Engineering Failures Found in the Champlain Towers South Drawings - Surfside Collapse
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- Опубликовано: 27 сен 2024
- In this video we dive deep into some of the more glaring errors in the design of Champlain Towers South and explore the most likely origin of the collapse from a structural engineering perspective.
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The 𝘾𝙝𝙖𝙢𝙥𝙡𝙖𝙞𝙣 𝙏𝙤𝙬𝙚𝙧𝙨 𝙎𝙤𝙪𝙩𝙝 𝙥𝙡𝙖𝙮𝙡𝙞𝙨𝙩 showcases Josh Porter’s expert analysis of the tragic Surfside condominium collapse. Josh’s ability to explain complicated material in a way understandable to anyone has created a high demand for his instruction. You can get it right here for free, at your leisure.
• Champlain Towers South
The 𝙊𝙣 𝙋𝙤𝙞𝙣𝙩 𝙥𝙡𝙖𝙮𝙡𝙞𝙨𝙩 offers viewers a deep dive into Josh Porter's decades of experience in the construction industry.
• On Point
In the 𝙊𝙣 𝙩𝙝𝙚 𝙅𝙤𝙗 𝙥𝙡𝙖𝙮𝙡𝙞𝙨𝙩 we take you out of the studio to where the real action happens, the job site.
• On the Job
The 𝙊𝙣𝙚 𝙤𝙣 𝙊𝙣𝙚 𝙥𝙡𝙖𝙮𝙡𝙞𝙨𝙩 contains interviews with industry professionals discussing everything related to condominiums, construction, and engineering.
• One on One
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#BuildingIntegrity #SurfsideCollapse
This video is already crazy long and I couldn't fit in everything I researched. What didn't I cover that you're curious about? I will take your ideas and try to put together a future video covering some of your questions.
How did the pool deck collapse pull down the building? How different is the North tower from the South tower with respect to the structural design changes you speak of in this video?
Is it possible you could talk about the crane collapse during the construction of the condos? Could that have played a part?
I know other places are evacuating now due to unsafe living. Do you think the engineers will be stricter moving forward when putting up the towers? 😬
The videos are so interesting that its a pleasure to watch them... Don't worry about being too long.
@Randy Carriere excellent question, we know a lever can be very powerful...
I never thought I’d be interested in engineering, but at age 64, I’m finding channels like this fascinating.
Subject novelty does wonders on the brain. I too find myself getting sucked down technical rabbit holes of domains I never received any formal training into. It's just fascinating
Engineering is a fascinating subject, and something we take for granted most of the time.
For that happened at 28. :) But still: In my early twenties I probably wouldn't have seen that coming. But there's something really fascinating in seeing physics work in real life and understanding so much more about the world around us.
For me there's something about studying the way our built environment is shaped that is fascinating to study regardless of what discipline you work in. We live with architecture and engineering almost constantly our whole lives, and it's always on our mind at some point, so opportunities to learn about it are always relatable and rarely fail to strike that flame of curiosity.
Yes, that's one thing that's great about RUclips! I love Karl Jobst's channel, for example. It's all about speedrunning video games. I don't play any video games, haven't for decades, and certainly don't do speedrunning. But his videos are quite fascinating and entertaining to me!
Watching this video, I felt a kinship with the people of times of old when "common" folks would pack halls to hear experts explain various scientific topics.
You make this so much easier to understand. Thanks for your work!
Wow! Thank you!
Yes, you are very good at explaining engineering and building terms so that a common person understands them very well. Thank you!
Now, this is what I call homeschooling.
@@chuckgilly It's not really schooling now is it? A Society for Home-Schooled Engineers should probably be on every terrorist watch list on the planet.
Schooling would teach us how to make a building stand. This excellent series taught us a single way in which a building can fall. (and lots of tips how to spot concrete going bad)
@@bramharms72 - I disagree, with all due respect. Teaching how to make buildings stand requires knowing the way that they fail, and this knowledge makes for better engineers and architects. How can one build into a structure a reasonable safety margin without knowing where that "line" needs to be? Failure analysis is one of the best ways of learning from others what not to do, in my opinion.
Allow me to put it another way: Would you live in a building that was built by people who didn't do failure analysis on the structure, remembering that modern buildings are built down to the last penny and right to the edge of code? I sure wouldn't, and this video reinforces my opinion significantly.
Just wanted to add that the woman's garage walk through video has been an invaluable record for verifying the construction and determining where the failures took place.
I know, what a blessing
It has and I have spent many hours on the phone with her as well
Perhaps people should start doing video walkthroughs of all such sub-grade parking areas -- who knows when the next one might collapse and such evidence will be invaluable. These days anyone with a mobile phone can record a video quickly, cheaply and easily at minimal/no cost. Perhaps this is a new hobby people could do as a community service?
Which is kind of why security guards tend to take photos of much anything unusual or a potential problem. Part of the job description to take note of anything unusual or a potential hazard or problem.
I think often many repairmen may also take before and after photos, documenting their work.
Perhaps the photos will never be useful for much. But if "something happens" the photos could turn into valuable documentation or evidence.
@Yosef MacGruber I’m a Plumber/HVAC tech and I learned years ago to document EVERYTHING I do with photos. The first thing I do is take photos of everything from every angle, take snapshots whenever necessary throughout, and then take photos of everything from every angle again. I found you never know when all of a sudden you’re asked to recall details from a repair you did last month, 6 months, a year, two years ago.. I never delete photos and have 100,000+ saved on iCloud. It’s been invaluable to me, being able to pull up detailed photo documentation of all my past jobs, and especially when you have a vindictive customer trying to make false claims.
The knowledge it takes to do forensic engineering is tremendous! On top of that you make it understandable for the average person. Thank you very much.
Wow, thank you!
Exactly. A very logical examination that determines the cause of failure. As with most structural failures, this most likely was a monetary cause and effect whereby the engineer was pressured by the developer and/or contractor to produce a design plan that reduced construction costs to increase profit...and in the process, the structure ended up being compromised. Always about the money!
@@BuildingIntegrity - you really do provide great presentations. I am addicted.
@@jameschristie4596 money and overpromised deadlines
I have a rudimentary understanding of engineering, as a result I really appreciate your explanation that not only enhances my understanding of engineering, but my knowledge of the collapse from a forensic standpoint as well.
As a concrete inspector and civil engineer I found the video very interesting. I find it unbelievable that the City could of approved of new planters at the pool deck without a structural analysis. Either it was installed without inspection or there were a lot of very negligent people involved in the remodel.
Yes do the load analysis but the couple tons of planter are a trivial addition for this beam system, given well made structure. The problem here is long term contact with water. Unprotected steel reinforced old mix concrete will corrode and fail in long term continuous contact. That roof deck didn’t drain. An earlier inspection on the building. now widely available pointed out water.
A bit of $$ in the right place and knowing certain people trumps engineering sense!
@@Nill757 well, no. many factors contributed together. long term contact with water is a problem, but shouldn't have lead to a catastrophic collapse of the whole tower. that's why inspectors noticed the problem but didn't condemn the building. if the structure was originally built with proper safety factors, proper rebar, and the extra load was not added, then the corroded rebar would be a problem but not an emergency. the fact that nobody noticed the bad original design OR the exacerbation of the bad design while adding additional load, are what lead to the catastrophic collapse of the whole tower. prematurely aging rebar would just mean work should be done to correct it, or the worst-case scenario where the pool/garage partially collapses but does not bring down the whole tower.
@@somedude-lc5dy Building Sinking due to being built on landfill over former water inlet certainly did not help. First day Engineer giving analysis I should have wrote down who where saying this going to be a large number of different failures certainly seams right.
they were only planters, what could go wrong?
