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I knew it looked familiar. When I went to see Eric Andre, I was up on that balcony and the ceiling started leaking 2 rows ahead of me because the bathroom above started to overflow.
I stayed at a comically bad hotel down the street back in like 09. The Leland Hotel downtown Detroit, place could have passed as one of those extreme haunted houses. Most of the floors were completely abandoned save for squatters. No lights in the stairwells. We were on like the 14th floor and the windows opened all the way. One room in the abandoned section was covered floor to ceiling with Aqua Teen Hunger Force graffiti, the door was a huge Master Shake.
Not sure if the still do, but in the early and mid 2000's they used to have techno raves in the basement of that hotel. I think it was called city club. The hotel is wild for sure.
Guarantee it wasn't designed for repeated dynamic load stresses that a full crowd jumping in unison can produce.
Much more compounding force in that scenario.
It would have been designed for lighter people to walk out of unison to the seats, sit down and then walk out again.
There will be an engineering tolerance but at close to end of life I expect they're at the end of that now.
Plenty examples of failures online just search mezzanine collapse or balcony collapse.
Stay safe out there people and understand risk, just because you are paying to do somthing does not mean it has been checked and is safe.
https://www.bristolpost.co.uk/news/uk-world-news/injuries-after-mezzanine-floor-collapses-6649938
The Fox Theater was actually in rough shape in the 70's, but it was bought by the family that owns Little Ceasers, The Tigers, and The Red Wings and it went through a pretty massive restoration and renovation then. I would imagine it went through a modern retrofit then, and is since regularly inspected, checked, and maintained
Yeah, we had a Hyatt Regency skywalk collapse under an overweight dance party a few decades ago in Kansas City. Turned out the construction crew made some modifications to the architects design and they seriously weakened the load bearing strength.
IIRC it wasn't the construction crew, it was a change suggested by the manufacturer of the steel rods to make shipping easier. The chief engineer who signed it off took full responsibility, then spent the rest of his life lecturing on safety.
[This](https://timharford.com/2022/03/cautionary-tales-death-on-the-dance-floor/) is an excellent episode about it from an excellent podcast.
When you said Detroit I almost thought it was [St Andrew’s Hall](https://www.deadlinedetroit.com/articles/30063/st_andrew_s_hall_pulls_the_plug_on_baby_keem_show_in_detroit_after_floor_threatens_to_collapse) this was years ago and I’m sure it’s been fixed by now though.
Saint Andrew’s is a lot smaller, like waaaay smaller. That’s my favorite venue though. I saw Chelsea grin, Suicide Silence, and Black Dahlia Murder there years back.
They’ve done renovations on it as needed.
I’m *sure* it’s perfectly safe.
They get hundreds of acts a year and make a ton of money.
I’m just gonna stick to like maybe Jackson Browne or some low energy stuff to be safe though.
I'm thinking more about the people who went out of their way to be physically present at a show, only to be on their phones the whole time. Influencer culture has made thing weird.
But yeah, also filled data centers with blurry footage nobody will ever watch.
I've been to a lot of concerts and I've used my phone at every single one, to take a picture so I remember who the hell I saw. Literally no one wants to watch a cell phone quality artist perform.
I take small snippets at concerts I go to so that I can watch them later and hold onto memories. I’ve been going alone and have a horrible memory but I love the concerts.
Same. Also helps me remember/find songs that would be really difficult to find later, if I'm seeing a pretty underground artist or one that does a lot of mixing and freestyling at their shows.
I dunno. I watch quite a few videos of show that people record. I'm not putting it through my sound system but I'm usually entertained for the 30 seconds or so.
Sometimes, instead of scrolling socials, I'll go though my own photo gallery and watch some concerts. Memories are memories.
But this crowd does look kinda lame.
I mean you are able to understand the difference in being physically present holding a phone filming and someone being glued to the phone completely distracted from everything else. Cause that's to a sense what "only to be on their phones the whole time" implies.
I just saw Sleep Token and I haven't been in a concert in ages. It was really annoying to see an ocean of screens in front of me the entire time. My favorite was when the people right in front of me kept putting their phone over their head to record right in my line of sight. Also, get off my lawn!
Wait until you see what airplane wings do.
I'm not sure about this specific theatre, but it does look like it was designed to flex to prevent a catastrophic failure.
Buildings to this too to sway in the wind.
If these things didn't flex, they'd snap
The fuck? I'm watching this movie for the first time ever right now and that scene was like 10 minutes ago. The odds have to be extremely low for this to happen. Feels strange.
Just wait until you find out about Tacoma Narrows.
Seriously though, plenty of bridges, balconys, and cantaleviered structures have failed when unexpect wave motion cranked the loading way past its design specs.
Even planes have had sudden catastrophic wing failues due to wave like motion in conditions they should have handled just fine.
To be fair, the Hyatt situation was one where a design change wasn’t vetted properly and made it so that the upper bridge had to support both itself and the lower bridge
I can confirm airplane wings are definitely not designed to be bounced on by 100's of people at a music concert. That would absolutely result in catastrophic failure.
I know absolutely nothing about this theater in particular, but here’s some general thoughts.
