one set of eyebrows. Due to this, I was surrounded by hundreds and hundreds of doll heads with scraped eyebrows.

As you can imagine, the sites of hundreds of eyebrows doll heads staring at you as you work is quite off putting. If their dead eyes just want you to know there were thousands of people working hard every day to ensure the products are safer you and your families. Thanks guys, keep up the great work. And that is Matt. Thank you. Matt. Hat is off to you for what you do for a living things, for keeping him with

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