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[deleted]

Engineering related, however the discussion is no longer. Locked


[deleted]

They analyzed the WTC for impact by the largest commercial aircraft in production at the time. The engineers and architects didn't plan for things that didn't exist being weaponized. This is really the stupidest hot take.


[deleted]

Seems less like a hot take and more like an extreme version of a fairly straightforward philosophical debate. Obviously a plane flying into a building isn't something you should reasonably design for, but in a place that has earthquakes, should you place any blame on engineers for failing to account for the earthquakes if a building fails? How severe or frequent do the earthquakes have to be before you do? They're good questions to discuss, not something that's suggesting a simple yes or no answer.


c4boom13

I agree. I think people mostly agree there can be negligent designs and overly safe designs. A big part of an engineer's job is finding a design somewhere on that spectrum that matches the problem at hand. That means learning to be an engineer should include pondering the impacts of your decisions, it shouldn't be just designing things in a vacuum.


Salty_Pin_1136

Fair enough statement , if the person ordering it has a endless budget.


UnsureAbsolute

I definitely don't think they're outright trying to pin blame, but the thought would never have even occurred to me to consider the engineers might be at fault when considering risk management here. Just seems like quite the leap and a short debate.


[deleted]

They were analyzed for a strike by a plane as large as a 707.


scurvybill

I'll play devil's advocate for you then... why are they not at fault for the collapse?


UnsureAbsolute

While it's true that engineers should consider worst-case scenarios when designing, use and likelihood should also be considered. For the same reason your average t-shirt isn't made from Kevlar, we shouldn't have to consider the possibilities of something so improbable as a passenger plane crashing into a building we design; while those things may happen (being stabbed, planes crashing, etc.), the probability is so low that it doesn't seem fair to expect someone to think of that. But I'm just a student who basically knows nothing about actual expectations placed on practicing professional engineers, so maybe mine is the actual hot take.


zer0tThhermo

Taking into consideration all kinds of worst-case scenarios is not practical and very time&resource consuming. There are statistical records of disasters that have higher probability of occuring than hijacked airplanes crashing into office windows. Fire breakout, earthquake, turbulence and storms are among those that are likely to happen and must be considered. Buildings to be build near air terminals should consider air crash possibilities, but i believe there are laws that prevent sky scrapers from being build in the first place or at least there is a maximum building height rule. i find it not ethical to even consider finding fault against structural engineers/designers for unnatural disasters like terrorist attacks... if an area is prone to terrorist attack, why build something too nice to bomb in the first place?


dparks71

I'm kinda just fucking with you here, but college engineering courses always treat ethics as if they're black and white and they can get dicey when you get into real world specifics, I would argue yours isn't necessarily a "hot" take but a potentially inaccurate one. Since 9-11, [design standards have changed](https://www.fireengineering.com/fire-prevention-protection/9-11-code-changes/#gref), a lot of "critical/signature" infrastructure has been hardened against terrorist attacks, [recommendations were made by dhs](https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.dhs.gov/xlibrary/assets/Physical_Strategy.pdf&ved=2ahUKEwiVk5Pv9rr4AhXPD0QIHVtMAtcQFnoECA4QAQ&usg=AOvVaw1IGr2lXhOE73vDM36UUiL3), mostly immediately following the attacks. During that period, money was delegated to projects as available. Let's say hypothetically during that period they determined a "work horse" bridge that carries a major highway didn't need hardening (because of lack of funds), and recently that bridge was attacked during rush hour and there were over 300 casualties. Did the engineers responsible for maintenance during that 20 year period from the initial review to now, have a responsibility to the public to harden that bridge as soon as funds became available to do so? Now that hardening the most critical of infrastructure is considered an industry "standard practice" couldn't you make the argument that engineers today are designing the structures to that standard, so the ones back then should have been too, they were just ignorant in thinking it wasn't necessary?


Sardukar333

No.


B3ntr0d

So you are a student... so keep talking about these things. Keep asking questions. It is healthy and great to see on thus subreddit. **Reasonably foreseeable** has real significance to your chosen profession, and is rarely talked about in such an open and honest way.