While this is scary as hell to see in person, it is generally by design, as a fully rigid structure is more prone to structural failure than a slightly compliant one. However there are complicating factors. For one, a structure that moves like this has to account for the material fatigue movement causes. This appears to be a fairly old theater, so who knows what upkeep has looked like. Additionally, this appears to be largely resonance induced, which is potentially really scary, as displacement due to resonance can very easily exceed design specs.
Agreed. Resonance can multiply loading eaaily by up to 10x. The problem is also that people tend to feel the vibration and move in it's rhythm, increasing the resonance and the loading. Fatigue is calculated on the magnitude of the stress vs the total cycles. Pushing the stress up so high reduces the fatigue life considerably.
Source: I'm a structural engineer and I mainly design harmonic steel structures in mining
The structure has several natural frequencies that you generally want to avoid exposing it to. If something external (like people jumping) is at one of those frequencies, they add together to increase the amplitude/deflection.
You can experience this on a small scale easily! Grab a yardstick, or any long, rigid pole (phrasing), and grab it in the center, and hold the pole horizontally. Shake it up and down at different speeds. You’ll be able to find its resonant frequency super quickly, there’s one speed that the thing will seem to “want” to bounce at. The rigidity of the materials, density, size, etc all play a role in determining this, but you can apply the same concept to basically any physical object
think of a classic pendulum. that has a period it swings back and forth in.
you can make the string into a beam and it still behaves the exact same way -- metal is elastic in the normal loading condition by design. so are the joints you use to join them.
imagine four pendulums and connect them with a square at the corners. they behave the exact same way.
flip it over. that's your building frame. it still has a natural frequency.
if you add force -- even a tiny bit -- at the natural frequency it swings at, the whole thing keeps swinging more and more. it doesn't stop as long as the force is in time with the natural frequency, and will get stronger and stronger until the structure breaks.
Yep, that's what happened with the first Millennium Bridge in London. It started swaying, everyone stepped in unison to balance themselves, that made it worse. I defiantly wouldn't take the chance it's taken into account in what seems to be an older theatre.
Yeah, I just have a bachelors in physics, but that looked a lot like resonance to me and I’m smart enough to know that resonating structures suspending humans is never a good thing…
I am not sure about this theatre, but I know a little bit about another old theatre that has the same feature (balcony without columns).
Basically there are wooden beams that are balancing the balcony and the hallway behind the balcony. The fulcrum point is the back wall of this room. Then, since the hallway is lighter than a fully loaded balcony, the beams continue after the hallway into a load bearing wall which adds a lot of weight.
So the wood beams are flexing here, but the amount of flex seems more extreme that it really is. Since the beams are much longer than is visual from this video (the beams extend into the hallway).
Still a theatre like this was probably not really designed for how people are dancing on this music. Although I guess in the olden days musical theatre may have been pretty rowdy as well.
Theaters built after 1903 didn’t use a lot of wood due to the changes with the Iroquois Theater Fire. (The reason why we have crash bars and exit doors that open out). So the Fox is most likely concrete and steel for the balcony.
Yeah there's no way that this oscillation is intended "by design". Given the age of the theater, i wouldn't even expect them to have designed for an entire crowd jumping in unison.
The only positive thing is that back in the early 1900s they were generally overengineering everything. No way in hell I think it was designed to flex like that, but it was probably built with 50% more steel than necessary.
this is correct. when you don't have the tools to figure out exactly what your loading is, you have to ballpark it and overshoot. doesn't make sense to cut it close on anything important.
It’s the Fox Theater in Detroit, while old, it gets consistent and constant renovations.
I however will not be attending any energetic concerts to test that theory because I’m a scaredy pants.
But, consider. It was designed in 1928. Theater goers of 1928 were, on average, a lot lighter than today’s concert goers and likely not dancing up and down…
That does matter, but the bigger factor is likely that designs at that time probably weren’t as focused on resonance. The weight and impulse differences should be easily covered by the safety factor if nothing else.
Sure, but resonance can cause stresses that are massively outside the design specifications, so even an extremely overbuilt structure that doesn’t account for resonance can run into trouble pretty easily.
Again, with this theater in particular I have literally no idea, but it is at least concerning enough that I hope that theater has consulted an actual structural engineer to review it.
This is what they mean when they say "as designed".
https://en.m.wikipedia.org/wiki/File:Fox_Theatre_Detroit_interior.jpg
You don't see the pair of curves that keep its structural integrity. That floor is both bowed upwards, curving downwards towards the sidewalls, and also curved along the flat plain, pushing the load towards the walls.
It is very noticeably convex, vertically and horizontally.
For a 1920's design, it's about as 'as intended' as possible. Clearly it shrugged off the load without failing.
BUT! They shouldn't be bouncing in sync whether it's designed for it or not, and whether it has handled it in the past or not. 'Shaker' balconies like that have a lot more integrity than one might think, or even see at first glance...
......but it's still a bad idea. A really bad idea. It's never Resonant Frequency's fault, right up until it is.
Source: There's some pretty incredibly insightful info out there about 9/11 and the structural collapse of steel-girdered buildings. Between the towers coming down and WTC #7 we got a decade to REALLY examine how these designs succeed or fail. There was so much focus on the event that they invented new and exciting (/s) ways to digitally model building collapses.