Honestly, this video could have been double the length and I still would have watched it all.
I enjoy your explanations please keep it up.
Yet another fascinating presentation. Your presentation of your forensics gives me the sense that I understand what your are talking about! Wow - a natural and gifted explainer!!
oh why dont you marry it then?
@@666goats this is a 2nd grade comeback
@@ko9446 i think you're being too generous.
@@charlesstockford5913 I’m only in 3rd grade, it’s lol I got 😂
Truly enjoy listening to you.
I worked with architects and engineers for 35 years. In general, the structural engineers were the least flexible and most conservative with designs, because they provided the parts of the building that made it stand up. I find it bizarre that the structural engineer made the changes you've shown without some kind of structural load compensation in the design.
Read up on the people involved, possible mob involvement and the Wild West nature of things at the time I'm a tad surprised there was a qualifies structural engineer involved at all but certainly in that environment only structural engineer's that were willing to break the rules in building things need apply.
@@RedRocket4000 really? That's fascinating. I do remember hearing that there was some mob activity in the area at that time.. I'm gonna check this out now.
@@RedRocket4000 You are entirely correct. At that time ( The Miami Vice era ), the Mafia needed a means of laundering large amounts from the booming Cocaine business. The Mafia turned to the construction business, hiring shady contractors and builders. They "cut corners" and constructed large, Glitzy, cheaply built ( under code ) buildings. ( Inspectors were paid off )… Later, to make these Condos more sellable, heavy marble flooring, tiling, granite countertops and heavier bathroom fixtures/ appliances.. Walls were removed to give a "more modern, open concept look ".. All of this created an added weight load (approximately that of 3 automobiles per condo ), to an already compromised building. The building codes were oddly "reduced" in 1972 and the early eighties ( Mafia and political intervention )...
@@RedRocket4000 I really don't care to "read up" on alleged Florida miscreants. I can only relate 35 years working for two of the world's largest engineering firms and knowing the conservative engineering approaches used for the projects I worked on. You couldn't buy your way into a design change that would cause potential liability and especially loss of reputation. This includes six projects done in Florida starting in 1992.
@@buckhorncortez, so you don't care about the politico-social potential root cause of problematic building design and construction in Miami-Dade in the era the building in question was designed and built? Cool beans. Thanks for letting us know.
As a professional engineer, I appreciate the enormous amount of work you put into this thoughtful and thorough analysis. Combine that effort with the excellent editing and you end up with an outstanding summary of the current knowledge available on CTS. Thank you for all the work. This will help avoid future tragedies like this.
As a lay person with no background in engineering, I am thankful for this channel. As a Florida resident 20+ yrs mostly beach living, this collapse affected me on a personal level. You deserve an award for helping us understand.
Josh at 5:00 you said you could not find the planters in the 1979 drawings, I have the answer for you. I had mentioned in a few of my videos in July that the HOA had a contractor come in back in 1996 and added the extra planters, as well as the palm trees. I had put up a few videos showing this, as well as what stressors and latent cracks might have happened if they drove any heavy machinery on the pool deck to install these palm trees, and later they removed them in 2018. On the Surfiside records web site, you'll see the file 8777 COLLINS AVENUE - LANDSCAPING P#96-0403.PDF, that has a drawing that shows their proposed added planters, as well as the palm trees. This is also when all that extra sand and heavy pavers were added, which I feel slowed down drainage of rain off pool deck, and often left pooling that I showed in many real estate agent MLS photos of the pool...
Love your vids and giveaways sir. Keep up the great work!
It looks like they added insult to injury over the years!
I'll look into that. If the planters were added in '96 I'm curious to know if an engineer was hired to evaluate the deck for that weight.
Thanks, Jeff -- you and Josh make great videos and i watch you both.
When an HOA gets involved, nothing good comes out of it.
I’ve learned so much about structural design from your channel. I live in a high rise in Boston with serious structural maintenance issues similar to the ones which you have reviewed. I only rent so I’m moving but I did notify the local building inspector and I think I was able to take good informational photos due to some of the wisdom that you have imparted. Thank you sir!
Glad you are moving!
@@cherylhoskins1679 Yes and remember a Military and good restaurant rule, it does not mater that something you see wrong is unimportant for safety you assume if they let you see something wrong the things that are important for safety are wrong too.
The owner of the building is probably also glad you're moving.
@@RedRocket4000 yeah maybe if you see some unexpected planters added around a building you can assume the building itself is unsound. Or if my car was originally blue and I repaint it red, now the car is unsound. After all it's suspicious, right? But that's why we have engineers, to get beyond such random suspicions and actually understand whether it's sound or not. That's what I did not see in this or any other of their videos.
@@davidquinn9676 hahaha
I don’t know anything about reading design documents, blueprints, etc but I have been watching your videos from the beginning and have learned so much. Your presentation and explanations of what is a complex subject are informative, educational and understandable. Thank you for all you are doing. I think anyone watching your videos has started to familiarize themselves a little more with their surroundings and has certainly become aware that a crack that we see might have a lot more going on that we don’t see.
I found an interview with a family member who lost his mother and grandmother in this tragedy and he said something interesting that I have not heard anywhere else. He said that the night before the collapse his mother got woken up at 3am by some very strange and loud noises and she was not able to go back to sleep after that. He said that it’s stuck in his mind because never would he think that the building was going to collapse .
There certainly were lots of warning signs just no one thought collapse was a possible result.
Yes it was like 45 minutes from the big noise to collapse. Or something like that. If you asleep you might think it was a sleeping phase noise and not real. I wonder if anyone saw sources that pets were uneasy. I couldnt find any but saw comments saying that pets were uneasy and they were taken out saving the owner. But it might be a mith.
Everyone wants to blame it on structural defects yet this building had no steel beams or posts in it. It was all concrete with rebar. How many holes needed to be drilled and small explosives put in to make a few posts fail to cause a failure? How many holes were drilled and explosives used to fell the rest of the building? Now we have the Saudi's putting up a bid to buy it. The Saudi's owned four floors of the Las Vegas Hotel where 50 people dies at the concert and I heard it was an assassination attempt on the Prince's life as he was in the Tropicana in disguise.
@@timsteinkamp2245 98 innocent people lost their lives. Spreading misinformation is a slap in the face to them and the families. Have some decency and respect.
My professional experience is in engineering and building sets for stage shows, but my family experience is in commercial design and construction. And I found your analysis to be quite interesting and informative.
And it raised an issue I have encountered many times in my professional career: revisions. I've had many arguments with theater companies, asking for a revision only to have them balk when I tell them the consequences and time involved in examining how their proposed changes affect the structure where the changes were to be made. I point to my experience with the family business to my attentiveness on set construction that no set I have built has ever collapsed or allowed an actor to fall through it and injure themselves.
Thank you for your work and effort on examining, and reporting on, this collapse.
is never having a stage collapse or break through really the only thing that matters? anyone can build something absolutely fail safe and indestructible.. its building something that meets the needs and any foreseeable changes or forces without grossly over building it
need a stage? pour solid concrete down to bedrock, there job done. the estimate is 7million dollars and itll be done in 6 years..
@@AndrewBrowner , you don’t understand the comment upon which you are commenting.
The original poster, @Bert van Aalsburg, doesn’t build stages; he builds stage *sets,* which are by their nature temporary and only have a life that spans the length of a show’s production, which is usually several weeks but in some cases can last months or, in the rare case of a long-running Broadway hit, several years. There are also touring sets designed to be repeatedly set-up, taken down, transported and set back up again. It’s a rather niche design domain.