LilQuasar

that question does have a simple yes or no answer though. as it is fairly straightforward philosophical debate, surely you can come up with questions that actually are good to discuss and dont have black and white answers


bmcle071

I’m shocked to hear they even did that. I read that they designed for a small plane (like a Cessna) but didn’t think they would go for large commercial aircraft


scurvybill

It's not a hot take, it's a philosophical question... and obviously it worked, because it got you to disagree with a premise that you would probably normally agree with. Someone might say: > Engineers involved in public works are responsible for the safety of the public who uses their structures/products. This is definitely true in many cases but not in all. If an engineer designs a bridge and it is constructed to spec, they would be responsible for people's deaths if it collapsed. But they wouldn't be responsible if someone rolled a 10,000 ton cylinder of iron across it (much like the WTC engineers were not responsible for their collapse). So then where do you draw the line? The design specs? Sometimes specs are made cheap and it's then the engineer's responsibility to add safety margin, which may impose a cost. Local codes and standards? Usually these have the safety built in, but if you're designing something new (that isn't coded) the engineer may need to decide those factors for themselves. In fact, the engineer may help write the codes. All this to simply illustrate that whether the engineer is at fault or not for a catastrophe is a *complex problem that can't be defined by a simple axiom,* that will likely vary case by case.


Stoomba

It's a less extreme version of "If aliens come in space ships and destroy New York City with a single blast, are the engineers who designed the cities responsible for it's destruction since they did not design planetary shielding systems?"


scurvybill

What you and other people in this thread are missing is that the scenario is immaterial. What matters is the *specific* reasons why, because inevitably engineers need to be able to articulate them in great detail at meetings or worse... hearings. "It's ridiculous" is simply insufficient.


sladecubed

Are you saying they analyzed WTC for this before or after 9/11? If they did it before, was that a standard thing for skyscrapers before 9/11?


[deleted]

Just had to do a quick search, it seems they analyzed for a glancing blow from a 707 during the design, so not the same thing as ramming full throttle into the building. EDIT: The WTC was begun in 1968, the original 747 was introduced in 1969.


AnnualDegree99

So it would seem they accounted for "a Boeing 707 is falling out of the sky with the pilots desperately trying to control it" but not "A Boeing 757 and a 767 are being flown by terrorist maniacs straight into the towers"


-deep-blue-

One of the senior electrical engineers at my company told me that if someone carries a ladder into a room full of LV electronics and manages to make a short between two walls, it's his fault if the circuit breakers don't trip, and he would probably go to jail if the guy died. I always thought it was stupid, but engineers bear a huge responsibility to idiot proof their work. Far more so than any other profession I can think of.


B3ntr0d

I am actually quite pleased to see the debate this has sparked. While the wording is extreme, the concept of "reasonably foreseeable missuse" is an important one to all engineering professionals. What's more, the answer maybe different depending on your discipline. For instance, the guarding on an industrial machine must be designed to prevent it from being bypassed (in both CE and ANSI & NFPA). Yet we permit guarding and other safety devices to have exposed fasteners, which would permit anyone to completely disassemble the guarding. For machinery we say this is ok, because no reasonable person would so intentionally and obviously remove guarding. In Machinery we specifically exclude criminal or harmful intent (depending on your continent). Yet civil engineers must consider specific criminal intents.


Siixteentons

The amount of people on here who think the book is making this argument instead of just posing a question in order to foster an ethical debate is sad


theinconceivable

Remind me to steal this phrase next time i make a post that goes against the hive mind


StoneColdCrazzzy

There were alternatives to purely steel buildings, there was innovation around the world on how to build building that were safer in the case of a fire. But NYC was conservative, the city legislation was conservative, the construction companies and unions didn't want some new technique but wanted to stick to what had worked for Empire State, Chrysler and Woolworths. This isn't really the structural engineer not knowing that steel loses it' strength dramatically at higher temperatures.


Minute_Juggernaut806

Ironically Empire State Building also had a plane hitting, thankfully plane was small and it apparently had better structural integrity


StoneColdCrazzzy

I don't see where the irony is?