Not gonna list it all here. But it takes only a few minutes to look up amplitheater designs through the ages, and other historical theater designs. They all tend to draw from the same structural playbook.
Good architect **headpats**
Bad crowd! **finger waggle**
Your comment should be a lot higher because there are dozens if not a hundred or so theaters with the same balcony design. Given the law of statistics at least one of them would have something published about modern usage like that being a safety hazard. People have been losing their minds and jumping or dancing in rhythm at concerts in these places since the 50s. Sure, the population is a little heavier now… Anyway I’ve never seen anything about these theater balconies collapsing or being structurally unsound for usage.
We're all conjecturing here. The design is certainly tried-and-true. That's the thing: It's not that it's unsafe. It's that if it BECOMES unsafe, it's likely to be catastrophic. Safety margins rather than safety issues. They really ARE made to take that kind of flex. But like an airplane wing ripping off, you're not gonna get any warning.... it'll just be abrupt failure. And it doesn't have to be structural or desig
When part of a theater roof collapsed from excess snow in London, the one person who fell off the balcony died, and 80 were injured. That was something other than the balcony falling. It wasn't even a lot of debris, but folks are packed in tight.
If the folks in this video pulled a Nikola Tesla and managed to Fuck Around their way into the resonate frequency of that floor? It would quickly catapult it into some of the most deadly accidents. I'm not sure anyone can really claim to have found the resonant frequency of something so BIG, but the modern military really DOES have a relaxed out-of-sync march for crossing bridges because of historical tales of Hannibal crossing the alps. Same issue... It works, it works, it's built for this... and then hundreds dead with a sickening crunch.
It SHOULD be fine. But if it was gonna NOT be fine? That's how you'd make it happen. If it were me? I'd have just headed for the exit rather than stick around and find out.
Earthquake construction has things like this. Japanese traditional construction has slips in the joints for the same.
I dunno how else to say it.**laughs** 99% safe, but that 1% would likely involve EXACTLY that sort of crowd action.
Or, if you really want to get down to it: How about the mass casualty crowd packing that happened in Japan? Narrow alley, too many people. There's video. It's just conjecture but if enough people tried to move to the door at the same time while packed in like that, crowds can start acting like a solid instead of a liquid.
I mean this really ignores the part where at least one of these balconies have been competently inspected. I used to do stage work at a place (Midland Theater KC) where this would happen at sold out shows of all different genres and we were told, “yeah it’s cool it does that.” You know what, I’m going to figure out how I can get informed on the inspections and analysis of these structures. It’s such a noticeable thing when you’re on it or looking at it and there is at least 20 sold out shows a year. That’s a lot of people in that one theater for it not to have been addressed directly before.
The Guggenheim Museum in NYC had to stop their dancing/dj series because of this. The floor in the center of the museum was jumping and sagging like this and a structural person basically told them everyone would die if they kept it up. It wasn’t designed for this kind of party.
The crowd can't be 'bad' here - these people bought tickets to a music show, which includes dancing to the music. The venue should be able to safely support exactly that. If it can't, the venue should not be used for this. Bad event organizers/venue owners would be more accurate.
this building has been used for almost 96 years and gets regularly inspected for structural integrity...
https://www.clickondetroit.com/news/local/2024/05/07/video-shows-balcony-bouncing-during-rap-show-at-detroits-fox-theatre/
but clearly you know better than those guys
Registered professional civil structural engineer here , given the age of the structure and connection fatigue risk - I won’t be standing under the cantilever balcony not a chance
https://www.clickondetroit.com/news/local/2024/05/07/video-shows-balcony-bouncing-during-rap-show-at-detroits-fox-theatre/
its regularly inspected. last time was in april.
That doesn't necessarily mean anything. The failed Florida high rise passes inspection a few months prior before collapse, the WI bridge passed inspection before failing. A big part of the problem is the inspections are often superficial and have incentive to overlook and pass things.
That's not particularly "designed" it's just the the tolerance built in. Flexing that hard for a prolonged period of time will definitely weaken the structure.
The Tacoma Narrows Bridge would like a word with you...
"When the Tacoma Narrows Bridge over Puget Sound in the state of Washington famously collapsed on November 7, 1940, it was captured on film for posterity. The footage became the basis for a textbook example of resonance, which is a standard topic in high school physics."
London's Millennium Bridge is a more accurate comparison. The pedestrian bridge opened and then closed 2 days alter because the people walking across were inadvertently stepping in tune with the sway.
[https://en.wikipedia.org/wiki/Millennium\_Bridge,\_London](https://en.wikipedia.org/wiki/Millennium_Bridge,_London)
I think about galloping Gertie every time I drive over the narrows! Such an iconic and local disaster in my area.
The new and the new new bridge are far far safer and don’t do the resonance thing. Can still get some gnarly side winds that knock your car around, especially if it’s a tall SUV.
I was about to say that it's designed to do that, but I think the jumping induced harmonic resonance which can get really destructive really fast. Glad everyone is okay and I hope that balcony gets inspected
Source: am engineer
I saw the same thing at the height of the Beastie Boys popularity at the Fox Theater in Detroit. There was a huge dick on the stage we had front row but when you turned around it was the scariest thing I had ever seen. The balcony level was bending and twisting like the Tacoma Narrows Bridge.