@@inkyguy i understand what he build, truly sorry i called them stages and not stage sets... my point isnt about stages or how he designs them at all, my point is that saying youve never had something break/collapse/fail doesnt make you a good engineer/designer in an of itself.. anyone can make something that will never fail, good engineers make something as good as it has to be in order to never fail but no more expensive than it needs to be, theres a safety factor built into this.. but theres certainly a point where youre going too far and just wasting money, time and effort "to be sure" rather than running the calculations and determining if the changes need to be made to accommodate the new use.. really you should have a pretty good idea where weight can be added and where it cant be without even looking at plans or picking up a calculator
@@AndrewBrowner It's not the only thing that matters, but it is a primary thing that matters. Weight stresses on a stage set are not as extreme as stresses on a four-story residential tower. And the accepted code authority is generally given to the judgement of IATSE, the technical stage hands' union.
And, since stage sets are meant to be disassembled at the end of a show's run, or to be packed into a truck for other performances in other locations, it cannot be built to the same degree of commercial buildings that are meant to remain in place for many years afterwards.
Whether you are being dismissive or snarky, in your response, do please be respectful. We may not all be building the same structures, but we are all building to insure the safety of those who are to occupy the structure. And that any revisions to the original plan must be vetted to ensure the changes do not compromise the original plan. Whether the plan is the set for "Spiderman: Turn off the Dark" or a 20-story office building.
@@AndrewBrowner I get you now. Yes, building it butch is not useful and is often wasteful. Often it's a matter of helping the client understand the why and how revisions need accessing to determine the best way to meld the changes into the plan.
Last minute construction changes are sometimes done without the full design team evaluating the change and the significance of a "simple" change isn't recognized. We all studied the Hyatt Regency collapse and you may be telling us about yet another story about a "simple change" with huge consequences. I'd be interested to know more about that 1980 change to this design. Was the original structural engineer the one who signed the 1980 print? As you point out, the design change may have also accelerated structural degradation as salt water, etc. weakened the structural elements. This was one of those "swiss cheese" type failures, when the elements lined up, people died. Your work is so important and your videos are lucid and have lessons for all of us who build and maintain the built environment. Thanks for your work.
In the digital world these changes can be quickly evaluated.
The sign off looked identical
My background is in software, but it's the same issue with changes. One of the problems with software is that the reason why something was done the way it was done gets lost. I highly doubt the person who did the original drawings was the person who signed them. It's the new guy straight out of college who does the grunt work in software. My bet is that the first person (probably more senior) who did the work with the stepdown had the beams in place for both the stepdown and the garage, but someone newer made the change to remove the stepdown and didn't understand that the beams served two purposes. If they didn't list removing the beams on the plans, the PE who signed the plans may not have noticed the beams were gone. The new guy might have had to work over Christmas holidays to get the new plans submitted in early January, when there was no one left in the office to ask questions.
@@OOpSjm The judgement of the structural engineer is still vital. In the Hyatt case, an engineer applied the wrong assumption. Yes, with digital models the ability to analyze changes is easier. We've interacted with a mathematical model of a seismically unsafe high rise to improve the constructability of an upgrade design however that exercise was guided by an experienced team of structural engineers and checked by peer review. BTW: They ultimately imploded the building and replaced it.... :-)
@@bbamboo3 I’m not familiar with “the Hyatt case”, would love more detail and if that is another building collapse, maybe Josh would tackle that situation in detail as well?
Excellent analysis: this is precisely the StrucE critique of the As-Built that I was hoping for.
Thank you for investing your time to do this.
I'm not an engineer, but this was a top-notch presentation that was clear and easy to follow and understand.
Thank you. As a country, we need more people like you who use facts, science, math, engineering and peer-reviewed data and publications to determine solutions to difficult problems. The world today is full to the brim with misinformation, rumors, conspiracies, pseudo-science, hear-say, bigotry, and other clap-trap that gets in the way of intelligent analysis and decision. Yes, this is RUclips and RUclips itself is overrun with crap, but your channel is one that the viewers can trust to get the facts.
But da maths is now rayciss.
Isn't that the truth! I love facts! We need more truth tellers
Yes yes Ruthless!
@@chumpchange1846 Wrong, Buckwheat.
empty buzzwords by those backing an Orwellian system.
WOW, this analysis was absolutely perfect, everything explained in detail, no nonsense like many others "it fall because it was old", thank you for your work, much appreciated
As an engineer I greatly appreciate the fairness and neutrality of your presentations on this, and the clarity with which you explain the issues (I'm electrical, not structural, so there''s a good deal that is not my field). This has been a really interesting series of videos and I look forward to seeing how close the final reports come to your analysis.
I can’t believe how informative this video is. You absolutely need to be on the team that figures this out. Thank you for all of this information.
oh why dont you marry it then?
Appreciate how you've kept these videos clear and concise, free from all the usual RUclipsr talking head distractions, so that even us "normies" who've never taken a single engineering course can follow along. Your videos, along with Mike Bell's animations, have really helped clear the fog of understanding the seemingly inexplicable event of a modern residential building suddenly collapsing.
Worked the urban planning side. The amount of shenanigans people do to get around bylaws (and the amount of bylaws waved as easements to developers) is ludicrous.
It's all "Government Red Tape we want to rip up" until no one will buy your buildings because they worry they will collapse.
Here in Australia, they privatised building inspectors and made the industry heavily self regulating. Unfortunately, the only way they can self regulate is if they build 10 buildings, then one of them almost (or does) fall over and they go bankrupt. They are removed from the market, but the last 10 buildings are garbage.
@@letsburn00
yep.. blame lies with neoliberal ideology and economy worship (the love of money above all).
To be fair, in the US, a lot of bylaws aren't on the books to protect people per se, but as legal ballast to get concessions from developers. Once this is the case, respect for all bylaws, not just the offending ones, go out the window.
@@hailexiao2770 There's a fine line between the right amount of regulation, and over-regulation for special interests. California is an example of the latter.
@@Dee-nonamnamrson8718 Exactly, and homeowners are the #1 special interest group screwing up California. If Republicans want any change of winning statewide office, this issue is their chance. But since the cult of homeownership is as strong, if not stronger, on the right as well as the left, the chances of them doing so are slim.
How could an engineering firm remove massive beams and not re-do the calculations? It boggles the mind.
Blame it on the approving engineer, or the construction company / contractors, architect, etc. There's many points of contact from the initial blueprint to finished project. Judging by the irregularities between the 4 building docs where half of them are undated and the engineering company stamp is missing, there seems to be at least 1 party that acted in bad faith or criminally negligent
Checkout the the collapse of the Hyatt Regency Skywalk collapse in Kansas City in 1981, killing over 100 people and you will find it was due to Engineering negligence. Failure to Recheck the numbers on a simple change that proved catastrophic.
@@stevelopez372 Yeah that is one of the go to examples for ethics in engineering to this day.
@@killjoy1887 Australia has it's example also. In Melbourne, Victoria the West Gate Bridge was being built. The unjoined segment of road deck was being held by concrete blocks to correct a camber error. Finally an order came through to loosen some bolts, at which point the bridge snapped back and collapsed, with 35 killed, 18 injured. Six twisted fragments of the bridge can be found in the grounds of a local university who was asked to participate in the investigation the collapse. Its said to remind engineers of the consequences of their errors.
@@gavin9088 This type of thing is common in construction. Bad plans, incompetent or criminal contractors, corrupt Building Officials. The miracle is that this doesn't happen daily.
You’re a brilliant teacher to be able to explain that in a way that i can actually understand. Thank you.
Thank you. Means a lot.
