Miami Beach, Champlain Towers South apartment building collapse, Part 17 14

[SFCharlie]

A continuation of our discussion of this failure. Best to read the other threads first to avoid rehashing things already discussed.
Miami Beach, Champlain Towers South apartment building collapse
Miami Beach, Champlain Towers South apartment building collapse, Part 02
Miami Beach, Champlain Towers South apartment building collapse, Part 03
Miami Beach, Champlain Towers South apartment building collapse, Part 04
Miami Beach, Champlain Towers South apartment building collapse, Part 05
Miami Beach, Champlain Towers South apartment building collapse, Part 06
Miami Beach, Champlain Towers South apartment building collapse, Part 07
Miami Beach, Champlain Towers South apartment building collapse, Part 08
Miami Beach, Champlain Towers South apartment building collapse, Part 09
Miami Beach, Champlain Towers South apartment building collapse, Part 10
Miami Beach, Champlain Towers South apartment building collapse, Part 11
Miami Beach, Champlain Towers South apartment building collapse, Part 12
Miami Beach, Champlain Towers South apartment building collapse, Part 13
Miami Beach, Champlain Towers South apartment building collapse, Part 14
Miami Beach, Champlain Towers South apartment building collapse, Part 15
Miami Beach, Champlain Towers South apartment building collapse, Part 16


SF Charlie
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[spsalso]

"Anybody see a CAP on top of that Exhaust Fan Assembly in those images? Don't see how the air exhausts immediately vertically without a hole in the top cap?"

In designs like that that I've seen, that "top cap" is a cover for the motor, with the centrifugal fan mounted below. The venting is often downwards out the bottom of the larger diameter cylinder--closer to the ground.



spsalso

 

[Nukeman948]

Anybody see a CAP on top of that Exhaust Fan Assembly in those images? Don't see how the air exhausts immediately vertically without a hole in the top cap?

Perhaps Nuke can explain???

Blah, blah, blah?

Begin here:

https://www.grainger.com/know-how/equipment-information/kh-choosing-the-right-rooftop-ventilator

You see, this type of fan is commonly available in both downblast and upblast designs, therefore no separate rain cap is needed. In fact, if you take the time to look closer at all of those nice pictures you just posted, you can see that they are all of the upblast design.

Perhaps you could take the time to study this cutaway image. (since you seem to be too busy to do your own research)

Now, Morabito's drawings show a tube axial fan style for the replacement unit and that is what I thought I had seen in a fuzzy picture somewhere. If CTS still had the original fan installed, it was completely hidden in all that moist humid vegetation in that waterlogged planter. So the fan would be blowing all that moisture on the wall where it could condense unevenly and cause a dust cloud to stick to it.

[sub]Sorry, I don't have any Powerpointy training so this is the best I can do.
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[FJBnomics]

I am unaware of any images of what type of exhaust fan was in the blocked in area beside the parking deck planters. It could have been upblast or perhaps it was downblast like the image below. Where does the rainwater go that gets into upblast discharge area? Perhaps the fan is capable of expelling any moisture that gets into discharge area? Downblast would solve that problem either way, when upblast is not required.

 

[Nukeman948]

Well, the model numbers for the original fan schedule are obsolete but all the original upblast fans have a similar model number. Good evidence but not proof.
If you were an architect trying to hide an exhaust fan in a blocked in area and the price is the same for upblast and downblast, why would you even consider downblast, especially if you were exhausting pool equipment room fumes. You would want to blow that up and away from sensitive stuff like pool guests and plants and concrete, right? Restaurants always use upblast for kitchen service to keep the grease off the roof.
All upblast models have a drain for rain water that is usually easy to see:

https://www.google.com/search?q=upb...w&bih=593&biw=1360&client=firefox-b-1-d&hl=en

Those that are intended to be used for restaurant service sometimes come equipped with a a grease trap on the drain. You can believe whatever you want.

[sub]
[/sub]​

 

[FJBnomics]

So even upblast exhaust fans drain condensed vapors and rain water at the base. If that drain port is not hooked up to say a drain line or that drain line has failed, then the condensate mix ends up on top of the parking garage ceiling, and able to soak into the concrete.

Either way, it appears pool chemicals would affect that area near and downwind of the exhaust fan significantly more. If it travels West to attach to say dew on plant leaves and run down into the soil in the planters to mix with the organic materials, salts, etc. then that mix is able to mix with water and soak down into concrete.

Further in Morabito's report there were ventilation fans that required new belts and bearings. So perhaps some of the ventilation fans were not operational? If that were the case, it also appears that the air intake for the pool room exhaust fan was thru louvered doors between the pool room and parking garage.

Thus auto exhaust would enter pool room where pool chemicals were stored, and mix vapors before exiting thru the pool exhaust fan. So another variable in the chemical stew.