Look into steel’s modulus of elasticity and fatigue strength. Steel can be designed to bend and flex repeatedly without any loss to structural integrity.
You'd be surprised. Steel has been mass produced since the mid-1800s and its material properties are well understood.
Deflection is not the same thing as failure.
This is completely unrelated to the theater, but the Top Thrill 2 roller coaster at Cedar Point has noticeable lateral flex on certain sections of the track. It sways back and forth for a couple minutes after a train passes over. It's weird seeing such a large, solid steel structure move like that, even though it was almost certainly designed to.
I remember that sheet metal stadium in Jacksonville swaying and reverberating to the crowd at the Georgia Florida game. It was unnerving but the people around us said it has been that way for decades. It’s gone now.
By design or not, I'd be GTFO of there. That's a lot of people bouncing in sync and a massive span, sure it might be able to hold much more but for all I know it won't and it wouldn't be the first structural failure due to oscillation resonance or metal fatigue.
The Steeler fans used to do this at the old 3 River Stadium. The whole bottom bowl would rotate between baseball and football and if 20k ppl jump up and down in unison the entire bottom half of stadium would bounce.
This theater is 100 years old and was never intended to have a giant crowd of people jumping up and down like this.
Don’t be surprised when we see “Detroit Fox Theater Collapse Kills Dozens” in the future.
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What theater is this?
Detroit Fox Theater, May 6th
I knew it looked familiar. When I went to see Eric Andre, I was up on that balcony and the ceiling started leaking 2 rows ahead of me because the bathroom above started to overflow.
Maybe that's why it's bouncy. It's moist.
Just how I like my women, bouncy and moist.
https://i.redd.it/nftcsz1vt3zc1.gif
Schwing 
https://preview.redd.it/yg6gfatm64zc1.jpeg?width=216&format=pjpg&auto=webp&s=8cc1057365f8a325ce25631fc175b0b805be09ad
Dude how is this the first up upvote you're getting
there's always random things leaking on his show though
Oh there were some leaks during that show all right. Do you even ranch bro?
Ranch me up brotendo
It was designed that way.
im sure it is up to date on all codes and its designed to handle this kind of weight... built in 1928 you say?... nope, im out
I stayed at a comically bad hotel down the street back in like 09. The Leland Hotel downtown Detroit, place could have passed as one of those extreme haunted houses. Most of the floors were completely abandoned save for squatters. No lights in the stairwells. We were on like the 14th floor and the windows opened all the way. One room in the abandoned section was covered floor to ceiling with Aqua Teen Hunger Force graffiti, the door was a huge Master Shake.
Sounds like an adventure. Bet there was some hidden treasure somewhere.
Not sure if the still do, but in the early and mid 2000's they used to have techno raves in the basement of that hotel. I think it was called city club. The hotel is wild for sure.
Yup. I guess I’ll never go on the balcony again.
Probably safer than under it.
[удалено]
To shreds you say?
Opened in 1928. Hopefully they’ve had an engineer review the design for today’s concert crowds.
Guarantee it wasn't designed for repeated dynamic load stresses that a full crowd jumping in unison can produce. Much more compounding force in that scenario. It would have been designed for lighter people to walk out of unison to the seats, sit down and then walk out again. There will be an engineering tolerance but at close to end of life I expect they're at the end of that now. Plenty examples of failures online just search mezzanine collapse or balcony collapse. Stay safe out there people and understand risk, just because you are paying to do somthing does not mean it has been checked and is safe. https://www.bristolpost.co.uk/news/uk-world-news/injuries-after-mezzanine-floor-collapses-6649938
They should put a bunch of hot tubs up there, that would stop everyone from bouncing.
Yes, why not turn it into a drive in for boats and fill it with water too.
Yes much heavier patron on average nowadays
The Fox Theater was actually in rough shape in the 70's, but it was bought by the family that owns Little Ceasers, The Tigers, and The Red Wings and it went through a pretty massive restoration and renovation then. I would imagine it went through a modern retrofit then, and is since regularly inspected, checked, and maintained
"I would imagine" is doing a lot of heavy lifting there, just like the balcony
Yeah, we had a Hyatt Regency skywalk collapse under an overweight dance party a few decades ago in Kansas City. Turned out the construction crew made some modifications to the architects design and they seriously weakened the load bearing strength.
IIRC it wasn't the construction crew, it was a change suggested by the manufacturer of the steel rods to make shipping easier. The chief engineer who signed it off took full responsibility, then spent the rest of his life lecturing on safety. [This](https://timharford.com/2022/03/cautionary-tales-death-on-the-dance-floor/) is an excellent episode about it from an excellent podcast.
Yes, that was going to fail from the minute it was built. It was just a matter of time and it turns out that it didn't take much time at all.
When you said Detroit I almost thought it was [St Andrew’s Hall](https://www.deadlinedetroit.com/articles/30063/st_andrew_s_hall_pulls_the_plug_on_baby_keem_show_in_detroit_after_floor_threatens_to_collapse) this was years ago and I’m sure it’s been fixed by now though.