@@BuildingIntegrity You explain things very well without talking down to people. Thank you
you know, a bunch of other youtubers post analysis on this topic. i ignore all of them and wait for your videos. i appreciate your deep analysis and through yet easy to understand explanations
Hearing all of those "it was at 100% load" makes me wince so much. Especially when you're right by the ocean...
"Underground parking garage" only 400 feet from the beach makes me wince whenever I think about it too hard. You don't see basements in seaside buildings for a large number of extremely valid reasons.
and then you remove additional supports from these sections that dont have much wiggle room to begin with...
@@micaheiber1419 Built Against Costal Mountains the key here way better bedrock than the basically non existent bedrock here in Florida. You actually have ingenious and metamorphic rock there. Although due to Earthquakes The basements and parking garages are build with massive reinforcement. I've seen Japanese under building parking that looks like each car slot was actually a bunker for a military plane (thick concrete walls three side and roof) inside a larger bunker like the Germans had for their Subs in WWII. No columns wide concrete walls holding up thick concrete cross members. Other cases columns bu three times wider going into thick concrete cross sections not punching though them.
In this case the building build on filled in inlet there was water were this building was before. Main part of Florida basically floats on limestone and water mix. Main part of State been under water totally several times and is made up of former sea floor, coral reef and ancient beaches. I expect another time under water in the next century or so.
And these are barrier islands for the most part shifting sand bars basically that should never be build on in the first place over all but are subsidized by the suckers who live inland. Thus the above comment on never build basements on seaside building.
@@Darkkfated I never gave it much thought but in Florida where I am this normal. If you go downtown areas many buildings have basement garage. But hey NY city and London do it too so I don't think it is a problem.
In aviation, when we are handed the performance specs and limits for an aircraft, we are reminded that these are for a brand new aircraft, with new engines, flown by a manufacturer's test pilot, under ideal conditions. In other words, the best it will ever do and don't ever expect to get those numbers in the real world.
Practical Engineering did a shot out to you👍all of you engineers have prospective outlooks that combined will help make buildings safer in the future. My heart goes out to the people that passed in the building. 🙏❤
Just watched Practical Engineering video and missed the shot out
Amazing analysis. You’ve clearly put enormous effort into this. An a non-engineer, I understood your explanation. Well done.
He knows how you feel. He's not an engineer either.
as a retired architect who specialised in construction, i am not surprised that USA also has 'building' problems, the aim of developers is to make money with less 'bother' (as they call it) and alas Local Authorities often do not have properly educated/experienced staff to scrupulously check everything....see our UK Cladding Scandal....should never have happened.....was my experience that the fellows on site were smarter than the suits on desks...
Most chilling conclusion: 40:40 "I'm actually kind of surprised that it took forty years for this thing to collapse."
and then collapsed all at once. Amazing. In fact, impossible!
@@davidquinn9676fake news. at best what you mean is unlikely. You're mistaken.
@@davidquinn9676 lol imagine thinking your take is worth sharing, and it's this.
@@davidquinn9676 Did not collapse all at once it collapsed in stages and even the final collapse was not all at once.
@@davidquinn9676 You have a hypothesis ? Why would you say that? I think you have another theory, right? Tell us please.
I love your programs! I stop what I am doing, sit down, and watch the whole show!
Me too Merry! I don't understand everything but love how Josh breaks it down so my non-engineering brain can somewhat comprehend it! Keep analyzing, Josh, & share with us please!!
Me too!!
I agree, and I like your first name 😉
@@merrywalsh2809 hey! I like yours too!
20:10 Regarding the pool deck being at 100% capacity, another source raised the issue of the palm trees. That is, driving a cherry picker across the pool deck to cut them down. I wonder if that could have greatly damaged the deck. Also, if a planter is, say 3x4x12, saturated soil would weigh around 8,000 pounds (water alone is just over 8,900 pounds).
There's also the core sample which I believe was 3' x 3' directly next to the pillar which is believed to have punched through first.
One cubic foot of water weighs 62.3 pounds. If it saturates the planter soil it will add a lot of weight!
My be misremembering, but notice the square planters that had the palm trees are not on the 79 or 80 design, and were just that much more added weight when built on top of those relatively tiny columns that were already overworked and built ot age prematurely.
So here is the question: is the North tower built the same way? We've established that it doesn't have the same water problems, but did it use toothpick columns and exclude beams beneath planter boxes?
yeah probably being that it is newer is why it is still standing for now probably how long it stays standing is anyones guess it may fall down soon to as well
I'm betting the property value of the North tower has plummeted. Who would want to buy into that now?
Good questions... just as with the collapsed CT South, the drawings from CT North are public record, and available from Town of Surfside... if you want to go through their bureaucratic procedures to get them. There may be per-page copying costs.
@@MajorCaliber Engineer said it safe But they need to assume that safe for now not the future. Get more opinions and have two different expert teams rework all the plans.
North was not built on former water and did not sink into the earth for a decade also like South so North might have another ten years but I would not trust it past a year.
@@RedRocket4000 CT North is only 1 year newer than the collapsed sister CT South, not 10 years. The CT East *is* 10-12 years newer, but very different design and construction.
Every time I get a notification on this channel, I clear the decks and watch. You are excellent! Thank you.
Thanks Merrill! Means a lot.
I just keep look and hoping there will be a new video. Thank you.
I'm hooked on your channel now. I've watched other past videos. You clearly explain to the layperson. Thanks Josh
Once again, a top notch presentation....Thank you for putting so much effort into these videos which help us understand how this building was designed.
As an Eng in a different field, I really appreciate that you Did take the time to explain and build up to your findings. Very insightful and have a much better understanding what may have led to the collapse. Thank you!
I'm so happy that you guys are gaining subs so quickly. You're top shelf when it comes to teaching. Thank you Josh for all of your research and work on the Champlain towers. This was soooo revealing.
You're the best! Thanks for the kind words!
Thank you for your succinct analysis of this building structure. As someone who has no knowledge of structural engineering even I understood the apparent error of omitting the transfer beams. All we can do is learn from our errors and pray for the souls and families of the dead, may they Rest In Peace, their struggles are over…
Can you bring it all together in your next video and explain how and initiation of collapse here would propagate through the rest of the structure and how it meshes with the video evidence of the initial partial collapse in the garage? You have made a lot of good points throughout the series, but it would really help us less technically minded folks to see it all put together into one timeline. Thanks for the great work you are doing!
Yes I seen is explained before and that things can be done to insure the failure in that area effected nothing else. Basic a Patio failure should never have been able to make anything else fail and vise versa.
Thanks for all the excellent work you do.
Thanks for watching!
@@BuildingIntegrity You literally deserve a medal for all your hard work, for helping us understand in lay terms, and for your integrity. 🙏
I would love to see if that sister building they build a few doors down has any of the same issues with the deck leaking and if it also had support beams that were not included under their planters.
_cough_ Shoring! RETRO-fit! _cough-cough_ Nothing to see here... moooove along.
Whomever is living in that sister building deserves what's coming to them... Common sense would be to move IMEDIATELY! I would even break a lease lol.
@@ricky4673 what if you own it with a mortgage?
@@ricky4673 , that's not a rational take. if your choices are: A) become homeless and bankrupt or B) rely on engineering firms to determine if there is risk of the same thing happening, rely on the engineers. there is no chance you can sell this condo now, so you either live there or you declare bankruptcy, which may put some people out on the street. it's a hard choice. eventually, you would hope that lawsuits or city programs will come through to take the burden off of you, but those things typically take a long time.
@@ricky4673 Why would the people living in the other building deserve what's coming to them? Some new resident deserves to die because they rented an apartment without doing a structural inspection first? Have you ever hired a company to do a structural inspection of an apartment you moved into? I don't understand that statement at all.