Also how were the pool chemicals stored and did the garage flood waters ever mix with stored chemicals sitting on pool room floor, or at least mix with perhaps pool chemical spills on floor?

Edit: And of course during the hot muggy days in Surfside, the ventilation fans are bringing in an endless supply of CFM’s of hot humid, salty air, to condense on colder surfaces in the underground parking garage.

Edit2: I question how effective an exhaust fan is at dispersing chemical vapors when it is raining ️, and there is not a chimney stack at adequate height to prevent the chemical vapors from attaching to the rain water for example near point of exhaust, and ending up on on top of deck mixed with the rain water and surrounding materials.

Edit3: If I was the architect, I would also be concerned about noise levels associated with that up or own blast exhaust fan, due to people close by. Therefore limiting super high velocity fans?

Edit4: For that single person thinking the ‘Supervisory Event’ I was referring to concerning exhaust fans, U ASS_U_med wrong. I was referring to the ‘Supervisory Event’ called Deferred Maintenance that was clearly robustly exercised by the Condo Association In their ‘Supervisory Role’ as Property Mgr.

However, In the event of fire, ventilation systems should be controlled by modern Fire Alarm Systems or sensors and actuators on equipment, so they don’t feed the fire.

 

[Jeff Ostroff]

MAn, I'm wasted!

I was up until 4 AM this morning uploading my video from the entire NIST presentation last week, and I found a 2-hour-long video online of live stream from the NIST zoom call, not just the 30-minute video we had seen until now.

I had to condense 10 presentations of slides from 6 hours of dissemination on Thursday into one video and get it under an hour. That was an engineering challenge on its own!

I spent 2 1/2 days working on this, and started the minute they uploaded the slides to the NIST site Wednesday.

I am still wondering if NIST has CTS security camera videos because their slide says they have "videos" plural high def. Would love to get my hands on them. I gotta have faith that there were videos and someone has them, unless the server was stores in the garage beneath the "11 Stack"

 

[SFCharlie]

There are some details of the collapse that puzzle me deeply:
I can understand that after the first column punched through, that the pool deck fell, impinging on adjacent columns. The weight would not have been transferred immediately as parts of the deck were in free fall. Maybe the deck nearest the first column hit the floor and the remainder snapped itself down on an adjacent column like a bull whip?
What amazes and confounds me is what was going on during the next three minutes. Was some crack propagating through some structural member until gravity brought the rest down?
I don’t know.


SF Charlie
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[MaudSTL]

What amazes and confounds me is what was going on during the next three minutes.

From a witness statement perspective, the deck collapsed all at once at ~1:15 AM. Witnesses say the deck did not collapse in stages…it collapsed as a single event. As soon as the deck collapsed, witnesses say the building itself began shaking. This implies that when the deck collapsed, it buckled some columns so that the building immediately began redistributing its weight among the remaining columns.

As I understand it, based on what Mike Stratton claims his late wife Cassondra told him, the shaking is what woke her up. As Mike talked to his wife, he claims she said the building was shaking when it collapsed at 1:22 AM. Gabe Nir was in 111 after the deck collapsed at ~1:15 AM, and he says the building was shaking. Shamoka Furman was in the lobby from 1:15 to 1:22, and she called the shaking an earthquake.

I am not sure what you mean by mentioning three minutes. After the deck collapsed at ~1:15 AM, there was no separate event at 1:18 AM…although that happens to be the time that Adriana Sarmiento shot her garage video after the 1:15 AM deck collapse.

 

[Sym P. le]

Nir's hurricane shutters? Note the shutters are framed and sit on the deck.

 

[Jeff Ostroff]

When I zoomed into your photo up above that does not look like the shutters to me as they would not be in one long piece like that remember they would be open like an accordion and probably in a 2 foot wide chunk. What that looks to me like is part of the pool deck in the black that you see on the top of it is the waterproofing membrane. That is where my money is bet

 

[Sym P. le]

I now see what you are pointing to and it is an interesting detail to be sure. It appears (ABC video) that the single buttress is uniquely dusted. It also appears to be in line with the direction of collapse of the east portion of the tower and a denser path/layer of dust.

I don't believe that it can add much to our understanding of the collapse initiation.

 

[FJBnomics]

I find it interesting that powder blast at column is Due South of where the slab dropped at the planter over K line, and we know that area dust exit is bound by slab drop to North, Pool/Hot Tub to East, and parking deck hinge to the West.

Perfect storm to force powdered concrete exhaust towards South Wall. Deferred maintenance could mean duct from pool room was rusted thru, or gone?

Edit: Perhaps pool exhaust fan duct work is damaged or drops at opening in slab,and exhaust fan rolls and leaves 19”x19” opening to parking deck below. Or tree roots pushed fan off base?