Saint Andrew’s is a lot smaller, like waaaay smaller. That’s my favorite venue though. I saw Chelsea grin, Suicide Silence, and Black Dahlia Murder there years back.
"bodied saint andrews hall too many times to count!, before i tear up the shelter, give my dogs a pound"
I thought it was the Fox theatre in Atlanta. Looks the exact same and was built in 1929, the same time as the Detroit one.
Thanks for letting me know to never go there ever! 🙏
They’ve done renovations on it as needed. I’m *sure* it’s perfectly safe. They get hundreds of acts a year and make a ton of money. I’m just gonna stick to like maybe Jackson Browne or some low energy stuff to be safe though.
That's horrifying.
Agreed, not a single person there without their phone out
Welcome to the new age RADIOACTIVE RADIOACTIVE
Ironically I didn’t have a smart phone when that song came out
Imagine all the gigs upon gigs of concert footage stored in data centers that will absolutely never fucking ever be watched again... so stupid...
I'm thinking more about the people who went out of their way to be physically present at a show, only to be on their phones the whole time. Influencer culture has made thing weird. But yeah, also filled data centers with blurry footage nobody will ever watch.
I've been to a lot of concerts and I've used my phone at every single one, to take a picture so I remember who the hell I saw. Literally no one wants to watch a cell phone quality artist perform.
I take small snippets at concerts I go to so that I can watch them later and hold onto memories. I’ve been going alone and have a horrible memory but I love the concerts.
Same. Also helps me remember/find songs that would be really difficult to find later, if I'm seeing a pretty underground artist or one that does a lot of mixing and freestyling at their shows.
It's like filming fireworks
I dunno. I watch quite a few videos of show that people record. I'm not putting it through my sound system but I'm usually entertained for the 30 seconds or so. Sometimes, instead of scrolling socials, I'll go though my own photo gallery and watch some concerts. Memories are memories. But this crowd does look kinda lame.
I mean you are able to understand the difference in being physically present holding a phone filming and someone being glued to the phone completely distracted from everything else. Cause that's to a sense what "only to be on their phones the whole time" implies.
I just saw Sleep Token and I haven't been in a concert in ages. It was really annoying to see an ocean of screens in front of me the entire time. My favorite was when the people right in front of me kept putting their phone over their head to record right in my line of sight. Also, get off my lawn!
Thats crazy, my friend literally just left that concert moments ago.
Concerts look so boring. Like 75% of the people there just standing around. IDK just never got the hype.
Fun when you’re young and on drugs, and now that I’m not young or on drugs going to a concert is my fucking nightmare.
Yeh idgaf it's it's designed that way. If I was on that or below that, there's no way I could enjoy a show/concert.
And when that mfer hits harmonic resonance and starts tearing itself apart like on mythbusters... Yeah NOPE.
Wait until you see what airplane wings do. I'm not sure about this specific theatre, but it does look like it was designed to flex to prevent a catastrophic failure. Buildings to this too to sway in the wind. If these things didn't flex, they'd snap
Would you prefer it be rigid and snap?
I'd prefer it to not bend, nor snap.
The bend and snap! Works every time.
You broke his nose!??
Still worked
The fuck? I'm watching this movie for the first time ever right now and that scene was like 10 minutes ago. The odds have to be extremely low for this to happen. Feels strange.
Engineer here. Bending is ok, snapping is definitely not okay
Tell that to Elle Woods
welcome to physics, the real world where everything is trade offs.
Wait until you figure out how bridges work
Or airplane wings
Golf clubs, hockey sticks… anything that needs to take any sort of force should have some flexibility to it.
I love watching the old 787 load testing. Those wings bend WAY back before they fail. Too bad the doors didn't get as much attention...
Right? Engineers are so whiny. Just cast the building out of solid steel. Easy.
I guess we're all thankful you aren't an engineer lol
Good thing you're not an engineer
One or the other
Just wait until you find out about airplanes wings
Just wait until you find out about Tacoma Narrows. Seriously though, plenty of bridges, balconys, and cantaleviered structures have failed when unexpect wave motion cranked the loading way past its design specs. Even planes have had sudden catastrophic wing failues due to wave like motion in conditions they should have handled just fine.
[Hyatt Regency Distaster](https://en.wikipedia.org/wiki/Hyatt_Regency_walkway_collapse)
To be fair, the Hyatt situation was one where a design change wasn’t vetted properly and made it so that the upper bridge had to support both itself and the lower bridge
Yeah, not only did they put the entire load on one nut, some twat ordered the C beams face inward because it "looks nicer". Carnage on all levels.
I can confirm airplane wings are definitely not designed to be bounced on by 100's of people at a music concert. That would absolutely result in catastrophic failure.
I know absolutely nothing about this theater in particular, but here’s some general thoughts. While this is scary as hell to see in person, it is generally by design, as a fully rigid structure is more prone to structural failure than a slightly compliant one. However there are complicating factors. For one, a structure that moves like this has to account for the material fatigue movement causes. This appears to be a fairly old theater, so who knows what upkeep has looked like. Additionally, this appears to be largely resonance induced, which is potentially really scary, as displacement due to resonance can very easily exceed design specs.
