This was a lot more informative than any of the documentaries I’ve watched on the Hyatt case. Most manage to somehow downplay the sheer incompetence of the engineering leadership.
Much of the structural detail on this collapse was shown in the excellent book "Why Buildings Fall Down" by Mario Salvadori and Matthys Levy. The book is an accompaniment to Salvadori's "Why Buildings Stand Up". I've read both several times and have found that they are a wonderful reference for the layman who is interested in the structure and function of significant buildings throughout history and around the world.
In my opinion as an engineer, the bad design was not as suggested here, and as in many other videos, but in the fact that the horizontal two FLANGES of the C channels were loaded as a CANTILEVER, and they did not transfer the vertical load to the vertical WIDER WEB, in a vertical manner. The vertical webs with a vertical load should have been used and not a twisting or torque load, on the flanges of the C beams. If wide THICK plates bridging across the two vertical wide webs were used with the loaded nuts, rather than using a thin washer with a small diameter, this would not have failed. Note, even the original design was no good as far as engineering logic goes, as it still loaded the two FLANGES in a cantilever torque mode, which should never be, in a C channel or an H channel. I would say that the original system would also have failed, as the welding holding the C channels together did not seem to be a good weld with no porosities and anyway, the original single rod was too close to the edge of the C beam. Exchanging the rods and placing the upper rod on the inner hole could have helped! . Thick plates with side limits, working in conjunction with the loaded nuts would even eliminate the need for welding the C beams, but I still would have used welding anyway.
So, the engineer makes an erroneous statement. He says that when the bridges collapsed “114 people who were dancing underneath it were killed.” This is not accurate. The 114 death toll included people who were on the second walkway and were crushed.
Ignorance of the law is one thing. Doing the right thing is a higher responsibility. I used to insure construction companies and I will tell you that this is why insurance for this type of thing is so expensive. We had excellent clients who I would trust to build anything but there were others who I would not trust to pour a flat concrete patio in my back yard. In this case, Jack Gillum, after his company failed, spent the rest of his life lecturing to engineering students the lessons learned from this disaster.
This accident is amazing, because the flaw in design was so obvious. It may have taken an engineer to see the flaw in altering the hanger rod design, but any ten year old could see that having the entire structure relying on bolts attached at welded seams is just moronic. I assume that nobody under the age of ten worked on this site, so at least one of the hundreds of people that saw this during construction should have noticed this ridiculous flaw in design.
I see another problem which could have contributed to the failure, where the rod passes through the tubing, there should have been an insert inside the tubing (solid bushing or rectangular ) to take the load, even if the tubing was DOM. And especially if it was welded! The stress where the bolts were placed would exceed the cross section of the tubing, causing it to cave in and split, as the results showed.
my exact thoughts, its unreal if they just bored the box beams and passed the rods tru and bolted it on the underside. box beams are usually relatively thin walled for their width and height and load bearing capacity. they are not designed to take on such point loads, they are good in bearing (entire width supported by a column or beam) or in axial, but not a point load like that. at the very least there should have been stiffeners and increasing of the wall thickness around the connection and some distance away.
Its unspoken that the engineers behind the walkway were unethical in behavior. This was the cause of the collapse, a lack of proper ethics on the engineers.
I dont understand how the engineer could think the fabricators were responsible for ensuring the overall structural soundness of the design. Isn't that EXACTLY what engineers are paid to do?
both designs are stupid and unsafe. one the original deisgn only a single nut holds each floor at each corner. and only a single rod at each corner holds all the floors. combined with metal fatigue= collapse and now a days look at how sloppy things are . very very sloppy.
The dangers of the design were known and swept under the rug to stay on schedule for profitable hotel bookings that depended on the construction completion date being met. The first collapse of atrium Steele was a bell weather of what was to come. Also the debris was removed before it could be analyzed to protect Hallmark and Hyatt. They made up some excuse as to why. Listen to the Swindeled Podcast about this.
both designs are stupid and unsafe. one the original deisgn only a single nut holds each floor at each corner. and only a single rod at each corner holds all the floors. combined with metal fatigue= collapse
This was a lot more informative than any of the documentaries I’ve watched on the Hyatt case. Most manage to somehow downplay the sheer incompetence of the engineering leadership.
Tragic story but a great video. I'm doing a case study on this for my engineering class.
Howd it go 🤨
Oh wait that was 2 yrs ago😭
Same!
This is the first thing that came to mind when I read about todays walkway collapse in Miami.
Much of the structural detail on this collapse was shown in the excellent book "Why Buildings Fall Down" by Mario Salvadori and Matthys Levy. The book is an accompaniment to Salvadori's "Why Buildings Stand Up". I've read both several times and have found that they are a wonderful reference for the layman who is interested in the structure and function of significant buildings throughout history and around the world.
Those are two great reads, thanks for sharing with folks about those books.