I’ve been glued to your videos since I discovered your channel. I grew up in North Miami Beach. I temped at two Miami Beach condo conversions while at college in 1980, and enjoyed working with all the contractors. I wish someone encouraged me to become an engineer back then! It’s fascinating and important work. Your explanations are so well constructed to explain the basics, while not dumbing down the material (as far as I can tell).
@Jim Flanders Oh yes, I remember the Alexander. I worked at Belle Plaza on Belle Isle, and also the South Bay Club, originally called Plaza West. If I could go back right now to Miami, I’d be tempted to personally inspect those locations. 🙂
My god. Columns and slabs being loaded to 100% on dead load alone is insane. It seems like their ability to carry live load for 40 years before collapsing was probably just down to the materials being stronger than specified and nothing more. This seems like gross malpractice.
Then add planters, sand, pavers, water, and 6,000 moving vehicles and it's just a matter of time.
Exactly...I would like to see a discussion on this.
I expect there is a lot of safety margin in the 100% load factor to allow for variances in construction, variations in concrete within even a single load, and to allow for some degradation over time. But, a building which is over 100% loaded is gross malpractice. Allowing a landscaping permit to put materials on a building at 100% load already is another surprise. The live load of people on a concrete structure is negligible. Cars which rapidly start and stop 6000 lb loads is another matter when considering live loads. There is a reason for speed limits in parking garages beyond preventing collisions, and it's to limit live load impact on the building.
@@johnhaller5851 Oh, that makes me remember why I HATE parking garages. Again. They mark it 10 or 5mph, and then put it on a ridiculous slope to accommodate the lack of footprint...
@@johnhaller5851 If you need people to follow a speed limit in a parking lot were you can't legally ticket people, the building is unsafe. And as others stated you can't have support column they can run into thus way less parking as one Japanese Building I saw every side parking space in effect a bunker for the Car with support walls on every side not columns. I was thinking what this a former fighter plane bunker each spot protected by blast walls from another. (It was certainly not any plane bunkers from the war on the surface)
You explain everything so well, in simple terms we can understand, while still telling us about technical terms and rules. It's a damn shame someone didn't look at this revision closer and/or put a stop to that penthouse that was added on. So many ticking time bombs in this fated building that I agree it's surprising it took that long to fall. 😞
I think that even if someone would notice, they (?) would just brush it away. Pfff.... Peasant!
@@johna5874 Because they down-think on/of you. If you see a fault, they will never admit it. And brush you off... pfff. Peasant.
It would slow the building time down.
John A Woooooshhh
I am not an engineer but I find your videos fascinating and very informative for non-intellectual as myself. Awesome job thanks for all this effort.
Very professional presentation! For laymen it was completely descriptive as to the Surfside Condo fails in construction. (Due the removal of load bearing essential beams eliminated between 79 and 80 revisions.) Add the planters, accident waiting to happen! The heat and cooling of materials was interesting to learn about. Then add the salty, sandy site influencing stability.
@@markonw6661 Thank you Mark, I am always interested in learning something new.
Many years ago, I remember a magazine article that suggested that engineering changes was one of the biggest hazards in design. This was based on observations going all the way back to the Romans. It looks like that same principle may have struck again.
I'm thinking last minute changes require going through all the calculations again, and that didn't happen. You would have to check everything else works with the last minute change. I have no mathematical ability whatsoever, but I sure wouldn't want to go without rechecking the original plans match the revision - that they still work. It sounds ridiculous that they wouldn't recheck. Should have delayed everything for that purpose. It's not like it's the paint color being changed.
The Hyatt Kansas City walkways collapse (1981) involved changes from original design. Probably what you are thinking about.
@@isveryrill1234567 Yes, it’s a failure to see the whole thing as a SYSTEM rather than discrete parts. That’s what he was saying about the secondary function of the beams I think - they may have been put in for the step down but they also played a role in the entire *system* of the building by directing forces along specific paths. Even ‘just’ adding an extra planter is changing the system because you’re putting a bunch of extra weight in one bit, which needs to be accounted for - if the part of the structure you put the planter on is already stressed due to the role it is playing in the system then it may not handle the extra stress even though the same sort of construction standing independently (I.e. unable to be stressed by other parts of a larger building) might be fine.
So changes need to be assessed systemically, not just locally.
When I heard for the first time they were designing the Space Shuttle around a pair of solid fuel rockets, my thought was "This will not end well!"
@@davidvoinier6008 LOL Same. Solid fuel and humans should not normally mix. But launching below the known temperature the units were rated to work it criminally bad as well. Damm things had a do not use below temperature rating and they launched substantially lower than that.
Been waiting for unsurprising ending, and I’m sure this is as close to saying “design flaw” as you will get (at least for now). I hope people are looking into other buildings designed by this firm and these specific engineers. Thanks for another excellent video, I know there is a lot of analysis invested in this and much work producing the video.
I remember about 25 years ago, when I was doing some of my first project work on commercial construction sites. What I was doing was the kind of video systems you find in a sports bar. Specifically, these were mostly BW3's. Most of them were in either end/corner units at higher end strip malls, or some kind of stand-alone, so other than just a few locations, like Chicago, we weren't dealing with multi-floor structures.
So I would get there after the shell was closed in, and I would do the wiring, make sure blocking & reinforcement went into the walls where TV's were going to get mounted, and build the ceiling mounts for the projectors.
Without exception, I would run into problems with multiple objects specified to be in the same location. Typically HVAC ducting, Sprinkler system piping (and sometimes a sprinkler head), and my projectors.
With ONE exception, which if I recall correctly was at Kings Island near Cincinnati, Ohio; I couldn't get a straight answer from any of the trades about what was happening that day or that week. Not because they were being difficult either, it was because they didn't know. And I did a LOT of these system installations. The one exception was a site super who ran the tightest operation I've ever seen. HE could tell you EXACTLY what was happening, off the top of his head.
This period in my career was when I learned how to read prints, because I had to. By the time I came in to do my work, we were about a week away from the soft open and there was NO buffer time left.
So the problems that I saw way back then, which is still going on today:
1. Too much stuff wasn't on the print. AT ALL. It was just taken for granted that it was part of the finish work, not the "real" construction, and it didn't matter.
2. People read the prints in two dimensions while building in three.
3. Nobody talked to anyone else outside of their individual crew. Nobody knew what anyone else was doing, when they were doing it or how they were planning to get it done. This was a total lack of a communications plan so that everyone knew what the big picture was, and every trade was siloed. My opinion...? This was down to a lack of a site superintendent, who was actually ON SITE. Having a G.C. does you no good if there isn't a conductor on site to lead the orchestra.
I was looking at those planters at about the 40 minute mark and I did a visual guesstimation of how much volume the encompassed, concrete and dirt included. Based on my SWAG (scientific wild-assed guess), I'd say I'm looking at 36,000 pounds of concentrated static load right next to probably 30,000 pounds of static load just based on the cars I can see. A load which would have been dynamic on a regular basis.
I'm not saying that the planters caused the collapse, I'm asking with what is admittedly hindsight; was there any communication between the architect/engineer and the builders? Any Change Management system at all?
A guy I used to know liked to say; "Any idiot can build a bridge that will last 1,000 years. It takes real skill and engineering to build one that will last 50 years."
He would probably agree that if you build something with no excess capacity, somebody fucked up.
I like that joke, keeping that one.
comforting that we're finally getting some genuine engineering analysis. An ancient dictum is that success may benefit our egos but knowledge comes from genuine understanding of our failures. The level of engineering analysis in this video - acknowledging that differing opinions will emerge - has to contribute to that end. Thank you
An excellent and well presented analysis in an understandable fashion for us non-engineers. While a lot of us can look at something and think, "that doesn't look right (or substantial)" in a construction, you are very talented in showing the reasons behind something that doesn't look quite right. I have learned a lot from each of your video presentations.