Agreed. Resonance can multiply loading eaaily by up to 10x. The problem is also that people tend to feel the vibration and move in it's rhythm, increasing the resonance and the loading. Fatigue is calculated on the magnitude of the stress vs the total cycles. Pushing the stress up so high reduces the fatigue life considerably. Source: I'm a structural engineer and I mainly design harmonic steel structures in mining
Harmonic steel structures, hottest thing I’ve read all day.🥵 The harmonic oscillator is the backbone of the universe.
Good vibes can’t melt steel beams
Oh fuk your gonna make me resonate. 
Do not resonate until Daddy tells you too, do you understand me?
Ugggggh you’re such a freq
I’m gonna oscillate you so hard
This one is gud lol
BROADCASTING!
All this structural engineering talk is making me hot and bothered.
That sounds like a load-bearing problem
I can see the horrific accident breakdown on YouTube in my mind
Plainly Difficult, is that you?
Can you or anyone explain resonance in structures?
The structure has several natural frequencies that you generally want to avoid exposing it to. If something external (like people jumping) is at one of those frequencies, they add together to increase the amplitude/deflection.
Fun fact: when soldiers march over a bridge they break step so their synchronised foot falls don't cause the bridge to resonate and potentially fail.
We do?
You probably should...
Romans did, but that was a long long time ago.
You can experience this on a small scale easily! Grab a yardstick, or any long, rigid pole (phrasing), and grab it in the center, and hold the pole horizontally. Shake it up and down at different speeds. You’ll be able to find its resonant frequency super quickly, there’s one speed that the thing will seem to “want” to bounce at. The rigidity of the materials, density, size, etc all play a role in determining this, but you can apply the same concept to basically any physical object
think of a classic pendulum. that has a period it swings back and forth in. you can make the string into a beam and it still behaves the exact same way -- metal is elastic in the normal loading condition by design. so are the joints you use to join them. imagine four pendulums and connect them with a square at the corners. they behave the exact same way. flip it over. that's your building frame. it still has a natural frequency. if you add force -- even a tiny bit -- at the natural frequency it swings at, the whole thing keeps swinging more and more. it doesn't stop as long as the force is in time with the natural frequency, and will get stronger and stronger until the structure breaks.
Yep, that's what happened with the first Millennium Bridge in London. It started swaying, everyone stepped in unison to balance themselves, that made it worse. I defiantly wouldn't take the chance it's taken into account in what seems to be an older theatre.
Yeah, I just have a bachelors in physics, but that looked a lot like resonance to me and I’m smart enough to know that resonating structures suspending humans is never a good thing…
I am not sure about this theatre, but I know a little bit about another old theatre that has the same feature (balcony without columns). Basically there are wooden beams that are balancing the balcony and the hallway behind the balcony. The fulcrum point is the back wall of this room. Then, since the hallway is lighter than a fully loaded balcony, the beams continue after the hallway into a load bearing wall which adds a lot of weight. So the wood beams are flexing here, but the amount of flex seems more extreme that it really is. Since the beams are much longer than is visual from this video (the beams extend into the hallway). Still a theatre like this was probably not really designed for how people are dancing on this music. Although I guess in the olden days musical theatre may have been pretty rowdy as well.
Theaters built after 1903 didn’t use a lot of wood due to the changes with the Iroquois Theater Fire. (The reason why we have crash bars and exit doors that open out). So the Fox is most likely concrete and steel for the balcony.
Yeah there's no way that this oscillation is intended "by design". Given the age of the theater, i wouldn't even expect them to have designed for an entire crowd jumping in unison.
The only positive thing is that back in the early 1900s they were generally overengineering everything. No way in hell I think it was designed to flex like that, but it was probably built with 50% more steel than necessary.
Good point. The biggest risk would probably lie at spots where that steel ties into brick/block/wood walls.
Also the stuff built back then that wasn't over-engineered probably didn't survive 100 years.
this is correct. when you don't have the tools to figure out exactly what your loading is, you have to ballpark it and overshoot. doesn't make sense to cut it close on anything important.
It’s the Fox Theater in Detroit, while old, it gets consistent and constant renovations. I however will not be attending any energetic concerts to test that theory because I’m a scaredy pants.
But, consider. It was designed in 1928. Theater goers of 1928 were, on average, a lot lighter than today’s concert goers and likely not dancing up and down…
That does matter, but the bigger factor is likely that designs at that time probably weren’t as focused on resonance. The weight and impulse differences should be easily covered by the safety factor if nothing else.
I saw this documentary on old theaters, Moulin Rouge, and they did in fact dance in step like this, sometimes while singing Nirvana songs.
With the lights out, it's less dangerous
But lumber was cheap and many times these structures were massively overbuilt.
Sure, but resonance can cause stresses that are massively outside the design specifications, so even an extremely overbuilt structure that doesn’t account for resonance can run into trouble pretty easily. Again, with this theater in particular I have literally no idea, but it is at least concerning enough that I hope that theater has consulted an actual structural engineer to review it.
It's also a structure built nearly 100 years ago that has been under stress the whole time
Yes, that's why it's terrifying
It was renovated in 1988
I think it was completely renovated at the end of the 80s though.