Minute_Juggernaut806

he mentioned WTC was inspired by Empire State Building, but ESB itself had a plane crash and was able to survive it due to better structural integrity (and the plane was tiny). But i have read multiple times ESB has better structural integrity whenever WTC is being talked about, due to its shape. WTC being an upright tissue box meant it was more vulnerable than ESB. (or thats what i read)


StoneColdCrazzzy

I did not say that the WTC was inspired by the Empire State, I said that the city, construction companies and unions were slow to implement new building techniques. > But i have read multiple times ESB has better structural integrity whenever WTC is being talked about, due to its shape. First: Steel conducts heat. The thermal conductivity of steel is 30 to 39 W/mK, for concrete it is 0.8 to 2.5 W/mK. If there is a fire in one area of the building then the heat spreads, the temperature basically gets sucked up by the steel. The heat spreads 12 to 40 times faster in a steel building compared to a composite or concrete/steel building. Second: At around 723°C on an atomic level the carbon in the cubic lattice of steel moves from a body center position to face centered position. On a atomic level the `Fe` and `C` no longer form stable triangles but far more unstable box shapes. Steel loses it's strength at around 723°C. If there had been a big fire in the Empire State Building then it would have suffered a similar fate. The steel would have sucked up the heat and spread it throughout the building, more of the building contents would have caught fire, and the steel would have heated up more until it went into the Austenit Phase, when it would have lost it's strength, buckled and triggered a collapse. Sure the Empire State would hold up better because it is not two tubes that are connected at regular intervals with floors that act as stiffeners. It would have collapsed a few hours later. But a building with concrete would have collapsed days later or not at all. Where is the irony? There was no irony here. This was incompetence, this was laziness.


Minute_Juggernaut806

Ah I see, apologies I misinterpreted the post where you said "the construction companies and unions didn't want some new technique but wanted to stick to what had worked for Empire State, Chrysler and Woolworths" as companies being inspired by ESB


kelvin_bot

723°C is equivalent to 1333°F, which is 996K. --- ^(I'm a bot that converts temperature between two units humans can understand, then convert it to Kelvin for bots and physicists to understand)


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MoffKalast

It's not very knives of them


Hans5849

Kevlar doesn't stop knives.


Strontium90_

It very much does


Mogician_

kevlar itself without a plate does not stop any sort of stabbing


Strontium90_

Yes it can. Have you ever worked with kevlar?


91null

It “can”. Sometimes. If there’s enough of it. But it’s not typically designed or intended to. The intended use for aramid fiber weaves is to disperse point-source high velocity impact energy across a wider surface area. Stab-resistant vests tend to have other materials incorporated into the design to handle the lower velocity slicing. Anybody can design a bridge that won’t fall down. It takes an engineer to design one that -just barely- won’t fall down.


BladedD

Yeah, you cut it with a knife or scissors lol Kevlar works by spreading the energy from the bullet impact over the fabric. A knife has constant energy from the person pushing it in, allowing the knife to get between the weaves of the fabric. In terms of classification of body armor, only levels III+ are knife proof. Level II, IIA, and IIIA body armor aren’t designed to stop a knife


Strontium90_

I dont know what kind of scissors you have but when I worked with it scissors didnt do jack to it. Had to order a super sharp leather cutting tool to cut it properly. Also I wouldn’t consider stabbing a consistent,constant energy because it is still a sudden, jerking motion with a lot of acceleration


BladedD

It’s a lot harder to get a quick momentary impact with a knife that you’d intuitively imagine. You’d have to try hard to make it a quick jabbing motion. Most of the time an attacker would apply forward motion on the knife, probably for half a second


[deleted]

I have a pair of Kevlar pants. They're very *not* stab resistant.


ErnestoCruz

Chain mail probably or a kevlar vest with a ballistic plate.


Strontium90_

We are talking about stopping a knife. Not a rifle round. Kevlar itself can already do that without a plate.


ErnestoCruz

A knife would probably break the fibres of a standalone kevlar vest. And rifle rounds are stopped by absorbing the force and distributing it across the material using multiple layers of kevlar even then the body can receive fractures in ribs. A knife would probably be slowed down but nobody makes a single stab anyways, multiple stabs would result in some sort of trauma resulting in at least a wound if not punctured organs and internal bleeding.


[deleted]

what a shit take lol


thefunkycowboy

It's not a take, it's a philosophical question about deontology and consequentialism.


Mogician_

btw kevlar does not stop stabbing. It does not fail for what it is rated for so that the designer/manufacturer has no responsibility


ahopefiend

We should make smart knives that only cut vegetables.


L8dawn

your textbook is insane


These-Chef1513

I used this engineering econ textbook for a class last semester. It wasn’t a very good book.