It's a pretty good video for those of us who were engineers as well!
The columns not being in line been noticed way back as a "that looks funny" as in it might not be a problem but it needs a serious look at.
Or Holland American Cruse line that takes maintenance seriously and clearly follows the Military and good restaurant rule that if something visible is messed up or untidy who cares if it not important for safety it an indicator that the things that are important are also not maintained time to turn every thing upside down In a inspection.
I had noticed the constant drills and no missing detail on Holland America till one year during life boat drill I noticed the screws holding a bottom rail on the life boat were clearly not of the same metal and a good deal rusted away which can happen very fast when salt water and different metals mix as the electrical connector involved rusts one fast, still fast in fresh but not as fast).
Turned out that was the worst looking life boats but all showed it when I looked. But within 6 days every single screw on the life boats were replaced they had noticed too reassuring me they on the job. Probably the life boats had been reworked recently and because that form of rusting can be super fast they noticed it and ordered new screws out as fast as possible out to what ever non US port they got them at probably not cheap shipping and then the crew slammed in the new screws in a few days. I don't think the bottom rails directly effect the ability of the boats to float the rails just protect the bottom of the boats when launched and recovered.
And Holland America they have to recover life boats as they regularly launch a few probably in rotation along with a life raft or two for the crews assigned to them to practice using them at a lot of ports when visiting.
On board in visiting ports places it can be a tad annoying all the emergency drills they running with alerts almost every day. But I don't mind much as drill, drill, drill, drill is how you make a good crew who acts in emergencies without even thinking of what they have to do.
I do like that Carnival runs each Cruse line it owns as a independent business. You would never be able to guess on Holland America it was not still a Dutch ran company. Ship Officers almost all trained in Holland, easy noticed by the constant good looking blond twenty something junior officers male and female best spotted in lifeboat drills. Clearly following the military system Officers right out of Holland's Marine Academy start commanding from day one no matter how many years a non officer been onboard. (although just like 2nd Lt in Army/Air force or Ensigns in Navy they all told to listen to experienced crew with higher crew rank) No signs anywhere on web site or materials that Carnival owns them and there are NO combined promotions.
This totally separate devisions system I learned in the 80's the only constant thing in that system normally is accounting systems so head office can be sure of financial data otherwise head office only gets involved to replace a head CEO of subsidiary if performance is bad but they try to avoid telling the CEO of any subsidiary what to do.
Josh, you are very thorough and professional, and I think you found the perverbial "smoking gun" that ultimately caused this collapse. Being at 100% of dead load capacity when it was built made it a ticking time bomb, and I agree that it's amazing the thing lasted for 40 years. What's also amazing is that those columns were only 16" x 12", and they removed all of those beams that would have carried the loads to the columns. To me, it really looks as if they skimped on lots of things when they designed this death trap. It's very sad that so many innocents died because of some truly piss-poor building engineering back in 1979/80.
That makes me wonder if the other Champlain Towers are built with shoddy construction just as the Champlain Towers South was.
Also remember that it was all done by hand. No computer aided design system to flag that these beams had dual purposes. Architects are human and unfortunately their was a failure. It’s so easy to sit back and place blame and yes it seems justified. If only everyone could be perfect but as you can see our society is plummeting into a sick hell all because humans cut corners or made a calculation error. It amazes be how hateful we humans are these days. Pointing fingers and yet none of the owners of these places is also being made to realize they played a role too. Ignorance is bliss. Humans adding granite and tile and all kinds of heavy materials as decorations which also contributed to its failure which the architect would have never known about or expected. Tragedy absolute tragedy and loss of lives all boiled down to explanation to punish human error. It is all just sickening.
Empire State Building & others were built very well. There was several causes in this structure failure unfortunately. I wouldnt be surprised if pay offs & kick backs played a part causing people to overlook obvious problems.
@@jwmiles In reality, the tenants may have played a role too. They may have voted against a lot of maintenance and pressured it to be deferred until the 40-year recertification. We don't know. In their defense though, engineers often use technical jargon that doesn't properly communicate urgency. Saying "if these issues are not addressed, a risk of continued structural deterioration is significant" is not the same as, "if these issues are not addressed with urgency, the building could be in danger of collapse." Lay people think a "loss of structural integrity" means repairs to some cracks - not a building collapse.
Please do your own calculations on those beams and tell us if they would carry the loads to the columns. Hint- no they wouldn't.
I think you nailed the root cause of failure here sir. 12" X 16" concrete columns supporting cars with 1000's of pounds of planters on them to boot? 39:25. Great analysis. Very thorough.
I think you could be right Glenn Davis. I would like to know if there is a reason why an incipient, creeping failure in this area could have caused popping noises or deformation in the part of the building that had the unit 11's....including that unit on the ground floor.
Cars... yes that's another issue. My sense is that in 1979, when this building was being designed, the cars that people drove weren't the monstrous SUVs that people often drive to day. Are current building codes and 40-year inspections of older buildings taking that into account?
@@Inkling777 cars and SUV are actually much lighter now than they were back then! Believe it or not. Everything now is made out of plastic and tin. Back then everything was solid steel, body on frame designs. Much heavier!
@@All-Miles-Matter You're mistaken.
Let's use a 1978 oldsmobile cutlass supreme since that was one of the most popular cars being sold. Curb weight is around 3300lb. This is also in the middle of the range of the 2018 Toyota Camry. Larger cars? How about a 1982 Ford Crown Vic; 3600lb. Modern counterpart? 2019 Ford Taurus weighs around 4100lb, give or take 200lb for options. 2019 Ford Explorer, popular choice? 4400-4900lb. How about that swanky guy with the purple dodge challenger from 2018? That car weighs 3900-4400lb. A modern challenger weighs the same as a 1978 Cadillac Fleetwood Brougham.
Old cars were larger and made of steel, yes. They also had a LOT more dead space... air. Modern cars cram structure, equipment, options, and all manner of things into every possible nook and cranny not intended for passenger space. Ever see someone work on an old car and stand between the core support and the engine? That space weighs nothing.
If that challenger didn't have all the aluminum suspension components and lightweight materials it does, it would probably outweigh a Lincoln Mark IV. Even a frickin' Ford Focus from the last couple years is 3200lb... the 1979 Mustang came out at 2550lb, just a couple golf bags heavier than a brand new Miata.
@@bitey-facepuppyguy2038 From Engineering forum the Pool Deck should have been designed so that anything that happened to it did not effect the rest of the building at all. In layman terms I thing that means breakaways and things like the pool deck slab not connected to any slab under the building as part of that. A rubber gasket or something filling the crack between them to help junk and people losing stuff in the crack.
Somebody's probably already mentioned this, but would it be wise to go check Champlain Towers North to see if the 21" beam was removed there too?
Right! I find myself wondering what kind of mindset those folks have right now since, I'm guessing, they're twins, right? I would prob be considering another living arrangement, regardless
@@carvalone3076 they would probably move, though I shudder to think that the best they will get away wjtb is a serious loss of capital as their apartment will simply not sell anymore.
@@hoihoi12250 It was rated ok for now but I'd get two more opinions including three different firms to go over the plans again. Probably find that even if it safe now it built close to failure and if safe now will not stay safe for long.
It shudders to think how true the saying "a doctor screws up and 1 person dies, an engineer screws up and many more die" is. And you only ever find out decades afterwards; it's a literal time bomb.