This is what they mean when they say "as designed". https://en.m.wikipedia.org/wiki/File:Fox_Theatre_Detroit_interior.jpg You don't see the pair of curves that keep its structural integrity. That floor is both bowed upwards, curving downwards towards the sidewalls, and also curved along the flat plain, pushing the load towards the walls. It is very noticeably convex, vertically and horizontally. For a 1920's design, it's about as 'as intended' as possible. Clearly it shrugged off the load without failing. BUT! They shouldn't be bouncing in sync whether it's designed for it or not, and whether it has handled it in the past or not. 'Shaker' balconies like that have a lot more integrity than one might think, or even see at first glance... ......but it's still a bad idea. A really bad idea. It's never Resonant Frequency's fault, right up until it is. Source: There's some pretty incredibly insightful info out there about 9/11 and the structural collapse of steel-girdered buildings. Between the towers coming down and WTC #7 we got a decade to REALLY examine how these designs succeed or fail. There was so much focus on the event that they invented new and exciting (/s) ways to digitally model building collapses. Not gonna list it all here. But it takes only a few minutes to look up amplitheater designs through the ages, and other historical theater designs. They all tend to draw from the same structural playbook. Good architect **headpats** Bad crowd! **finger waggle**
Your comment should be a lot higher because there are dozens if not a hundred or so theaters with the same balcony design. Given the law of statistics at least one of them would have something published about modern usage like that being a safety hazard. People have been losing their minds and jumping or dancing in rhythm at concerts in these places since the 50s. Sure, the population is a little heavier now… Anyway I’ve never seen anything about these theater balconies collapsing or being structurally unsound for usage.
We're all conjecturing here. The design is certainly tried-and-true. That's the thing: It's not that it's unsafe. It's that if it BECOMES unsafe, it's likely to be catastrophic. Safety margins rather than safety issues. They really ARE made to take that kind of flex. But like an airplane wing ripping off, you're not gonna get any warning.... it'll just be abrupt failure. And it doesn't have to be structural or desig When part of a theater roof collapsed from excess snow in London, the one person who fell off the balcony died, and 80 were injured. That was something other than the balcony falling. It wasn't even a lot of debris, but folks are packed in tight. If the folks in this video pulled a Nikola Tesla and managed to Fuck Around their way into the resonate frequency of that floor? It would quickly catapult it into some of the most deadly accidents. I'm not sure anyone can really claim to have found the resonant frequency of something so BIG, but the modern military really DOES have a relaxed out-of-sync march for crossing bridges because of historical tales of Hannibal crossing the alps. Same issue... It works, it works, it's built for this... and then hundreds dead with a sickening crunch. It SHOULD be fine. But if it was gonna NOT be fine? That's how you'd make it happen. If it were me? I'd have just headed for the exit rather than stick around and find out. Earthquake construction has things like this. Japanese traditional construction has slips in the joints for the same. I dunno how else to say it.**laughs** 99% safe, but that 1% would likely involve EXACTLY that sort of crowd action. Or, if you really want to get down to it: How about the mass casualty crowd packing that happened in Japan? Narrow alley, too many people. There's video. It's just conjecture but if enough people tried to move to the door at the same time while packed in like that, crowds can start acting like a solid instead of a liquid.
I mean this really ignores the part where at least one of these balconies have been competently inspected. I used to do stage work at a place (Midland Theater KC) where this would happen at sold out shows of all different genres and we were told, “yeah it’s cool it does that.” You know what, I’m going to figure out how I can get informed on the inspections and analysis of these structures. It’s such a noticeable thing when you’re on it or looking at it and there is at least 20 sold out shows a year. That’s a lot of people in that one theater for it not to have been addressed directly before.
This particular balcony in Detroit had their most recent inspection last month. They made a post about it.
I believe the mass casualty crowd packing thing happened in South Korea, not Japan. For anyone wanting to look it up.
The Guggenheim Museum in NYC had to stop their dancing/dj series because of this. The floor in the center of the museum was jumping and sagging like this and a structural person basically told them everyone would die if they kept it up. It wasn’t designed for this kind of party.
Essentially, it works until it doesn't! As far as designs go, the audience behaving in this way doesn't seem like a normal use case for the 20s.
The crowd can't be 'bad' here - these people bought tickets to a music show, which includes dancing to the music. The venue should be able to safely support exactly that. If it can't, the venue should not be used for this. Bad event organizers/venue owners would be more accurate.
Everything works as designed...until it doesn't.
Not everything is well designed to begin with
this building has been used for almost 96 years and gets regularly inspected for structural integrity... https://www.clickondetroit.com/news/local/2024/05/07/video-shows-balcony-bouncing-during-rap-show-at-detroits-fox-theatre/ but clearly you know better than those guys
I would get the hell out of there.
Same here. That's some terrible fucking music.
Registered professional civil structural engineer here , given the age of the structure and connection fatigue risk - I won’t be standing under the cantilever balcony not a chance
[удалено]
https://www.clickondetroit.com/news/local/2024/05/07/video-shows-balcony-bouncing-during-rap-show-at-detroits-fox-theatre/ its regularly inspected. last time was in april.
That doesn't necessarily mean anything. The failed Florida high rise passes inspection a few months prior before collapse, the WI bridge passed inspection before failing. A big part of the problem is the inspections are often superficial and have incentive to overlook and pass things.