Aren’t we seeing hinge effect in middle section of building dropping 1-1-1/2 floors instantly at K/L 9.1 etc. All floor slabs swing down making it appear building is falling down and back (North) at same time?

 

[SFCharlie]

Thank you Maud. So the building was shaking from the deck drop at about 1:15 till the collapse at 1:22, or about 7 minutes.

SF Charlie
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[zebraso]

What that looks to me like is part of the pool deck in the black that you see on the top of it is the waterproofing membrane. That is where my money is bet

I don't recall much long past discussion about what that dark area is (as a singular item). I think maybe it was conjectured that the dark coloration was due to shadow as it it might be the edge of a slab. Now that you mention the membrane it makes a little more sense. But the thing that nags me is that it looks to have certain geometric features that are not consistent with slab or shutters and it is dark colored from all angles of illumination could be truly black on one side and in shadow on others. I could name some things that it sort of looks like but that would be pointless and nothing that I image should actually be there.

To add: the membrane being overlaying randomly configured rubble could give the false impression if a contiguous 3 dimensional multifaceted object that could be imaged to be just about anything.

 

[MaudSTL]

So the building was shaking from the deck drop at about 1:15 till the collapse at 1:22, or about 7 minutes.

That’s more or less what the surviving witnesses have said. In the early interviews, they didn’t mention the shaking as often as they started doing in the later interviews. Plus all of the survivors were on the move or otherwise occupied during those seven minutes. So they would have been less likely to be noticing whether the shaking/rumbling/earthquake was continuous if they were running to escape or making calls to 911.

None of the witnesses explicitly said the shaking was continuous. I suspect the shaking was not continuous, based on an interview with Mike Stratton (410.)

Bear in mind that Mike Stratton has reported secondhand information and has also “refined” his version of what his late wife told him just about every time he has been interviewed. However, in one of his more recent interviews, he did say that it was shaking (not the deck collapse) that woke up his late wife Cassie, and that right before she screamed and the line went dead, she said the building was shaking again. He did not state explicitly that the building shook, stopped shaking, and then started shaking again, but there is that implication in the word again. If there was indeed a pause in the shaking, it would imply that the building lost its balance when the deck collapsed, then briefly caught it, and finally couldn’t maintain it.

 

[SFCharlie]

Thanks again.

SF Charlie
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[FJBnomics]

Does anyone have a good photo of the pool equipment area, after the debris was removed?

I am not sure whether you were talking about the deck/hot tub area Jeff furnsished or the actually pool equipment room. Here is a better photo of equipment room area behind louvered doors, if that is what you were asking?

 

[Reverse_Bias]

The "shaking again" comment might match up with the jolt that woke the 711 ring cam. Mike Stratton didn't say when in the call she said it though so you can't really tell.
Gabe Nir mentioned the building started shaking violently in the few seconds between the time they exited and the collapse started. That does imply the shaking accelerated just before the collapse.

 

[MaudSTL]

The "shaking again" comment might match up with the jolt that woke the 711 ring cam.

Per the Miami Herald, Mike Stratton claims his late wife said “the building is shaking again” right before she screamed and it collapsed at 1:22. I agree that the shaking at that time may be the same shaking that woke up the Ring camera in 711.

In contrast, the Nirs were long gone by that time, having crossed Collins Ave and run up the street.

Also per the Miami Herald, Gabe Nir (111) has stated that he felt the building rumble and shake after the deck collapsed at about 1:15. Gabe and Chani ran to the door of the apartment, and their mom came back from the lobby to roust them. They ran to the lobby at about 1:16, and you can hear their voices in the background of the first three 911 calls that Shamoka Furman placed from the lobby. So they were in the lobby from about 1:16 to about 1:18. By 1:19 they were out on the street, and Gabe was calling 911.

My point with all that is that Gabe Nir wasn’t in the building in the seconds before the collapse at 1:22. The Nirs had left CTS between three and four minutes earlier.

 

[IanCA]

It also appears to be in line with the direction of collapse of the east portion of the tower and a denser path/layer of dust.

Thank you very much for taking the time to study the photos and search for alternatives. Please can you take a look at the image below and let me know why you think the dust did not stick to the East face of that column as shown below:

Edit: I found an earlier image that does appear to show some dust on the East side of that column but it looks as though the lighter dusting on the East was reduced after it rained. Judging by the cars and other objects.

Just speculating but high local humidity from vegetation and pool equipment room fan may have caused condensation to form on that column causing the dust to stick there more than the other ones.

If the humidity on the column is coming from the vent and vegetation would it be consistent up the entire height of the column even if the bottom of the column were masked from that humidity by the adjacent wall as shown below:

The dust on the North face of the column appears to be quite consistent in its coverage.