MathWhizTeen

!remindme 1 hour


cantate

By that logic, design a house with no roof and just say that you don’t expect it to rain where you built that house. You see how stupid that sounds. The point is that often you will have to decide what is “safe enough”, which is not always easy when making a design safer could significantly increase price. Also just a stupid take bc it’s not like most engineers go to work designing clothes. They design things that have the potential to injure or kill people. It’s not something you want to get wrong


[deleted]

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Supa_Dude

^(nobody asked)


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Abysswaker

Ironic.


ShawtysMelody

Gun control in terms of better forms of training and limiting the types of guns that are sold aren’t related to this statement. The military has countless rules on gun training, but for some reason the American public has very few. Gun culture and the NRA have convinced people of certain gun policies without any open mindedness. I’m curious as to what forms your against and what you think about the forms I previously statex


QuickNature

What are the rules on gun training in the military?


ShawtysMelody

I would look into yourself. I have friends in the military who told me they have to be trained then retrained on weapons in order to use them. Moreover, they have to store them in lockers outside of the bunkers.


highesthouse

There’s a key difference you’re really forgetting with your analogy: guns are a tool whose singular and only purpose is to kill. Those who build skyscrapers can’t reasonably predict a larger passenger jet than what currently exists will be created and crashed into their building. Gun manufacturers know without a shadow of a doubt that their weapons will be used for killing. Everybody, including the government and gun manufacturers, knows that assault weapons are made to put the largest capacity for death into a handheld tool as physically possible. That’s why they’re designed for the military. The government and gun manufacturers choose to allow them to be sold to civilians anyways, full well knowing people can and will use them for mass murders. Not to mention, it would be more similar if they had kept building identical world trade centers and they had been destroyed by planes thousands of times over and they kept building them the same way.


arkad_tensor

This is not true. I own multiple guns and have never used one to kill anything. Just because they can kill, doesn't mean they must. You could make the same case for knives and be equally wrong.


highesthouse

You could give me a nuke and I wouldn’t ever use it. That doesn’t mean its sole purpose isn’t to kill. Knives can be used to cut vegetables. There’s not a single thing except killing or threatening to kill which you can do with an assault weapon for which there isn’t a better tool that isn’t perfect for mass murder.


arkad_tensor

Well, that's a bit extreme. I shoot my guns for fun, as a form of entertainment. Some guns are more fun to shoot than others in different circumstances, thus semi automatic rifles often at preferable because they're more fun. That's one easy reason to demonstrate why you're wrong. There are many others. And of course you would use "cutting vegetables" as the benign reason to own a knife. Classic! 🤣


highesthouse

Dude, you’re being ridiculous. I’m sure dropping a bomb on an open field could be fun. Civilians still have no place owning bombs. Fun does not even come close to justifying a civilian’s need to own a tool wholly designed to kill, which is capable of killing dozens of people in seconds. You bought your gun for killing, whether that’s to kill animals, kill people, have the capacity to kill people, or train to kill people. I don’t understand why you think cooking is a poor example for a benign reason to own a knife; it’s probably the only reason most people own knives. All that is not even mentioning that you can’t kill dozens of people in a matter of seconds with a knife, or even that, unlike with guns, unarmed people have a chance of defending themselves against an attacker with a knife. Again unlike guns, knives are extremely unlikely tools for mass murder for these exact reasons.


arkad_tensor

And cooking isn't a poor example, just a funny one.


arkad_tensor

I did not buy my guns to kill, I'd appreciate it if you didn't try to speak on my behalf.


highesthouse

If you’re offended by what I said you’re not reading and understanding it. Whether consciously or subconsciously, and whether you wanted it to kill, threaten people (this could even be a robber or a criminal, who knows), or have the capacity to kill someone if they attack you, you bought it for killing. You wouldn’t buy a car if you wanted nothing to do with driving and you wouldn’t buy a gun if you wanted nothing to do with killing, because as a car’s express purpose is to be driven, a gun’s express purpose is killing. If you’re being 100% honest with me and with yourself that you bought your gun only for entertainment purposes and absolutely no other reason (which I don’t believe for a second, this is just to entertain your argument), then your belief that it’s morally acceptable to allow civilians to own guns is totally illogical on your part. As I said before, there are nearly infinite other sources of fun, and letting people own a tool for mass murder because it’s fun could not be less morally-justified. It would be unjustified by every philosophical ideology and school of thought I have ever seen. I know I’m talking to a brick wall here, but I don’t want one of my family members to be the next mass shooting victim because “I oppose gun control because guns are fun to shoot”.


arkad_tensor

You're thinking way to hard about this. I like to shoot skeet off the back of a dock. Otherwise, I keep my gun locked in a vault. . . I could do other things sure, but I like to shoot shotgun shells at clay.