In my opinion as an engineer, the bad design was not as suggested here, and as in many other videos, but in the fact that the horizontal two FLANGES of the C channels were loaded as a CANTILEVER, and they did not transfer the vertical load to the vertical WIDER WEB, in a vertical manner. The vertical webs with a vertical load should have been used and not a twisting or torque load, on the flanges of the C beams. If wide THICK plates bridging across the two vertical wide webs were used with the loaded nuts, rather than using a thin washer with a small diameter, this would not have failed. Note, even the original design was no good as far as engineering logic goes, as it still loaded the two FLANGES in a cantilever torque mode, which should never be, in a C channel or an H channel. I would say that the original system would also have failed, as the welding holding the C channels together did not seem to be a good weld with no porosities and anyway, the original single rod was too close to the edge of the C beam. Exchanging the rods and placing the upper rod on the inner hole could have helped! . Thick plates with side limits, working in conjunction with the loaded nuts would even eliminate the need for welding the C beams, but I still would have used welding anyway.
So, the engineer makes an erroneous statement. He says that when the bridges collapsed “114 people who were dancing underneath it were killed.” This is not accurate. The 114 death toll included people who were on the second walkway and were crushed.
At the end of every project like this there should be one final independent engineer brought in to go over everything.
I'm sure that since the accident the health and safety rules have changed significantly...
This collapse changed engineering standards in a significant way.
Ignorance of the law is one thing. Doing the right thing is a higher responsibility. I used to insure construction companies and I will tell you that this is why insurance for this type of thing is so expensive. We had excellent clients who I would trust to build anything but there were others who I would not trust to pour a flat concrete patio in my back yard. In this case, Jack Gillum, after his company failed, spent the rest of his life lecturing to engineering students the lessons learned from this disaster.
This accident is amazing, because the flaw in design was so obvious. It may have taken an engineer to see the flaw in altering the hanger rod design, but any ten year old could see that having the entire structure relying on bolts attached at welded seams is just moronic. I assume that nobody under the age of ten worked on this site, so at least one of the hundreds of people that saw this during construction should have noticed this ridiculous flaw in design.
I see another problem which could have contributed to the failure, where the rod passes through the tubing, there should have been an insert inside
the tubing (solid bushing or rectangular ) to take the load, even if the tubing was DOM. And especially if it was welded! The stress where the bolts
were placed would exceed the cross section of the tubing, causing it to cave in and split, as the results showed.
my exact thoughts, its unreal if they just bored the box beams and passed the rods tru and bolted it on the underside. box beams are usually relatively thin walled for their width and height and load bearing capacity. they are not designed to take on such point loads, they are good in bearing (entire width supported by a column or beam) or in axial, but not a point load like that. at the very least there should have been stiffeners and increasing of the wall thickness around the connection and some distance away.
The speaker never mentioned ethics. He only discussed legal responsibilities.
Its unspoken that the engineers behind the walkway were unethical in behavior. This was the cause of the collapse, a lack of proper ethics on the engineers.
Communication was lax among the engineers.
Anyone know where I can find a source on Greg Louth's involvement?
I dont understand how the engineer could think the fabricators were responsible for ensuring the overall structural soundness of the design. Isn't that EXACTLY what engineers are paid to do?
That's what comes to mind when I hear the title "engineer."
Now a days i guarantee that this tragedy would have resulted in serious prison time for anyone who had a hand in this.
Mike Uhlir - Don’t bet on that. Have there been criminal charges in connection with the collapse at Florida International University?
both designs are stupid and unsafe. one the original deisgn only a single nut holds each floor at each corner. and only a single rod at each corner holds all the floors. combined with metal fatigue= collapse and now a days look at how sloppy things are . very very sloppy.
pass the buck, pass the buck, money speaks louder than lives
Liberty University?!?!?!
How wasn't Hyatt bankrupted from the civil lawsuits?
Hyatt actually leased the building to operate the hotel and weren’t actual owners
The other walkway in the Middle if these other ones fell the middle one would go too
How got the POE hw?
How could the designer just say he has no responsibility regarding the fabrication and construction
Of his plans?
The dangers of the design were known and swept under the rug to stay on schedule for profitable hotel bookings that depended on the construction completion date being met. The first collapse of atrium Steele was a bell weather of what was to come. Also the debris was removed before it could be analyzed to protect Hallmark and Hyatt. They made up some excuse as to why. Listen to the Swindeled Podcast about this.
Liberty university?
Hind sight is 20 20. It’s easy to be critical of what people have done.
Are you dumb
Too many high noon power bourbon meetings regarding pay offs and greed.
I wouldn't stay in that hotel what if collapsed I don't trust that building
That hotel is safe now. I have been there lots of times for the local science fiction convention.
both designs are stupid and unsafe. one the original deisgn only a single nut holds each floor at each corner. and only a single rod at each corner holds all the floors. combined with metal fatigue= collapse
UNI-FIC