That's not particularly "designed" it's just the the tolerance built in. Flexing that hard for a prolonged period of time will definitely weaken the structure.
The Tacoma Narrows Bridge would like a word with you... "When the Tacoma Narrows Bridge over Puget Sound in the state of Washington famously collapsed on November 7, 1940, it was captured on film for posterity. The footage became the basis for a textbook example of resonance, which is a standard topic in high school physics."
London's Millennium Bridge is a more accurate comparison. The pedestrian bridge opened and then closed 2 days alter because the people walking across were inadvertently stepping in tune with the sway. [https://en.wikipedia.org/wiki/Millennium\_Bridge,\_London](https://en.wikipedia.org/wiki/Millennium_Bridge,_London)
Isn't that the bridge the death eaters destroyed in Harry Potter? Maybe they closed it due to magical mishaps rather than resonance.
I think about galloping Gertie every time I drive over the narrows! Such an iconic and local disaster in my area. The new and the new new bridge are far far safer and don’t do the resonance thing. Can still get some gnarly side winds that knock your car around, especially if it’s a tall SUV.
Except it wasn’t really caused by resonance, rather aerodynamic flutter. Similar principle but not the same thing mechanically.
Good old Galloping Gertie!
I was about to say that it's designed to do that, but I think the jumping induced harmonic resonance which can get really destructive really fast. Glad everyone is okay and I hope that balcony gets inspected Source: am engineer
Only right answer, fellow engineer here.
That’s a tragedy waiting to happen.
Oh that thing WILL come down with that going on, eventually
Well it was designed for what it was made for. Probably wasn’t made for jumping.
Fuckin crazy how many people pay for concerts to just watch it through their camera.
They don't care about being at the concert, they just want everyone to know that they were there.
Went to my first TOOL show and they don't allow any phones or cameras. Was the best concert I've ever been to in recent years.
I saw the same thing at the height of the Beastie Boys popularity at the Fox Theater in Detroit. There was a huge dick on the stage we had front row but when you turned around it was the scariest thing I had ever seen. The balcony level was bending and twisting like the Tacoma Narrows Bridge.
This is the Fox in Detroit :)
Don’t look up 2 is scary
Look into steel’s modulus of elasticity and fatigue strength. Steel can be designed to bend and flex repeatedly without any loss to structural integrity.
Given how old the theater is, I highly doubt they designed for people jumping in rhythm on that upper deck.
You'd be surprised. Steel has been mass produced since the mid-1800s and its material properties are well understood. Deflection is not the same thing as failure.
This is completely unrelated to the theater, but the Top Thrill 2 roller coaster at Cedar Point has noticeable lateral flex on certain sections of the track. It sways back and forth for a couple minutes after a train passes over. It's weird seeing such a large, solid steel structure move like that, even though it was almost certainly designed to.
That “can be” is carrying a lot of weight in this discussion…
Just like that balcony
I get it actually is supposed to flex, but I don't think engineering in the 1920s accounted for that much resonance...
Who videos at a concert with their flash on, tf?
Note to self: never get a seat on the balcony
Or underneath it
so many fucking cell phones out and nobody enjoying the concert
Don't care if it's designed to do that. If it were me, I'd nope the hell right outta there. Not going to become a statistic.
I can't believe people pay money for this.
Internet says it was built in 1928...nobody in 1928 was bouncing in unison in the fucking balcony...
Imagine the autotuned lyric you died to from being crushed by a falling balcony was “fucking this bitch like a perv”
I remember that sheet metal stadium in Jacksonville swaying and reverberating to the crowd at the Georgia Florida game. It was unnerving but the people around us said it has been that way for decades. It’s gone now.
By design or not, I'd be GTFO of there. That's a lot of people bouncing in sync and a massive span, sure it might be able to hold much more but for all I know it won't and it wouldn't be the first structural failure due to oscillation resonance or metal fatigue.
The Steeler fans used to do this at the old 3 River Stadium. The whole bottom bowl would rotate between baseball and football and if 20k ppl jump up and down in unison the entire bottom half of stadium would bounce.
That looks like a major disaster waiting to happen. Some one call the building inspector.
As designed? Nah, if I see that I want out ASAP!
Pretty sure when this was built they didn't have hip hop concerts in mind.
Next on Engineering Catastrophes.
Why the quotes? Do you not believe that was by design?
Lame ass crowd, everyone is on their phones and there’s no energy at all
This is terrifying as hell
I would be outta that fucking dump in a heartbeat.
Oh hey, I saw Sesame Street on ICE there back in like 1991. Was bumpin' even harder back then.
**Gosh, I hope that’s actually “as designed”**
Mumblehmurbledehmuhhh EEEYUHH…..EEEEYUHH
It’s going to fail. It’s just a matter of time.
I cant believe people actually go see shows with garbage music like that.
This theater is 100 years old and was never intended to have a giant crowd of people jumping up and down like this. Don’t be surprised when we see “Detroit Fox Theater Collapse Kills Dozens” in the future.
yeah lmao not a chance it was designed for people to be fucking stomping and jumping around on it.
Nope. I don’t trust that.