Another profession that affects a lot of people is software developer. They are usually not killing people directly, but if 10 million people spend one minute each working around a bug (or something loading slowly, etc), you lost 160000 man hours. Assuming ~250 8 hour work days in a year, that's 80 years of work. Considering that people usually work about 40 years during their life, that's equivalent of killing two people.
That really gave me appreciation of how time wasted accumulates over multiple uses.
@@wumi2419 that made no sense at all. Computer coding doesn’t risk human life like professions such as doctors, pilots, engineers, etc. Coding languages are always changing with improvements in computer technology, so what does losing man hours have to do with deaths of innocent people?
I think you have found the 'smoking gun'!
Your professional analysis and knowledge of structural engineering has resulted in videos (on this topic) that outclass others by a wide margin.
IKR. I have recommended this excellent channel to many others.
You are so clear with your explanations and so intelligent. I surely hope you are in a position to be appreciated for this fine work.
Wow. Your analysis is really interesting. I can completely see how this design would have initiated the collapse. I don't think I will ever go into a tall building with the same care free attitude that I have in the past.
These videos are like doing a crash course on engineering and I never thought I'd be interested but I'm goddamn addicted by now. Thank you so much for these detailed classes!
This.
Literal crash course.
Your careful examination of the construction of this building on RUclips serves to uphold the dignity of all the innocent individuals, couples and families who were lost in an instant, on a calm and quiet night, in the supposed safety of their homes.
Thanks again for all your hard work. I thoroughly enjoy your videos and find them incredibly informative.
Another youtuber covering the Champlain Towers collapse found that originally the pool deck planters had palm trees in them. At some point those trees were removed with the use of heavy boom lifts on the concrete that was already at 100% capacity...
Yes that was Jeffostroff👍
@@alienblackgoo_gle So your are adding the weight of a crane on there? or not?
@nuclearusa16120, Can you clarify your comment?
Are you certain that the concrete slabs were already at their 100% load bearing capacity, or is this speculation or hyperbole? That they would have been at their full “100%” capacity is an astounding claim because structures are engineered and constructed with a specific safety factor, which is often 2, meaning that a structure with a safety factor of 2 is built to support two times its maximum intended load. What you’re saying is that these slabs were constructed and installed with a safety factor of just 1, so that ANY additional load would cause structural failure. That seems extraordinarily unlikely to me. If it is, however, true then it would be, by design, an inevitable point of failure.
@@inkyguy, based on the calculations by the creator of this video, the slabs analyzed here were at 100% load *with* the beams, and *without* the planters.
That means the elimination of the beams *or* the addition of the planters would have significantly overloaded the structure. And both appear to have happened.
Thank you for explaining about the 24” and 16” columns, plus the smaller 12”x16” columns for the pool deck. Very interesting! 👍👍👍
I have seen many youtubers go over these plans, but you are one of few who goes through them with a professional eye, using your knowledge and actual calculations/analysis, instead of "what I think". You actually know what you are talking about and what to pay attention to:)
The beams you point out were removed from the build!!! Oh my goodness. Its like taking out the box frame and hoping the box skinny sides will keep the box square under a full load!. How this lasted 40 years, like you said, is sheer luck. All the other things you discovered were just bad, but the loss of the live load distribution was pure bone headed criminal. All for looks sake too. The guy who did this has probably passed on, but he must have not passed his statics class. Any person who took basic statics and dynamics, and graduated with just a little FEA (finite element analysis) under his belt would have increased the column size and kept the box transfer beams. But this???? Better check the other building right away.
JOSH - Thank you for this detailed analysis. We should hope that your analyses will find their way into textbooks on this subject. ♥
These videos have been incredibly insightful and well researched. I'm imaging most people here right now aren't engineers by training or by trade, and it's clear you've taken that into consideration in how it is you're explaining out all of these otherwise highly complex and technical concepts in laymen terms. It's recognized and greatly appreciated, and I wanted to make sure to call this out specifically because you've done an exceptional job in putting all of these together. So thank you for that.
Long, detailed, and very interesting, Thanks. Designed in the 80s when cars were getting smaller & lighter due to the oil shortage may have not helped. And as they say 'designed to a budget' - the contractor wants to build the most for the least, the architect wants to make it look pretty, and the engineer is the one who has to take responsibility for everything.
Yeah, I was thinking that too, cars now are getting heavier and heavier, especially in the US where they keep growing in size. Electric cars weigh even more still, it makes me wonder if we should be re-evaluating the designs of a lot if the older parking garages to check they can still handle these increasing loads...
I feel like you will be getting calls from attorneys regarding this case if you haven't already.
I can’t imagine a better expert witness.
I doubt the engineer who mucked this building up is still alive. I know the developer died in 2014. No one to sue.
@@johnbergstrom2931 Right now I'm almost Medieval in feeling on this and like then did they guy up and symbolically hang him before dumping the remains in medical waste at least.
@@RedRocket4000 There are first and second stories, and it seems like you're interested in the first story. First stories are always written from the perspective of "Who do we blame?" while second stories are always written from the perspective of "What happened, and how do we prevent that from happening again?"
Take airplane crashes. You have the FAA (who's interested in first story answers) and the NTSB (who's interested in the second story answers). When an aircraft crashes in the US, while both FAA and NTSB investigators are on the scene, it is understood that the NTSB is in charge of the investigation from the start, and the FAA usually waits for the NTSB report to do their investigation. They'll reconstruct the plane to identify mechanical issues. examine the flight data and voice recorder to see what the flight crew knew and did. They go through employee personnel files, training documents and notes, the ERG (Emergency Response Guide) binder the airline publishes for the crew, and even airline and FAA policies and guidelines. All of this analysis to write a report that says "These events contributed to and led up to the fatal event we're reporting on, and these changes should prevent that from ever happening again." Notice it has no where to say, "We blame these people." And there have been times that the NTSB has recommended that the FAA even change their own policies and rules to make the airspace above us safer. After the report is out, then the FAA goes and sees who they can cite and fine for the mess.
As for me, I know there isn't anything we can do to bring the people lost from this disaster back. And "Tar and Feathering" someone, even if in digital effigy only, isn't going to bring those lives back. Hell, it won't even server to provide a sense of justice. I'd like to see the information used to identify other possible buildings that may have this same flaw identified and those buildings repaired so they don't fail like this one did. That's the power of a second story.
@@johnbergstrom2931 Lawyers always can find someone to sue.
35 years of commercial construction I've seen this type of mistake made first hand. Not structural, but in electrical. Engineers making a change but forgetting to take into consideration other trades or drawings that could be impacted by those changes.
Nowadays, weekly meetings and asbuilt drawings play an important roll in preventing these types of conflicts. Plus the simple fact that everything is generally done using CAD drawings which speeds up the processes considerably. I dreaded doing my daily and weekly asbuilt drawings but did them as required anyway.
It seems like a lot of people are making comments without watching the video.
Thanks BI for creating this. Usually the public are not told the details. Only what the head people want us to know.
I find it also noteworthy that none of the columns in the parking garage had protective barriers (crash barriers). In my opinion, it's quite likely that there would have been minor crashes in the 40 years of use, especially around the ramp area with the tight turns. This could have further weakened the columns and/or introduced additional cracks where water could seep in and damaged the rebar.
In my early years I was trained for reinforced concrete detailing and so learned the calculations needed to design a building from the top down.
Adding a penthouse after the fact does not seem a prudent move.
Also I am struck by the fact that there is no thickening of the slab around the columns to offset the punching forces.
Also I learned over time to avoid detailing reinforcing steel so that it ends in one plane but rather to stagger the laps so that alternate bars are offset. I also learned that it is never a good idea to go with someone's good idea to do a design change on the fly because inevitably you are going to miss something. I noticed there were places where steel was not continuous but a series of short straight bars with minimal lap.