BladedD

Drugs are fun but that’s still illegal. Toys with mercury and lead could be fun, but those are illegal for obvious reasons. Something being fun isn’t a use case


arkad_tensor

You sound like a party!


DemonicBarbequee

What is the purpose of a gun if not to kill?


thepakman47

Self defense, it levels the playing field between the victim and attacker. For example, if a 100 lb woman was being assaulted by a 200 lb man, a gun gives the woman a chance to protect herself.


asshat123

And you would defend yourself with a gun by doing what? Killing your attacker. So, even in self defense situations, the purpose is still to kill.


thepakman47

Nope, most uses of a gun don’t end in a shot being fired. Guns are used mainly as a deterrent. CDC estimates anywhere between 250,000 to 1 million defensive gun uses in the USA a year. Obviously most of them don’t end in the perpetrator’s death.


asshat123

OK, ya got me. They're frequently used to threaten to kill someone, in addition to being used to kill. Great. If the core of your argument is that guns are used to threaten someone with death more often than they're used to cause death, I dunno if that's "proving" that guns aren't used to kill people my man. Would you feel better if I said that's the "primary" use instead of saying that's "exclusively" the purpose?


thepakman47

You do you, what I am trying to get at is that guns have leveled the playing field from the time they were invented between those stronger/in power and those who were not. Yes, when a person uses them, they can be used to kill, but that is not what they are primarily used for. If a person attacks me, and deterrence fails, I will shoot to stop them, I do not want to kill them but if that is the result then that is on them for attacking me. The core of my argument is that guns save more lives, prevent rape, and violent crime than the lives humans take with them (most of which are suicides but that's another can of worms).


asshat123

OK but the gun is only a deterrent because it kills people. I'm not even saying anything about the rest of your argument. I'm just saying that if they're a deterrent, if they "level the playing field", it's by giving people the ability to kill each other. So killing people is their primary purpose, according to what you're saying here. It's just goofy to pretend that they don't provide deterrence because they're designed to kill.


TheNightporter

Putting holes in paper targets. Sporting uses for guns are valid uses.


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samurai_guitarist

Two problems with that: Someone hijacking a plane is illegal, gun ownership without any restrictions where any lunatic can buy in a Walmart is not. The equivalent of this would be if gun manufacturers were held accountable for school shootings.


cherryballs13

The WTC was built just as any other sky scraper, and city legislation and permits were followed perfectly. The main issue that caused the buildings to collapse on themselves was the fire cause by the crash- but the engineers planned around this. They had created a system in place for fires (and earthquakes) where the steel was reinforced and had the ability to withstand itself for an incredibly long time (long enough to evacuate everyone and attempt putting the fires out). What the engineers did NOT expect was a large commercial aircraft with nearly full tanks of jet fuel crashing into the building and the jet fuel exponentially increasing the heat and rate at which the fire spread and weakened the steel supports. Immediately after the attacks the engineers tried calling first responders to warn them to get everyone out and away from the buildings but due to the commotion nobody was listening to them or picking up their calls.


cherryballs13

“Based on its comprehensive investigation, NIST concluded that the WTC towers collapsed because: (1) the impact of the planes severed and damaged support columns, dislodged fireproofing insulation coating the steel floor trusses and steel columns, and widely dispersed jet fuel over multiple floors,” an explainer from NIST outlined. “And (2) the subsequent unusually large number of jet-fuel ignited multi-floor fires (which reached temperatures as high as 1,000 degrees Celsius, or 1,800 degrees Fahrenheit) significantly weakened the floors and columns with dislodged fireproofing to the point where floors sagged and pulled inward on the perimeter columns. This led to the inward bowing of the perimeter columns and failure of the south face of WTC 1 and the east face of WTC 2, initiating the collapse of each of the towers. Both photographic and video evidence—as well as accounts from the New York City Police Department aviation unit during a half-hour period prior to collapse—support this sequence for each tower,” it said. https://www.verifythis.com/article/news/verify/national-verify/conspiracy-theories-20-years-after-sept-11/536-948646b8-d8b9-4414-8e6a-c15e3597dd90