During all the video I was wondering why there was nothing to prevent columns from punshing through, thickening like you're saying, or a steel plate or something. I mean look at the Parthenon built 2500 years ago, there is something at the top of the columns !
@@aesma2522
You know there was no reinforcing steel back then. Everything was based on stone arches in compression.
@@imconsequetau5275 No there wasnt but the same concepts still apply. Its why they have stone slabs on top of the columns instead of having the floor straight on top. It helps spread the load of the column on the floor above it out. Load is not just a 1 way thing, forces acts in multiple directions
If you look at the google maps imaging of the North and South tower, which were both based on the same design, but with the North building being shorter front to back, you can see that there are some similarities and some differences in the planters. The North tower has the same planter around the parking area. If that was indeed the epicenter of the collapse of the South building then the potential for the same thing could exist. There are actually more planters against the North building than the South building so depending on what went into that design process, may cause it to be even more over loaded. From what has been said, and by available google imaging, the North building was clearly better maintained than the South building. Hopefully the variable of corrosion caused structural damage isn't an issue with the North building, but I would agree that no cars should be allowed to park on any of that lobby level parking area until it can be deemed structurally sound.
Good analysis again. In regard to temperatures steel, I think the engineer meant to extend each bottom #4 bar over the columns as a minimum, not as a lap. However, as you pointed, this does not work for temperature steel. Catching the removed beams bit is huge. I can hardly believe the engineer would do that. Good stuff thank you for taking the time to do this!
Everyone is saying the collapse was caused by multiple issues so every new theory is very important. Thanks for making these videos somewhat easy and interesting for us novices to try to follow along.
Yes, there is rarely a single explanation for a building collapse. New insights are not new theories, they are new factors in the overall analysis.
Interestingly, there are many details in the column/slab designs which would not have satisfied UK codes 40 years ago but the underlying issue seems to me to be that any building loaded to 100% of capacity by its "as built" dead weight leaves no room at all for construction defects, alterations, change of use, deterioration or subsidence.
Awesome job explaining as so many have already expressed! If teachers around the world took the time to learn to teach and explain like you do ...at all levels elementary school to University....kids would learn easily and stress free.
Wonderfully clear and concise explanations with no waffle. Everything science-based and grounded in reality. Cheers, Josh. You're doing good work.
The alarming point here is that these changes were made, apparently, on the fly, with no sign of a redundant "check-out" by a second engineer or inspector to approve the revised (and reduced- capacity) design.
Engineers who think their designs don't need scrutiny from a second set of eyes is the cause of disasters immemorial. The hubris that somehow manifests itself in the trade is something that deserves study, and measures should be taken in the engineering schools and in the firms to identify and eradicate this lethal flaw...........................
Citys Planning Depts have plan check & no changes are allowed to a Design without another approval. How can you catch a Developer or Contractor who makes changes that arent on the Plans? That is why the Inspectors go out & sign off at stages. They have the power to shut down a job.
The same of which you speak they did with pilots of commercial jets. The adage of two heads are better than one will live on in time.
@@Userxyz-z2d Apparently that didn't happen here.
So who do we bring to justice?
@@larrybe2900 You've the right of it.
Any profession that proclaims advocation is to be immediately suspect. Just as professional pilots rallied and protested for additional training, instrumentation and procedures to increase the safety of their field, Engineers should be actively advocating for increased oversight, continuing-education and at least two-person sign-offs on projects that possibly hazard human life.
@@Userxyz-z2d Not all city planning departments have plan check, and that was more common in the 1980’s than it is today.
What is your safety factor for my building?
Engineer: Dont worry it is 100 percent sharp 😉
Its funny because a non-engineer would probably interpret that as being a good thing.
Very well presented and extremely fascinating for a non engineer such as myself.
If your video went on for hours I would be watching every second of it. It is so well presnted... and you make it so easy to understand. Excellent job.
Maybe it's time to look at other buildings this engineer designed.
yeah like all of them because there are no telling how many others might be designed to collapse and yet to do so
...Or changed for alterations.
Especially the sister buildings! I heard, there is not only the North Towers but other very similar so called sister buildings!
@@Iwoasasaned And maybe look at the buildings that were inspected by the same people from the city. I suspect a patterm will emerge.
The building was designed by an architect: William Friedman of William M. Friedman & Associates Architects, Inc. At least, he did the original 1979 plans. Not sure who did the 1980 mods.
I’ve got so much out of this series of videos. I’ve learned so much. You have taken the stress of a tragedy with no answers and given us understanding and rational explanation for many things. Understanding helps us cope with stress. So not only are you a fantastic teacher, you helped to stop me fixating on the unknown and stressing over it.
Why did the third part of the collapse, the last bit to fall, appear to twist a bit and then right itself before it started to go down?
He covered that in his video about Sheering
So who is responsible to review and approve plan changes and corresponding structural engineering drawings when a change request comes forward ? It seems like the original design was fine but when they changed the design they either overlooked something or just made a huge error and nobody reviewed it.
For a building like this the buck stops and starts with the design engineer. The building department rarely has staff qualified to review these designs to this level.
@@BuildingIntegrity Would liability fall at the engineer’s feet or at the firm they worked for in a case like this? Do we know if the firm or the engineer are even still around?
See the Hyatt Regency disaster in Kansas City,. This is part of the same problem, redesigned elements are not held to the same scrutiny and calculations because all the load paths are assumed to be the same.
@@Record3677 I think the owner of the company that built this condo is dead and his company no longer exists.
@@jeffreyhueseman7061 right on.....this also was true with the CITIBANK building in Manhattan.
I am a good bit less Ignorant now, than I was 41 minutes ago. Outstanding work, outstanding! Thank you.
Absolutely amazing work, thank you for taking the time and explaining this in such an accessible manner. I can only imagine how much time you’ve spent pouring over the documentation.
A LOT and honestly, if I was doing this for court I'd have spent even more... but I would have also been paid for that time hehe. Thanks for watching!
@@BuildingIntegrity these videos demonstrate how good you are at what you do and will help you get many many clients in the future! Great job!
Love your work!!!
Thank you so much for all of the work that you have put into this series and the channel as a whole. I have learned so much from it. Also, as a person that is looking to buy a condo in the next year or so, I now know that I 100% want to be on the board if it is a large multi-story building of any kind.
Excellent research and presentation. I am an electrical engineer with considerable large project management experience. This is a good example how change orders cause problems when initiated in later phases of the project. They do not have to cause problems but there is a a tendency to treat them lightly in order to keep project schedule and to control engineering costs. I hope this tragedy helps project owners and the public understand this.
As a layman this is really explaining a lot about WHY and HOW. Thank you.
AH YES! A 41 MINUTE VIDEO!
I always watch these at 2X speed.
From the sounds of your analysis. This building was doomed by its own design that probably should have collapsed much sooner. The neglect sort of aided the process.. Once again a great presentation by someone like Mr.Porter whom knows how to explain this tragedy to even non engineers like myself.
Yeah it seems to have a lot in common with the Collapse of the Hotel New World which happened in Signapore.
Wow. Such analysis. "Yep we want to take out these beams that are under everything", , , , "okay then".
Thanks for taking the time to make this, and other, videos. I mainly design steel structures and take for granted the 'what you see is what you get' aspect of it. It's been years since my basic reinforced concrete class, so this was a nice refresher on those topics as well. Thanks, again.
Absolutely phenomenal analysis sir, thank you for your efforts, that's clearly a lot of scouring, researching, and note taking to get where you got.
Incredible information.
The changes turned into a ticking time bomb in addition to the other problems.
I'm not an engineer, but you make a really convincing argument in the analysis. Thanks for putting this together.